Flac-in-mp4 draft v0.0.0.
authorRalph Giles <giles@thaumas.net>
Tue, 4 Oct 2016 15:41:07 +0000 (08:41 -0700)
committerErik de Castro Lopo <erikd@mega-nerd.com>
Tue, 4 Oct 2016 16:30:21 +0000 (03:30 +1100)
We've been working on a draft spec for encapsulation of FLAC
in the ISO Base Media File Format (mp4). This is the initial
draft created by Monty Montgomery based on Yusuke Nakamura's
Opus-in-mp4 draft.

More details at https://bugzilla.mozilla.org/show_bug.cgi?id=1286097

Signed-off-by: Erik de Castro Lopo <erikd@mega-nerd.com>
doc/isoflac.txt [new file with mode: 0644]

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+Encapsulation of FLAC in ISO Base Media File Format
+Version 0.0.0 (early draft)
+
+Table of Contents
+1 Scope
+2 Supproting Normative References
+3 Terms and Definitions
+4 Design Rules of Encapsulation
+  4.1 File Type Indentification
+  4.2 Overview of Track Structure
+  4.3 Definition of FLAC sample
+        4.3.1 Sample entry format
+        4.3.2 FLAC Specific Box
+        4.3.3 Sample format
+        4.3.4 Duration of FLAC sample
+        4.3.5 Sub-sample
+        4.3.6 Random Access
+            4.3.6.1 Random Access Point
+   4.4 Basic Structure (informative)
+        4.4.1 Initial Movie
+   4.5 Example of Encapsulation (informative)
+5 Author's Address
+
+1 Scope
+
+    This document specifies the normative mapping for encapsulation of
+    FLAC coded audio bitstreams in ISO Base Media file format and its
+    derivatives. The encapsulation of FLAC coded bitstreams in
+    QuickTime file format is outside the scope of this specification.
+
+2 Supporting Normative References
+
+    [1] ISO/IEC 14496-12:2012 Corrected version
+
+        Information technology — Coding of audio-visual objects — Part
+        12: ISO base media file format
+
+    [2] ISO/IEC 14496-12:2012/Amd.1:2013
+
+        Information technology — Coding of audio-visual objects — Part
+        12: ISO base media file format AMENDMENT 1: Various
+        enhancements including support for large metadata
+
+    [3] FLAC format specification
+
+        https://xiph.org/flac/format.html
+
+       Definition of the FLAC Audio Codec stream format
+
+    [4] FLAC-in-Ogg mapping specification
+
+       https://xiph.org/flac/ogg_mapping.html
+
+       Ogg Encapsulation for the FLAC Audio Codec
+
+    [5] Matroska specification
+
+3 Terms and Definitions
+
+    3.1 active track
+
+        enabled track from the non-alternate group or selected track
+        from alternate group
+
+    3.2 edit
+
+        entry in the Edit List Box
+
+    3.3 sample-accurate
+
+        for any PCM sample, a timestamp exactly matching its sampling
+        timestamp is present in the media timeline.
+
+    3.4 native metadata
+    
+
+4 Design Rules of Encapsulation
+
+    4.1 File Type Indentification
+    
+        This specification does not define any brand to declare files
+        are conformant to this specification.  Files conformant to
+        this specification shall contain at least one brand which
+        supports the requirements and the requirements described in
+        this clause without contradiction in the compatible brands
+        list of the File Type Box.  The minimal support of the
+        encapsulation of FLAC bitstreams in ISO Base Media file format
+        requires the 'isom' brand.
+       
+    4.2 Overview of Track Structure
+
+        FLAC coded audio shall be encapsulated into the ISO Base
+        Media File Format as media data within an audio track.
+       
+            + The handler_type field in the Handler Reference Box
+              shall be set to 'soun'.
+           
+            + The Media Information Box shall contain the Sound Media
+              Header Box.
+           
+            + The codingname of the sample entry is 'fLaC'.
+           
+                This specification does not define any encapsulation
+                using MP4AudioSampleEntry with objectTypeIndication
+                specified by the MPEG-4 Registration Authority
+                (http://www.mp4ra.org/).  See section 'Sample entry
+                format' for the definition of the the sample entry.
+               
+            + The 'dfLa' box is added to the sample entry to convey
+                initializing information for the decoder.
+
+               See section 'FLAC Specific Box' for the definition of
+                the box contents.
+               
+            + A FLAC sample is exactly one FLAC packet.  See section
+                'Sample format' for details of the packet contents.
+               
+            + Every FLAC sample is a sync sample.  No pre-roll or
+                lapping is required.  See section 'Random Access' for
+                further details.
+
+       FLAC native metadata 
+
+    4.3 Definition of a FLAC sample
+    
+        4.3.1 Sample entry format
+
+           For any track containing one or more FLAC bitstreams, a
+            sample entry describing the corresponding FLAC bitstream
+            shall be present inside the Sample Table Box. This version
+            of the specification defines only one sample entry format
+            named FLACSampleEntry whose codingname is 'fLaC'. This
+            sample entry includes exactly one FLAC Specific Box
+            defined in section 'FLAC specific box' as a mandatory box
+            and indicates that FLAC samples described by this sample
+            entry are stored by the sample format described in section
+            'Sample format'.
+
+            The syntax and semantics of the FLACSampleEntry is shown
+            as follows.  The data fields of this box and native
+            FLAC[3] structures encoded within FLAC blocks are both
+            stored in big-endian format, though for purposes of the
+            ISO BMFF container, FLAC native metadata and data blocks
+            are treated as unstructured octet streams.
+           
+            class FLACSampleEntry() extends AudioSampleEntry ('fLaC'){
+                FLACSpecificBox();
+            }
+
+            + channelcount:
+
+               The channelcount field shall be set equal to the
+               channel count specified by the FLAC bitstream's native
+               METADATA_BLOCK_STREAMINFO header as described in [3].
+               Note that the FLAC FRAME_HEADER structure that begins
+               each FLAC sample redundantly encodes channel number;
+               the number of channels declared in each FRAME_HEADER
+               MUST match the number of channels declared here and in
+               the METADATA_BLOCK_STREAMINFO header.
+
+            + samplesize:
+
+               The samplesize field shall be set equal to the bits
+               per sample specified by the FLAC bitstream's native
+               METADATA_BLOCK_STREAMINFO header as described in [3].
+               Note that the FLAC FRAME_HEADER structure that begins
+               each FLAC sample redundantly encodes the number of
+               bits per sample; the bits per sample declared in each
+               FRAME_HEADER MUST match the samplesize declared here
+               and the bits per sample field declared in the
+               METADATA_BLOCK_STREAMINFO header.
+               
+            + samplerate:
+
+                The samplerate field shall be set equal to the sample
+                rate specified by the FLAC bitstream's native
+                METADATA_BLOCK_STREAMINFO header as described in [3],
+                left-shifted by 16 bits.  Note that the FLAC
+                FRAME_HEADER structure that begins each FLAC sample
+                redundantly encodes the sample rate; the sample rate
+                declared in each FRAME_HEADER MUST match the sample
+                rate declared here and in the
+                METADATA_BLOCK_STREAMINFO header.
+               
+            + FLACSpecificBox
+           
+                This box contains initializing information for the
+                decoder as defined in section 'FLAC specific box'
+
+        4.3.2 FLAC Specific Box
+       
+            Exactly one FLAC Specific Box shall be present in each
+            FLACSampleEntry.  The FLAC Specific Box contains the
+            Version field and this specification defines version 0 of
+            this box.  If incompatible changes occur in the fields
+            after the Version field within the FLACSpecificBox in the
+            future versions of this specification, another version
+            will be defined.  The data fields of this box and native
+            FLAC[3] structures encoded within FLAC blocks are both
+            stored in big-endian format, though for purposes of the
+            ISO BMFF container, FLAC native metadata and data blocks
+            are treated as unstructured octet streams.
+
+            The syntax and semantics of the FLAC Specific Box is shown
+            as follows.
+
+            aligned(8) class FLACMetadataBlock {
+               unsigned int(1) LastMetadataBlockFlag;
+               unsigned int(7) BlockType;
+               unsigned int(24) Length;
+                unsigned int(8) MetadataBlockData[BlockLength];
+            }
+
+           aligned(8) class FLACSpecificBox extends Box('dfLa'){
+                unsigned int(8) Version;
+               unsigned int(8) MetadataBlocks;
+               for(i=0; i <= MetadataBlocks; i++){
+                   FLACMetadataBlock();
+               }
+            }
+
+            + Version:
+
+               The Version field shall be set to 0.
+
+               In the future versions of this specification, this
+                field may be set to other values. And without support
+                of those values, the reader shall not read the fields
+                after this within the FLACSpecificBox.
+
+           + MetadataBlocks:
+
+               The number of FLAC[3] native metadata blocks to
+               follow.  This value must be at least 1 as a native
+               METADATA_BLOCK_STREAMINFO structure is required to
+               decode FLAC audio data.
+
+           These fields are followed by a sequence of FLAC[3]
+           native-metadata block structures that fill the remainder
+           of the box length.
+
+           + LastMetadataBlockFlag:
+
+               The LastMetadataBlockFlag field maps semantically to
+               the FLAC[3] native MEATADATA_BLOCK_HEADER
+               Last-metadata-block flag as defined in the FLAC[3]
+               file specification.
+               
+               The LastMetadataBlockFlag is set to 1 if this
+               MetadataBlock is the last metadata block in the
+               FLACSpecificBox.  It is set to 0 otherwise.
+              
+           + BlockType:
+
+               The BlockType field maps semantically to the FLAC[3]
+               native MEATADATA_BLOCK_HEADER BLOCK_TYPE field as
+               defined in the FLAC[3] file specification.
+
+               The BlockType is set to a valid FLAC[3] BLOCK_TYPE
+               value that identifies the type of this native metadata
+               block.  The BlockType of the first FLACMetadataBlock
+               must be set to 0, signifying this is a FLAC[3] native
+               METADATA_BLOCK_STREAMINFO block.
+              
+           + Length:
+
+               The Length field maps semantically to the FLAC[3]
+               native MEATADATA_BLOCK_HEADER Length field as
+               defined in the FLAC[3] file specification.
+
+               The length field specifies the number of bytes of
+               MetadataBlockData to follow.
+
+           + MetadataBlockData
+
+               The MetadataBlockData field maps semantically to the
+               FLAC[3] native MEATADATA_BLOCK_HEADER
+               METADATA_BLOCKDATA as defined in the FLAC[3] file
+               specification.
+
+           The FLACMetadataBlock structure consists of three fields
+           filling a total of four bytes that form a FLAC[3] native
+           METADATA_BLOCK_HEADER, followed by raw octet bytes that
+           comprise the FLAC[3] native METADATA_BLOCK_DATA.  Taken
+           together, the bytes of the FLACMetadataBlock form a
+           complete FLAC[3] native METADATA_BLOCK structure.
+
+           Note that a minimum of a single FLACMetadataBlock,
+           consisting of a FLAC[3] native METADATA_BLOCK_STREAMINFO
+           structure, is required.  Should the FLACSpecificBox
+           contain more than a single FLACMetadataBlock structure,
+           the FLACMetadataBlock contianing the FLAC[3] native
+           METADATA_BLOCK_STREAMINFO must occur first in the list.
+
+           Other containers that package FLAC audio streams, such as
+           Ogg[4] and Matroska[5], wrap FLAC[3] native metadata without
+           modification similar to this specification.  When
+           repackaging or remuxing FLAC[3] streams from another
+           format that contains FLAC[3] native metadata into an ISO
+           BMFF file, the complete FLAC[3] native metadata should be
+           preserved in the ISO BMFF stream as described above.  It
+           is also allowed to parse this native metadata and include
+           contextually redundant ISO BMFF-native repackagings and/or
+           reparsings of FLAC[3] native metadata, so long as the
+           native metadata is also preserved.
+
+        4.3.3 Sample format
+       
+            A FLAC sample is exactly one FLAC audio FRAME packet (as
+            defined in the FLAC[3] file specification) belonging to a
+            FLAC bitstreams. The FLAC sample data begins with a
+            complete FLAC FRAME_HEADER, followed by one FLAC SUBFRAME
+            per channel, any necessary bit padding, and ends with the
+            usual FLAC FRAME_FOOTER.
+
+           Note that the FLAC native FRAME_HEADER structure that
+           begins each FLAC sample redundantly encodes channel count,
+           sample rate, and sample size.  The values of these fields
+           must agree both with the values declared in the FLAC
+           METADATA_BLOCK_STREAMINFO structure as well as the
+           FLACDSampleEntry box.
+
+        4.3.4 Duration of a FLAC sample
+
+           The duration of any given FLAC sample is determined by
+            dividing the decoded block size of a FLAC frame, as
+            encoded in the FLAC FRAME's FRAME_HEADER structure, by the
+            value of the timescale field in the Media Header Box.
+            FLAC samples are permitted to have variable durations
+            within a given audio stream.  FLAC does not use padding
+            values.
+
+        4.3.5 Sub-sample
+
+            Sub-samples are not defined for FLAC samples in this
+            specification.
+
+        4.3.6 Random Access
+       
+            This subclause describes the nature of the random access of FLAC sample.
+
+            4.3.6.1 Random Access Point
+           
+                All FLAC samples can be independently decoded
+                i.e. every FLAC sample is a sync sample. The Sync
+                Sample Box shall not be present as long as there are
+                no samples other than FLAC samples in the same
+                track. The sample_is_non_sync_sample field for FLAC
+                samples shall be set to 0.
+
+            4.3.6.2 Pre-roll
+           
+                FLAC bitstreams do not require pre-roll or
+                multi-sample synchronization.  All samples
+                independently decode directly to a complete set of
+                valid samples. NeitherAudioRollRecoveryEntry nor AudioPreRollEntry
+                shall be used.
+               
+    4.4 Basic Structure (informative)
+
+        4.4.1 Initial Movie
+       
+            This subclause shows a basic structure of the Movie Box as follows:
+
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |moov|    |    |    |    |    |    |    | Movie Box                    |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |mvhd|    |    |    |    |    |    | Movie Header Box             |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |trak|    |    |    |    |    |    | Track Box                    |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |tkhd|    |    |    |    |    | Track Header Box             |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |edts|*   |    |    |    |    | Edit Box                     |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |elst|*   |    |    |    | Edit List Box                |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |mdia|    |    |    |    |    | Media Box                    |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |mdhd|    |    |    |    | Media Header Box             |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |hdlr|    |    |    |    | Handler Reference Box        |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |minf|    |    |    |    | Media Information Box        |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |smhd|    |    |    | Sound Media Header Box       |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |dinf|    |    |    | Data Information Box         |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |dref|    |    | Data Reference Box           |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |    |url |    | DataEntryUrlBox              |
+            +----+----+----+----+----+----+ or +----+------------------------------+
+            |    |    |    |    |    |    |urn |    | DataEntryUrnBox              |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |stbl|    |    |    | Sample Table                 |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stsd|    |    | Sample Description Box       |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |    |fLaC|    | FLACSampleEntry              |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |    |    |dfLa| FLAC Specific Box            |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stts|    |    | Decoding Time to Sample Box  |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stsc|    |    | Sample To Chunk Box          |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stsz|    |    | Sample Size Box              |
+            +----+----+----+----+----+ or +----+----+------------------------------+
+            |    |    |    |    |    |stz2|    |    | Compact Sample Size Box      |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stco|    |    | Chunk Offset Box             |
+            +----+----+----+----+----+ or +----+----+------------------------------+
+            |    |    |    |    |    |co64|    |    | Chunk Large Offset Box       |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |mvex|*   |    |    |    |    |    | Movie Extends Box            |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |trex|*   |    |    |    |    | Track Extends Box            |
+            +----+----+----+----+----+----+----+----+------------------------------+
+
+                    Figure 1 - Basic structure of Movie Box
+
+            It is strongly recommended that the order of boxes should
+            follow the above structure.  Boxes marked with an asterisk
+            (*) may be present.  For most boxes listed above, the
+            definition is as is defined in ISO/IEC 14496-12 [1]. The
+            additional boxes and the additional requirements,
+            restrictions and recommendations to the other boxes are
+            described in this specification.
+           
+    4.5 Example of Encapsulation (informative)
+        [File]
+            size = 17790
+            [ftyp: File Type Box]
+                position = 0
+                size = 24
+                major_brand = mp42 : MP4 version 2
+                minor_version = 0
+                compatible_brands
+                    brand[0] = mp42 : MP4 version 2
+                    brand[1] = isom : ISO Base Media file format
+            [moov: Movie Box]
+                position = 24
+                size = 757
+                [mvhd: Movie Header Box]
+                    position = 32
+                    size = 108
+                    version = 0
+                    flags = 0x000000
+                    creation_time = UTC 2014/12/12, 18:41:19
+                    modification_time = UTC 2014/12/12, 18:41:19
+                    timescale = 48000
+                    duration = 33600 (00:00:00.700)
+                    rate = 1.000000
+                    volume = 1.000000
+                    reserved = 0x0000
+                    reserved = 0x00000000
+                    reserved = 0x00000000
+                    transformation matrix
+                        | a, b, u |   | 1.000000, 0.000000, 0.000000 |
+                        | c, d, v | = | 0.000000, 1.000000, 0.000000 |
+                        | x, y, w |   | 0.000000, 0.000000, 1.000000 |
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    next_track_ID = 2
+                [iods: Object Descriptor Box]
+                    position = 140
+                    size = 33
+                    version = 0
+                    flags = 0x000000
+                    [tag = 0x10: MP4_IOD]
+                        expandableClassSize = 16
+                        ObjectDescriptorID = 1
+                        URL_Flag = 0
+                        includeInlineProfileLevelFlag = 0
+                        reserved = 0xf
+                        ODProfileLevelIndication = 0xff
+                        sceneProfileLevelIndication = 0xff
+                        audioProfileLevelIndication = 0xfe
+                        visualProfileLevelIndication = 0xff
+                        graphicsProfileLevelIndication = 0xff
+                        [tag = 0x0e: ES_ID_Inc]
+                            expandableClassSize = 4
+                            Track_ID = 1
+                [trak: Track Box]
+                    position = 173
+                    size = 608
+                    [tkhd: Track Header Box]
+                        position = 181
+                        size = 92
+                        version = 0
+                        flags = 0x000007
+                            Track enabled
+                            Track in movie
+                            Track in preview
+                        creation_time = UTC 2014/12/12, 18:41:19
+                        modification_time = UTC 2014/12/12, 18:41:19
+                        track_ID = 1
+                        reserved = 0x00000000
+                        duration = 33600 (00:00:00.700)
+                        reserved = 0x00000000
+                        reserved = 0x00000000
+                        layer = 0
+                        alternate_group = 0
+                        volume = 1.000000
+                        reserved = 0x0000
+                        transformation matrix
+                            | a, b, u |   | 1.000000, 0.000000, 0.000000 |
+                            | c, d, v | = | 0.000000, 1.000000, 0.000000 |
+                            | x, y, w |   | 0.000000, 0.000000, 1.000000 |
+                        width = 0.000000
+                        height = 0.000000
+                    [mdia: Media Box]
+                        position = 273
+                        size = 472
+                        [mdhd: Media Header Box]
+                            position = 281
+                            size = 32
+                            version = 0
+                            flags = 0x000000
+                            creation_time = UTC 2014/12/12, 18:41:19
+                            modification_time = UTC 2014/12/12, 18:41:19
+                            timescale = 48000
+                            duration = 34560 (00:00:00.720)
+                            language = und
+                            pre_defined = 0x0000
+                        [hdlr: Handler Reference Box]
+                            position = 313
+                            size = 51
+                            version = 0
+                            flags = 0x000000
+                            pre_defined = 0x00000000
+                            handler_type = soun
+                            reserved = 0x00000000
+                            reserved = 0x00000000
+                            reserved = 0x00000000
+                            name = Xiph Audio Handler
+                        [minf: Media Information Box]
+                            position = 364
+                            size = 381
+                            [smhd: Sound Media Header Box]
+                                position = 372
+                                size = 16
+                                version = 0
+                                flags = 0x000000
+                                balance = 0.000000
+                                reserved = 0x0000
+                            [dinf: Data Information Box]
+                                position = 388
+                                size = 36
+                                [dref: Data Reference Box]
+                                    position = 396
+                                    size = 28
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 1
+                                    [url : Data Entry Url Box]
+                                        position = 412
+                                        size = 12
+                                        version = 0
+                                        flags = 0x000001
+                                        location = in the same file
+                            [stbl: Sample Table Box]
+                                position = 424
+                                size = 321
+                                [stsd: Sample Description Box]
+                                    position = 432
+                                    size = 79
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 1
+                                    [fLaC: Audio Description]
+                                        position = 448
+                                        size = 63
+                                        reserved = 0x000000000000
+                                        data_reference_index = 1
+                                        reserved = 0x0000
+                                        reserved = 0x0000
+                                        reserved = 0x00000000
+                                        channelcount = 2
+                                        samplesize = 16
+                                        pre_defined = 0
+                                        reserved = 0
+                                        samplerate = 48000.000000
+                                        [dfLa: FLAC Specific Box]
+                                            position = 484
+                                            size = 48
+                                            Version = 0
+                                           MetadataBlocks = 1
+                                           LastMetadataBlockFlag = 1
+                                           BlockType = 0
+                                           Length = 34
+                                           MetadataBlockData[34];
+                                [stts: Decoding Time to Sample Box]
+                                    position = 490
+                                    size = 24
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 1
+                                    entry[0]
+                                        sample_count = 18
+                                        sample_delta = 1920
+                                [stsc: Sample To Chunk Box]
+                                    position = 514
+                                    size = 40
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 2
+                                    entry[0]
+                                        first_chunk = 1
+                                        samples_per_chunk = 13
+                                        sample_description_index = 1
+                                    entry[1]
+                                        first_chunk = 2
+                                        samples_per_chunk = 5
+                                        sample_description_index = 1
+                                [stsz: Sample Size Box]
+                                    position = 554
+                                    size = 92
+                                    version = 0
+                                    flags = 0x000000
+                                    sample_size = 0 (variable)
+                                    sample_count = 18
+                                    entry_size[0] = 977
+                                    entry_size[1] = 938
+                                    entry_size[2] = 939
+                                    entry_size[3] = 938
+                                    entry_size[4] = 934
+                                    entry_size[5] = 945
+                                    entry_size[6] = 948
+                                    entry_size[7] = 956
+                                    entry_size[8] = 955
+                                    entry_size[9] = 930
+                                    entry_size[10] = 933
+                                    entry_size[11] = 934
+                                    entry_size[12] = 972
+                                    entry_size[13] = 977
+                                    entry_size[14] = 958
+                                    entry_size[15] = 949
+                                    entry_size[16] = 962
+                                    entry_size[17] = 848
+                                [stco: Chunk Offset Box]
+                                    position = 646
+                                    size = 24
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 2
+                                    chunk_offset[0] = 686
+                                    chunk_offset[1] = 12985
+            [free: Free Space Box]
+                position = 670
+                size = 8
+            [mdat: Media Data Box]
+                position = 678
+                size = 17001
+
+5 Authors' Address
+    Monty Montgomery <monty@xiph.org>