FFmpeg: libavformat/riffdec.c Source File

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libavformat

riffdec.c

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1 /*

2 * RIFF demuxing functions and data

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 */

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"

32 const AVCodecGuid ff_codec_wav_guids[] = {

33 { AV_CODEC_ID_AC3, { 0x2C, 0x80, 0x6D, 0xE0, 0x46, 0xDB, 0xCF, 0x11, 0xB4, 0xD1, 0x00, 0x80, 0x5F, 0x6C, 0xBB, 0xEA } },

34 { AV_CODEC_ID_ATRAC3P, { 0xBF, 0xAA, 0x23, 0xE9, 0x58, 0xCB, 0x71, 0x44, 0xA1, 0x19, 0xFF, 0xFA, 0x01, 0xE4, 0xCE, 0x62 } },

35 { AV_CODEC_ID_EAC3, { 0xAF, 0x87, 0xFB, 0xA7, 0x02, 0x2D, 0xFB, 0x42, 0xA4, 0xD4, 0x05, 0xCD, 0x93, 0x84, 0x3B, 0xDD } },

36 { AV_CODEC_ID_MP2, { 0x2B, 0x80, 0x6D, 0xE0, 0x46, 0xDB, 0xCF, 0x11, 0xB4, 0xD1, 0x00, 0x80, 0x5F, 0x6C, 0xBB, 0xEA } },

37 { AV_CODEC_ID_NONE }

38 };

40 void ff_get_guid(AVIOContext *s, ff_asf_guid *g)

41 {

42 av_assert0(sizeof(*g) == 16); //compiler will optimize this out

43 if (avio_read(s, *g, sizeof(*g)) < (int)sizeof(*g))

44 memset(*g, 0, sizeof(*g));

45 }

47 enum AVCodecID ff_codec_guid_get_id(const AVCodecGuid *guids, ff_asf_guid guid)

48 {

49 int i;

50 for (i = 0; guids[i].id != AV_CODEC_ID_NONE; i++)

51 if (!ff_guidcmp(guids[i].guid, guid))

52 return guids[i].id;

53 return AV_CODEC_ID_NONE;

54 }

56 /* We could be given one of the three possible structures here:

57 * WAVEFORMAT, PCMWAVEFORMAT or WAVEFORMATEX. Each structure

58 * is an expansion of the previous one with the fields added

59 * at the bottom. PCMWAVEFORMAT adds 'WORD wBitsPerSample' and

60 * WAVEFORMATEX adds 'WORD cbSize' and basically makes itself

61 * an openended structure.

62 */

64 static void parse_waveformatex(AVIOContext *pb, AVCodecContext *c)

65 {

66 ff_asf_guid subformat;

67 int bps = avio_rl16(pb);

68 if (bps)

69 c->bits_per_coded_sample = bps;

71 c->channel_layout = avio_rl32(pb); /* dwChannelMask */

73 ff_get_guid(pb, &subformat);

74 if (!memcmp(subformat + 4,

75 (const uint8_t[]){ FF_MEDIASUBTYPE_BASE_GUID }, 12)) {

76 c->codec_tag = AV_RL32(subformat);

77 c->codec_id = ff_wav_codec_get_id(c->codec_tag,

78 c->bits_per_coded_sample);

79 } else {

80 c->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subformat);

81 if (!c->codec_id)

82 av_log(c, AV_LOG_WARNING,

83 "unknown subformat:"FF_PRI_GUID "\n",

84 FF_ARG_GUID(subformat));

85 }

86 }

88 int ff_get_wav_header(AVIOContext *pb, AVCodecContext *codec, int size)

89 {

90 int id;

92 id = avio_rl16(pb);

93 codec->codec_type = AVMEDIA_TYPE_AUDIO;

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 if (size == 14) { /* We're dealing with plain vanilla WAVEFORMAT */

99 codec->bits_per_coded_sample = 8;

100 } else

101 codec->bits_per_coded_sample = avio_rl16(pb);

102 if (id == 0xFFFE) {

103 codec->codec_tag = 0;

104 } else {

105 codec->codec_tag = id;

106 codec->codec_id = ff_wav_codec_get_id(id,

107 codec->bits_per_coded_sample);

108 }

109 if (size >= 18) { /* We're obviously dealing with WAVEFORMATEX */

110 int cbSize = avio_rl16(pb); /* cbSize */

111 size -= 18;

112 cbSize = FFMIN(size, cbSize);

113 if (cbSize >= 22 && id == 0xfffe) { /* WAVEFORMATEXTENSIBLE */

114 parse_waveformatex(pb, codec);

115 cbSize -= 22;

116 size -= 22;

117 }

118 if (cbSize > 0) {

119 av_free(codec->extradata);

120 if (ff_alloc_extradata(codec, cbSize))

121 return AVERROR(ENOMEM);

122 avio_read(pb, codec->extradata, codec->extradata_size);

123 size -= cbSize;

124 }

125

126 /* It is possible for the chunk to contain garbage at the end */

127 if (size > 0)

128 avio_skip(pb, size);

129 }

130 if (codec->sample_rate <= 0) {

131 av_log(NULL, AV_LOG_ERROR,

132 "Invalid sample rate: %d\n", codec->sample_rate);

133 return AVERROR_INVALIDDATA;

134 }

135 if (codec->codec_id == AV_CODEC_ID_AAC_LATM) {

136 /* Channels and sample_rate values are those prior to applying SBR

137 * and/or PS. */

138 codec->channels = 0;

139 codec->sample_rate = 0;

140 }

141 /* override bits_per_coded_sample for G.726 */

142 if (codec->codec_id == AV_CODEC_ID_ADPCM_G726 && codec->sample_rate)

143 codec->bits_per_coded_sample = codec->bit_rate / codec->sample_rate;

144

145 return 0;

146 }

147

148 enum AVCodecID ff_wav_codec_get_id(unsigned int tag, int bps)

149 {

150 enum AVCodecID id;

151 id = ff_codec_get_id(ff_codec_wav_tags, tag);

152 if (id <= 0)

153 return id;

154

155 if (id == AV_CODEC_ID_PCM_S16LE)

156 id = ff_get_pcm_codec_id(bps, 0, 0, ~1);

157 else if (id == AV_CODEC_ID_PCM_F32LE)

158 id = ff_get_pcm_codec_id(bps, 1, 0, 0);

159

160 if (id == AV_CODEC_ID_ADPCM_IMA_WAV && bps == 8)

161 id = AV_CODEC_ID_PCM_ZORK;

162 return id;

163 }

164

165 int ff_get_bmp_header(AVIOContext *pb, AVStream *st, unsigned *esize)

166 {

167 int tag1;

168 if(esize) *esize = avio_rl32(pb);

169 else avio_rl32(pb);

170 st->codec->width = avio_rl32(pb);

171 st->codec->height = (int32_t)avio_rl32(pb);

172 avio_rl16(pb); /* planes */

173 st->codec->bits_per_coded_sample = avio_rl16(pb); /* depth */

174 tag1 = avio_rl32(pb);

175 avio_rl32(pb); /* ImageSize */

176 avio_rl32(pb); /* XPelsPerMeter */

177 avio_rl32(pb); /* YPelsPerMeter */

178 avio_rl32(pb); /* ClrUsed */

179 avio_rl32(pb); /* ClrImportant */

180 return tag1;

181 }

182

183 int ff_read_riff_info(AVFormatContext *s, int64_t size)

184 {

185 int64_t start, end, cur;

186 AVIOContext *pb = s->pb;

187

188 start = avio_tell(pb);

189 end = start + size;

190

191 while ((cur = avio_tell(pb)) >= 0 &&

192 cur <= end - 8 /* = tag + size */) {

193 uint32_t chunk_code;

194 int64_t chunk_size;

195 char key[5] = { 0 };

196 char *value;

197

198 chunk_code = avio_rl32(pb);

199 chunk_size = avio_rl32(pb);

200 if (url_feof(pb)) {

201 if (chunk_code || chunk_size) {

202 av_log(s, AV_LOG_WARNING, "INFO subchunk truncated\n");

203 return AVERROR_INVALIDDATA;

204 }

205 return AVERROR_EOF;

206 }

207 if (chunk_size > end ||

208 end - chunk_size < cur ||

209 chunk_size == UINT_MAX) {

210 avio_seek(pb, -9, SEEK_CUR);

211 chunk_code = avio_rl32(pb);

212 chunk_size = avio_rl32(pb);

213 if (chunk_size > end || end - chunk_size < cur || chunk_size == UINT_MAX) {

214 av_log(s, AV_LOG_WARNING, "too big INFO subchunk\n");

215 return AVERROR_INVALIDDATA;

216 }

217 }

218

219 chunk_size += (chunk_size & 1);

220

221 if (!chunk_code) {

222 if (chunk_size)

223 avio_skip(pb, chunk_size);

224 else if (pb->eof_reached) {

225 av_log(s, AV_LOG_WARNING, "truncated file\n");

226 return AVERROR_EOF;

227 }

228 continue;

229 }

230

231 value = av_mallocz(chunk_size + 1);

232 if (!value) {

233 av_log(s, AV_LOG_ERROR,

234 "out of memory, unable to read INFO tag\n");

235 return AVERROR(ENOMEM);

236 }

237

238 AV_WL32(key, chunk_code);

239

240 if (avio_read(pb, value, chunk_size) != chunk_size) {

241 av_log(s, AV_LOG_WARNING,

242 "premature end of file while reading INFO tag\n");

243 }

244

245 av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);

246 }

247

248 return 0;

249 }

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