initial import
authorJosh Coalson <jcoalson@users.sourceforce.net>
Sat, 4 May 2002 17:30:32 +0000 (17:30 +0000)
committerJosh Coalson <jcoalson@users.sourceforce.net>
Sat, 4 May 2002 17:30:32 +0000 (17:30 +0000)
include/FLAC/metadata.h [new file with mode: 0644]
src/libFLAC/metadata.c [new file with mode: 0644]

diff --git a/include/FLAC/metadata.h b/include/FLAC/metadata.h
new file mode 100644 (file)
index 0000000..0948c0e
--- /dev/null
@@ -0,0 +1,534 @@
+/* libFLAC - Free Lossless Audio Codec library
+ * Copyright (C) 2001,2002  Josh Coalson
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA  02111-1307, USA.
+ */
+
+#ifndef FLAC__METADATA_H
+#define FLAC__METADATA_H
+
+#include "format.h"
+
+/******************************************************************************
+       (For an example of how all these routines are used, see the source
+       code to metaflac.)
+******************************************************************************/
+
+/******************************************************************************
+       This module provides read and write access to FLAC file metadata at
+       three increasing levels of complexity:
+
+       level 0:
+       read-only access to the STREAMINFO block.
+
+       level 1:
+       read-write access to all metadata blocks.  This level is write-
+       efficient in most cases (more on this later), and uses less memory
+       than level 2.
+
+       level 2:
+       read-write access to all metadata blocks.  This level is write-
+       efficient in all cases, but uses more memory since all metadata for
+       the whole file is read into memory and manipulated before writing
+       out again.
+
+       What do we mean by efficient?  When writing metadata back to a FLAC file
+       it is possible to grow or shrink the metadata such that the entire file
+       must be rewritten.  However, if the size remains the same during changes
+       or PADDING blocks are utilized, only the metadata needs to be rewritten,
+       which is much faster.
+
+       Efficient means the whole file is rewritten at most one time, and only
+       when necessary.  Level 1 is not efficient only in the case that you
+       cause more than one metadata block to grow or shrink beyond what can
+       be accomodated by padding.  In this case you should probably use level
+       2, which allows you to edit all the metadata for a file in memory and
+       write it out all at once.
+
+       WATCHOUT: levels 1 and 2 do not support id3v2 tags at the front of the
+       file.  You will get an error that it is not a valid FLAC file.
+******************************************************************************/
+
+/******************************************************************************
+       After the three interfaces, methods for creating and manipulating
+       the various metadata blocks are defined.  Unless you will be using
+       level 1 or 2 to modify existing metadata you will not need these.
+******************************************************************************/
+
+
+/***********************************************************************
+ * level 0
+ * ---------------------------------------------------------------------
+ * Only one routine to read the STREAMINFO.  Skips any id3v2 tag at the
+ * head of the file.  Useful for file-based player plugins.
+ *
+ * Provide the address of a FLAC__StreamMetaData_StreamInfo object to
+ * fill.
+ */
+
+FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetaData_StreamInfo *streaminfo);
+
+
+/***********************************************************************
+ * level 1
+ * ---------------------------------------------------------------------
+ * The general usage of this interface is:
+ *
+ * Create an iterator using FLAC__metadata_simple_iterator_new()
+ * Attach it to a file using FLAC__metadata_simple_iterator_init() and check
+ *    the exit code.  Call FLAC__metadata_simple_iterator_is_writable() to
+ *    see if the file is writable, or read-only access is allowed.
+ * Use _next() and _prev() to move around the blocks.  This is does not
+ *    read the actual blocks themselves.  _next() is relatively fast.
+ *    _prev() is slower since it needs to search forward from the front
+ *    of the file.
+ * Use _get_block_type() or _get_block() to access the actual data.  The
+ *    returned object is yours to modify and free.
+ * Use _set_block() to write a modified block back.  You must have write
+ *    permission to the original file.  Make sure to read the whole
+ *    comment to _set_block() below.
+ * Use _insert_block_after() to add new blocks.  Use the object creation
+ *    functions from the end of this header file to generate new objects.
+ * Use _delete_block() to remove the block currently referred to by the
+ *    iterator, or replace it with padding.
+ * Destroy the iterator with FLAC__metadata_simple_iterator_delete()
+ *    when finished.
+ *
+ * NOTE: The FLAC file remains open the whole time between _init() and
+ *       _delete(), so make sure you are not altering the file during
+ *       this time.
+ *
+ * NOTE: Do not modify the is_last, length, or type fields of returned
+ *       FLAC__MetaDataType objects.  These are managed automatically.
+ *
+ * NOTE: If any of the modification functions (_set_block, _delete_block,
+ *       _insert_block_after, etc) return false, you should delete the
+ *       iterator as it may no longer be valid.
+ */
+
+/*
+ * opaque structure definition
+ */
+struct FLAC__MetaData_SimpleIterator;
+typedef struct FLAC__MetaData_SimpleIterator FLAC__MetaData_SimpleIterator;
+
+typedef enum {
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK = 0,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR,
+       FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR
+} FLAC__MetaData_SimpleIteratorStatus;
+extern const char *FLAC__MetaData_SimpleIteratorStatusString[];
+
+/*
+ * Constructor/destructor
+ */
+FLAC__MetaData_SimpleIterator *FLAC__metadata_simple_iterator_new();
+void FLAC__metadata_simple_iterator_delete(FLAC__MetaData_SimpleIterator *iterator);
+
+/*
+ * Get the current status of the iterator.  Call this after a function
+ * returns false to get the reason for the error.  Also resets the status
+ * to FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK
+ */
+FLAC__MetaData_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__MetaData_SimpleIterator *iterator);
+
+/*
+ * Initialize the iterator to point to the first metadata block in the
+ * given FLAC file.  If 'preserve_file_stats' is true, the owner and
+ * modification time will be preserved even if the FLAC file is written.
+ */
+FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__MetaData_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats);
+
+/*
+ * Returns true if the FLAC file is writable.  If false, calls to
+ * FLAC__metadata_simple_iterator_set_block() and
+ * FLAC__metadata_simple_iterator_insert_block_after() will fail.
+ */
+FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__MetaData_SimpleIterator *iterator);
+
+/*
+ * These move the iterator forwards or backwards, returning false if
+ * already at the end.
+ */
+FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__MetaData_SimpleIterator *iterator);
+FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__MetaData_SimpleIterator *iterator);
+
+/*
+ * Get the type of the metadata block at the current position.  This
+ * avoids reading the actual block data which can save time for large
+ * blocks.
+ */
+FLAC__MetaDataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__MetaData_SimpleIterator *iterator);
+
+/*
+ * Get the metadata block at the current position.  You can modify the
+ * block but must use FLAC__metadata_simple_iterator_set_block() to
+ * write it back to the FLAC file.
+ *
+ * You must call FLAC__metadata_object_delete() on the returned object
+ * when you are finished with it.
+ */
+FLAC__StreamMetaData *FLAC__metadata_simple_iterator_get_block(FLAC__MetaData_SimpleIterator *iterator);
+
+/*
+ * Write a block back to the FLAC file.  This function tries to be
+ * as efficient as possible; how the block is actually written is
+ * shown by the following:
+ *
+ * Existing block is a STREAMINFO block and the new block is a
+ * STREAMINFO block: the new block is written in place.  Make sure
+ * you know what you're doing when changing the values of a
+ * STREAMINFO block.
+ *
+ * Existing block is a STREAMINFO block and the new block is a
+ * not a STREAMINFO block: this is an error since the first block
+ * must be a STREAMINFO block.  Returns false without altering the
+ * file.
+ *
+ * Existing block is not a STREAMINFO block and the new block is a
+ * STREAMINFO block: this is an error since there may be only one
+ * STREAMINFO block.  Returns false without altering the file.
+ *
+ * Existing block and new block are the same length: the existing
+ * block will be replaced by the new block, written in place.
+ *
+ * Existing block is longer than new block: if use_padding is true,
+ * the existing block will be overwritten in place with the new
+ * block followed by a PADDING block, if possible, to make the total
+ * size the same as the existing block.  Remember that a padding
+ * block requires at least four bytes so if the difference in size
+ * between the new block and existing block is less than that, the
+ * entire file will have to be rewritten, using the new block's
+ * exact size.  If use_padding is false, the entire file will be
+ * rewritten, replacing the existing block by the new block.
+ *
+ * Existing block is shorter than new block: if use_padding is true,
+ * the function will try and expand the new block into the following
+ * PADDING block, if it exists and doing so won't shrink the PADDING
+ * block to less than 4 bytes.  If there is no following PADDING
+ * block, or it will shrink to less than 4 bytes, or use_padding is
+ * false, the entire file is rewritten, replacing the existing block
+ * with the new block.  Note that in this case any following PADDING
+ * block is preserved as is.
+ *
+ * After writing the block, the iterator will remain in the same
+ * place, i.e. pointing to the new block.
+ */
+FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block, FLAC__bool use_padding);
+
+/*
+ * This is similar to FLAC__metadata_simple_iterator_set_block()
+ * except that instead of writing over an existing block, it appends
+ * a block after the existing block.  'use_padding' is again used to
+ * tell the function to try an expand into following padding in an
+ * attempt to avoid rewriting the entire file.
+ *
+ * This function will fail and return false if given a STREAMINFO
+ * block.
+ *
+ * After writing the block, the iterator will be pointing to the
+ * new block.
+ */
+FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block, FLAC__bool use_padding);
+
+/*
+ * Deletes the block at the current position.  This will cause the
+ * entire FLAC file to be rewritten, unless 'use_padding' is true,
+ * in which case the block will be replaced by an equal-sized PADDING
+ * block.  The iterator will be left pointing to the block before the
+ * one just deleted.
+ *
+ * You may not delete the STREAMINFO block.
+ */
+FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__MetaData_SimpleIterator *iterator, FLAC__bool use_padding);
+
+
+/***********************************************************************
+ * level 2
+ * ---------------------------------------------------------------------
+ * The general usage of this interface is:
+ *
+ * Create a new chain using FLAC__metadata_chain_new().  A chain is a
+ *    linked list of metadata blocks.
+ * Read all metadata into the the chain from a FLAC file using
+ *    FLAC__metadata_chain_read() and check the status.
+ * Optionally, consolidate the padding using
+ *    FLAC__metadata_chain_merge_padding() or
+ *    FLAC__metadata_chain_sort_padding().
+ * Create a new iterator using FLAC__metadata_iterator_new()
+ * Initialize the iterator to point to the first element in the chain
+ *    using FLAC__metadata_iterator_init()
+ * Traverse the chain using FLAC__metadata_iterator_next/prev().
+ * Get a block for reading or modification using
+ *    FLAC__metadata_iterator_get_block().  The pointer to the object
+ *    inside the chain is returned, so the block is yours to modify.
+ *    Changes will be reflected in the FLAC file when you write the
+ *    chain.  You can also add and delete blocks (see functions below).
+ * When done, write out the chain using FLAC__metadata_chain_write().
+ *    Make sure to read the whole comment to the function below.
+ * Delete the chain using FLAC__metadata_chain_delete().
+ *
+ * NOTE: Even though the FLAC file is not open while the chain is being
+ *       manipulated, you must not alter the file externally during
+ *       this time.  The chain assumes the FLAC file will not change
+ *       between the time of FLAC__metadata_chain_read() and
+ *       FLAC__metadata_chain_write().
+ *
+ * NOTE: Do not modify the is_last, length, or type fields of returned
+ *       FLAC__MetaDataType objects.  These are managed automatically.
+ */
+
+/*
+ * opaque structure definitions
+ */
+struct FLAC__MetaData_Chain;
+typedef struct FLAC__MetaData_Chain FLAC__MetaData_Chain;
+struct FLAC__MetaData_Iterator;
+typedef struct FLAC__MetaData_Iterator FLAC__MetaData_Iterator;
+
+typedef enum {
+       FLAC__METADATA_CHAIN_STATUS_OK = 0,
+       FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT,
+       FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE,
+       FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE,
+       FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE,
+       FLAC__METADATA_CHAIN_STATUS_READ_ERROR,
+       FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR,
+       FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR,
+       FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR,
+       FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR,
+       FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR,
+       FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR
+} FLAC__MetaData_ChainStatus;
+extern const char *FLAC__MetaData_ChainStatusString[];
+
+/*********** FLAC__MetaData_Chain ***********/
+
+/*
+ * Constructor/destructor
+ */
+FLAC__MetaData_Chain *FLAC__metadata_chain_new();
+void FLAC__metadata_chain_delete(FLAC__MetaData_Chain *chain);
+
+/*
+ * Get the current status of the chain.  Call this after a function
+ * returns false to get the reason for the error.  Also resets the status
+ * to FLAC__METADATA_CHAIN_STATUS_OK
+ */
+FLAC__MetaData_ChainStatus FLAC__metadata_chain_status(FLAC__MetaData_Chain *chain);
+
+/*
+ * Read all metadata into the chain
+ */
+FLAC__bool FLAC__metadata_chain_read(FLAC__MetaData_Chain *chain, const char *filename);
+
+/*
+ * Write all metadata out to the FLAC file.  This function tries to be as
+ * efficient as possible; how the metadata is actually written is shown by
+ * the following:
+ *
+ * If the current chain is the same size as the existing metadata, the new
+ * data is written in place.
+ *
+ * If the current chain is longer than the existing metadata, the entire
+ * FLAC file must be rewritten.
+ *
+ * If the current chain is shorter than the existing metadata, and
+ * use_padding is true, a PADDING block is added to the end of the new
+ * data to make it the same size as the existing data (if possible, see
+ * the note to FLAC__metadata_simple_iterator_set_block() about the four
+ * byte limit) and the new data is written in place.  If use_padding is
+ * false, the entire FLAC file is rewritten.
+ *
+ * If 'preserve_file_stats' is true, the owner and modification time will
+ * be preserved even if the FLAC file is written.
+ */
+FLAC__bool FLAC__metadata_chain_write(FLAC__MetaData_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats);
+
+/*
+ * This function will merge adjacent PADDING blocks into a single block.
+ *
+ * NOTE: this function does not write to the FLAC file, it only
+ * modifies the chain.
+ *
+ * NOTE: Any iterator on the current chain will become invalid after this
+ * call.  You should delete the iterator and get a new one.
+ */
+void FLAC__metadata_chain_merge_padding(FLAC__MetaData_Chain *chain);
+
+/*
+ * This function will move all PADDING blocks to the end on the metadata,
+ * then merge them into a single block.
+ *
+ * NOTE: this function does not write to the FLAC file, it only
+ * modifies the chain.
+ *
+ * NOTE: Any iterator on the current chain will become invalid after this
+ * call.  You should delete the iterator and get a new one.
+ */
+void FLAC__metadata_chain_sort_padding(FLAC__MetaData_Chain *chain);
+
+
+/*********** FLAC__MetaData_Iterator ***********/
+
+/*
+ * Constructor/destructor
+ */
+FLAC__MetaData_Iterator *FLAC__metadata_iterator_new();
+void FLAC__metadata_iterator_delete(FLAC__MetaData_Iterator *iterator);
+
+/*
+ * Initialize the iterator to point to the first metadata block in the
+ * given chain.
+ */
+void FLAC__metadata_iterator_init(FLAC__MetaData_Iterator *iterator, FLAC__MetaData_Chain *chain);
+
+/*
+ * These move the iterator forwards or backwards, returning false if
+ * already at the end.
+ */
+FLAC__bool FLAC__metadata_iterator_next(FLAC__MetaData_Iterator *iterator);
+FLAC__bool FLAC__metadata_iterator_prev(FLAC__MetaData_Iterator *iterator);
+
+/*
+ * Get the type of the metadata block at the current position.
+ */
+FLAC__MetaDataType FLAC__metadata_iterator_get_block_type(const FLAC__MetaData_Iterator *iterator);
+
+/*
+ * Get the metadata block at the current position.  You can modify
+ * the block in place but must write the chain before the changes
+ * are reflected to the FLAC file.
+ *
+ * Do not call FLAC__metadata_object_delete() on the returned object;
+ * to delete a block use FLAC__metadata_iterator_delete_block().
+ */
+FLAC__StreamMetaData *FLAC__metadata_iterator_get_block(FLAC__MetaData_Iterator *iterator);
+
+/*
+ * Removes the current block from the chain.  If replace_with_padding is
+ * true, the block will instead be replaced with a padding block of equal
+ * size.  You can not delete the STREAMINFO block.  The iterator will be
+ * left pointing to the block before the one just 'deleted', even if
+ * 'replace_with_padding' is true.
+ */
+FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__MetaData_Iterator *iterator, FLAC__bool replace_with_padding);
+
+/*
+ * Insert a new block before or after the current block.  You cannot
+ * insert a block before the first STREAMINFO block.  You cannot
+ * insert a STREAMINFO block as there can be only one, the one that
+ * already exists at the head when you read in a chain.  The iterator
+ * will be left pointing to the new block.
+ */
+FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__MetaData_Iterator *iterator, FLAC__StreamMetaData *block);
+FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__MetaData_Iterator *iterator, FLAC__StreamMetaData *block);
+
+
+/******************************************************************************
+       The following are methods for manipulating the defined block types.
+       Since many are variable length we have to be careful about the memory
+       management.  We decree that all pointers to data in the object are
+       owned by the object and memory-managed by the object.
+
+       Use the _new and _delete functions to create all instances.  When
+       using the _set_ functions to set pointers to data, set 'copy' to true
+       to have the function make it's own copy of the data, or to false to
+       give the object ownership of your data.  In the latter case your pointer
+       must be freeable by free() and will be free()d when the object is
+       _delete()d.
+
+       The _new and _copy function will return NULL in the case of a memory
+       allocation error, otherwise a new object.  The _set_ functions return
+       false in the case of a memory allocation error.
+
+       We don't have the convenience of C++ here, so note that the library
+       relies on you to keep the types straight.  In other words, if you pass,
+       for example, a FLAC__StreamMetaData* that represents a STREAMINFO block
+       to FLAC__metadata_object_application_set_data(), you will get an
+       assertion failure.
+
+       There is no need to recalculate the length field on metadata blocks
+       you have modified.  They will be calculated automatically before they
+       are written back to a file.  @@@NO LONGER NEEDED? If you need to know the length to can
+       explicitly call FLAC__metadata_object_calculate_length(), then read
+       object->length
+******************************************************************************/
+
+
+/******************************************************************
+ * Common to all the types derived from FLAC__StreamMetaData:
+ */
+FLAC__StreamMetaData *FLAC__metadata_object_new(FLAC__MetaDataType type);
+FLAC__StreamMetaData *FLAC__metadata_object_copy(const FLAC__StreamMetaData *object);
+void FLAC__metadata_object_delete(FLAC__StreamMetaData *object);
+#if 0
+@@@ no longer needed
+void FLAC__metadata_object_calculate_length(FLAC__StreamMetaData *object);
+#endif
+
+/******************************************************************
+ * FLAC__StreamMetaData_Application
+ * ----------------------------------------------------------------
+ * Note: 'length' is in bytes.
+ */
+FLAC__bool FLAC__metadata_object_application_set_data(FLAC__StreamMetaData *object, FLAC__byte *data, unsigned length, FLAC__bool copy);
+
+/******************************************************************
+ * FLAC__StreamMetaData_SeekPoint
+ * ----------------------------------------------------------------
+ * Note that we do not manipulate individual seek points as the
+ * seek table holds a pointer to an array of seek points.  You can
+ * use the _resize function to alter in.  If the size shrinks,
+ * elements will truncated; if it grows, new elements will be added
+ * to the end.
+ */
+FLAC__StreamMetaData_SeekPoint *FLAC__metadata_object_seekpoint_array_new(unsigned num_points);
+FLAC__StreamMetaData_SeekPoint *FLAC__metadata_object_seekpoint_array_copy(const FLAC__StreamMetaData_SeekPoint *object_array, unsigned num_points);
+void FLAC__metadata_object_seekpoint_array_delete(FLAC__StreamMetaData_SeekPoint *object_array);
+FLAC__bool FLAC__metadata_object_seekpoint_array_resize(FLAC__StreamMetaData_SeekPoint **object_array, unsigned old_num_points, unsigned new_num_points);
+
+/******************************************************************
+ * FLAC__StreamMetaData_SeekTable
+ */
+FLAC__bool FLAC__metadata_object_seektable_set_points(FLAC__StreamMetaData *object, FLAC__StreamMetaData_SeekPoint *points, unsigned num_points, FLAC__bool copy);
+
+/******************************************************************
+ * FLAC__StreamMetaData_VorbisComment_Entry
+ * ----------------------------------------------------------------
+ * This is similar to FLAC__StreamMetaData_SeekPoint.
+ */
+FLAC__StreamMetaData_VorbisComment_Entry *FLAC__metadata_object_vorbiscomment_entry_array_new(unsigned num_comments);
+FLAC__StreamMetaData_VorbisComment_Entry *FLAC__metadata_object_vorbiscomment_entry_array_copy(const FLAC__StreamMetaData_VorbisComment_Entry *object_array, unsigned num_comments);
+void FLAC__metadata_object_vorbiscomment_entry_array_delete(FLAC__StreamMetaData_VorbisComment_Entry *object_array, unsigned num_comments);
+FLAC__bool FLAC__metadata_object_vorbiscomment_entry_array_resize(FLAC__StreamMetaData_VorbisComment_Entry **object_array, unsigned old_num_comments, unsigned new_num_comments);
+
+/******************************************************************
+ * FLAC__StreamMetaData_VorbisComment
+ */
+FLAC__bool FLAC__metadata_object_vorbiscomment_set_vendor_string(FLAC__StreamMetaData *object, FLAC__byte *entry, unsigned length, FLAC__bool copy);
+FLAC__bool FLAC__metadata_object_vorbiscomment_set_comments(FLAC__StreamMetaData *object, FLAC__StreamMetaData_VorbisComment_Entry *comments, unsigned num_comments, FLAC__bool copy);
+
+#endif
diff --git a/src/libFLAC/metadata.c b/src/libFLAC/metadata.c
new file mode 100644 (file)
index 0000000..cf320a0
--- /dev/null
@@ -0,0 +1,2462 @@
+/* libFLAC - Free Lossless Audio Codec library
+ * Copyright (C) 2001,2002  Josh Coalson
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA  02111-1307, USA.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if defined _MSC_VER || defined __MINGW32__
+#include <sys/utime.h> /* for utime() */
+#include <io.h> /* for chmod() */
+#else
+#include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
+#include <utime.h> /* for utime() */
+#include <unistd.h> /* for chown(), unlink() */
+#endif
+#include <sys/stat.h> /* for stat(), maybe chmod() */
+
+#include "FLAC/assert.h"
+#include "FLAC/metadata.h"
+#include "FLAC/file_decoder.h"
+
+#ifdef max
+#undef max
+#endif
+#define max(a,b) ((a)>(b)?(a):(b))
+#ifdef min
+#undef min
+#endif
+#define min(a,b) ((a)<(b)?(a):(b))
+
+
+/****************************************************************************
+ *
+ * Local function declarations
+ *
+ ***************************************************************************/
+
+/* this one should probably not go in the public interface: */
+static void FLAC__metadata_object_delete_data_(FLAC__StreamMetaData *object);
+
+static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
+static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
+static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
+static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
+static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
+static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
+
+static FLAC__bool read_metadata_block_header_(FLAC__MetaData_SimpleIterator *iterator);
+static FLAC__bool read_metadata_block_data_(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block);
+static FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_streaminfo_(FILE *file, FLAC__StreamMetaData_StreamInfo *block);
+static FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_padding_(FILE *file, FLAC__StreamMetaData_Padding *block, unsigned block_length);
+static FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_application_(FILE *file, FLAC__StreamMetaData_Application *block, unsigned block_length);
+static FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_seektable_(FILE *file, FLAC__StreamMetaData_SeekTable *block, unsigned block_length);
+static FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_(FILE *file, FLAC__StreamMetaData_VorbisComment_Entry *entry);
+static FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_(FILE *file, FLAC__StreamMetaData_VorbisComment *block);
+
+static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__MetaData_SimpleIteratorStatus *status, const FLAC__StreamMetaData *block);
+static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__MetaData_SimpleIteratorStatus *status, const FLAC__StreamMetaData *block);
+static FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_streaminfo_(FILE *file, const FLAC__StreamMetaData_StreamInfo *block);
+static FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_padding_(FILE *file, const FLAC__StreamMetaData_Padding *block, unsigned block_length);
+static FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_application_(FILE *file, const FLAC__StreamMetaData_Application *block, unsigned block_length);
+static FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_seektable_(FILE *file, const FLAC__StreamMetaData_SeekTable *block);
+static FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_vorbis_comment_(FILE *file, const FLAC__StreamMetaData_VorbisComment *block);
+static FLAC__bool write_metadata_block_stationary_(FLAC__MetaData_SimpleIterator *iterator, const FLAC__StreamMetaData *block);
+static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block, unsigned padding_length, FLAC__bool padding_is_last);
+static FLAC__bool rewrite_whole_file_(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block, FLAC__bool append);
+
+static FLAC__bool chain_rewrite_chain_(FLAC__MetaData_Chain *chain);
+static FLAC__bool chain_rewrite_file_(FLAC__MetaData_Chain *chain, const char *tempfile_path_prefix);
+
+static void simple_iterator_push_(FLAC__MetaData_SimpleIterator *iterator);
+static FLAC__bool simple_iterator_pop_(FLAC__MetaData_SimpleIterator *iterator);
+
+/* return 0 if OK, 1 if read error, 2 if not a FLAC file */
+static unsigned seek_to_first_metadata_block_(FILE *f);
+
+static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__MetaData_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
+static FLAC__bool simple_iterator_copy_file_postfix_(FLAC__MetaData_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, long fixup_is_last_flag_offset, FLAC__bool backup);
+
+static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__MetaData_SimpleIteratorStatus *status);
+static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__MetaData_SimpleIteratorStatus *status);
+
+static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__MetaData_SimpleIteratorStatus *status);
+static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__MetaData_SimpleIteratorStatus *status);
+static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
+
+static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
+static void set_file_stats_(const char *filename, struct stat *stats);
+
+static FLAC__MetaData_ChainStatus get_equivalent_status_(FLAC__MetaData_SimpleIteratorStatus status);
+
+
+/****************************************************************************
+ *
+ * Level 0 implementation
+ *
+ ***************************************************************************/
+
+static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *buffer[], void *client_data);
+static void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data);
+static void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
+
+FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetaData_StreamInfo *streaminfo)
+{
+       FLAC__FileDecoder *decoder = FLAC__file_decoder_new();
+
+       if(0 == decoder)
+               return false;
+
+       FLAC__file_decoder_set_md5_checking(decoder, false);
+       FLAC__file_decoder_set_filename(decoder, filename);
+       FLAC__file_decoder_set_write_callback(decoder, write_callback_);
+       FLAC__file_decoder_set_metadata_callback(decoder, metadata_callback_);
+       FLAC__file_decoder_set_error_callback(decoder, error_callback_);
+       FLAC__file_decoder_set_client_data(decoder, &streaminfo);
+
+       if(FLAC__file_decoder_init(decoder) != FLAC__FILE_DECODER_OK)
+               return false;
+
+       if(!FLAC__file_decoder_process_metadata(decoder))
+               return false;
+
+       if(FLAC__file_decoder_get_state(decoder) != FLAC__FILE_DECODER_UNINITIALIZED)
+               FLAC__file_decoder_finish(decoder);
+
+       FLAC__file_decoder_delete(decoder);
+
+       return 0 != streaminfo; /* the metadata_callback_() will set streaminfo to 0 on an error */
+}
+
+FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *buffer[], void *client_data)
+{
+       (void)decoder, (void)frame, (void)buffer, (void)client_data;
+
+       return FLAC__STREAM_DECODER_WRITE_CONTINUE;
+}
+
+void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data)
+{
+       FLAC__StreamMetaData_StreamInfo **streaminfo = (FLAC__StreamMetaData_StreamInfo **)client_data;
+       (void)decoder;
+
+       if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO && 0 != *streaminfo)
+               **streaminfo = metadata->data.stream_info;
+}
+
+void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
+{
+       FLAC__StreamMetaData_StreamInfo **streaminfo = (FLAC__StreamMetaData_StreamInfo **)client_data;
+       (void)decoder;
+
+       if(status != FLAC__STREAM_DECODER_ERROR_LOST_SYNC)
+               *streaminfo = 0;
+}
+
+
+/****************************************************************************
+ *
+ * Level 1 implementation
+ *
+ ***************************************************************************/
+
+#define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
+/* 1 for initial offset, +4 for our own personal use */
+
+struct FLAC__MetaData_SimpleIterator {
+       FILE *file;
+       char *filename, *tempfile_path_prefix;
+       struct stat stats;
+       FLAC__bool has_stats;
+       FLAC__bool is_writable;
+       FLAC__MetaData_SimpleIteratorStatus status;
+       /*@@@ 2G limits here because of the offset type: */
+       long offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
+       long first_offset; /* this is the offset to the STREAMINFO block */
+       unsigned depth;
+       /* this is the metadata block header of the current block we are pointing to: */
+       FLAC__bool is_last;
+       FLAC__MetaDataType type;
+       unsigned length;
+};
+
+const char *FLAC__MetaData_SimpleIteratorStatusString[] = {
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
+       "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
+};
+
+
+FLAC__MetaData_SimpleIterator *FLAC__metadata_simple_iterator_new()
+{
+       FLAC__MetaData_SimpleIterator *iterator = malloc(sizeof(FLAC__MetaData_SimpleIterator));
+
+       if(0 != iterator) {
+               iterator->file = 0;
+               iterator->filename = 0;
+               iterator->tempfile_path_prefix = 0;
+               iterator->has_stats = false;
+               iterator->is_writable = false;
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+               iterator->first_offset = iterator->offset[0] = -1;
+               iterator->depth = 0;
+       }
+
+       return iterator;
+}
+
+static void simple_iterator_free_guts_(FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+
+       if(0 != iterator->file) {
+               fclose(iterator->file);
+               iterator->file = 0;
+               if(iterator->has_stats)
+                       set_file_stats_(iterator->filename, &iterator->stats);
+       }
+       if(0 != iterator->filename) {
+               free(iterator->filename);
+               iterator->filename = 0;
+       }
+       if(0 != iterator->tempfile_path_prefix) {
+               free(iterator->tempfile_path_prefix);
+               iterator->tempfile_path_prefix = 0;
+       }
+}
+
+void FLAC__metadata_simple_iterator_delete(FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+
+       simple_iterator_free_guts_(iterator);
+       free(iterator);
+}
+
+FLAC__MetaData_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__MetaData_SimpleIteratorStatus status;
+
+       FLAC__ASSERT(0 != iterator);
+
+       status = iterator->status;
+       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+       return status;
+}
+
+static FLAC__bool simple_iterator_prime_input_(FLAC__MetaData_SimpleIterator *iterator)
+{
+       unsigned ret;
+
+       FLAC__ASSERT(0 != iterator);
+
+       iterator->is_writable = false;
+
+       if(0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
+               if(errno == EACCES) {
+                       if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
+                               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
+                               return false;
+                       }
+               }
+               else {
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
+                       return false;
+               }
+       }
+       else {
+               iterator->is_writable = true;
+       }
+
+       ret = seek_to_first_metadata_block_(iterator->file);
+       switch(ret) {
+               case 0:
+                       iterator->depth = 0;
+                       iterator->first_offset = iterator->offset[iterator->depth] = ftell(iterator->file);
+                       return read_metadata_block_header_(iterator);
+               case 1:
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+                       return false;
+               case 2:
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
+                       return false;
+               default:
+                       FLAC__ASSERT(0);
+                       return false;
+       }
+}
+
+#if 0
+@@@ If we decide to finish implementing this, put this comment back in metadata.h
+/*
+ * The 'tempfile_path_prefix' allows you to specify a directory where
+ * tempfiles should go.  Remember that if your metadata edits cause the
+ * FLAC file to grow, the entire file will have to be rewritten.  If
+ * 'tempfile_path_prefix' is NULL, the temp file will be written in the
+ * same directory as the original FLAC file.  This makes replacing the
+ * original with the tempfile fast but requires extra space in the same
+ * partition for the tempfile.  If space is a problem, you can pass a
+ * directory name belonging to a different partition in
+ * 'tempfile_path_prefix'.  Note that you should use the forward slash
+ * '/' as the directory separator.  A trailing slash is not needed; it
+ * will be added automatically.
+ */
+FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__MetaData_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
+#endif
+
+FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__MetaData_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats)
+{
+       const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(' for what it will take to finish implementing this */
+
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != filename);
+
+       simple_iterator_free_guts_(iterator);
+
+       if(preserve_file_stats)
+               iterator->has_stats = get_file_stats_(filename, &iterator->stats);
+
+       if(0 == (iterator->filename = strdup(filename))) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+               return false;
+       }
+       if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+               return false;
+       }
+
+       return simple_iterator_prime_input_(iterator);
+}
+
+FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       return iterator->is_writable;
+}
+
+FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       if(iterator->is_last)
+               return false;
+
+       if(0 != fseek(iterator->file, iterator->length, SEEK_CUR)) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+
+       iterator->offset[iterator->depth] = ftell(iterator->file);
+
+       return read_metadata_block_header_(iterator);
+}
+
+FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__MetaData_SimpleIterator *iterator)
+{
+       long this_offset;
+
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       if(iterator->offset[iterator->depth] == iterator->first_offset)
+               return false;
+
+       if(0 != fseek(iterator->file, iterator->first_offset, SEEK_SET)) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+       this_offset = iterator->first_offset;
+       if(!read_metadata_block_header_(iterator))
+               return false;
+
+       /* we ignore any error from ftell() and catch it in fseek() */
+       while(ftell(iterator->file) + (long)iterator->length < iterator->offset[iterator->depth]) {
+               if(0 != fseek(iterator->file, iterator->length, SEEK_CUR)) {
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+                       return false;
+               }
+               this_offset = ftell(iterator->file);
+               if(!read_metadata_block_header_(iterator))
+                       return false;
+       }
+
+       iterator->offset[iterator->depth] = this_offset;
+
+       return true;
+}
+
+FLAC__MetaDataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       return iterator->type;
+}
+
+FLAC__StreamMetaData *FLAC__metadata_simple_iterator_get_block(FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__StreamMetaData *block = FLAC__metadata_object_new(iterator->type);
+
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       if(0 != block) {
+               block->is_last = iterator->is_last;
+               block->length = iterator->length;
+
+               if(!read_metadata_block_data_(iterator, block)) {
+                       FLAC__metadata_object_delete(block);
+                       return 0;
+               }
+
+               /* back up to the beginning of the block data to stay consistent */
+               if(0 != fseek(iterator->file, iterator->offset[iterator->depth] + 4, SEEK_SET)) { /*@@@ 4 = MAGIC NUMBER for metadata block header bytes */
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+                       FLAC__metadata_object_delete(block);
+                       return 0;
+               }
+       }
+       else
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+
+       return block;
+}
+
+FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block, FLAC__bool use_padding)
+{
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       if(!iterator->is_writable) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
+               return false;
+       }
+
+       if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
+               if(iterator->type != block->type) {
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
+                       return false;
+               }
+       }
+
+       block->is_last = iterator->is_last;
+       //@@@@FLAC__metadata_object_calculate_length(block);
+
+       if(iterator->length == block->length)
+               return write_metadata_block_stationary_(iterator, block);
+       else if(iterator->length > block->length) {
+               if(use_padding && iterator->length >= 4 + block->length) /*@@@ 4 = MAGIC NUMBER for metadata block header bytes */
+                       return write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - block->length - 4, block->is_last);
+               else
+                       return rewrite_whole_file_(iterator, block, /*append=*/false);
+       }
+       else /* iterator->length < block->length */ {
+               unsigned padding_leftover = 0;
+               FLAC__bool padding_is_last = false;
+               if(use_padding) {
+                       /* first see if we can even use padding */
+                       if(iterator->is_last) {
+                               use_padding = false;
+                       }
+                       else {
+                               unsigned existing_block_length = iterator->length;
+                               simple_iterator_push_(iterator);
+                               if(!FLAC__metadata_simple_iterator_next(iterator)) {
+                                       (void)simple_iterator_pop_(iterator);
+                                       return false;
+                               }
+                               if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
+                                       use_padding = false;
+                               }
+                               else {
+                                       /*@@@ MAGIC NUMBER 4 = metadata block header length, appears 3 times here: */
+                                       const unsigned available_size = existing_block_length + 4 + iterator->length;
+                                       if(available_size == block->length) {
+                                               padding_leftover = 0;
+                                               block->is_last = iterator->is_last;
+                                       }
+                                       else if(available_size - 4 < block->length)
+                                               use_padding = false;
+                                       else {
+                                               padding_leftover = available_size - 4 - block->length;
+                                               padding_is_last = iterator->is_last;
+                                               block->is_last = false;
+                                       }
+                               }
+                               if(!simple_iterator_pop_(iterator))
+                                       return false;
+                       }
+               }
+               if(use_padding) {
+                       if(padding_leftover == 0)
+                               return write_metadata_block_stationary_(iterator, block);
+                       else
+                               return write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover, padding_is_last);
+               }
+               else {
+                       return rewrite_whole_file_(iterator, block, /*append=*/false);
+               }
+       }
+}
+
+FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block, FLAC__bool use_padding)
+{
+       unsigned padding_leftover = 0;
+       FLAC__bool padding_is_last = false;
+
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       if(!iterator->is_writable)
+               return false;
+
+       if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
+               return false;
+       }
+
+       if(use_padding) {
+               /* first see if we can even use padding */
+               if(iterator->is_last) {
+                       use_padding = false;
+               }
+               else {
+                       simple_iterator_push_(iterator);
+                       if(!FLAC__metadata_simple_iterator_next(iterator)) {
+                               (void)simple_iterator_pop_(iterator);
+                               return false;
+                       }
+                       if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
+                               use_padding = false;
+                       }
+                       else {
+                               /*@@@ MAGIC NUMBER 4 = metadata block header length, appears 2 times here: */
+                               if(iterator->length == block->length) {
+                                       padding_leftover = 0;
+                                       block->is_last = iterator->is_last;
+                               }
+                               else if(iterator->length < 4 + block->length)
+                                       use_padding = false;
+                               else {
+                                       padding_leftover = iterator->length - 4 - block->length;
+                                       padding_is_last = iterator->is_last;
+                                       block->is_last = false;
+                               }
+                       }
+                       if(!simple_iterator_pop_(iterator))
+                               return false;
+               }
+       }
+       if(use_padding) {
+               /* move to the next block, which is suitable padding */
+               if(!FLAC__metadata_simple_iterator_next(iterator))
+                       return false;
+               if(padding_leftover == 0)
+                       return write_metadata_block_stationary_(iterator, block);
+               else
+                       return write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover, padding_is_last);
+       }
+       else {
+               return rewrite_whole_file_(iterator, block, /*append=*/true);
+       }
+}
+
+/*
+ * Deletes the block at the current position.  This will cause the
+ * entire FLAC file to be rewritten, unless 'use_padding' is true,
+ * in which case the block will be replaced by an equal-sized PADDING
+ * block.
+ *
+ * You may not delete the STREAMINFO block
+ */
+FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__MetaData_SimpleIterator *iterator, FLAC__bool use_padding)
+{
+       if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
+               return false;
+       }
+
+       if(use_padding) {
+               FLAC__StreamMetaData *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
+               if(0 == padding) {
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+                       return false;
+               }
+               padding->length = iterator->length;
+               if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
+                       FLAC__metadata_object_delete(padding);
+                       return false;
+               }
+               FLAC__metadata_object_delete(padding);
+               return true;
+       }
+       else {
+               return rewrite_whole_file_(iterator, 0, /*append=*/false);
+       }
+}
+
+
+
+/****************************************************************************
+ *
+ * Level 2 implementation
+ *
+ ***************************************************************************/
+
+
+typedef struct FLAC__MetaData_Node {
+       FLAC__StreamMetaData *data;
+       struct FLAC__MetaData_Node *prev, *next;
+} FLAC__MetaData_Node;
+
+struct FLAC__MetaData_Chain {
+       char *filename;
+       FLAC__MetaData_Node *head;
+       FLAC__MetaData_Node *tail;
+       unsigned nodes;
+       FLAC__MetaData_ChainStatus status;
+       long first_offset, last_offset; /*@@@ 2G limit */
+       /*
+        * This is the length of the chain initially read from the FLAC file.
+        * it is used to compare against the current_length to decide whether
+        * or not the whole file has to be rewritten.
+        */
+       unsigned initial_length; /*@@@ 4G limit */
+       unsigned current_length; /*@@@ 4G limit */
+};
+
+struct FLAC__MetaData_Iterator {
+       FLAC__MetaData_Chain *chain;
+       FLAC__MetaData_Node *current;
+};
+
+const char *FLAC__MetaData_ChainStatusString[] = {
+       "FLAC__METADATA_CHAIN_STATUS_OK",
+       "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
+       "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
+       "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
+       "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
+       "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
+       "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
+       "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
+       "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
+       "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
+       "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
+       "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR"
+};
+
+
+static FLAC__MetaData_Node *node_new_()
+{
+       FLAC__MetaData_Node *node = (FLAC__MetaData_Node*)malloc(sizeof(FLAC__MetaData_Node));
+       if(0 != node)
+               memset(node, 0, sizeof(FLAC__MetaData_Node));
+       return node;
+}
+
+static void node_delete_(FLAC__MetaData_Node *node)
+{
+       FLAC__ASSERT(0 != node);
+       if(0 != node->data)
+               FLAC__metadata_object_delete(node->data);
+       free(node);
+}
+
+static void chain_append_node_(FLAC__MetaData_Chain *chain, FLAC__MetaData_Node *node)
+{
+       FLAC__ASSERT(0 != chain);
+       FLAC__ASSERT(0 != node);
+
+       node->data->is_last = true;
+       if(0 != chain->tail)
+               chain->tail->data->is_last = false;
+
+       if(0 == chain->head)
+               chain->head = node;
+       else {
+               chain->tail->next = node;
+               node->prev = chain->tail;
+       }
+       chain->tail = node;
+       chain->nodes++;
+       chain->current_length += (4 + node->data->length); /*@@@ MAGIC NUMBER 4 = metadata block header bytes */
+}
+
+static void chain_remove_node_(FLAC__MetaData_Chain *chain, FLAC__MetaData_Node *node)
+{
+       FLAC__ASSERT(0 != chain);
+       FLAC__ASSERT(0 != node);
+
+       if(node == chain->head)
+               chain->head = node->next;
+       else
+               node->prev->next = node->next;
+
+       if(node == chain->tail)
+               chain->tail = node->prev;
+       else
+               node->next->prev = node->prev;
+
+       chain->nodes--;
+       chain->current_length -= (4 + node->data->length); /*@@@ MAGIC NUMBER 4 = metadata block header bytes */
+}
+
+static void chain_delete_node_(FLAC__MetaData_Chain *chain, FLAC__MetaData_Node *node)
+{
+       chain_remove_node_(chain, node);
+       node_delete_(node);
+}
+
+static void iterator_insert_node_(FLAC__MetaData_Iterator *iterator, FLAC__MetaData_Node *node)
+{
+       FLAC__ASSERT(0 != node);
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->current);
+       FLAC__ASSERT(0 != iterator->chain);
+       FLAC__ASSERT(0 != iterator->chain->head);
+       FLAC__ASSERT(0 != iterator->chain->tail);
+
+       node->prev = iterator->current->prev;
+       if(0 == node->prev)
+               iterator->chain->head = node;
+       else
+               node->prev->next = node;
+
+       node->next = iterator->current;
+       iterator->current->prev = node;
+
+       iterator->chain->nodes++;
+       iterator->chain->current_length += (4 + node->data->length); /*@@@ MAGIC NUMBER 4 = metadata block header bytes */
+}
+
+static void iterator_insert_node_after_(FLAC__MetaData_Iterator *iterator, FLAC__MetaData_Node *node)
+{
+       FLAC__ASSERT(0 != node);
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->current);
+       FLAC__ASSERT(0 != iterator->chain);
+       FLAC__ASSERT(0 != iterator->chain->head);
+       FLAC__ASSERT(0 != iterator->chain->tail);
+
+       iterator->current->data->is_last = false;
+
+       node->prev = iterator->current;
+       iterator->current->next = node;
+
+       node->next = iterator->current->next;
+       if(0 == node->next)
+               iterator->chain->tail = node;
+       else
+               node->next->prev = node;
+
+       iterator->chain->tail->data->is_last = true;
+
+       iterator->chain->nodes++;
+       iterator->chain->current_length += (4 + node->data->length); /*@@@ MAGIC NUMBER 4 = metadata block header bytes */
+}
+
+FLAC__MetaData_Chain *FLAC__metadata_chain_new()
+{
+       FLAC__MetaData_Chain *chain = malloc(sizeof(FLAC__MetaData_Chain));
+
+       if(0 != chain) {
+               chain->filename = 0;
+               chain->head = chain->tail = 0;
+               chain->nodes = 0;
+               chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
+               chain->initial_length = chain->current_length = 0;
+       }
+
+       return chain;
+}
+
+void FLAC__metadata_chain_delete(FLAC__MetaData_Chain *chain)
+{
+       FLAC__MetaData_Node *node, *next;
+
+       FLAC__ASSERT(0 != chain);
+
+       for(node = chain->head; node; ) {
+               next = node->next;
+               node_delete_(node);
+               node = next;
+       }
+
+       if(0 != chain->filename)
+               free(chain->filename);
+
+       free(chain);
+}
+
+FLAC__MetaData_ChainStatus FLAC__metadata_chain_status(FLAC__MetaData_Chain *chain)
+{
+       FLAC__MetaData_ChainStatus status;
+
+       FLAC__ASSERT(0 != chain);
+
+       status = chain->status;
+       chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
+       return status;
+}
+
+FLAC__bool FLAC__metadata_chain_read(FLAC__MetaData_Chain *chain, const char *filename)
+{
+       FLAC__MetaData_SimpleIterator *iterator;
+       FLAC__MetaData_Node *node;
+
+       FLAC__ASSERT(0 != chain);
+       FLAC__ASSERT(0 != filename);
+
+       if(0 == (chain->filename = strdup(filename))) {
+               chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
+               return false;
+       }
+
+       if(0 == (iterator = FLAC__metadata_simple_iterator_new())) {
+               chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
+               return false;
+       }
+
+       if(!FLAC__metadata_simple_iterator_init(iterator, filename, /*preserve_file_stats=*/false)) {
+               chain->status = get_equivalent_status_(iterator->status);
+               return false;
+       }
+
+       do {
+               node = node_new_();
+               if(0 == node) {
+                       chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
+                       return false;
+               }
+               node->data = FLAC__metadata_simple_iterator_get_block(iterator);
+               if(0 == node->data) {
+                       node_delete_(node);
+                       chain->status = get_equivalent_status_(iterator->status);
+                       return false;
+               }
+               chain_append_node_(chain, node);
+       } while(FLAC__metadata_simple_iterator_next(iterator));
+
+       if(!iterator->is_last || iterator->status != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK) {
+               chain->status = get_equivalent_status_(iterator->status);
+               return false;
+       }
+
+       chain->last_offset = ftell(iterator->file);
+       FLAC__metadata_simple_iterator_delete(iterator);
+
+       chain->initial_length = chain->current_length;
+       return true;
+}
+
+/*
+ * Write all metadata out to the FLAC file.  This function tries to be as
+ * efficient as possible; how the metadata is actually written is shown by
+ * the following:
+ *
+ * If the current chain is the same size as the existing metadata, the new
+ * data is written in place.
+ *
+ * If the current chain is longer than the existing metadata, the entire
+ * FLAC file must be rewritten.
+ *
+ * If the current chain is shorted than the existing metadata, and
+ * use_padding is true, a PADDING block is added to the end of the new
+ * data to make it the same size as the existing data (if possible, see
+ * the note to FLAC__metadata_simple_iterator_set_block() about the four
+ * byte limit) and the new data is written in place.  If use_padding is
+ * false, the entire FLAC file is rewritten.
+ */
+FLAC__bool FLAC__metadata_chain_write(FLAC__MetaData_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
+{
+       struct stat stats;
+       const char *tempfile_path_prefix = 0;
+
+       if(use_padding && chain->current_length + 4 <= chain->initial_length) {
+               FLAC__StreamMetaData *padding;
+               FLAC__MetaData_Node *node;
+               if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
+                       chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
+                       return false;
+               }
+               padding->length = chain->initial_length - (4 + chain->current_length);
+               if(0 == (node = node_new_())) {
+                       FLAC__metadata_object_delete(padding);
+                       chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
+                       return false;
+               }
+               node->data = padding;
+               chain_append_node_(chain, node);
+       }
+
+       if(preserve_file_stats)
+               get_file_stats_(chain->filename, &stats);
+
+       if(chain->current_length == chain->initial_length) {
+               if(!chain_rewrite_chain_(chain))
+                       return false;
+       }
+       else {
+               if(!chain_rewrite_file_(chain, tempfile_path_prefix))
+                       return false;
+       }
+
+       if(preserve_file_stats)
+               set_file_stats_(chain->filename, &stats);
+
+       chain->initial_length = chain->current_length;
+       return true;
+}
+
+void FLAC__metadata_chain_merge_padding(FLAC__MetaData_Chain *chain)
+{
+       FLAC__MetaData_Node *node;
+
+       FLAC__ASSERT(0 != chain);
+
+       for(node = chain->head; node; ) {
+               if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
+                       node->data->length += (4 + node->next->data->length); /*@@@ MAGIC NUMBER 4 = metadata data block header bytes */
+                       chain_delete_node_(chain, node->next);
+               }
+               else {
+                       node = node->next;
+               }
+       }
+       if(0 != chain->tail)
+               chain->tail->data->is_last = true;
+}
+
+void FLAC__metadata_chain_sort_padding(FLAC__MetaData_Chain *chain)
+{
+       FLAC__MetaData_Node *node, *save;
+       unsigned i;
+
+       FLAC__ASSERT(0 != chain);
+
+       /*
+        * Don't try and be too smart... this simple algo is good enough for
+        * the small number of nodes that we deal with.
+        */
+       for(i = 0, node = chain->head; i < chain->nodes; i++) {
+               node->data->is_last = false; /* we'll fix at the end */
+               if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
+                       save = node->next;
+                       chain_remove_node_(chain, node);
+                       chain_append_node_(chain, node);
+                       node = save;
+               }
+               else {
+                       node = node->next;
+               }
+       }
+       if(0 != chain->tail)
+               chain->tail->data->is_last = true;
+
+       FLAC__metadata_chain_merge_padding(chain);
+}
+
+
+FLAC__MetaData_Iterator *FLAC__metadata_iterator_new()
+{
+       FLAC__MetaData_Iterator *iterator = malloc(sizeof(FLAC__MetaData_Iterator));
+
+       if(0 != iterator) {
+               iterator->current = 0;
+               iterator->chain = 0;
+       }
+
+       return iterator;
+}
+
+void FLAC__metadata_iterator_delete(FLAC__MetaData_Iterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+
+       free(iterator);
+}
+
+/*
+ * Initialize the iterator to point to the first metadata block in the
+ * given chain.
+ */
+void FLAC__metadata_iterator_init(FLAC__MetaData_Iterator *iterator, FLAC__MetaData_Chain *chain)
+{
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != chain);
+       FLAC__ASSERT(0 != chain->head);
+
+       iterator->chain = chain;
+       iterator->current = chain->head;
+}
+
+FLAC__bool FLAC__metadata_iterator_next(FLAC__MetaData_Iterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+
+       if(0 == iterator->current || 0 == iterator->current->next)
+               return false;
+
+       iterator->current = iterator->current->next;
+       return true;
+}
+
+FLAC__bool FLAC__metadata_iterator_prev(FLAC__MetaData_Iterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+
+       if(0 == iterator->current || 0 == iterator->current->prev)
+               return false;
+
+       iterator->current = iterator->current->prev;
+       return true;
+}
+
+FLAC__MetaDataType FLAC__metadata_iterator_get_block_type(const FLAC__MetaData_Iterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->current);
+
+       return iterator->current->data->type;
+}
+
+FLAC__StreamMetaData *FLAC__metadata_iterator_get_block(FLAC__MetaData_Iterator *iterator)
+{
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->current);
+
+       return iterator->current->data;
+}
+
+FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__MetaData_Iterator *iterator, FLAC__bool replace_with_padding)
+{
+       FLAC__MetaData_Node *save;
+
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->current);
+
+       if(0 == iterator->current->prev) {
+               FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
+               return false;
+       }
+
+       save = iterator->current->prev;
+
+       if(replace_with_padding) {
+               FLAC__metadata_object_delete_data_(iterator->current->data);
+               iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
+       }
+       else {
+               chain_delete_node_(iterator->chain, iterator->current);
+       }
+
+       iterator->current = save;
+       return true;
+}
+
+FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__MetaData_Iterator *iterator, FLAC__StreamMetaData *block)
+{
+       FLAC__MetaData_Node *node;
+
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->current);
+
+       if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
+               return false;
+
+       if(0 == iterator->current->prev) {
+               FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
+               return false;
+       }
+
+       if(0 == (node = node_new_()))
+               return false;
+
+       node->data = block;
+       iterator_insert_node_(iterator, node);
+       iterator->current = node;
+       return true;
+}
+
+FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__MetaData_Iterator *iterator, FLAC__StreamMetaData *block)
+{
+       FLAC__MetaData_Node *node;
+
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->current);
+
+       if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
+               return false;
+
+       if(0 == (node = node_new_()))
+               return false;
+
+       node->data = block;
+       iterator_insert_node_after_(iterator, node);
+       iterator->current = node;
+       return true;
+}
+
+
+/****************************************************************************
+ *
+ * Metadata object routines
+ *
+ ***************************************************************************/
+
+FLAC__StreamMetaData *FLAC__metadata_object_new(FLAC__MetaDataType type)
+{
+       FLAC__StreamMetaData *object = malloc(sizeof(FLAC__StreamMetaData));
+       if(0 != object) {
+               memset(object, 0, sizeof(FLAC__StreamMetaData));
+               object->is_last = false;
+               object->type = type;
+               switch(type) {
+                       case FLAC__METADATA_TYPE_STREAMINFO:
+                               object->length = FLAC__STREAM_METADATA_STREAMINFO_LENGTH;
+                               break;
+                       case FLAC__METADATA_TYPE_PADDING:
+                               break;
+                       case FLAC__METADATA_TYPE_APPLICATION:
+                               object->length = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
+                               break;
+                       case FLAC__METADATA_TYPE_SEEKTABLE:
+                               break;
+                       case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                               object->length = (FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN + FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8;
+                               break;
+                       default:
+                               FLAC__ASSERT(0);
+               }
+       }
+
+       return object;
+}
+
+static FLAC__bool copy_bytes_(FLAC__byte **to, const FLAC__byte *from, unsigned bytes)
+{
+       if(0 == (*to = malloc(bytes)))
+               return false;
+       memcpy(*to, from, bytes);
+       return true;
+}
+
+static FLAC__bool copy_vcentry_(FLAC__StreamMetaData_VorbisComment_Entry *to, const FLAC__StreamMetaData_VorbisComment_Entry *from)
+{
+       to->length = from->length;
+       if(0 == from->entry) {
+               FLAC__ASSERT(0 == from->length);
+               to->entry = 0;
+       }
+       else {
+               if(0 == (to->entry = malloc(from->length)))
+                       return false;
+               memcpy(to->entry, from->entry, from->length);
+       }
+       return true;
+}
+
+FLAC__StreamMetaData *FLAC__metadata_object_copy(const FLAC__StreamMetaData *object)
+{
+       FLAC__StreamMetaData *to;
+       unsigned i;
+
+       FLAC__ASSERT(0 != object);
+
+       if(0 != (to = FLAC__metadata_object_new(object->type))) {
+               to->is_last = object->is_last;
+               to->type = object->type;
+               to->length = object->length;
+               switch(to->type) {
+                       case FLAC__METADATA_TYPE_STREAMINFO:
+                               memcpy(&to->data.stream_info, &object->data.stream_info, sizeof(FLAC__StreamMetaData_StreamInfo));
+                               break;
+                       case FLAC__METADATA_TYPE_PADDING:
+                               break;
+                       case FLAC__METADATA_TYPE_APPLICATION:
+                               memcpy(&to->data.application.id, &object->data.application.id, FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8);
+                               if(0 == object->data.application.data)
+                                       to->data.application.data = 0;
+                               else {
+                                       if(!copy_bytes_(&to->data.application.data, object->data.application.data, object->length - FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8)) {
+                                               FLAC__metadata_object_delete(to);
+                                               return 0;
+                                       }
+                               }
+                               break;
+                       case FLAC__METADATA_TYPE_SEEKTABLE:
+                               to->data.seek_table.num_points = object->data.seek_table.num_points;
+                               if(0 == object->data.seek_table.points)
+                                       to->data.seek_table.points = 0;
+                               else {
+                                       if(!copy_bytes_((FLAC__byte**)&to->data.seek_table.points, (FLAC__byte*)object->data.seek_table.points, object->data.seek_table.num_points * sizeof(FLAC__StreamMetaData_SeekPoint))) {
+                                               FLAC__metadata_object_delete(to);
+                                               return 0;
+                                       }
+                               }
+                               break;
+                       case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                               if(!copy_vcentry_(&to->data.vorbis_comment.vendor_string, &object->data.vorbis_comment.vendor_string)) {
+                                       FLAC__metadata_object_delete(to);
+                                       return 0;
+                               }
+                               to->data.vorbis_comment.num_comments = object->data.vorbis_comment.num_comments;
+                               if(0 == (to->data.vorbis_comment.comments = malloc(object->data.vorbis_comment.num_comments * sizeof(FLAC__StreamMetaData_VorbisComment_Entry*)))) {
+                                       FLAC__metadata_object_delete(to);
+                                       return 0;
+                               }
+                               /* Need to do this to set the pointers inside the comments to 0.
+                                * In case of an error in the following loop, the object will be
+                                * deleted and we don't want the destructor freeing uninitialized
+                                * pointers.
+                                */
+                               memset(to->data.vorbis_comment.comments, 0, object->data.vorbis_comment.num_comments * sizeof(FLAC__StreamMetaData_VorbisComment_Entry*));
+                               for(i = 0; i < object->data.vorbis_comment.num_comments; i++) {
+                                       if(!copy_vcentry_(to->data.vorbis_comment.comments+i, object->data.vorbis_comment.comments+i)) {
+                                               FLAC__metadata_object_delete(to);
+                                               return 0;
+                                       }
+                               }
+                               break;
+                       default:
+                               FLAC__ASSERT(0);
+               }
+       }
+
+       return to;
+}
+
+void FLAC__metadata_object_delete_data_(FLAC__StreamMetaData *object)
+{
+       unsigned i;
+
+       FLAC__ASSERT(0 != object);
+
+       switch(object->type) {
+               case FLAC__METADATA_TYPE_STREAMINFO:
+               case FLAC__METADATA_TYPE_PADDING:
+                       break;
+               case FLAC__METADATA_TYPE_APPLICATION:
+                       if(0 != object->data.application.data)
+                               free(object->data.application.data);
+                       break;
+               case FLAC__METADATA_TYPE_SEEKTABLE:
+                       if(0 != object->data.seek_table.points)
+                               free(object->data.seek_table.points);
+                       break;
+               case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                       if(0 != object->data.vorbis_comment.vendor_string.entry)
+                               free(object->data.vorbis_comment.vendor_string.entry);
+                       for(i = 0; i < object->data.vorbis_comment.num_comments; i++) {
+                               if(0 != object->data.vorbis_comment.comments[i].entry)
+                                       free(object->data.vorbis_comment.comments[i].entry);
+                       }
+                       break;
+               default:
+                       FLAC__ASSERT(0);
+       }
+}
+
+void FLAC__metadata_object_delete(FLAC__StreamMetaData *object)
+{
+       FLAC__metadata_object_delete_data_(object);
+       free(object);
+}
+
+#if 0
+@@@@ should no longer be needed
+void FLAC__metadata_object_calculate_length(FLAC__StreamMetaData *object)
+{
+       unsigned i;
+
+       FLAC__ASSERT(0 != object);
+
+       switch(type) {
+               case FLAC__METADATA_TYPE_STREAMINFO:
+               case FLAC__METADATA_TYPE_PADDING:
+                       /* already calculated on object creation */
+                       break;
+               case FLAC__METADATA_TYPE_APPLICATION:
+               case FLAC__METADATA_TYPE_SEEKTABLE:
+                       /* already calculated on object creation or _set */
+                       break;
+               case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                       object->length = (FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN) / 8;
+                       object->length += object->data.vorbis_comment.vendor_string.length;
+                       object->length += (FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8;
+                       for(i = 0; i < object->data.vorbis_comment.num_comments; i++) {
+                               object->length += (FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8);
+                               object->length += object->data.vorbis_comment.comments[i].length;
+                       }
+                       break;
+               default:
+                       FLAC__ASSERT(0);
+       }
+}
+#endif
+
+/*@@@@ Allow setting pointer to 0 to free, or let length be 0 also.   fix everywhere */
+FLAC__bool FLAC__metadata_object_application_set_data(FLAC__StreamMetaData *object, FLAC__byte *data, unsigned length, FLAC__bool copy)
+{
+       FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_APPLICATION);
+
+       if(0 != object->data.application.data)
+               free(object->data.application.data);
+
+       if(copy) {
+               if(!copy_bytes_(&object->data.application.data, data, length))
+                       return false;
+       }
+       else {
+               object->data.application.data = data;
+       }
+       object->length = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8 + length;
+       return true;
+}
+
+FLAC__StreamMetaData_SeekPoint *FLAC__metadata_object_seekpoint_array_new(unsigned num_points)
+{
+       FLAC__StreamMetaData_SeekPoint *object_array = malloc(num_points * sizeof(FLAC__StreamMetaData_SeekPoint));
+
+       if(0 != object_array)
+               memset(object_array, 0, num_points * sizeof(FLAC__StreamMetaData_SeekPoint));
+
+       return object_array;
+}
+
+FLAC__StreamMetaData_SeekPoint *FLAC__metadata_object_seekpoint_array_copy(const FLAC__StreamMetaData_SeekPoint *object_array, unsigned num_points)
+{
+       FLAC__StreamMetaData_SeekPoint *return_array;
+
+       FLAC__ASSERT(0 != object_array);
+
+       return_array = FLAC__metadata_object_seekpoint_array_new(num_points);
+
+       if(0 != return_array)
+               memcpy(return_array, object_array, num_points * sizeof(FLAC__StreamMetaData_SeekPoint));
+
+       return return_array;
+}
+
+void FLAC__metadata_object_seekpoint_array_delete(FLAC__StreamMetaData_SeekPoint *object_array)
+{
+       FLAC__ASSERT(0 != object_array);
+
+       free(object_array);
+}
+
+FLAC__bool FLAC__metadata_object_seekpoint_array_resize(FLAC__StreamMetaData_SeekPoint **object_array, unsigned old_num_points, unsigned new_num_points)
+{
+       FLAC__ASSERT(0 != object_array);
+
+       if(0 == *object_array) {
+               FLAC__ASSERT(old_num_points == 0);
+               return 0 != (*object_array = FLAC__metadata_object_seekpoint_array_new(new_num_points));
+       }
+       else {
+               const unsigned old_size = old_num_points * sizeof(FLAC__StreamMetaData_SeekPoint);
+               const unsigned new_size = new_num_points * sizeof(FLAC__StreamMetaData_SeekPoint);
+
+               if(0 == (*object_array = realloc(*object_array, new_size)))
+                       return false;
+
+               if(new_size > old_size)
+                       memset(*object_array + old_num_points, 0, new_size - old_size);
+
+               return true;
+       }
+}
+
+FLAC__bool FLAC__metadata_object_seektable_set_points(FLAC__StreamMetaData *object, FLAC__StreamMetaData_SeekPoint *points, unsigned num_points, FLAC__bool copy)
+{
+       FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+
+       object->data.seek_table.num_points = num_points;
+
+       if(0 != object->data.seek_table.points)
+               FLAC__metadata_object_seekpoint_array_delete(object->data.seek_table.points);
+
+       if(copy) {
+               if(0 == (object->data.seek_table.points = FLAC__metadata_object_seekpoint_array_copy(points, num_points)))
+                       return false;
+       }
+       else {
+               object->data.seek_table.points = points;
+       }
+       object->length = num_points * FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
+       return true;
+}
+
+FLAC__StreamMetaData_VorbisComment_Entry *FLAC__metadata_object_vorbiscomment_entry_array_new(unsigned num_comments)
+{
+       FLAC__StreamMetaData_VorbisComment_Entry *object_array = malloc(num_comments * sizeof(FLAC__StreamMetaData_VorbisComment_Entry));
+
+       if(0 != object_array)
+               memset(object_array, 0, num_comments * sizeof(FLAC__StreamMetaData_VorbisComment_Entry));
+
+       return object_array;
+}
+
+FLAC__StreamMetaData_VorbisComment_Entry *FLAC__metadata_object_vorbiscomment_entry_array_copy(const FLAC__StreamMetaData_VorbisComment_Entry *object_array, unsigned num_comments)
+{
+       FLAC__StreamMetaData_VorbisComment_Entry *return_array;
+
+       FLAC__ASSERT(0 != object_array);
+
+       return_array = FLAC__metadata_object_vorbiscomment_entry_array_new(num_comments);
+
+       if(0 != return_array) {
+               unsigned i;
+               for(i = 0; i < num_comments; i++) {
+                       return_array[i].length = object_array[i].length;
+                       if(!copy_bytes_(&(return_array[i].entry), object_array[i].entry, object_array[i].length)) {
+                               FLAC__metadata_object_vorbiscomment_entry_array_delete(return_array, num_comments);
+                               return 0;
+                       }
+               }
+       }
+
+       return return_array;
+}
+
+void FLAC__metadata_object_vorbiscomment_entry_array_delete(FLAC__StreamMetaData_VorbisComment_Entry *object_array, unsigned num_comments)
+{
+       unsigned i;
+
+       FLAC__ASSERT(0 != object_array);
+
+       for(i = 0; i < num_comments; i++)
+               if(0 != object_array[i].entry)
+                       free(object_array[i].entry);
+
+       free(object_array);
+}
+
+FLAC__bool FLAC__metadata_object_vorbiscomment_entry_array_resize(FLAC__StreamMetaData_VorbisComment_Entry **object_array, unsigned old_num_comments, unsigned new_num_comments)
+{
+       FLAC__ASSERT(0 != object_array);
+
+       if(0 == *object_array) {
+               FLAC__ASSERT(old_num_comments == 0);
+               return 0 != (*object_array = FLAC__metadata_object_vorbiscomment_entry_array_new(new_num_comments));
+       }
+       else {
+               const unsigned old_size = old_num_comments * sizeof(FLAC__StreamMetaData_VorbisComment_Entry);
+               const unsigned new_size = new_num_comments * sizeof(FLAC__StreamMetaData_VorbisComment_Entry);
+
+               /* if shrinking, free the truncated entries */
+               if(new_num_comments < old_num_comments) {
+                       unsigned i;
+                       for(i = new_num_comments; i < old_num_comments; i++)
+                               free((*object_array)[i].entry);
+               }
+
+               if(0 == (*object_array = realloc(*object_array, new_size)))
+                       return false;
+
+               /* if growing, zero all the length/pointers of new elements */
+               if(new_size > old_size)
+                       memset(*object_array + old_num_comments, 0, new_size - old_size);
+
+               return true;
+       }
+}
+
+FLAC__bool FLAC__metadata_object_vorbiscomment_set_vendor_string(FLAC__StreamMetaData *object, FLAC__byte *entry, unsigned length, FLAC__bool copy)
+{
+       FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+       if(0 != object->data.vorbis_comment.vendor_string.entry)
+               free(object->data.vorbis_comment.vendor_string.entry);
+
+       object->length -= object->data.vorbis_comment.vendor_string.length;
+
+       if(copy) {
+               if(!copy_bytes_(&object->data.vorbis_comment.vendor_string.entry, entry, length)) {
+                       object->data.vorbis_comment.vendor_string.length = 0;
+                       return false;
+               }
+       }
+       else {
+               object->data.vorbis_comment.vendor_string.entry = entry;
+       }
+
+       object->data.vorbis_comment.vendor_string.length = length;
+       object->length += object->data.vorbis_comment.vendor_string.length;
+
+       return true;
+}
+
+FLAC__bool FLAC__metadata_object_vorbiscomment_set_comments(FLAC__StreamMetaData *object, FLAC__StreamMetaData_VorbisComment_Entry *comments, unsigned num_comments, FLAC__bool copy)
+{
+       unsigned i;
+
+       FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+       object->data.vorbis_comment.num_comments = num_comments;
+
+       if(0 != object->data.vorbis_comment.comments)
+               FLAC__metadata_object_vorbiscomment_entry_array_delete(object->data.vorbis_comment.comments, num_comments);
+
+       if(copy) {
+               if(0 == (object->data.vorbis_comment.comments = FLAC__metadata_object_vorbiscomment_entry_array_copy(comments, num_comments)))
+                       return false;
+       }
+       else {
+               object->data.vorbis_comment.comments = comments;
+       }
+       object->length = num_comments * FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
+
+       /* calculate the new length */
+       object->length = (FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN) / 8;
+       object->length += object->data.vorbis_comment.vendor_string.length;
+       object->length += (FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8;
+       for(i = 0; i < object->data.vorbis_comment.num_comments; i++) {
+               object->length += (FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8);
+               object->length += object->data.vorbis_comment.comments[i].length;
+       }
+
+       return true;
+}
+
+
+/****************************************************************************
+ *
+ * Local function definitions
+ *
+ ***************************************************************************/
+
+void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
+{
+       unsigned i;
+
+       b += bytes;
+
+       for(i = 0; i < bytes; i++) {
+               *(--b) = val & 0xff;
+               val >>= 8;
+       }
+}
+
+void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
+{
+       unsigned i;
+
+       for(i = 0; i < bytes; i++) {
+               *(b++) = val & 0xff;
+               val >>= 8;
+       }
+}
+
+void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
+{
+       unsigned i;
+
+       b += bytes;
+
+       for(i = 0; i < bytes; i++) {
+               *(--b) = val & 0xff;
+               val >>= 8;
+       }
+}
+
+FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
+{
+       FLAC__uint32 ret = 0;
+       unsigned i;
+
+       for(i = 0; i < bytes; i++)
+               ret = (ret << 8) | (FLAC__uint32)(*b++);
+
+       return ret;
+}
+
+FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
+{
+       FLAC__uint32 ret = 0;
+       unsigned i;
+
+       b += bytes;
+
+       for(i = 0; i < bytes; i++)
+               ret = (ret << 8) | (FLAC__uint32)(*--b);
+
+       return ret;
+}
+
+FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
+{
+       FLAC__uint64 ret = 0;
+       unsigned i;
+
+       for(i = 0; i < bytes; i++)
+               ret = (ret << 8) | (FLAC__uint64)(*b++);
+
+       return ret;
+}
+
+FLAC__bool read_metadata_block_header_(FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__byte raw_header[4]; /*@@@ 4 = MAGIC NUMBER for metadata block header bytes */
+
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       if(fread(raw_header, 1, 4, iterator->file) != 4) { /*@@@ 4 = MAGIC NUMBER for metadata block header bytes */
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+               return false;
+       }
+
+       iterator->is_last = raw_header[0] & 0x80? true : false;
+       iterator->type = (FLAC__MetaDataType)(raw_header[0] & 0x7f);
+       iterator->length = unpack_uint32_(raw_header + 1, 3);
+
+       return true;
+}
+
+FLAC__bool read_metadata_block_data_(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block)
+{
+       FLAC__ASSERT(0 != iterator);
+       FLAC__ASSERT(0 != iterator->file);
+
+       switch(block->type) {
+               case FLAC__METADATA_TYPE_STREAMINFO:
+                       iterator->status = read_metadata_block_data_streaminfo_(iterator->file, &block->data.stream_info);
+                       break;
+               case FLAC__METADATA_TYPE_PADDING:
+                       iterator->status = read_metadata_block_data_padding_(iterator->file, &block->data.padding, block->length);
+                       break;
+               case FLAC__METADATA_TYPE_APPLICATION:
+                       iterator->status = read_metadata_block_data_application_(iterator->file, &block->data.application, block->length);
+                       break;
+               case FLAC__METADATA_TYPE_SEEKTABLE:
+                       iterator->status = read_metadata_block_data_seektable_(iterator->file, &block->data.seek_table, block->length);
+                       break;
+               case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                       iterator->status = read_metadata_block_data_vorbis_comment_(iterator->file, &block->data.vorbis_comment);
+                       break;
+               default:
+                       FLAC__ASSERT(0);
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR;
+       }
+
+       return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
+}
+
+FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_streaminfo_(FILE *file, FLAC__StreamMetaData_StreamInfo *block)
+{
+       FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
+
+       FLAC__ASSERT(0 != file);
+
+       if(fread(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, file) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+
+       b = buffer;
+
+       /* @@@ we are using hardcoded numbers for simplicity but we should
+        * probably eventually write a bit-level unpacker and use the
+        * _STREAMINFO_ constants.
+        */
+       block->min_blocksize = unpack_uint32_(b, 2); b += 2;
+       block->max_blocksize = unpack_uint32_(b, 2); b += 2;
+       block->min_framesize = unpack_uint32_(b, 3); b += 3;
+       block->max_framesize = unpack_uint32_(b, 3); b += 3;
+       block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
+       block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
+       block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 1) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
+       block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
+       memcpy(block->md5sum, b+8, 16);
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+
+FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_padding_(FILE *file, FLAC__StreamMetaData_Padding *block, unsigned block_length)
+{
+       FLAC__ASSERT(0 != file);
+
+       (void)block; /* nothing to do; we don't care about reading the padding bytes */
+
+       if(0 != fseek(file, block_length, SEEK_CUR))
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_application_(FILE *file, FLAC__StreamMetaData_Application *block, unsigned block_length)
+{
+       const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
+
+       FLAC__ASSERT(0 != file);
+
+       if(fread(block->id, 1, id_bytes, file) != id_bytes)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+
+       block_length -= id_bytes;
+
+       if(0 == (block->data = malloc(block_length)))
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+
+       if(fread(block->data, 1, block_length, file) != block_length)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_seektable_(FILE *file, FLAC__StreamMetaData_SeekTable *block, unsigned block_length)
+{
+       unsigned i;
+       FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
+
+       FLAC__ASSERT(0 != file);
+       FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
+
+       block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
+
+       if(0 == (block->points = malloc(block->num_points * sizeof(FLAC__StreamMetaData_SeekPoint))))
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+
+       for(i = 0; i < block->num_points; i++) {
+               if(fread(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, file) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
+                       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+               /*@@@ some MAGIC NUMBERs here */
+               block->points[i].sample_number = unpack_uint64_(buffer, 8);
+               block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
+               block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
+       }
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_(FILE *file, FLAC__StreamMetaData_VorbisComment_Entry *entry)
+{
+       const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
+       FLAC__byte buffer[FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8];
+
+       FLAC__ASSERT(0 != file);
+
+       if(fread(buffer, 1, entry_length_len, file) != entry_length_len)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+       entry->length = unpack_uint32_little_endian_(buffer, 4);
+
+       if(0 == (entry->entry = malloc(entry->length)))
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+
+       if(fread(entry->entry, 1, entry->length, file) != entry->length)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__MetaData_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_(FILE *file, FLAC__StreamMetaData_VorbisComment *block)
+{
+       unsigned i;
+       FLAC__MetaData_SimpleIteratorStatus status;
+       const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
+       FLAC__byte buffer[FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8];
+
+       FLAC__ASSERT(0 != file);
+
+       if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_(file, &(block->vendor_string))))
+               return status;
+
+       if(fread(buffer, 1, num_comments_len, file) != num_comments_len)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+       block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
+
+       if(0 == (block->comments = malloc(block->num_comments * sizeof(FLAC__StreamMetaData_VorbisComment_Entry))))
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+
+       for(i = 0; i < block->num_comments; i++) {
+               if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_(file, block->comments + i)))
+                       return status;
+       }
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__bool write_metadata_block_header_(FILE *file, FLAC__MetaData_SimpleIteratorStatus *status, const FLAC__StreamMetaData *block)
+{
+       FLAC__byte buffer[4];
+
+       FLAC__ASSERT(0 != file);
+       FLAC__ASSERT(0 != status);
+       FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
+
+       buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
+       pack_uint32_(block->length, buffer + 1, 3);
+
+       if(fwrite(buffer, 1, 4, file) != 4) {
+               *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+               return false;
+       }
+
+       return true;
+}
+
+FLAC__bool write_metadata_block_data_(FILE *file, FLAC__MetaData_SimpleIteratorStatus *status, const FLAC__StreamMetaData *block)
+{
+       FLAC__ASSERT(0 != file);
+       FLAC__ASSERT(0 != status);
+
+       switch(block->type) {
+               case FLAC__METADATA_TYPE_STREAMINFO:
+                       *status = write_metadata_block_data_streaminfo_(file, &block->data.stream_info);
+                       break;
+               case FLAC__METADATA_TYPE_PADDING:
+                       *status = write_metadata_block_data_padding_(file, &block->data.padding, block->length);
+                       break;
+               case FLAC__METADATA_TYPE_APPLICATION:
+                       *status = write_metadata_block_data_application_(file, &block->data.application, block->length);
+                       break;
+               case FLAC__METADATA_TYPE_SEEKTABLE:
+                       *status = write_metadata_block_data_seektable_(file, &block->data.seek_table);
+                       break;
+               case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                       *status = write_metadata_block_data_vorbis_comment_(file, &block->data.vorbis_comment);
+                       break;
+               default:
+                       FLAC__ASSERT(0);
+                       *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR;
+       }
+       return (*status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
+}
+
+FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_streaminfo_(FILE *file, const FLAC__StreamMetaData_StreamInfo *block)
+{
+       FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
+       const unsigned channels1 = block->channels - 1;
+       const unsigned bps1 = block->bits_per_sample - 1;
+
+       FLAC__ASSERT(0 != file);
+
+       /* @@@ we are using hardcoded numbers for simplicity but we should
+        * probably eventually write a bit-level packer and use the
+        * _STREAMINFO_ constants.
+        */
+       pack_uint32_(block->min_blocksize, buffer, 2);
+       pack_uint32_(block->max_blocksize, buffer+2, 2);
+       pack_uint32_(block->min_framesize, buffer+4, 3);
+       pack_uint32_(block->max_framesize, buffer+7, 3);
+       buffer[10] = (block->sample_rate >> 12) & 0xff;
+       buffer[11] = (block->sample_rate >> 4) & 0xff;
+       buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
+       buffer[13] = ((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f);
+       pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
+       memcpy(buffer+18, block->md5sum, 16);
+
+       if(fwrite(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, file) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_padding_(FILE *file, const FLAC__StreamMetaData_Padding *block, unsigned block_length)
+{
+       unsigned i, n = block_length;
+       FLAC__byte buffer[1024];
+
+       FLAC__ASSERT(0 != file);
+
+       (void)block;
+
+       memset(buffer, 0, 1024);
+
+       for(i = 0; i < n/1024; i++)
+               if(fwrite(buffer, 1, 1024, file) != 1024)
+                       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+
+       n %= 1024;
+       
+       if(fwrite(buffer, 1, n, file) != n)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_application_(FILE *file, const FLAC__StreamMetaData_Application *block, unsigned block_length)
+{
+       const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
+
+       FLAC__ASSERT(0 != file);
+
+       if(fwrite(block->id, 1, id_bytes, file) != id_bytes)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+
+       block_length -= id_bytes;
+
+       if(fwrite(block->data, 1, block_length, file) != block_length)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_seektable_(FILE *file, const FLAC__StreamMetaData_SeekTable *block)
+{
+       unsigned i;
+       FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
+
+       FLAC__ASSERT(0 != file);
+
+       for(i = 0; i < block->num_points; i++) {
+               /*@@@ some MAGIC NUMBERs here */
+               pack_uint64_(block->points[i].sample_number, buffer, 8);
+               pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
+               pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
+               if(fwrite(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, file) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
+                       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+       }
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__MetaData_SimpleIteratorStatus write_metadata_block_data_vorbis_comment_(FILE *file, const FLAC__StreamMetaData_VorbisComment *block)
+{
+       unsigned i;
+       const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
+       const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
+       FLAC__byte buffer[max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8];
+
+       FLAC__ASSERT(0 != file);
+
+       pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
+       if(fwrite(buffer, 1, entry_length_len, file) != entry_length_len)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+       if(fwrite(block->vendor_string.entry, 1, block->vendor_string.length, file) != block->vendor_string.length)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+
+       pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
+       if(fwrite(buffer, 1, num_comments_len, file) != num_comments_len)
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+
+       for(i = 0; i < block->num_comments; i++) {
+               pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
+               if(fwrite(buffer, 1, entry_length_len, file) != entry_length_len)
+                       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+               if(fwrite(block->comments[i].entry, 1, block->comments[i].length, file) != block->comments[i].length)
+                       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+       }
+
+       return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
+}
+
+FLAC__bool write_metadata_block_stationary_(FLAC__MetaData_SimpleIterator *iterator, const FLAC__StreamMetaData *block)
+{
+       if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+
+       if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
+               return false;
+
+       if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
+               return false;
+
+       if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+
+       return read_metadata_block_header_(iterator);
+}
+
+FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block, unsigned padding_length, FLAC__bool padding_is_last)
+{
+       FLAC__StreamMetaData *padding;
+
+       if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+
+       block->is_last = false;
+
+       if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
+               return false;
+
+       if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
+               return false;
+
+       if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
+               return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+
+       padding->is_last = padding_is_last;
+       padding->length = padding_length;
+
+       if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
+               FLAC__metadata_object_delete(padding);
+               return false;
+       }
+
+       if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
+               FLAC__metadata_object_delete(padding);
+               return false;
+       }
+
+       FLAC__metadata_object_delete(padding);
+
+       if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+
+       return read_metadata_block_header_(iterator);
+}
+
+FLAC__bool rewrite_whole_file_(FLAC__MetaData_SimpleIterator *iterator, FLAC__StreamMetaData *block, FLAC__bool append)
+{
+       FILE *tempfile;
+       char *tempfilename;
+       long fixup_is_last_flag_offset;
+
+       if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
+               return false;
+
+       if(0 != block) {
+               if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
+                       cleanup_tempfile_(&tempfile, &tempfilename);
+                       return false;
+               }
+
+               if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
+                       cleanup_tempfile_(&tempfile, &tempfilename);
+                       return false;
+               }
+       }
+
+       if(append && iterator->is_last)
+               fixup_is_last_flag_offset = iterator->offset[iterator->depth]; /*@@@ MAGIC NUMBER; we know the is_last flag is here */
+       else
+               fixup_is_last_flag_offset = -1;
+       if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_flag_offset, block==0))
+               return false;
+
+       return true;
+}
+
+FLAC__bool chain_rewrite_chain_(FLAC__MetaData_Chain *chain)
+{
+       FILE *f;
+       FLAC__MetaData_Node *node;
+       FLAC__MetaData_SimpleIteratorStatus status;
+
+       FLAC__ASSERT(0 != chain);
+       FLAC__ASSERT(0 != chain->filename);
+       FLAC__ASSERT(0 != chain->head);
+
+       if(0 == (f = fopen(chain->filename, "r+b"))) {
+               chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
+               return false;
+       }
+       if(0 != fseek(f, chain->first_offset, SEEK_SET)) {
+               chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
+               return false;
+       }
+
+       for(node = chain->head; node; node = node->next) {
+               if(!write_metadata_block_header_(f, &status, node->data)) {
+                       chain->status = get_equivalent_status_(status);
+                       return false;
+               }
+               if(!write_metadata_block_data_(f, &status, node->data)) {
+                       chain->status = get_equivalent_status_(status);
+                       return false;
+               }
+       }
+
+       /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
+
+       (void)fclose(f);
+
+       return true;
+}
+
+FLAC__bool chain_rewrite_file_(FLAC__MetaData_Chain *chain, const char *tempfile_path_prefix)
+{
+       FILE *f, *tempfile;
+       char *tempfilename;
+       FLAC__MetaData_SimpleIteratorStatus status;
+       const FLAC__MetaData_Node *node;
+
+       FLAC__ASSERT(0 != chain);
+       FLAC__ASSERT(0 != chain->filename);
+       FLAC__ASSERT(0 != chain->head);
+
+       /* copy the file prefix (data up to first metadata block */
+       if(0 == (f = fopen(chain->filename, "rb"))) {
+               chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
+               return false;
+       }
+       if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
+               chain->status = get_equivalent_status_(status);
+               cleanup_tempfile_(&tempfile, &tempfilename);
+               return false;
+       }
+       if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
+               chain->status = get_equivalent_status_(status);
+               cleanup_tempfile_(&tempfile, &tempfilename);
+               return false;
+       }
+
+       /* write the metadata */
+       for(node = chain->head; node; node = node->next) {
+               if(!write_metadata_block_header_(tempfile, &status, node->data)) {
+                       chain->status = get_equivalent_status_(status);
+                       return false;
+               }
+               if(!write_metadata_block_data_(tempfile, &status, node->data)) {
+                       chain->status = get_equivalent_status_(status);
+                       return false;
+               }
+       }
+       /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
+
+       /* copy the file postfix (everything after the metadata) */
+       if(0 != fseek(f, chain->last_offset, SEEK_SET)) {
+               cleanup_tempfile_(&tempfile, &tempfilename);
+               chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
+               return false;
+       }
+       if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
+               cleanup_tempfile_(&tempfile, &tempfilename);
+               chain->status = get_equivalent_status_(status);
+               return false;
+       }
+
+       /* move the tempfile on top of the original */
+       (void)fclose(f);
+       if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
+               return false;
+
+       return true;
+}
+
+void simple_iterator_push_(FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
+       iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
+       iterator->depth++;
+}
+
+FLAC__bool simple_iterator_pop_(FLAC__MetaData_SimpleIterator *iterator)
+{
+       FLAC__ASSERT(iterator->depth > 0);
+       iterator->depth--;
+       if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+
+       return read_metadata_block_header_(iterator);
+}
+
+unsigned seek_to_first_metadata_block_(FILE *f)
+{
+       FLAC__byte signature[4]; /*@@@ 4 = MAGIC NUMBER for signature bytes */
+
+       FLAC__ASSERT(0 != f);
+
+       /*@@@@ skip id3v2, change comment about id3v2 in metadata.h*/
+
+       /* search for the fLaC signature */
+       if(fread(signature, 1, 4, f) == 4) { /*@@@ 4 = MAGIC NUMBER for signature bytes */
+               if(0 == memcmp(FLAC__STREAM_SYNC_STRING, signature, 4)) {
+                       return 0;
+               }
+               else {
+                       return 2;
+               }
+       }
+       else {
+               return 1;
+       }
+}
+
+FLAC__bool simple_iterator_copy_file_prefix_(FLAC__MetaData_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
+{
+       const long offset_end = append? iterator->offset[iterator->depth] + 4 + (long)iterator->length : iterator->offset[iterator->depth]; /*@@@ MAGIC NUMBER 4 = metadata block header bytes */
+
+       if(0 != fseek(iterator->file, 0, SEEK_SET)) {
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+       if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
+               cleanup_tempfile_(tempfile, tempfilename);
+               return false;
+       }
+       if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
+               cleanup_tempfile_(tempfile, tempfilename);
+               return false;
+       }
+
+       return true;
+}
+
+FLAC__bool simple_iterator_copy_file_postfix_(FLAC__MetaData_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, long fixup_is_last_flag_offset, FLAC__bool backup)
+{
+       long save_offset = iterator->offset[iterator->depth]; /*@@@ 2G limit */
+       FLAC__ASSERT(0 != *tempfile);
+
+       /*@@@ MAGIC NUMBER 4 = metadata header bytes */
+       if(0 != fseek(iterator->file, save_offset + 4 + iterator->length, SEEK_SET)) {
+               cleanup_tempfile_(tempfile, tempfilename);
+               iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+               return false;
+       }
+       if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
+               cleanup_tempfile_(tempfile, tempfilename);
+               return false;
+       }
+
+       if(fixup_is_last_flag_offset >= 0) {
+               /* this means a block was appended to the end so we have to clear the is_last flag of the previous block */
+               /*@@@ MAGIC NUMBERs here; we know the is_last flag is the hit bit of the byte at this location */
+               FLAC__byte x;
+               if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
+                       cleanup_tempfile_(tempfile, tempfilename);
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+                       return false;
+               }
+               if(fread(&x, 1, 1, *tempfile) != 1) {
+                       cleanup_tempfile_(tempfile, tempfilename);
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+                       return false;
+               }
+               FLAC__ASSERT(x & 0x80);
+               x &= 0x7f;
+               if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
+                       cleanup_tempfile_(tempfile, tempfilename);
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
+                       return false;
+               }
+               if(fwrite(&x, 1, 1, *tempfile) != 1) {
+                       cleanup_tempfile_(tempfile, tempfilename);
+                       iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+                       return false;
+               }
+       }
+
+       (void)fclose(iterator->file);
+
+       if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
+               return false;
+
+       if(iterator->has_stats)
+               set_file_stats_(iterator->filename, &iterator->stats);
+
+       if(!simple_iterator_prime_input_(iterator))
+               return false;
+       if(backup) {
+               while(iterator->offset[iterator->depth] + 4 + (long)iterator->length < save_offset)
+                       if(!FLAC__metadata_simple_iterator_next(iterator))
+                               return false;
+               return true;
+       }
+       else {
+               /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
+               FLAC__ASSERT(iterator->depth == 0);
+               iterator->offset[0] = save_offset;
+               iterator->depth++;
+               return simple_iterator_pop_(iterator);
+       }
+}
+
+FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__MetaData_SimpleIteratorStatus *status)
+{
+       FLAC__byte buffer[8192];
+       unsigned n;
+
+       while(bytes > 0) {
+               n = min(sizeof(buffer), bytes);
+               if(fread(buffer, 1, n, file) != n) {
+                       *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+                       return false;
+               }
+               if(fwrite(buffer, 1, n, tempfile) != n) {
+                       *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+                       return false;
+               }
+               bytes -= n;
+       }
+
+       return true;
+}
+
+FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__MetaData_SimpleIteratorStatus *status)
+{
+       FLAC__byte buffer[8192];
+       size_t n;
+
+       while(!feof(file)) {
+               n = fread(buffer, 1, sizeof(buffer), file);
+               if(n == 0 && !feof(file)) {
+                       *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
+                       return false;
+               }
+               if(n > 0 && fwrite(buffer, 1, n, tempfile) != n) {
+                       *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
+                       return false;
+               }
+       }
+
+       return true;
+}
+
+FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__MetaData_SimpleIteratorStatus *status)
+{
+       static const char *tempfile_suffix = ".metadata_edit";
+       if(0 == tempfile_path_prefix) {
+               if(0 == (*tempfilename = malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
+                       *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+                       return false;
+               }
+               strcpy(*tempfilename, filename);
+               strcat(*tempfilename, tempfile_suffix);
+       }
+       else {
+               const char *p = strrchr(filename, '/');
+               if(0 == p)
+                       p = filename;
+               else
+                       p++;
+
+               if(0 == (*tempfilename = malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
+                       *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
+                       return false;
+               }
+               strcpy(*tempfilename, tempfile_path_prefix);
+               strcat(*tempfilename, "/");
+               strcat(*tempfilename, p);
+               strcat(*tempfilename, tempfile_suffix);
+       }
+
+       if(0 == (*tempfile = fopen(*tempfilename, "wb"))) {
+               *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
+               return false;
+       }
+
+       return true;
+}
+
+FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__MetaData_SimpleIteratorStatus *status)
+{
+       FLAC__ASSERT(0 != filename);
+       FLAC__ASSERT(0 != tempfile);
+       FLAC__ASSERT(0 != *tempfile);
+       FLAC__ASSERT(0 != tempfilename);
+       FLAC__ASSERT(0 != *tempfilename);
+       FLAC__ASSERT(0 != status);
+
+       (void)fclose(*tempfile);
+       *tempfile = 0;
+       /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
+       if(0 != rename(*tempfilename, filename)) {
+               cleanup_tempfile_(tempfile, tempfilename);
+               *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
+               return false;
+       }
+
+       cleanup_tempfile_(tempfile, tempfilename);
+
+       return true;
+}
+
+void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
+{
+       if(0 != *tempfile) {
+               (void)fclose(*tempfile);
+               *tempfile = 0;
+       }
+
+       if(0 != *tempfilename) {
+               (void)unlink(*tempfilename);
+               free(*tempfilename);
+               *tempfilename = 0;
+       }
+}
+
+FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
+{
+       FLAC__ASSERT(0 != filename);
+       FLAC__ASSERT(0 != stats);
+       return (0 == stat(filename, stats));
+}
+
+void set_file_stats_(const char *filename, struct stat *stats)
+{
+       struct utimbuf srctime;
+
+       FLAC__ASSERT(0 != filename);
+       FLAC__ASSERT(0 != stats);
+
+       srctime.actime = stats->st_atime;
+       srctime.modtime = stats->st_mtime;
+       (void)chmod(filename, stats->st_mode);
+       (void)utime(filename, &srctime);
+#if !defined _MSC_VER && !defined __MINGW32__
+       (void)chown(filename, stats->st_uid, -1);
+       (void)chown(filename, -1, stats->st_gid);
+#endif
+}
+
+FLAC__MetaData_ChainStatus get_equivalent_status_(FLAC__MetaData_SimpleIteratorStatus status)
+{
+       switch(status) {
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
+                       return FLAC__METADATA_CHAIN_STATUS_OK;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
+                       return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
+                       return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
+                       return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
+                       return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
+                       return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
+                       return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
+                       return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
+                       return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
+                       return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
+                       return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
+               case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
+               default:
+                       return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
+       }
+}