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  1. /*
  2.  * Creative Voice File demuxer.
  3.  * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
  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 "libavutil/intreadwrite.h"
  23. #include "voc.h"
  24. #include "internal.h"
  25.  
  26.  
  27. static int voc_probe(AVProbeData *p)
  28. {
  29.     int version, check;
  30.  
  31.     if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))
  32.         return 0;
  33.     version = AV_RL16(p->buf + 22);
  34.     check = AV_RL16(p->buf + 24);
  35.     if (~version + 0x1234 != check)
  36.         return 10;
  37.  
  38.     return AVPROBE_SCORE_MAX;
  39. }
  40.  
  41. static int voc_read_header(AVFormatContext *s)
  42. {
  43.     VocDecContext *voc = s->priv_data;
  44.     AVIOContext *pb = s->pb;
  45.     int header_size;
  46.     AVStream *st;
  47.  
  48.     avio_skip(pb, 20);
  49.     header_size = avio_rl16(pb) - 22;
  50.     if (header_size != 4) {
  51.         av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
  52.         return AVERROR(ENOSYS);
  53.     }
  54.     avio_skip(pb, header_size);
  55.     st = avformat_new_stream(s, NULL);
  56.     if (!st)
  57.         return AVERROR(ENOMEM);
  58.     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
  59.  
  60.     voc->remaining_size = 0;
  61.     return 0;
  62. }
  63.  
  64. int
  65. ff_voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
  66. {
  67.     VocDecContext *voc = s->priv_data;
  68.     AVCodecContext *dec = st->codec;
  69.     AVIOContext *pb = s->pb;
  70.     VocType type;
  71.     int size, tmp_codec=-1;
  72.     int sample_rate = 0;
  73.     int channels = 1;
  74.  
  75.     while (!voc->remaining_size) {
  76.         type = avio_r8(pb);
  77.         if (type == VOC_TYPE_EOF)
  78.             return AVERROR_EOF;
  79.         voc->remaining_size = avio_rl24(pb);
  80.         if (!voc->remaining_size) {
  81.             if (!s->pb->seekable)
  82.                 return AVERROR(EIO);
  83.             voc->remaining_size = avio_size(pb) - avio_tell(pb);
  84.         }
  85.         max_size -= 4;
  86.  
  87.         switch (type) {
  88.         case VOC_TYPE_VOICE_DATA:
  89.             if (!dec->sample_rate) {
  90.                 dec->sample_rate = 1000000 / (256 - avio_r8(pb));
  91.                 if (sample_rate)
  92.                     dec->sample_rate = sample_rate;
  93.                 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
  94.                 dec->channels = channels;
  95.                 dec->bits_per_coded_sample = av_get_bits_per_sample(dec->codec_id);
  96.             } else
  97.                 avio_skip(pb, 1);
  98.             tmp_codec = avio_r8(pb);
  99.             voc->remaining_size -= 2;
  100.             max_size -= 2;
  101.             channels = 1;
  102.             break;
  103.  
  104.         case VOC_TYPE_VOICE_DATA_CONT:
  105.             break;
  106.  
  107.         case VOC_TYPE_EXTENDED:
  108.             sample_rate = avio_rl16(pb);
  109.             avio_r8(pb);
  110.             channels = avio_r8(pb) + 1;
  111.             sample_rate = 256000000 / (channels * (65536 - sample_rate));
  112.             voc->remaining_size = 0;
  113.             max_size -= 4;
  114.             break;
  115.  
  116.         case VOC_TYPE_NEW_VOICE_DATA:
  117.             if (!dec->sample_rate) {
  118.                 dec->sample_rate = avio_rl32(pb);
  119.                 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
  120.                 dec->bits_per_coded_sample = avio_r8(pb);
  121.                 dec->channels = avio_r8(pb);
  122.             } else
  123.                 avio_skip(pb, 6);
  124.             tmp_codec = avio_rl16(pb);
  125.             avio_skip(pb, 4);
  126.             voc->remaining_size -= 12;
  127.             max_size -= 12;
  128.             break;
  129.  
  130.         default:
  131.             avio_skip(pb, voc->remaining_size);
  132.             max_size -= voc->remaining_size;
  133.             voc->remaining_size = 0;
  134.             break;
  135.         }
  136.     }
  137.  
  138.     if (tmp_codec >= 0) {
  139.         tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);
  140.         if (dec->codec_id == AV_CODEC_ID_NONE)
  141.             dec->codec_id = tmp_codec;
  142.         else if (dec->codec_id != tmp_codec)
  143.             av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");
  144.         if (dec->codec_id == AV_CODEC_ID_NONE) {
  145.             if (s->audio_codec_id == AV_CODEC_ID_NONE) {
  146.                 av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
  147.                 return AVERROR(EINVAL);
  148.             }
  149.             av_log(s, AV_LOG_WARNING, "unknown codec tag\n");
  150.         }
  151.     }
  152.  
  153.     dec->bit_rate = dec->sample_rate * dec->channels * dec->bits_per_coded_sample;
  154.  
  155.     if (max_size <= 0)
  156.         max_size = 2048;
  157.     size = FFMIN(voc->remaining_size, max_size);
  158.     voc->remaining_size -= size;
  159.     return av_get_packet(pb, pkt, size);
  160. }
  161.  
  162. static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
  163. {
  164.     return ff_voc_get_packet(s, pkt, s->streams[0], 0);
  165. }
  166.  
  167. AVInputFormat ff_voc_demuxer = {
  168.     .name           = "voc",
  169.     .long_name      = NULL_IF_CONFIG_SMALL("Creative Voice"),
  170.     .priv_data_size = sizeof(VocDecContext),
  171.     .read_probe     = voc_probe,
  172.     .read_header    = voc_read_header,
  173.     .read_packet    = voc_read_packet,
  174.     .codec_tag      = (const AVCodecTag* const []){ ff_voc_codec_tags, 0 },
  175. };
  176.