libavformat/omadec.c

   1 /*
   2  * Sony OpenMG (OMA) demuxer
   3  *
   4  * Copyright (c) 2008, 2013 Maxim Poliakovski
   5  *               2008 Benjamin Larsson
   6  *               2011 David Goldwich
   7  *
   8  * This file is part of FFmpeg.
   9  *
  10  * FFmpeg is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * FFmpeg is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with FFmpeg; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 /**
  26  * @file
  27  * This is a demuxer for Sony OpenMG Music files
  28  *
  29  * Known file extensions: ".oma", "aa3"
  30  * The format of such files consists of three parts:
  31  * - "ea3" header carrying overall info and metadata. Except for starting with
  32  *   "ea" instead of "ID", it's an ID3v2 header.
  33  * - "EA3" header is a Sony-specific header containing information about
  34  *   the OpenMG file: codec type (usually ATRAC, can also be MP3 or WMA),
  35  *   codec specific info (packet size, sample rate, channels and so on)
  36  *   and DRM related info (file encryption, content id).
  37  * - Sound data organized in packets follow the EA3 header
  38  *   (can be encrypted using the Sony DRM!).
  39  *
  40  * Supported decoders: ATRAC3, ATRAC3+, MP3, LPCM
  41  */
  42
  43 #include <inttypes.h>
  44
  45 #include "libavutil/channel_layout.h"
  46 #include "libavutil/mem.h"
  47 #include "avformat.h"
  48 #include "demux.h"
  49 #include "internal.h"
  50 #include "libavutil/intreadwrite.h"
  51 #include "libavutil/des.h"
  52 #include "libavutil/mathematics.h"
  53 #include "oma.h"
  54 #include "pcm.h"
  55 #include "id3v2.h"
  56
  57
  58 static const uint64_t leaf_table[] = {
  59     0xd79e8283acea4620, 0x7a9762f445afd0d8,
  60     0x354d60a60b8c79f1, 0x584e1cde00b07aee,
  61     0x1573cd93da7df623, 0x47f98d79620dd535
  62 };
  63
  64 /** map ATRAC-X channel id to internal channel layout */
  65 static const AVChannelLayout  oma_chid_to_native_layout[7] = {
  66     AV_CHANNEL_LAYOUT_MONO,
  67     AV_CHANNEL_LAYOUT_STEREO,
  68     AV_CHANNEL_LAYOUT_SURROUND,
  69     AV_CHANNEL_LAYOUT_4POINT0,
  70     AV_CHANNEL_LAYOUT_5POINT1_BACK,
  71     AV_CHANNEL_LAYOUT_6POINT1_BACK,
  72     AV_CHANNEL_LAYOUT_7POINT1
  73 };
  74
  75 typedef struct OMAContext {
  76     uint64_t content_start;
  77     int encrypted;
  78     uint16_t k_size;
  79     uint16_t e_size;
  80     uint16_t i_size;
  81     uint16_t s_size;
  82     uint32_t rid;
  83     uint8_t r_val[24];
  84     uint8_t n_val[24];
  85     uint8_t m_val[8];
  86     uint8_t s_val[8];
  87     uint8_t sm_val[8];
  88     uint8_t e_val[8];
  89     uint8_t iv[8];
  90     struct AVDES *av_des;
  91
  92     int (*read_packet)(AVFormatContext *s, AVPacket *pkt);
  93 } OMAContext;
  94
  95 static int oma_read_close(AVFormatContext *s)
  96 {
  97     OMAContext *oc = s->priv_data;
  98     av_freep(&oc->av_des);
  99     return 0;
 100 }
 101
 102 static void hex_log(AVFormatContext *s, int level,
 103                     const char *name, const uint8_t *value, int len)
 104 {
 105     char buf[33];
 106     len = FFMIN(len, 16);
 107     if (av_log_get_level() < level)
 108         return;
 109     ff_data_to_hex(buf, value, len, 1);
 110     av_log(s, level, "%s: %s\n", name, buf);
 111 }
 112
 113 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val,
 114                 int len)
 115 {
 116     OMAContext *oc = s->priv_data;
 117
 118     if (!r_val && !n_val)
 119         return -1;
 120
 121     len = FFMIN(len, 16);
 122
 123     /* use first 64 bits in the third round again */
 124     if (r_val) {
 125         if (r_val != oc->r_val) {
 126             memset(oc->r_val, 0, 24);
 127             memcpy(oc->r_val, r_val, len);
 128         }
 129         memcpy(&oc->r_val[16], r_val, 8);
 130     }
 131     if (n_val) {
 132         if (n_val != oc->n_val) {
 133             memset(oc->n_val, 0, 24);
 134             memcpy(oc->n_val, n_val, len);
 135         }
 136         memcpy(&oc->n_val[16], n_val, 8);
 137     }
 138
 139     return 0;
 140 }
 141
 142 #define OMA_RPROBE_M_VAL 48 + 1
 143
 144 static int rprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
 145                   const uint8_t *r_val)
 146 {
 147     OMAContext *oc = s->priv_data;
 148     unsigned int pos;
 149     struct AVDES *av_des;
 150
 151     if (!enc_header || !r_val ||
 152         size < OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size ||
 153         size < OMA_RPROBE_M_VAL)
 154         return -1;
 155
 156     av_des = av_des_alloc();
 157     if (!av_des)
 158         return AVERROR(ENOMEM);
 159
 160     /* m_val */
 161     av_des_init(av_des, r_val, 192, 1);
 162     av_des_crypt(av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
 163
 164     /* s_val */
 165     av_des_init(av_des, oc->m_val, 64, 0);
 166     av_des_crypt(av_des, oc->s_val, NULL, 1, NULL, 0);
 167
 168     /* sm_val */
 169     pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
 170     av_des_init(av_des, oc->s_val, 64, 0);
 171     av_des_mac(av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
 172
 173     pos += oc->i_size;
 174
 175     av_free(av_des);
 176
 177     return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
 178 }
 179
 180 static int nprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
 181                   const uint8_t *n_val)
 182 {
 183     OMAContext *oc = s->priv_data;
 184     uint64_t pos;
 185     uint32_t taglen, datalen;
 186     struct AVDES *av_des;
 187
 188     if (!enc_header || !n_val ||
 189         size < OMA_ENC_HEADER_SIZE + oc->k_size + 4)
 190         return -1;
 191
 192     pos = OMA_ENC_HEADER_SIZE + oc->k_size;
 193     if (!memcmp(&enc_header[pos], "EKB ", 4))
 194         pos += 32;
 195
 196     if (size < pos + 44)
 197         return -1;
 198
 199     if (AV_RB32(&enc_header[pos]) != oc->rid)
 200         av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
 201
 202     taglen  = AV_RB32(&enc_header[pos + 32]);
 203     datalen = AV_RB32(&enc_header[pos + 36]) >> 4;
 204
 205     pos += 44LL + taglen;
 206
 207     if (pos + (((uint64_t)datalen) << 4) > size)
 208         return -1;
 209
 210     av_des = av_des_alloc();
 211     if (!av_des)
 212         return AVERROR(ENOMEM);
 213
 214     av_des_init(av_des, n_val, 192, 1);
 215     while (datalen-- > 0) {
 216         av_des_crypt(av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
 217         kset(s, oc->r_val, NULL, 16);
 218         if (!rprobe(s, enc_header, size, oc->r_val)) {
 219             av_free(av_des);
 220             return 0;
 221         }
 222         pos += 16;
 223     }
 224
 225     av_free(av_des);
 226     return -1;
 227 }
 228
 229 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
 230 {
 231     OMAContext *oc = s->priv_data;
 232     ID3v2ExtraMetaGEOB *geob = NULL;
 233     uint8_t *gdata;
 234
 235     oc->encrypted = 1;
 236     av_log(s, AV_LOG_INFO, "File is encrypted\n");
 237
 238     /* find GEOB metadata */
 239     for (; em; em = em->next) {
 240         if (strcmp(em->tag, "GEOB"))
 241             continue;
 242         geob = &em->data.geob;
 243         if (!strcmp(geob->description, "OMG_LSI") ||
 244             !strcmp(geob->description, "OMG_BKLSI"))
 245             break;
 246     }
 247     if (!em) {
 248         av_log(s, AV_LOG_ERROR, "No encryption header found\n");
 249         return AVERROR_INVALIDDATA;
 250     }
 251
 252     if (geob->datasize < 64) {
 253         av_log(s, AV_LOG_ERROR,
 254                "Invalid GEOB data size: %"PRIu32"\n", geob->datasize);
 255         return AVERROR_INVALIDDATA;
 256     }
 257
 258     gdata = geob->data;
 259
 260     if (AV_RB16(gdata) != 1)
 261         av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
 262
 263     oc->k_size = AV_RB16(&gdata[2]);
 264     oc->e_size = AV_RB16(&gdata[4]);
 265     oc->i_size = AV_RB16(&gdata[6]);
 266     oc->s_size = AV_RB16(&gdata[8]);
 267
 268     if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING     ", 12)) {
 269         av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
 270         return AVERROR_INVALIDDATA;
 271     }
 272     if (OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize ||
 273         OMA_ENC_HEADER_SIZE + 48 > geob->datasize) {
 274         av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");
 275         return AVERROR_INVALIDDATA;
 276     }
 277     oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
 278     av_log(s, AV_LOG_DEBUG, "RID: %.8"PRIx32"\n", oc->rid);
 279
 280     memcpy(oc->iv, &header[0x58], 8);
 281     hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
 282
 283     hex_log(s, AV_LOG_DEBUG, "CBC-MAC",
 284             &gdata[OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size],
 285             8);
 286
 287     if (s->keylen > 0) {
 288         kset(s, s->key, s->key, s->keylen);
 289     }
 290     if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
 291         rprobe(s, gdata, geob->datasize, oc->r_val) < 0 &&
 292         nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
 293         int i;
 294         for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
 295             uint8_t buf[16];
 296             AV_WL64(buf,     leaf_table[i]);
 297             AV_WL64(&buf[8], leaf_table[i + 1]);
 298             kset(s, buf, buf, 16);
 299             if (!rprobe(s, gdata, geob->datasize, oc->r_val) ||
 300                 !nprobe(s, gdata, geob->datasize, oc->n_val))
 301                 break;
 302         }
 303         if (i >= FF_ARRAY_ELEMS(leaf_table)) {
 304             av_log(s, AV_LOG_ERROR, "Invalid key\n");
 305             return AVERROR_INVALIDDATA;
 306         }
 307     }
 308
 309     oc->av_des = av_des_alloc();
 310     if (!oc->av_des)
 311         return AVERROR(ENOMEM);
 312
 313     /* e_val */
 314     av_des_init(oc->av_des, oc->m_val, 64, 0);
 315     av_des_crypt(oc->av_des, oc->e_val,
 316                  &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
 317     hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
 318
 319     /* init e_val */
 320     av_des_init(oc->av_des, oc->e_val, 64, 1);
 321
 322     return 0;
 323 }
 324
 325 static int read_packet(AVFormatContext *s, AVPacket *pkt)
 326 {
 327     OMAContext *oc  = s->priv_data;
 328     AVStream *st    = s->streams[0];
 329     int packet_size = st->codecpar->block_align;
 330     int byte_rate   = st->codecpar->bit_rate >> 3;
 331     int64_t pos     = avio_tell(s->pb);
 332     int ret         = av_get_packet(s->pb, pkt, packet_size);
 333
 334     if (ret < packet_size)
 335         pkt->flags |= AV_PKT_FLAG_CORRUPT;
 336
 337     if (ret < 0)
 338         return ret;
 339     if (!ret)
 340         return AVERROR_EOF;
 341
 342     pkt->stream_index = 0;
 343
 344     if (pos >= oc->content_start && byte_rate > 0) {
 345         pkt->pts =
 346         pkt->dts = av_rescale(pos - oc->content_start, st->time_base.den,
 347                               byte_rate * (int64_t)st->time_base.num);
 348     }
 349
 350     if (oc->encrypted) {
 351         /* previous unencrypted block saved in IV for
 352          * the next packet (CBC mode) */
 353         if (ret == packet_size)
 354             av_des_crypt(oc->av_des, pkt->data, pkt->data,
 355                          (packet_size >> 3), oc->iv, 1);
 356         else
 357             memset(oc->iv, 0, 8);
 358     }
 359
 360     return ret;
 361 }
 362
 363 static int aal_read_packet(AVFormatContext *s, AVPacket *pkt)
 364 {
 365     int64_t pos = avio_tell(s->pb);
 366     int ret, pts;
 367     int packet_size;
 368     unsigned tag;
 369
 370     if (avio_feof(s->pb))
 371         return AVERROR_EOF;
 372
 373     tag = avio_rb24(s->pb);
 374     if (tag == 0)
 375         return AVERROR_EOF;
 376     else if (tag != MKBETAG(0,'B','L','K'))
 377         return AVERROR_INVALIDDATA;
 378
 379     avio_skip(s->pb, 1);
 380     packet_size = avio_rb16(s->pb);
 381     avio_skip(s->pb, 2);
 382     pts = avio_rb32(s->pb);
 383     avio_skip(s->pb, 12);
 384     ret = av_get_packet(s->pb, pkt, packet_size);
 385     if (ret < packet_size)
 386         pkt->flags |= AV_PKT_FLAG_CORRUPT;
 387
 388     if (ret < 0)
 389         return ret;
 390     if (!ret)
 391         return AVERROR_EOF;
 392
 393     pkt->stream_index = 0;
 394     pkt->pos = pos;
 395     if (s->streams[0]->codecpar->codec_id == AV_CODEC_ID_ATRAC3AL) {
 396         pkt->duration = 1024;
 397         pkt->pts = pts * 1024LL;
 398     } else {
 399         pkt->duration = 2048;
 400         pkt->pts = pts * 2048LL;
 401     }
 402
 403     return ret;
 404 }
 405
 406 static int oma_read_header(AVFormatContext *s)
 407 {
 408     int     ret, framesize, jsflag, samplerate;
 409     uint32_t codec_params, channel_id;
 410     int16_t eid;
 411     uint8_t buf[EA3_HEADER_SIZE];
 412     uint8_t *edata;
 413     AVStream *st;
 414     ID3v2ExtraMeta *extra_meta;
 415     OMAContext *oc = s->priv_data;
 416
 417     ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta, 0);
 418     if ((ret = ff_id3v2_parse_chapters(s, extra_meta)) < 0) {
 419         ff_id3v2_free_extra_meta(&extra_meta);
 420         return ret;
 421     }
 422
 423     ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
 424     if (ret < EA3_HEADER_SIZE) {
 425         ff_id3v2_free_extra_meta(&extra_meta);
 426         return -1;
 427     }
 428
 429     if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}), 3) ||
 430         buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
 431         ff_id3v2_free_extra_meta(&extra_meta);
 432         av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
 433         return AVERROR_INVALIDDATA;
 434     }
 435
 436     oc->content_start = avio_tell(s->pb);
 437
 438     /* encrypted file */
 439     eid = AV_RB16(&buf[6]);
 440     if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
 441         ff_id3v2_free_extra_meta(&extra_meta);
 442         return -1;
 443     }
 444
 445     ff_id3v2_free_extra_meta(&extra_meta);
 446
 447     codec_params = AV_RB24(&buf[33]);
 448
 449     st = avformat_new_stream(s, NULL);
 450     if (!st)
 451         return AVERROR(ENOMEM);
 452
 453     st->start_time = 0;
 454     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
 455     st->codecpar->codec_tag  = buf[32];
 456     st->codecpar->codec_id   = ff_codec_get_id(ff_oma_codec_tags,
 457                                                st->codecpar->codec_tag);
 458
 459     oc->read_packet = read_packet;
 460
 461     switch (buf[32]) {
 462     case OMA_CODECID_ATRAC3:
 463         samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
 464         if (!samplerate) {
 465             av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
 466             return AVERROR_INVALIDDATA;
 467         }
 468         if (samplerate != 44100)
 469             avpriv_request_sample(s, "Sample rate %d", samplerate);
 470
 471         framesize = (codec_params & 0x3FF) * 8;
 472
 473         /* get stereo coding mode, 1 for joint-stereo */
 474         jsflag = (codec_params >> 17) & 1;
 475
 476         st->codecpar->ch_layout   = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
 477         st->codecpar->sample_rate = samplerate;
 478         st->codecpar->bit_rate    = st->codecpar->sample_rate * framesize / (1024 / 8);
 479
 480         /* fake the ATRAC3 extradata
 481          * (wav format, makes stream copy to wav work) */
 482         if ((ret = ff_alloc_extradata(st->codecpar, 14)) < 0)
 483             return ret;
 484
 485         edata = st->codecpar->extradata;
 486         AV_WL16(&edata[0],  1);             // always 1
 487         AV_WL32(&edata[2],  samplerate);    // samples rate
 488         AV_WL16(&edata[6],  jsflag);        // coding mode
 489         AV_WL16(&edata[8],  jsflag);        // coding mode
 490         AV_WL16(&edata[10], 1);             // always 1
 491         AV_WL16(&edata[12], 0);             // always 0
 492
 493         avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
 494         break;
 495     case OMA_CODECID_ATRAC3P:
 496         channel_id = (codec_params >> 10) & 7;
 497         if (!channel_id) {
 498             av_log(s, AV_LOG_ERROR,
 499                    "Invalid ATRAC-X channel id: %"PRIu32"\n", channel_id);
 500             return AVERROR_INVALIDDATA;
 501         }
 502         av_channel_layout_copy(&st->codecpar->ch_layout,
 503                                &oma_chid_to_native_layout[channel_id - 1]);
 504         framesize = ((codec_params & 0x3FF) * 8) + 8;
 505         samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
 506         if (!samplerate) {
 507             av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
 508             return AVERROR_INVALIDDATA;
 509         }
 510         st->codecpar->sample_rate = samplerate;
 511         st->codecpar->bit_rate    = samplerate * framesize / (2048 / 8);
 512         avpriv_set_pts_info(st, 64, 1, samplerate);
 513         break;
 514     case OMA_CODECID_AAC:
 515     case OMA_CODECID_MP3:
 516         ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL_RAW;
 517         framesize = 1024;
 518         break;
 519     case OMA_CODECID_LPCM:
 520         /* PCM 44.1 kHz 16 bit stereo big-endian */
 521         st->codecpar->ch_layout   = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
 522         st->codecpar->sample_rate = 44100;
 523         framesize = 1024;
 524         /* bit rate = sample rate x PCM block align (= 4) x 8 */
 525         st->codecpar->bit_rate = st->codecpar->sample_rate * 32;
 526         st->codecpar->bits_per_coded_sample =
 527             av_get_bits_per_sample(st->codecpar->codec_id);
 528         avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
 529         break;
 530     case OMA_CODECID_ATRAC3AL:
 531         st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
 532         st->codecpar->sample_rate = 44100;
 533         avpriv_set_pts_info(st, 64, 1, 44100);
 534         oc->read_packet = aal_read_packet;
 535         framesize = 4096;
 536         break;
 537     case OMA_CODECID_ATRAC3PAL:
 538         st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
 539         st->codecpar->sample_rate = 44100;
 540         avpriv_set_pts_info(st, 64, 1, 44100);
 541         oc->read_packet = aal_read_packet;
 542         framesize = 4096;
 543         break;
 544     default:
 545         av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n", buf[32]);
 546         return AVERROR(ENOSYS);
 547     }
 548
 549     st->codecpar->block_align = framesize;
 550
 551     return 0;
 552 }
 553
 554 static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)
 555 {
 556     OMAContext *oc  = s->priv_data;
 557     return oc->read_packet(s, pkt);
 558 }
 559
 560 static int oma_read_probe(const AVProbeData *p)
 561 {
 562     const uint8_t *buf = p->buf;
 563     unsigned tag_len = 0;
 564
 565     if (p->buf_size >= ID3v2_HEADER_SIZE && ff_id3v2_match(buf, ID3v2_EA3_MAGIC))
 566         tag_len = ff_id3v2_tag_len(buf);
 567
 568     /* This check cannot overflow as tag_len has at most 28 bits */
 569     if (p->buf_size < tag_len + 5)
 570         /* EA3 header comes late, might be outside of the probe buffer */
 571         return tag_len ? AVPROBE_SCORE_EXTENSION/2 : 0;
 572
 573     buf += tag_len;
 574
 575     if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
 576         return AVPROBE_SCORE_MAX;
 577     else
 578         return 0;
 579 }
 580
 581 static int oma_read_seek(struct AVFormatContext *s,
 582                          int stream_index, int64_t timestamp, int flags)
 583 {
 584     OMAContext *oc = s->priv_data;
 585     AVStream *st = s->streams[0];
 586     int64_t err;
 587
 588     if (st->codecpar->codec_id == AV_CODEC_ID_ATRAC3PAL ||
 589         st->codecpar->codec_id == AV_CODEC_ID_ATRAC3AL)
 590         return -1;
 591
 592     err = ff_pcm_read_seek(s, stream_index, timestamp, flags);
 593     if (!oc->encrypted)
 594         return err;
 595
 596     /* readjust IV for CBC */
 597     if (err || avio_tell(s->pb) < oc->content_start)
 598         goto wipe;
 599     if ((err = avio_seek(s->pb, -8, SEEK_CUR)) < 0)
 600         goto wipe;
 601     if ((err = avio_read(s->pb, oc->iv, 8)) < 8) {
 602         if (err >= 0)
 603             err = AVERROR_EOF;
 604         goto wipe;
 605     }
 606
 607     return 0;
 608 wipe:
 609     memset(oc->iv, 0, 8);
 610     return err;
 611 }
 612
 613 const FFInputFormat ff_oma_demuxer = {
 614     .p.name         = "oma",
 615     .p.long_name    = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
 616     .p.flags        = AVFMT_GENERIC_INDEX,
 617     .p.extensions   = "oma,omg,aa3",
 618     .p.codec_tag    = ff_oma_codec_tags_list,
 619     .priv_data_size = sizeof(OMAContext),
 620     .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
 621     .read_probe     = oma_read_probe,
 622     .read_header    = oma_read_header,
 623     .read_packet    = oma_read_packet,
 624     .read_seek      = oma_read_seek,
 625     .read_close     = oma_read_close,
 626 };