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  1. /*
  2.  * TTA demuxer
  3.  * Copyright (c) 2006 Alex Beregszaszi
  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 "libavcodec/get_bits.h"
  23. #include "apetag.h"
  24. #include "avformat.h"
  25. #include "avio_internal.h"
  26. #include "internal.h"
  27. #include "id3v1.h"
  28. #include "libavutil/crc.h"
  29. #include "libavutil/dict.h"
  30.  
  31. typedef struct {
  32.     int totalframes, currentframe;
  33.     int frame_size;
  34.     int last_frame_size;
  35. } TTAContext;
  36.  
  37. static unsigned long tta_check_crc(unsigned long checksum, const uint8_t *buf,
  38.                                    unsigned int len)
  39. {
  40.     return av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), checksum, buf, len);
  41. }
  42.  
  43. static int tta_probe(AVProbeData *p)
  44. {
  45.     if (AV_RL32(&p->buf[0]) == MKTAG('T', 'T', 'A', '1') &&
  46.         (AV_RL16(&p->buf[4]) == 1 || AV_RL16(&p->buf[4]) == 2) &&
  47.         AV_RL16(&p->buf[6]) > 0 &&
  48.         AV_RL16(&p->buf[8]) > 0 &&
  49.         AV_RL32(&p->buf[10]) > 0)
  50.         return AVPROBE_SCORE_EXTENSION + 30;
  51.     return 0;
  52. }
  53.  
  54. static int tta_read_header(AVFormatContext *s)
  55. {
  56.     TTAContext *c = s->priv_data;
  57.     AVStream *st;
  58.     int i, channels, bps, samplerate;
  59.     uint64_t framepos, start_offset;
  60.     uint32_t nb_samples, crc;
  61.  
  62.     ff_id3v1_read(s);
  63.  
  64.     start_offset = avio_tell(s->pb);
  65.     ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
  66.     if (avio_rl32(s->pb) != AV_RL32("TTA1"))
  67.         return AVERROR_INVALIDDATA;
  68.  
  69.     avio_skip(s->pb, 2); // FIXME: flags
  70.     channels = avio_rl16(s->pb);
  71.     bps = avio_rl16(s->pb);
  72.     samplerate = avio_rl32(s->pb);
  73.     if(samplerate <= 0 || samplerate > 1000000){
  74.         av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
  75.         return AVERROR_INVALIDDATA;
  76.     }
  77.  
  78.     nb_samples = avio_rl32(s->pb);
  79.     if (!nb_samples) {
  80.         av_log(s, AV_LOG_ERROR, "invalid number of samples\n");
  81.         return AVERROR_INVALIDDATA;
  82.     }
  83.  
  84.     crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
  85.     if (crc != avio_rl32(s->pb)) {
  86.         av_log(s, AV_LOG_ERROR, "Header CRC error\n");
  87.         return AVERROR_INVALIDDATA;
  88.     }
  89.  
  90.     c->frame_size      = samplerate * 256 / 245;
  91.     c->last_frame_size = nb_samples % c->frame_size;
  92.     if (!c->last_frame_size)
  93.         c->last_frame_size = c->frame_size;
  94.     c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);
  95.     c->currentframe = 0;
  96.  
  97.     if(c->totalframes >= UINT_MAX/sizeof(uint32_t) || c->totalframes <= 0){
  98.         av_log(s, AV_LOG_ERROR, "totalframes %d invalid\n", c->totalframes);
  99.         return AVERROR_INVALIDDATA;
  100.     }
  101.  
  102.     st = avformat_new_stream(s, NULL);
  103.     if (!st)
  104.         return AVERROR(ENOMEM);
  105.  
  106.     avpriv_set_pts_info(st, 64, 1, samplerate);
  107.     st->start_time = 0;
  108.     st->duration = nb_samples;
  109.  
  110.     framepos = avio_tell(s->pb) + 4*c->totalframes + 4;
  111.  
  112.     if (ff_alloc_extradata(st->codec, avio_tell(s->pb) - start_offset))
  113.         return AVERROR(ENOMEM);
  114.  
  115.     avio_seek(s->pb, start_offset, SEEK_SET);
  116.     avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
  117.  
  118.     ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
  119.     for (i = 0; i < c->totalframes; i++) {
  120.         uint32_t size = avio_rl32(s->pb);
  121.         av_add_index_entry(st, framepos, i * c->frame_size, size, 0,
  122.                            AVINDEX_KEYFRAME);
  123.         framepos += size;
  124.     }
  125.     crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
  126.     if (crc != avio_rl32(s->pb)) {
  127.         av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");
  128.         return AVERROR_INVALIDDATA;
  129.     }
  130.  
  131.     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
  132.     st->codec->codec_id = AV_CODEC_ID_TTA;
  133.     st->codec->channels = channels;
  134.     st->codec->sample_rate = samplerate;
  135.     st->codec->bits_per_coded_sample = bps;
  136.  
  137.     if (s->pb->seekable) {
  138.         int64_t pos = avio_tell(s->pb);
  139.         ff_ape_parse_tag(s);
  140.         avio_seek(s->pb, pos, SEEK_SET);
  141.     }
  142.  
  143.     return 0;
  144. }
  145.  
  146. static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
  147. {
  148.     TTAContext *c = s->priv_data;
  149.     AVStream *st = s->streams[0];
  150.     int size, ret;
  151.  
  152.     // FIXME!
  153.     if (c->currentframe >= c->totalframes)
  154.         return AVERROR_EOF;
  155.  
  156.     size = st->index_entries[c->currentframe].size;
  157.  
  158.     ret = av_get_packet(s->pb, pkt, size);
  159.     pkt->dts = st->index_entries[c->currentframe++].timestamp;
  160.     pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
  161.                                                         c->frame_size;
  162.     return ret;
  163. }
  164.  
  165. static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
  166. {
  167.     TTAContext *c = s->priv_data;
  168.     AVStream *st = s->streams[stream_index];
  169.     int index = av_index_search_timestamp(st, timestamp, flags);
  170.     if (index < 0)
  171.         return -1;
  172.     if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
  173.         return -1;
  174.  
  175.     c->currentframe = index;
  176.  
  177.     return 0;
  178. }
  179.  
  180. AVInputFormat ff_tta_demuxer = {
  181.     .name           = "tta",
  182.     .long_name      = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
  183.     .priv_data_size = sizeof(TTAContext),
  184.     .read_probe     = tta_probe,
  185.     .read_header    = tta_read_header,
  186.     .read_packet    = tta_read_packet,
  187.     .read_seek      = tta_read_seek,
  188.     .extensions     = "tta",
  189. };
  190.