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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 
83 /* "big_endian" values are needed for RIFX file format */
84 int ff_get_wav_header(AVIOContext *pb, AVCodecContext *codec, int size, int big_endian)
85 {
86  int id;
87 
88  if (size < 14)
89  avpriv_request_sample(codec, "wav header size < 14");
90 
92  if (!big_endian) {
93  id = avio_rl16(pb);
94  codec->channels = avio_rl16(pb);
95  codec->sample_rate = avio_rl32(pb);
96  codec->bit_rate = avio_rl32(pb) * 8;
97  codec->block_align = avio_rl16(pb);
98  } else {
99  id = avio_rb16(pb);
100  codec->channels = avio_rb16(pb);
101  codec->sample_rate = avio_rb32(pb);
102  codec->bit_rate = avio_rb32(pb) * 8;
103  codec->block_align = avio_rb16(pb);
104  }
105  if (size == 14) { /* We're dealing with plain vanilla WAVEFORMAT */
106  codec->bits_per_coded_sample = 8;
107  } else {
108  if (!big_endian) {
109  codec->bits_per_coded_sample = avio_rl16(pb);
110  } else {
111  codec->bits_per_coded_sample = avio_rb16(pb);
112  }
113  }
114  if (id == 0xFFFE) {
115  codec->codec_tag = 0;
116  } else {
117  codec->codec_tag = id;
118  codec->codec_id = ff_wav_codec_get_id(id,
119  codec->bits_per_coded_sample);
120  }
121  if (size >= 18) { /* We're obviously dealing with WAVEFORMATEX */
122  int cbSize = avio_rl16(pb); /* cbSize */
123  if (big_endian) {
124  avpriv_report_missing_feature(codec, "WAVEFORMATEX support for RIFX files\n");
125  return AVERROR_PATCHWELCOME;
126  }
127  size -= 18;
128  cbSize = FFMIN(size, cbSize);
129  if (cbSize >= 22 && id == 0xfffe) { /* WAVEFORMATEXTENSIBLE */
130  parse_waveformatex(pb, codec);
131  cbSize -= 22;
132  size -= 22;
133  }
134  if (cbSize > 0) {
135  av_freep(&codec->extradata);
136  if (ff_get_extradata(codec, pb, cbSize) < 0)
137  return AVERROR(ENOMEM);
138  size -= cbSize;
139  }
140 
141  /* It is possible for the chunk to contain garbage at the end */
142  if (size > 0)
143  avio_skip(pb, size);
144  }
145  if (codec->sample_rate <= 0) {
147  "Invalid sample rate: %d\n", codec->sample_rate);
148  return AVERROR_INVALIDDATA;
149  }
150  if (codec->codec_id == AV_CODEC_ID_AAC_LATM) {
151  /* Channels and sample_rate values are those prior to applying SBR
152  * and/or PS. */
153  codec->channels = 0;
154  codec->sample_rate = 0;
155  }
156  /* override bits_per_coded_sample for G.726 */
157  if (codec->codec_id == AV_CODEC_ID_ADPCM_G726 && codec->sample_rate)
158  codec->bits_per_coded_sample = codec->bit_rate / codec->sample_rate;
159 
160  return 0;
161 }
162 
163 enum AVCodecID ff_wav_codec_get_id(unsigned int tag, int bps)
164 {
165  enum AVCodecID id;
167  if (id <= 0)
168  return id;
169 
170  if (id == AV_CODEC_ID_PCM_S16LE)
171  id = ff_get_pcm_codec_id(bps, 0, 0, ~1);
172  else if (id == AV_CODEC_ID_PCM_F32LE)
173  id = ff_get_pcm_codec_id(bps, 1, 0, 0);
174 
175  if (id == AV_CODEC_ID_ADPCM_IMA_WAV && bps == 8)
177  return id;
178 }
179 
180 int ff_get_bmp_header(AVIOContext *pb, AVStream *st, unsigned *esize)
181 {
182  int tag1;
183  if(esize) *esize = avio_rl32(pb);
184  else avio_rl32(pb);
185  st->codec->width = avio_rl32(pb);
186  st->codec->height = (int32_t)avio_rl32(pb);
187  avio_rl16(pb); /* planes */
188  st->codec->bits_per_coded_sample = avio_rl16(pb); /* depth */
189  tag1 = avio_rl32(pb);
190  avio_rl32(pb); /* ImageSize */
191  avio_rl32(pb); /* XPelsPerMeter */
192  avio_rl32(pb); /* YPelsPerMeter */
193  avio_rl32(pb); /* ClrUsed */
194  avio_rl32(pb); /* ClrImportant */
195  return tag1;
196 }
197 
199 {
200  int64_t start, end, cur;
201  AVIOContext *pb = s->pb;
202 
203  start = avio_tell(pb);
204  end = start + size;
205 
206  while ((cur = avio_tell(pb)) >= 0 &&
207  cur <= end - 8 /* = tag + size */) {
208  uint32_t chunk_code;
209  int64_t chunk_size;
210  char key[5] = { 0 };
211  char *value;
212 
213  chunk_code = avio_rl32(pb);
214  chunk_size = avio_rl32(pb);
215  if (avio_feof(pb)) {
216  if (chunk_code || chunk_size) {
217  av_log(s, AV_LOG_WARNING, "INFO subchunk truncated\n");
218  return AVERROR_INVALIDDATA;
219  }
220  return AVERROR_EOF;
221  }
222  if (chunk_size > end ||
223  end - chunk_size < cur ||
224  chunk_size == UINT_MAX) {
225  avio_seek(pb, -9, SEEK_CUR);
226  chunk_code = avio_rl32(pb);
227  chunk_size = avio_rl32(pb);
228  if (chunk_size > end || end - chunk_size < cur || chunk_size == UINT_MAX) {
229  av_log(s, AV_LOG_WARNING, "too big INFO subchunk\n");
230  return AVERROR_INVALIDDATA;
231  }
232  }
233 
234  chunk_size += (chunk_size & 1);
235 
236  if (!chunk_code) {
237  if (chunk_size)
238  avio_skip(pb, chunk_size);
239  else if (pb->eof_reached) {
240  av_log(s, AV_LOG_WARNING, "truncated file\n");
241  return AVERROR_EOF;
242  }
243  continue;
244  }
245 
246  value = av_mallocz(chunk_size + 1);
247  if (!value) {
248  av_log(s, AV_LOG_ERROR,
249  "out of memory, unable to read INFO tag\n");
250  return AVERROR(ENOMEM);
251  }
252 
253  AV_WL32(key, chunk_code);
254 
255  if (avio_read(pb, value, chunk_size) != chunk_size) {
257  "premature end of file while reading INFO tag\n");
258  }
259 
260  av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
261  }
262 
263  return 0;
264 }