1 /* libFLAC - Free Lossless Audio Codec
2 * Copyright (C) 2002,2003,2004,2005,2006,2007,2008,2009 Josh Coalson
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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.
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.
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.
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 #include "private/macros.h"
43 /***********************************************************************
45 * Public class methods
47 ***********************************************************************/
49 FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect)
51 /* we will determine the serial number later if necessary */
52 if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0)
55 if(ogg_sync_init(&aspect->sync_state) != 0)
58 aspect->version_major = ~(0u);
59 aspect->version_minor = ~(0u);
61 aspect->need_serial_number = aspect->use_first_serial_number;
63 aspect->end_of_stream = false;
64 aspect->have_working_page = false;
69 void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect)
71 (void)ogg_sync_clear(&aspect->sync_state);
72 (void)ogg_stream_clear(&aspect->stream_state);
75 void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value)
77 aspect->use_first_serial_number = false;
78 aspect->serial_number = value;
81 void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect)
83 aspect->use_first_serial_number = true;
86 void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect)
88 (void)ogg_stream_reset(&aspect->stream_state);
89 (void)ogg_sync_reset(&aspect->sync_state);
90 aspect->end_of_stream = false;
91 aspect->have_working_page = false;
94 void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect)
96 FLAC__ogg_decoder_aspect_flush(aspect);
98 if(aspect->use_first_serial_number)
99 aspect->need_serial_number = true;
102 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)
104 static const size_t OGG_BYTES_CHUNK = 8192;
105 const size_t bytes_requested = *bytes;
108 * The FLAC decoding API uses pull-based reads, whereas Ogg decoding
109 * is push-based. In libFLAC, when you ask to decode a frame, the
110 * decoder will eventually call the read callback to supply some data,
111 * but how much it asks for depends on how much free space it has in
112 * its internal buffer. It does not try to grow its internal buffer
113 * to accomodate a whole frame because then the internal buffer size
114 * could not be limited, which is necessary in embedded applications.
116 * Ogg however grows its internal buffer until a whole page is present;
117 * only then can you get decoded data out. So we can't just ask for
118 * the same number of bytes from Ogg, then pass what's decoded down to
119 * libFLAC. If what libFLAC is asking for will not contain a whole
120 * page, then we will get no data from ogg_sync_pageout(), and at the
121 * same time cannot just read more data from the client for the purpose
122 * of getting a whole decoded page because the decoded size might be
123 * larger than libFLAC's internal buffer.
125 * Instead, whenever this read callback wrapper is called, we will
126 * continually request data from the client until we have at least one
127 * page, and manage pages internally so that we can send pieces of
128 * pages down to libFLAC in such a way that we obey its size
129 * requirement. To limit the amount of callbacks, we will always try
130 * to read in enough pages to return the full number of bytes
134 while (*bytes < bytes_requested && !aspect->end_of_stream) {
135 if (aspect->have_working_page) {
136 if (aspect->have_working_packet) {
137 size_t n = bytes_requested - *bytes;
138 if ((size_t)aspect->working_packet.bytes <= n) {
139 /* the rest of the packet will fit in the buffer */
140 n = aspect->working_packet.bytes;
141 memcpy(buffer, aspect->working_packet.packet, n);
144 aspect->have_working_packet = false;
147 /* only n bytes of the packet will fit in the buffer */
148 memcpy(buffer, aspect->working_packet.packet, n);
151 aspect->working_packet.packet += n;
152 aspect->working_packet.bytes -= n;
156 /* try and get another packet */
157 const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet);
159 aspect->have_working_packet = true;
160 /* if it is the first header packet, check for magic and a supported Ogg FLAC mapping version */
161 if (aspect->working_packet.bytes > 0 && aspect->working_packet.packet[0] == FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE) {
162 const FLAC__byte *b = aspect->working_packet.packet;
163 const unsigned header_length =
164 FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH +
165 FLAC__OGG_MAPPING_MAGIC_LENGTH +
166 FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH +
167 FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH +
168 FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH;
169 if (aspect->working_packet.bytes < (long)header_length)
170 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
171 b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH;
172 if (memcmp(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH))
173 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
174 b += FLAC__OGG_MAPPING_MAGIC_LENGTH;
175 aspect->version_major = (unsigned)(*b);
176 b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH;
177 aspect->version_minor = (unsigned)(*b);
178 if (aspect->version_major != 1)
179 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_UNSUPPORTED_MAPPING_VERSION;
180 aspect->working_packet.packet += header_length;
181 aspect->working_packet.bytes -= header_length;
185 aspect->have_working_page = false;
188 /* lost sync, we'll leave the working page for the next call */
189 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
194 /* try and get another page */
195 const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page);
197 /* got a page, grab the serial number if necessary */
198 if(aspect->need_serial_number) {
199 aspect->stream_state.serialno = aspect->serial_number = ogg_page_serialno(&aspect->working_page);
200 aspect->need_serial_number = false;
202 if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) {
203 aspect->have_working_page = true;
204 aspect->have_working_packet = false;
206 /* else do nothing, could be a page from another stream */
210 const size_t ogg_bytes_to_read = flac_max(bytes_requested - *bytes, OGG_BYTES_CHUNK);
211 char *oggbuf = ogg_sync_buffer(&aspect->sync_state, ogg_bytes_to_read);
214 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR;
217 size_t ogg_bytes_read = ogg_bytes_to_read;
219 switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) {
220 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK:
222 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM:
223 aspect->end_of_stream = true;
225 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT:
226 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT;
231 if(ogg_sync_wrote(&aspect->sync_state, ogg_bytes_read) < 0) {
232 /* double protection; this will happen if the read callback returns more bytes than the max requested, which would overflow Ogg's internal buffer */
234 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR;
239 /* lost sync, bail out */
240 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
245 if (aspect->end_of_stream && *bytes == 0) {
246 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM;
249 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK;