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riffdec.c
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1 /*
2  * RIFF demuxing functions and data
3  * Copyright (c) 2000 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/dict.h"
23 #include "libavutil/error.h"
24 #include "libavutil/log.h"
25 #include "libavutil/mathematics.h"
26 #include "libavcodec/avcodec.h"
27 #include "libavcodec/bytestream.h"
28 #include "avformat.h"
29 #include "avio_internal.h"
30 #include "riff.h"
31 
33 {
34  av_assert0(sizeof(*g) == 16); //compiler will optimize this out
35  if (avio_read(s, *g, sizeof(*g)) < (int)sizeof(*g)) {
36  memset(*g, 0, sizeof(*g));
37  return AVERROR_INVALIDDATA;
38  }
39  return 0;
40 }
41 
43 {
44  int i;
45  for (i = 0; guids[i].id != AV_CODEC_ID_NONE; i++)
46  if (!ff_guidcmp(guids[i].guid, guid))
47  return guids[i].id;
48  return AV_CODEC_ID_NONE;
49 }
50 
51 /* We could be given one of the three possible structures here:
52  * WAVEFORMAT, PCMWAVEFORMAT or WAVEFORMATEX. Each structure
53  * is an expansion of the previous one with the fields added
54  * at the bottom. PCMWAVEFORMAT adds 'WORD wBitsPerSample' and
55  * WAVEFORMATEX adds 'WORD cbSize' and basically makes itself
56  * an openended structure.
57  */
58 
60 {
61  ff_asf_guid subformat;
62  int bps = avio_rl16(pb);
63  if (bps)
65 
66  c->channel_layout = avio_rl32(pb); /* dwChannelMask */
67 
68  ff_get_guid(pb, &subformat);
69  if (!memcmp(subformat + 4,
70  (const uint8_t[]){ FF_MEDIASUBTYPE_BASE_GUID }, 12)) {
71  c->codec_tag = AV_RL32(subformat);
74  } else {
76  if (!c->codec_id)
78  "unknown subformat:"FF_PRI_GUID"\n",
79  FF_ARG_GUID(subformat));
80  }
81 }
82 
84 {
85  int id;
86 
87  id = avio_rl16(pb);
89  codec->channels = avio_rl16(pb);
90  codec->sample_rate = avio_rl32(pb);
91  codec->bit_rate = avio_rl32(pb) * 8;
92  codec->block_align = avio_rl16(pb);
93  if (size == 14) { /* We're dealing with plain vanilla WAVEFORMAT */
94  codec->bits_per_coded_sample = 8;
95  } else
96  codec->bits_per_coded_sample = avio_rl16(pb);
97  if (id == 0xFFFE) {
98  codec->codec_tag = 0;
99  } else {
100  codec->codec_tag = id;
101  codec->codec_id = ff_wav_codec_get_id(id,
102  codec->bits_per_coded_sample);
103  }
104  if (size >= 18) { /* We're obviously dealing with WAVEFORMATEX */
105  int cbSize = avio_rl16(pb); /* cbSize */
106  size -= 18;
107  cbSize = FFMIN(size, cbSize);
108  if (cbSize >= 22 && id == 0xfffe) { /* WAVEFORMATEXTENSIBLE */
109  parse_waveformatex(pb, codec);
110  cbSize -= 22;
111  size -= 22;
112  }
113  if (cbSize > 0) {
114  av_free(codec->extradata);
115  if (ff_get_extradata(codec, pb, cbSize) < 0)
116  return AVERROR(ENOMEM);
117  size -= cbSize;
118  }
119 
120  /* It is possible for the chunk to contain garbage at the end */
121  if (size > 0)
122  avio_skip(pb, size);
123  }
124  if (codec->sample_rate <= 0) {
125  av_log(NULL, AV_LOG_ERROR,
126  "Invalid sample rate: %d\n", codec->sample_rate);
127  return AVERROR_INVALIDDATA;
128  }
129  if (codec->codec_id == AV_CODEC_ID_AAC_LATM) {
130  /* Channels and sample_rate values are those prior to applying SBR
131  * and/or PS. */
132  codec->channels = 0;
133  codec->sample_rate = 0;
134  }
135  /* override bits_per_coded_sample for G.726 */
136  if (codec->codec_id == AV_CODEC_ID_ADPCM_G726 && codec->sample_rate)
137  codec->bits_per_coded_sample = codec->bit_rate / codec->sample_rate;
138 
139  return 0;
140 }
141 
142 enum AVCodecID ff_wav_codec_get_id(unsigned int tag, int bps)
143 {
144  enum AVCodecID id;
146  if (id <= 0)
147  return id;
148 
149  if (id == AV_CODEC_ID_PCM_S16LE)
150  id = ff_get_pcm_codec_id(bps, 0, 0, ~1);
151  else if (id == AV_CODEC_ID_PCM_F32LE)
152  id = ff_get_pcm_codec_id(bps, 1, 0, 0);
153 
154  if (id == AV_CODEC_ID_ADPCM_IMA_WAV && bps == 8)
156  return id;
157 }
158 
159 int ff_get_bmp_header(AVIOContext *pb, AVStream *st, unsigned *esize)
160 {
161  int tag1;
162  if(esize) *esize = avio_rl32(pb);
163  else avio_rl32(pb);
164  st->codec->width = avio_rl32(pb);
165  st->codec->height = (int32_t)avio_rl32(pb);
166  avio_rl16(pb); /* planes */
167  st->codec->bits_per_coded_sample = avio_rl16(pb); /* depth */
168  tag1 = avio_rl32(pb);
169  avio_rl32(pb); /* ImageSize */
170  avio_rl32(pb); /* XPelsPerMeter */
171  avio_rl32(pb); /* YPelsPerMeter */
172  avio_rl32(pb); /* ClrUsed */
173  avio_rl32(pb); /* ClrImportant */
174  return tag1;
175 }
176 
178 {
179  int64_t start, end, cur;
180  AVIOContext *pb = s->pb;
181 
182  start = avio_tell(pb);
183  end = start + size;
184 
185  while ((cur = avio_tell(pb)) >= 0 &&
186  cur <= end - 8 /* = tag + size */) {
187  uint32_t chunk_code;
188  int64_t chunk_size;
189  char key[5] = { 0 };
190  char *value;
191 
192  chunk_code = avio_rl32(pb);
193  chunk_size = avio_rl32(pb);
194  if (url_feof(pb)) {
195  if (chunk_code || chunk_size) {
196  av_log(s, AV_LOG_WARNING, "INFO subchunk truncated\n");
197  return AVERROR_INVALIDDATA;
198  }
199  return AVERROR_EOF;
200  }
201  if (chunk_size > end ||
202  end - chunk_size < cur ||
203  chunk_size == UINT_MAX) {
204  avio_seek(pb, -9, SEEK_CUR);
205  chunk_code = avio_rl32(pb);
206  chunk_size = avio_rl32(pb);
207  if (chunk_size > end || end - chunk_size < cur || chunk_size == UINT_MAX) {
208  av_log(s, AV_LOG_WARNING, "too big INFO subchunk\n");
209  return AVERROR_INVALIDDATA;
210  }
211  }
212 
213  chunk_size += (chunk_size & 1);
214 
215  if (!chunk_code) {
216  if (chunk_size)
217  avio_skip(pb, chunk_size);
218  else if (pb->eof_reached) {
219  av_log(s, AV_LOG_WARNING, "truncated file\n");
220  return AVERROR_EOF;
221  }
222  continue;
223  }
224 
225  value = av_mallocz(chunk_size + 1);
226  if (!value) {
227  av_log(s, AV_LOG_ERROR,
228  "out of memory, unable to read INFO tag\n");
229  return AVERROR(ENOMEM);
230  }
231 
232  AV_WL32(key, chunk_code);
233 
234  if (avio_read(pb, value, chunk_size) != chunk_size) {
236  "premature end of file while reading INFO tag\n");
237  }
238 
239  av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
240  }
241 
242  return 0;
243 }