FFmpeg: libavformat/aiffdec.c Source File

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libavformat

aiffdec.c

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1 /*

2 * AIFF/AIFF-C demuxer

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/intreadwrite.h"

23 #include "libavutil/mathematics.h"

24 #include "libavutil/dict.h"

25 #include "avformat.h"

26 #include "internal.h"

27 #include "pcm.h"

28 #include "aiff.h"

29 #include "isom.h"

30 #include "id3v2.h"

31 #include "mov_chan.h"

33 #define AIFF 0

34 #define AIFF_C_VERSION1 0xA2805140

36 typedef struct {

37 int64_t data_end;

38 int block_duration;

39 } AIFFInputContext;

41 static enum AVCodecID aiff_codec_get_id(int bps)

42 {

43 if (bps <= 8)

44 return AV_CODEC_ID_PCM_S8;

45 if (bps <= 16)

46 return AV_CODEC_ID_PCM_S16BE;

47 if (bps <= 24)

48 return AV_CODEC_ID_PCM_S24BE;

49 if (bps <= 32)

50 return AV_CODEC_ID_PCM_S32BE;

52 /* bigger than 32 isn't allowed */

53 return AV_CODEC_ID_NONE;

54 }

56 /* returns the size of the found tag */

57 static int get_tag(AVIOContext *pb, uint32_t * tag)

58 {

59 int size;

61 if (url_feof(pb))

62 return AVERROR(EIO);

64 *tag = avio_rl32(pb);

65 size = avio_rb32(pb);

67 if (size < 0)

68 size = 0x7fffffff;

70 return size;

71 }

73 /* Metadata string read */

74 static void get_meta(AVFormatContext *s, const char *key, int size)

75 {

76 uint8_t *str = av_malloc(size+1);

78 if (str) {

79 int res = avio_read(s->pb, str, size);

80 if (res < 0){

81 av_free(str);

82 return;

83 }

84 size += (size&1)-res;

85 str[res] = 0;

86 av_dict_set(&s->metadata, key, str, AV_DICT_DONT_STRDUP_VAL);

87 }else

88 size+= size&1;

90 avio_skip(s->pb, size);

91 }

93 /* Returns the number of sound data frames or negative on error */

94 static unsigned int get_aiff_header(AVFormatContext *s, int size,

95 unsigned version)

96 {

97 AVIOContext *pb = s->pb;

98 AVCodecContext *codec = s->streams[0]->codec;

99 AIFFInputContext *aiff = s->priv_data;

100 int exp;

101 uint64_t val;

102 double sample_rate;

103 unsigned int num_frames;

104

105 if (size & 1)

106 size++;

107 codec->codec_type = AVMEDIA_TYPE_AUDIO;

108 codec->channels = avio_rb16(pb);

109 num_frames = avio_rb32(pb);

110 codec->bits_per_coded_sample = avio_rb16(pb);

111

112 exp = avio_rb16(pb);

113 val = avio_rb64(pb);

114 sample_rate = ldexp(val, exp - 16383 - 63);

115 codec->sample_rate = sample_rate;

116 size -= 18;

117

118 /* get codec id for AIFF-C */

119 if (version == AIFF_C_VERSION1) {

120 codec->codec_tag = avio_rl32(pb);

121 codec->codec_id = ff_codec_get_id(ff_codec_aiff_tags, codec->codec_tag);

122 size -= 4;

123 }

124

125 if (version != AIFF_C_VERSION1 || codec->codec_id == AV_CODEC_ID_PCM_S16BE) {

126 codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);

127 codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);

128 aiff->block_duration = 1;

129 } else {

130 switch (codec->codec_id) {

131 case AV_CODEC_ID_PCM_F32BE:

132 case AV_CODEC_ID_PCM_F64BE:

133 case AV_CODEC_ID_PCM_S16LE:

134 case AV_CODEC_ID_PCM_ALAW:

135 case AV_CODEC_ID_PCM_MULAW:

136 aiff->block_duration = 1;

137 break;

138 case AV_CODEC_ID_ADPCM_IMA_QT:

139 codec->block_align = 34*codec->channels;

140 break;

141 case AV_CODEC_ID_MACE3:

142 codec->block_align = 2*codec->channels;

143 break;

144 case AV_CODEC_ID_ADPCM_G722:

145 case AV_CODEC_ID_MACE6:

146 codec->block_align = 1*codec->channels;

147 break;

148 case AV_CODEC_ID_GSM:

149 codec->block_align = 33;

150 break;

151 default:

152 aiff->block_duration = 1;

153 break;

154 }

155 if (codec->block_align > 0)

156 aiff->block_duration = av_get_audio_frame_duration(codec,

157 codec->block_align);

158 }

159

160 /* Block align needs to be computed in all cases, as the definition

161 * is specific to applications -> here we use the WAVE format definition */

162 if (!codec->block_align)

163 codec->block_align = (av_get_bits_per_sample(codec->codec_id) * codec->channels) >> 3;

164

165 if (aiff->block_duration) {

166 codec->bit_rate = codec->sample_rate * (codec->block_align << 3) /

167 aiff->block_duration;

168 }

169

170 /* Chunk is over */

171 if (size)

172 avio_skip(pb, size);

173

174 return num_frames;

175 }

176

177 static int aiff_probe(AVProbeData *p)

178 {

179 /* check file header */

180 if (p->buf[0] == 'F' && p->buf[1] == 'O' &&

181 p->buf[2] == 'R' && p->buf[3] == 'M' &&

182 p->buf[8] == 'A' && p->buf[9] == 'I' &&

183 p->buf[10] == 'F' && (p->buf[11] == 'F' || p->buf[11] == 'C'))

184 return AVPROBE_SCORE_MAX;

185 else

186 return 0;

187 }

188

189 /* aiff input */

190 static int aiff_read_header(AVFormatContext *s)

191 {

192 int ret, size, filesize;

193 int64_t offset = 0, position;

194 uint32_t tag;

195 unsigned version = AIFF_C_VERSION1;

196 AVIOContext *pb = s->pb;

197 AVStream * st;

198 AIFFInputContext *aiff = s->priv_data;

199 ID3v2ExtraMeta *id3v2_extra_meta = NULL;

200

201 /* check FORM header */

202 filesize = get_tag(pb, &tag);

203 if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))

204 return AVERROR_INVALIDDATA;

205

206 /* AIFF data type */

207 tag = avio_rl32(pb);

208 if (tag == MKTAG('A', 'I', 'F', 'F')) /* Got an AIFF file */

209 version = AIFF;

210 else if (tag != MKTAG('A', 'I', 'F', 'C')) /* An AIFF-C file then */

211 return AVERROR_INVALIDDATA;

212

213 filesize -= 4;

214

215 st = avformat_new_stream(s, NULL);

216 if (!st)

217 return AVERROR(ENOMEM);

218

219 while (filesize > 0) {

220 /* parse different chunks */

221 size = get_tag(pb, &tag);

222 if (size < 0)

223 return size;

224

225 filesize -= size + 8;

226

227 switch (tag) {

228 case MKTAG('C', 'O', 'M', 'M'): /* Common chunk */

229 /* Then for the complete header info */

230 st->nb_frames = get_aiff_header(s, size, version);

231 if (st->nb_frames < 0)

232 return st->nb_frames;

233 if (offset > 0) // COMM is after SSND

234 goto got_sound;

235 break;

236 case MKTAG('I', 'D', '3', ' '):

237 position = avio_tell(pb);

238 ff_id3v2_read(s, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);

239 if (id3v2_extra_meta)

240 if ((ret = ff_id3v2_parse_apic(s, &id3v2_extra_meta)) < 0) {

241 ff_id3v2_free_extra_meta(&id3v2_extra_meta);

242 return ret;

243 }

244 ff_id3v2_free_extra_meta(&id3v2_extra_meta);

245 if (position + size > avio_tell(pb))

246 avio_skip(pb, position + size - avio_tell(pb));

247 break;

248 case MKTAG('F', 'V', 'E', 'R'): /* Version chunk */

249 version = avio_rb32(pb);

250 break;

251 case MKTAG('N', 'A', 'M', 'E'): /* Sample name chunk */

252 get_meta(s, "title" , size);

253 break;

254 case MKTAG('A', 'U', 'T', 'H'): /* Author chunk */

255 get_meta(s, "author" , size);

256 break;

257 case MKTAG('(', 'c', ')', ' '): /* Copyright chunk */

258 get_meta(s, "copyright", size);

259 break;

260 case MKTAG('A', 'N', 'N', 'O'): /* Annotation chunk */

261 get_meta(s, "comment" , size);

262 break;

263 case MKTAG('S', 'S', 'N', 'D'): /* Sampled sound chunk */

264 aiff->data_end = avio_tell(pb) + size;

265 offset = avio_rb32(pb); /* Offset of sound data */

266 avio_rb32(pb); /* BlockSize... don't care */

267 offset += avio_tell(pb); /* Compute absolute data offset */

268 if (st->codec->block_align && !pb->seekable) /* Assume COMM already parsed */

269 goto got_sound;

270 if (!pb->seekable) {

271 av_log(s, AV_LOG_ERROR, "file is not seekable\n");

272 return -1;

273 }

274 avio_skip(pb, size - 8);

275 break;

276 case MKTAG('w', 'a', 'v', 'e'):

277 if ((uint64_t)size > (1<<30))

278 return -1;

279 st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);

280 if (!st->codec->extradata)

281 return AVERROR(ENOMEM);

282 st->codec->extradata_size = size;

283 avio_read(pb, st->codec->extradata, size);

284 if (st->codec->codec_id == AV_CODEC_ID_QDM2 && size>=12*4 && !st->codec->block_align) {

285 st->codec->block_align = AV_RB32(st->codec->extradata+11*4);

286 aiff->block_duration = AV_RB32(st->codec->extradata+9*4);

287 } else if (st->codec->codec_id == AV_CODEC_ID_QCELP) {

288 char rate = 0;

289 if (size >= 25)

290 rate = st->codec->extradata[24];

291 switch (rate) {

292 case 'H': // RATE_HALF

293 st->codec->block_align = 17;

294 break;

295 case 'F': // RATE_FULL

296 default:

297 st->codec->block_align = 35;

298 }

299 aiff->block_duration = 160;

300 st->codec->bit_rate = st->codec->sample_rate * (st->codec->block_align << 3) /

301 aiff->block_duration;

302 }

303 break;

304 case MKTAG('C','H','A','N'):

305 if(ff_mov_read_chan(s, pb, st, size) < 0)

306 return AVERROR_INVALIDDATA;

307 break;

308 default: /* Jump */

309 if (size & 1) /* Always even aligned */

310 size++;

311 avio_skip(pb, size);

312 }

313 }

314

315 got_sound:

316 if (!st->codec->block_align) {

317 av_log(s, AV_LOG_ERROR, "could not find COMM tag or invalid block_align value\n");

318 return -1;

319 }

320

321 /* Now positioned, get the sound data start and end */

322 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

323 st->start_time = 0;

324 st->duration = st->nb_frames * aiff->block_duration;

325

326 /* Position the stream at the first block */

327 avio_seek(pb, offset, SEEK_SET);

328

329 return 0;

330 }

331

332 #define MAX_SIZE 4096

333

334 static int aiff_read_packet(AVFormatContext *s,

335 AVPacket *pkt)

336 {

337 AVStream *st = s->streams[0];

338 AIFFInputContext *aiff = s->priv_data;

339 int64_t max_size;

340 int res, size;

341

342 /* calculate size of remaining data */

343 max_size = aiff->data_end - avio_tell(s->pb);

344 if (max_size <= 0)

345 return AVERROR_EOF;

346

347 /* Now for that packet */

348 if (st->codec->block_align >= 17) // GSM, QCLP, IMA4

349 size = st->codec->block_align;

350 else

351 size = (MAX_SIZE / st->codec->block_align) * st->codec->block_align;

352 size = FFMIN(max_size, size);

353 res = av_get_packet(s->pb, pkt, size);

354 if (res < 0)

355 return res;

356

357 if (size >= st->codec->block_align)

358 pkt->flags &= ~AV_PKT_FLAG_CORRUPT;

359 /* Only one stream in an AIFF file */

360 pkt->stream_index = 0;

361 pkt->duration = (res / st->codec->block_align) * aiff->block_duration;

362 return 0;

363 }

364

365 AVInputFormat ff_aiff_demuxer = {

366 .name = "aiff",

367 .long_name = NULL_IF_CONFIG_SMALL("Audio IFF"),

368 .priv_data_size = sizeof(AIFFInputContext),

369 .read_probe = aiff_probe,

370 .read_header = aiff_read_header,

371 .read_packet = aiff_read_packet,

372 .read_seek = ff_pcm_read_seek,

373 .codec_tag = (const AVCodecTag* const []){ ff_codec_aiff_tags, 0 },

374 };

Generated on Wed Jul 10 2013 23:48:11 for FFmpeg by doxygen 1.8.2