ce188d4d |
1 | /* libFLAC - Free Lossless Audio Codec |
2 | * Copyright (C) 2002-2009 Josh Coalson |
3 | * Copyright (C) 2011-2016 Xiph.Org Foundation |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * |
12 | * - Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * |
16 | * - Neither the name of the Xiph.org Foundation nor the names of its |
17 | * contributors may be used to endorse or promote products derived from |
18 | * this software without specific prior written permission. |
19 | * |
20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
23 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR |
24 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
25 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
26 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
27 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
28 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
29 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
30 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
31 | */ |
32 | |
33 | #ifdef HAVE_CONFIG_H |
34 | # include <config.h> |
35 | #endif |
36 | |
37 | #include <string.h> /* for memcpy() */ |
38 | #include "FLAC/assert.h" |
39 | #include "private/ogg_decoder_aspect.h" |
40 | #include "private/ogg_mapping.h" |
41 | #include "private/macros.h" |
42 | |
43 | |
44 | /*********************************************************************** |
45 | * |
46 | * Public class methods |
47 | * |
48 | ***********************************************************************/ |
49 | |
50 | FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect) |
51 | { |
52 | /* we will determine the serial number later if necessary */ |
53 | if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0) |
54 | return false; |
55 | |
56 | if(ogg_sync_init(&aspect->sync_state) != 0) |
57 | return false; |
58 | |
59 | aspect->version_major = ~(0u); |
60 | aspect->version_minor = ~(0u); |
61 | |
62 | aspect->need_serial_number = aspect->use_first_serial_number; |
63 | |
64 | aspect->end_of_stream = false; |
65 | aspect->have_working_page = false; |
66 | |
67 | return true; |
68 | } |
69 | |
70 | void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect) |
71 | { |
72 | (void)ogg_sync_clear(&aspect->sync_state); |
73 | (void)ogg_stream_clear(&aspect->stream_state); |
74 | } |
75 | |
76 | void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value) |
77 | { |
78 | aspect->use_first_serial_number = false; |
79 | aspect->serial_number = value; |
80 | } |
81 | |
82 | void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect) |
83 | { |
84 | aspect->use_first_serial_number = true; |
85 | } |
86 | |
87 | void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect) |
88 | { |
89 | (void)ogg_stream_reset(&aspect->stream_state); |
90 | (void)ogg_sync_reset(&aspect->sync_state); |
91 | aspect->end_of_stream = false; |
92 | aspect->have_working_page = false; |
93 | } |
94 | |
95 | void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect) |
96 | { |
97 | FLAC__ogg_decoder_aspect_flush(aspect); |
98 | |
99 | if(aspect->use_first_serial_number) |
100 | aspect->need_serial_number = true; |
101 | } |
102 | |
103 | 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 | { |
105 | static const size_t OGG_BYTES_CHUNK = 8192; |
106 | const size_t bytes_requested = *bytes; |
107 | |
108 | /* |
109 | * The FLAC decoding API uses pull-based reads, whereas Ogg decoding |
110 | * is push-based. In libFLAC, when you ask to decode a frame, the |
111 | * decoder will eventually call the read callback to supply some data, |
112 | * but how much it asks for depends on how much free space it has in |
113 | * its internal buffer. It does not try to grow its internal buffer |
114 | * to accomodate a whole frame because then the internal buffer size |
115 | * could not be limited, which is necessary in embedded applications. |
116 | * |
117 | * Ogg however grows its internal buffer until a whole page is present; |
118 | * only then can you get decoded data out. So we can't just ask for |
119 | * the same number of bytes from Ogg, then pass what's decoded down to |
120 | * libFLAC. If what libFLAC is asking for will not contain a whole |
121 | * page, then we will get no data from ogg_sync_pageout(), and at the |
122 | * same time cannot just read more data from the client for the purpose |
123 | * of getting a whole decoded page because the decoded size might be |
124 | * larger than libFLAC's internal buffer. |
125 | * |
126 | * Instead, whenever this read callback wrapper is called, we will |
127 | * continually request data from the client until we have at least one |
128 | * page, and manage pages internally so that we can send pieces of |
129 | * pages down to libFLAC in such a way that we obey its size |
130 | * requirement. To limit the amount of callbacks, we will always try |
131 | * to read in enough pages to return the full number of bytes |
132 | * requested. |
133 | */ |
134 | *bytes = 0; |
135 | while (*bytes < bytes_requested && !aspect->end_of_stream) { |
136 | if (aspect->have_working_page) { |
137 | if (aspect->have_working_packet) { |
138 | size_t n = bytes_requested - *bytes; |
139 | if ((size_t)aspect->working_packet.bytes <= n) { |
140 | /* the rest of the packet will fit in the buffer */ |
141 | n = aspect->working_packet.bytes; |
142 | memcpy(buffer, aspect->working_packet.packet, n); |
143 | *bytes += n; |
144 | buffer += n; |
145 | aspect->have_working_packet = false; |
146 | } |
147 | else { |
148 | /* only n bytes of the packet will fit in the buffer */ |
149 | memcpy(buffer, aspect->working_packet.packet, n); |
150 | *bytes += n; |
151 | buffer += n; |
152 | aspect->working_packet.packet += n; |
153 | aspect->working_packet.bytes -= n; |
154 | } |
155 | } |
156 | else { |
157 | /* try and get another packet */ |
158 | const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet); |
159 | if (ret > 0) { |
160 | aspect->have_working_packet = true; |
161 | /* if it is the first header packet, check for magic and a supported Ogg FLAC mapping version */ |
162 | if (aspect->working_packet.bytes > 0 && aspect->working_packet.packet[0] == FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE) { |
163 | const FLAC__byte *b = aspect->working_packet.packet; |
164 | const unsigned header_length = |
165 | FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH + |
166 | FLAC__OGG_MAPPING_MAGIC_LENGTH + |
167 | FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH + |
168 | FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH + |
169 | FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH; |
170 | if (aspect->working_packet.bytes < (long)header_length) |
171 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC; |
172 | b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH; |
173 | if (memcmp(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH)) |
174 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC; |
175 | b += FLAC__OGG_MAPPING_MAGIC_LENGTH; |
176 | aspect->version_major = (unsigned)(*b); |
177 | b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH; |
178 | aspect->version_minor = (unsigned)(*b); |
179 | if (aspect->version_major != 1) |
180 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_UNSUPPORTED_MAPPING_VERSION; |
181 | aspect->working_packet.packet += header_length; |
182 | aspect->working_packet.bytes -= header_length; |
183 | } |
184 | } |
185 | else if (ret == 0) { |
186 | aspect->have_working_page = false; |
187 | } |
188 | else { /* ret < 0 */ |
189 | /* lost sync, we'll leave the working page for the next call */ |
190 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC; |
191 | } |
192 | } |
193 | } |
194 | else { |
195 | /* try and get another page */ |
196 | const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page); |
197 | if (ret > 0) { |
198 | /* got a page, grab the serial number if necessary */ |
199 | if(aspect->need_serial_number) { |
200 | aspect->stream_state.serialno = aspect->serial_number = ogg_page_serialno(&aspect->working_page); |
201 | aspect->need_serial_number = false; |
202 | } |
203 | if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) { |
204 | aspect->have_working_page = true; |
205 | aspect->have_working_packet = false; |
206 | } |
207 | /* else do nothing, could be a page from another stream */ |
208 | } |
209 | else if (ret == 0) { |
210 | /* need more data */ |
211 | const size_t ogg_bytes_to_read = flac_max(bytes_requested - *bytes, OGG_BYTES_CHUNK); |
212 | char *oggbuf = ogg_sync_buffer(&aspect->sync_state, ogg_bytes_to_read); |
213 | |
214 | if(0 == oggbuf) { |
215 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR; |
216 | } |
217 | else { |
218 | size_t ogg_bytes_read = ogg_bytes_to_read; |
219 | |
220 | switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) { |
221 | case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK: |
222 | break; |
223 | case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM: |
224 | aspect->end_of_stream = true; |
225 | break; |
226 | case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT: |
227 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT; |
228 | default: |
229 | FLAC__ASSERT(0); |
230 | } |
231 | |
232 | if(ogg_sync_wrote(&aspect->sync_state, ogg_bytes_read) < 0) { |
233 | /* double protection; this will happen if the read callback returns more bytes than the max requested, which would overflow Ogg's internal buffer */ |
234 | FLAC__ASSERT(0); |
235 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR; |
236 | } |
237 | } |
238 | } |
239 | else { /* ret < 0 */ |
240 | /* lost sync, bail out */ |
241 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC; |
242 | } |
243 | } |
244 | } |
245 | |
246 | if (aspect->end_of_stream && *bytes == 0) { |
247 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM; |
248 | } |
249 | |
250 | return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK; |
251 | } |