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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 TTAContext {
  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.     int64_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.     if (start_offset < 0)
  66.         return start_offset;
  67.     ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
  68.     if (avio_rl32(s->pb) != AV_RL32("TTA1"))
  69.         return AVERROR_INVALIDDATA;
  70.  
  71.     avio_skip(s->pb, 2); // FIXME: flags
  72.     channels = avio_rl16(s->pb);
  73.     bps = avio_rl16(s->pb);
  74.     samplerate = avio_rl32(s->pb);
  75.     if(samplerate <= 0 || samplerate > 1000000){
  76.         av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
  77.         return AVERROR_INVALIDDATA;
  78.     }
  79.  
  80.     nb_samples = avio_rl32(s->pb);
  81.     if (!nb_samples) {
  82.         av_log(s, AV_LOG_ERROR, "invalid number of samples\n");
  83.         return AVERROR_INVALIDDATA;
  84.     }
  85.  
  86.     crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
  87.     if (crc != avio_rl32(s->pb) && s->error_recognition & AV_EF_CRCCHECK) {
  88.         av_log(s, AV_LOG_ERROR, "Header CRC error\n");
  89.         return AVERROR_INVALIDDATA;
  90.     }
  91.  
  92.     c->frame_size      = samplerate * 256 / 245;
  93.     c->last_frame_size = nb_samples % c->frame_size;
  94.     if (!c->last_frame_size)
  95.         c->last_frame_size = c->frame_size;
  96.     c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);
  97.     c->currentframe = 0;
  98.  
  99.     if(c->totalframes >= UINT_MAX/sizeof(uint32_t) || c->totalframes <= 0){
  100.         av_log(s, AV_LOG_ERROR, "totalframes %d invalid\n", c->totalframes);
  101.         return AVERROR_INVALIDDATA;
  102.     }
  103.  
  104.     st = avformat_new_stream(s, NULL);
  105.     if (!st)
  106.         return AVERROR(ENOMEM);
  107.  
  108.     avpriv_set_pts_info(st, 64, 1, samplerate);
  109.     st->start_time = 0;
  110.     st->duration = nb_samples;
  111.  
  112.     framepos = avio_tell(s->pb);
  113.     if (framepos < 0)
  114.         return framepos;
  115.     framepos += 4 * c->totalframes + 4;
  116.  
  117.     if (ff_alloc_extradata(st->codec, avio_tell(s->pb) - start_offset))
  118.         return AVERROR(ENOMEM);
  119.  
  120.     avio_seek(s->pb, start_offset, SEEK_SET);
  121.     avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
  122.  
  123.     ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
  124.     for (i = 0; i < c->totalframes; i++) {
  125.         uint32_t size = avio_rl32(s->pb);
  126.         int r;
  127.         if ((r = av_add_index_entry(st, framepos, i * c->frame_size, size, 0,
  128.                                     AVINDEX_KEYFRAME)) < 0)
  129.             return r;
  130.         framepos += size;
  131.     }
  132.     crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
  133.     if (crc != avio_rl32(s->pb) && s->error_recognition & AV_EF_CRCCHECK) {
  134.         av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");
  135.         return AVERROR_INVALIDDATA;
  136.     }
  137.  
  138.     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
  139.     st->codec->codec_id = AV_CODEC_ID_TTA;
  140.     st->codec->channels = channels;
  141.     st->codec->sample_rate = samplerate;
  142.     st->codec->bits_per_coded_sample = bps;
  143.  
  144.     if (s->pb->seekable) {
  145.         int64_t pos = avio_tell(s->pb);
  146.         ff_ape_parse_tag(s);
  147.         avio_seek(s->pb, pos, SEEK_SET);
  148.     }
  149.  
  150.     return 0;
  151. }
  152.  
  153. static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
  154. {
  155.     TTAContext *c = s->priv_data;
  156.     AVStream *st = s->streams[0];
  157.     int size, ret;
  158.  
  159.     // FIXME!
  160.     if (c->currentframe >= c->totalframes)
  161.         return AVERROR_EOF;
  162.  
  163.     if (st->nb_index_entries < c->totalframes) {
  164.         av_log(s, AV_LOG_ERROR, "Index entry disappeared\n");
  165.         return AVERROR_INVALIDDATA;
  166.     }
  167.  
  168.     size = st->index_entries[c->currentframe].size;
  169.  
  170.     ret = av_get_packet(s->pb, pkt, size);
  171.     pkt->dts = st->index_entries[c->currentframe++].timestamp;
  172.     pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
  173.                                                         c->frame_size;
  174.     return ret;
  175. }
  176.  
  177. static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
  178. {
  179.     TTAContext *c = s->priv_data;
  180.     AVStream *st = s->streams[stream_index];
  181.     int index = av_index_search_timestamp(st, timestamp, flags);
  182.     if (index < 0)
  183.         return -1;
  184.     if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
  185.         return -1;
  186.  
  187.     c->currentframe = index;
  188.  
  189.     return 0;
  190. }
  191.  
  192. AVInputFormat ff_tta_demuxer = {
  193.     .name           = "tta",
  194.     .long_name      = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
  195.     .priv_data_size = sizeof(TTAContext),
  196.     .read_probe     = tta_probe,
  197.     .read_header    = tta_read_header,
  198.     .read_packet    = tta_read_packet,
  199.     .read_seek      = tta_read_seek,
  200.     .extensions     = "tta",
  201. };
  202.