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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.     int64_t duration;
  75.     int ret;
  76.  
  77.     av_add_index_entry(st,
  78.                        avio_tell(pb),
  79.                        voc->pts,
  80.                        voc->remaining_size,
  81.                        0,
  82.                        AVINDEX_KEYFRAME);
  83.  
  84.     while (!voc->remaining_size) {
  85.         type = avio_r8(pb);
  86.         if (type == VOC_TYPE_EOF)
  87.             return AVERROR_EOF;
  88.         voc->remaining_size = avio_rl24(pb);
  89.         if (!voc->remaining_size) {
  90.             if (!s->pb->seekable)
  91.                 return AVERROR(EIO);
  92.             voc->remaining_size = avio_size(pb) - avio_tell(pb);
  93.         }
  94.         max_size -= 4;
  95.  
  96.         switch (type) {
  97.         case VOC_TYPE_VOICE_DATA:
  98.             if (!dec->sample_rate) {
  99.                 dec->sample_rate = 1000000 / (256 - avio_r8(pb));
  100.                 if (sample_rate)
  101.                     dec->sample_rate = sample_rate;
  102.                 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
  103.                 dec->channels = channels;
  104.                 dec->bits_per_coded_sample = av_get_bits_per_sample(dec->codec_id);
  105.             } else
  106.                 avio_skip(pb, 1);
  107.             tmp_codec = avio_r8(pb);
  108.             voc->remaining_size -= 2;
  109.             max_size -= 2;
  110.             channels = 1;
  111.             break;
  112.  
  113.         case VOC_TYPE_VOICE_DATA_CONT:
  114.             break;
  115.  
  116.         case VOC_TYPE_EXTENDED:
  117.             sample_rate = avio_rl16(pb);
  118.             avio_r8(pb);
  119.             channels = avio_r8(pb) + 1;
  120.             sample_rate = 256000000 / (channels * (65536 - sample_rate));
  121.             voc->remaining_size = 0;
  122.             max_size -= 4;
  123.             break;
  124.  
  125.         case VOC_TYPE_NEW_VOICE_DATA:
  126.             if (!dec->sample_rate) {
  127.                 dec->sample_rate = avio_rl32(pb);
  128.                 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
  129.                 dec->bits_per_coded_sample = avio_r8(pb);
  130.                 dec->channels = avio_r8(pb);
  131.             } else
  132.                 avio_skip(pb, 6);
  133.             tmp_codec = avio_rl16(pb);
  134.             avio_skip(pb, 4);
  135.             voc->remaining_size -= 12;
  136.             max_size -= 12;
  137.             break;
  138.  
  139.         default:
  140.             avio_skip(pb, voc->remaining_size);
  141.             max_size -= voc->remaining_size;
  142.             voc->remaining_size = 0;
  143.             break;
  144.         }
  145.     }
  146.  
  147.     if (tmp_codec >= 0) {
  148.         tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);
  149.         if (dec->codec_id == AV_CODEC_ID_NONE)
  150.             dec->codec_id = tmp_codec;
  151.         else if (dec->codec_id != tmp_codec)
  152.             av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");
  153.         if (dec->codec_id == AV_CODEC_ID_NONE) {
  154.             if (s->audio_codec_id == AV_CODEC_ID_NONE) {
  155.                 av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
  156.                 return AVERROR(EINVAL);
  157.             }
  158.             av_log(s, AV_LOG_WARNING, "unknown codec tag\n");
  159.         }
  160.     }
  161.  
  162.     dec->bit_rate = dec->sample_rate * dec->channels * dec->bits_per_coded_sample;
  163.  
  164.     if (max_size <= 0)
  165.         max_size = 2048;
  166.     size = FFMIN(voc->remaining_size, max_size);
  167.     voc->remaining_size -= size;
  168.  
  169.     ret = av_get_packet(pb, pkt, size);
  170.     pkt->dts = pkt->pts = voc->pts;
  171.  
  172.     duration = av_get_audio_frame_duration(st->codec, size);
  173.     if (duration > 0 && voc->pts != AV_NOPTS_VALUE)
  174.         voc->pts += duration;
  175.     else
  176.         voc->pts = AV_NOPTS_VALUE;
  177.  
  178.     return ret;
  179. }
  180.  
  181. static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
  182. {
  183.     return ff_voc_get_packet(s, pkt, s->streams[0], 0);
  184. }
  185.  
  186. static int voc_read_seek(AVFormatContext *s, int stream_index,
  187.                          int64_t timestamp, int flags)
  188. {
  189.     VocDecContext *voc = s->priv_data;
  190.     AVStream *st = s->streams[stream_index];
  191.     int index = av_index_search_timestamp(st, timestamp, flags);
  192.  
  193.     if (index >= 0 && index < st->nb_index_entries - 1) {
  194.         AVIndexEntry *e = &st->index_entries[index];
  195.         avio_seek(s->pb, e->pos, SEEK_SET);
  196.         voc->pts = e->timestamp;
  197.         voc->remaining_size = e->size;
  198.         return 0;
  199.     } else if (st->nb_index_entries && st->index_entries[0].timestamp <= timestamp) {
  200.         AVIndexEntry *e = &st->index_entries[st->nb_index_entries - 1];
  201.         // prepare context for seek_frame_generic()
  202.         voc->pts = e->timestamp;
  203.         voc->remaining_size = e->size;
  204.     }
  205.     return -1;
  206. }
  207.  
  208. AVInputFormat ff_voc_demuxer = {
  209.     .name           = "voc",
  210.     .long_name      = NULL_IF_CONFIG_SMALL("Creative Voice"),
  211.     .priv_data_size = sizeof(VocDecContext),
  212.     .read_probe     = voc_probe,
  213.     .read_header    = voc_read_header,
  214.     .read_packet    = voc_read_packet,
  215.     .read_seek      = voc_read_seek,
  216.     .codec_tag      = (const AVCodecTag* const []){ ff_voc_codec_tags, 0 },
  217. };
  218.