0e8519c790416a2ec76b9b87b8586d9b6fc00224
[flac.git] / src / libFLAC / ogg_decoder_aspect.c
1 /* libFLAC - Free Lossless Audio Codec
2  * Copyright (C) 2002,2003,2004,2005,2006,2007,2008,2009  Josh Coalson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * - Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *
11  * - Redistributions in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the distribution.
14  *
15  * - Neither the name of the Xiph.org Foundation nor the names of its
16  * contributors may be used to endorse or promote products derived from
17  * this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31
32 #if HAVE_CONFIG_H
33 #  include <config.h>
34 #endif
35
36 #include <string.h> /* for memcpy() */
37 #include "FLAC/assert.h"
38 #include "private/ogg_decoder_aspect.h"
39 #include "private/ogg_mapping.h"
40
41 #ifdef max
42 #undef max
43 #endif
44 #define max(x,y) ((x)>(y)?(x):(y))
45
46 /***********************************************************************
47  *
48  * Public class methods
49  *
50  ***********************************************************************/
51
52 FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect)
53 {
54         /* we will determine the serial number later if necessary */
55         if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0)
56                 return false;
57
58         if(ogg_sync_init(&aspect->sync_state) != 0)
59                 return false;
60
61         aspect->version_major = ~(0u);
62         aspect->version_minor = ~(0u);
63
64         aspect->need_serial_number = aspect->use_first_serial_number;
65
66         aspect->end_of_stream = false;
67         aspect->have_working_page = false;
68
69         return true;
70 }
71
72 void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect)
73 {
74         (void)ogg_sync_clear(&aspect->sync_state);
75         (void)ogg_stream_clear(&aspect->stream_state);
76 }
77
78 void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value)
79 {
80         aspect->use_first_serial_number = false;
81         aspect->serial_number = value;
82 }
83
84 void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect)
85 {
86         aspect->use_first_serial_number = true;
87 }
88
89 void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect)
90 {
91         (void)ogg_stream_reset(&aspect->stream_state);
92         (void)ogg_sync_reset(&aspect->sync_state);
93         aspect->end_of_stream = false;
94         aspect->have_working_page = false;
95 }
96
97 void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect)
98 {
99         FLAC__ogg_decoder_aspect_flush(aspect);
100
101         if(aspect->use_first_serial_number)
102                 aspect->need_serial_number = true;
103 }
104
105 FLAC__OggDecoderAspectReadStatus FLAC__ogg_decoder_aspect_read_callback_wrapper(FLAC__OggDecoderAspect *aspect, FLAC__byte buffer[], size_t *bytes, FLAC__OggDecoderAspectReadCallbackProxy read_callback, const FLAC__StreamDecoder *decoder, void *client_data)
106 {
107         static const size_t OGG_BYTES_CHUNK = 8192;
108         const size_t bytes_requested = *bytes;
109
110         /*
111          * The FLAC decoding API uses pull-based reads, whereas Ogg decoding
112          * is push-based.  In libFLAC, when you ask to decode a frame, the
113          * decoder will eventually call the read callback to supply some data,
114          * but how much it asks for depends on how much free space it has in
115          * its internal buffer.  It does not try to grow its internal buffer
116          * to accomodate a whole frame because then the internal buffer size
117          * could not be limited, which is necessary in embedded applications.
118          *
119          * Ogg however grows its internal buffer until a whole page is present;
120          * only then can you get decoded data out.  So we can't just ask for
121          * the same number of bytes from Ogg, then pass what's decoded down to
122          * libFLAC.  If what libFLAC is asking for will not contain a whole
123          * page, then we will get no data from ogg_sync_pageout(), and at the
124          * same time cannot just read more data from the client for the purpose
125          * of getting a whole decoded page because the decoded size might be
126          * larger than libFLAC's internal buffer.
127          *
128          * Instead, whenever this read callback wrapper is called, we will
129          * continually request data from the client until we have at least one
130          * page, and manage pages internally so that we can send pieces of
131          * pages down to libFLAC in such a way that we obey its size
132          * requirement.  To limit the amount of callbacks, we will always try
133          * to read in enough pages to return the full number of bytes
134          * requested.
135          */
136         *bytes = 0;
137         while (*bytes < bytes_requested && !aspect->end_of_stream) {
138                 if (aspect->have_working_page) {
139                         if (aspect->have_working_packet) {
140                                 size_t n = bytes_requested - *bytes;
141                                 if ((size_t)aspect->working_packet.bytes <= n) {
142                                         /* the rest of the packet will fit in the buffer */
143                                         n = aspect->working_packet.bytes;
144                                         memcpy(buffer, aspect->working_packet.packet, n);
145                                         *bytes += n;
146                                         buffer += n;
147                                         aspect->have_working_packet = false;
148                                 }
149                                 else {
150                                         /* only n bytes of the packet will fit in the buffer */
151                                         memcpy(buffer, aspect->working_packet.packet, n);
152                                         *bytes += n;
153                                         buffer += n;
154                                         aspect->working_packet.packet += n;
155                                         aspect->working_packet.bytes -= n;
156                                 }
157                         }
158                         else {
159                                 /* try and get another packet */
160                                 const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet);
161                                 if (ret > 0) {
162                                         aspect->have_working_packet = true;
163                                         /* if it is the first header packet, check for magic and a supported Ogg FLAC mapping version */
164                                         if (aspect->working_packet.bytes > 0 && aspect->working_packet.packet[0] == FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE) {
165                                                 const FLAC__byte *b = aspect->working_packet.packet;
166                                                 const unsigned header_length =
167                                                         FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH +
168                                                         FLAC__OGG_MAPPING_MAGIC_LENGTH +
169                                                         FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH +
170                                                         FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH +
171                                                         FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH;
172                                                 if (aspect->working_packet.bytes < (long)header_length)
173                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
174                                                 b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH;
175                                                 if (memcmp(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH))
176                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
177                                                 b += FLAC__OGG_MAPPING_MAGIC_LENGTH;
178                                                 aspect->version_major = (unsigned)(*b);
179                                                 b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH;
180                                                 aspect->version_minor = (unsigned)(*b);
181                                                 if (aspect->version_major != 1)
182                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_UNSUPPORTED_MAPPING_VERSION;
183                                                 aspect->working_packet.packet += header_length;
184                                                 aspect->working_packet.bytes -= header_length;
185                                         }
186                                 }
187                                 else if (ret == 0) {
188                                         aspect->have_working_page = false;
189                                 }
190                                 else { /* ret < 0 */
191                                         /* lost sync, we'll leave the working page for the next call */
192                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
193                                 }
194                         }
195                 }
196                 else {
197                         /* try and get another page */
198                         const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page);
199                         if (ret > 0) {
200                                 /* got a page, grab the serial number if necessary */
201                                 if(aspect->need_serial_number) {
202                                         aspect->stream_state.serialno = aspect->serial_number = ogg_page_serialno(&aspect->working_page);
203                                         aspect->need_serial_number = false;
204                                 }
205                                 if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) {
206                                         aspect->have_working_page = true;
207                                         aspect->have_working_packet = false;
208                                 }
209                                 /* else do nothing, could be a page from another stream */
210                         }
211                         else if (ret == 0) {
212                                 /* need more data */
213                                 const size_t ogg_bytes_to_read = max(bytes_requested - *bytes, OGG_BYTES_CHUNK);
214                                 char *oggbuf = ogg_sync_buffer(&aspect->sync_state, ogg_bytes_to_read);
215
216                                 if(0 == oggbuf) {
217                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR;
218                                 }
219                                 else {
220                                         size_t ogg_bytes_read = ogg_bytes_to_read;
221
222                                         switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) {
223                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK:
224                                                         break;
225                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM:
226                                                         aspect->end_of_stream = true;
227                                                         break;
228                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT:
229                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT;
230                                                 default:
231                                                         FLAC__ASSERT(0);
232                                         }
233
234                                         if(ogg_sync_wrote(&aspect->sync_state, ogg_bytes_read) < 0) {
235                                                 /* double protection; this will happen if the read callback returns more bytes than the max requested, which would overflow Ogg's internal buffer */
236                                                 FLAC__ASSERT(0);
237                                                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR;
238                                         }
239                                 }
240                         }
241                         else { /* ret < 0 */
242                                 /* lost sync, bail out */
243                                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
244                         }
245                 }
246         }
247
248         if (aspect->end_of_stream && *bytes == 0) {
249                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM;
250         }
251
252         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK;
253 }