混入MPEG-TS：音频流参数错误

Question

我正在尝试使用ffmpeg将视频（H.264）和音频（PCM_S16LE，无压缩）混合到MPEG传输流中。视频显示良好。但是，音频流无法播放。ff探针显示的音频流是AAC，这显然不是我的意图。所以我在添加音频流时一定做错了什么。知道如何纠正吗？

这是我添加音频流的代码：

void add_audio_stream()
{

    CodecID codec_id = CODEC_ID_PCM_S16LE;

    AVStream *p_ast = av_new_stream(fc, 1);

    if (!p_ast) {
        fprintf(stderr, "Could not alloc audio stream\n");
        exit(1);
    }

    ai = p_ast->index;

    AVCodecContext *pcc = p_ast->codec;
    avcodec_get_context_defaults2( pcc, AVMEDIA_TYPE_AUDIO );

    pcc->codec_type = AVMEDIA_TYPE_AUDIO;
    pcc->codec_id = codec_id;
    pcc->sample_fmt = AV_SAMPLE_FMT_S16;
    //pcc->bit_rate = 44100*16*2;
    pcc->bit_rate = 0;
    pcc->sample_rate = 44100;
    pcc->channels = 2;
    pcc->time_base = (AVRational){1, 44100};


    // some formats want stream headers to be separate
    if (fc->oformat->flags & AVFMT_GLOBALHEADER)
    {
        printf(" **** 1 ****\n");
        pcc->flags |= CODEC_FLAG_GLOBAL_HEADER;
    }
    else
        printf(" **** 2 ****\n");


    AVCodec *codec;

    /* find the audio encoder */
    codec = avcodec_find_encoder(pcc->codec_id);
    if (!codec) {
        fprintf(stderr, "codec not found\n");
        exit(1);
    }


    /* open it */
    if (avcodec_open(pcc, codec) < 0) 
    {
        fprintf(stderr, "could not open codec\n");
        exit(1);
    }
}

以下是ffprobe的输出：

ffprobe version N-32405-g6337de9, Copyright (c) 2007-2011 the FFmpeg developers
  built on Sep  8 2011 11:20:12 with gcc 4.4.3
  configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-libfaac --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-x11grab --enable-libmp3lame
  libavutil    51. 16. 0 / 51. 16. 0
  libavcodec   53. 13. 0 / 53. 13. 0
  libavformat  53. 12. 0 / 53. 12. 0
  libavdevice  53.  3. 0 / 53.  3. 0
  libavfilter   2. 39. 0 /  2. 39. 0
  libswscale    2.  1. 0 /  2.  1. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[mpegts @ 0xa96daa0] Continuity Check Failed
[mpegts @ 0xa96daa0] Continuity Check Failed
[aac @ 0xa974da0] channel element 0.1 is not allocated
[aac @ 0xa974da0] More than one AAC RDB per ADTS frame is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.

.
.
lot of gobbly-gook about missing AAC parameters . . . 
.
.

[aac @ 0xa974da0] More than one AAC RDB per ADTS frame is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.
[aac @ 0xa974da0] Error decoding AAC frame header.
[mpegts @ 0xa96daa0] max_analyze_duration 5000000 reached at 5429789
[mpegts @ 0xa96daa0] Continuity Check Failed
[mpegts @ 0xa96daa0] Continuity Check Failed

Input #0, mpegts, from 'test_audio_video.mts':
  Duration: 00:00:40.35, start: 0.010000, bitrate: 1907 kb/s
  Program 1 
    Metadata:
      service_name    : Service01
      service_provider: FFmpeg
Stream #0.0[0x100]: Video: h264 (Constrained Baseline) ([27][0][0][0] / 0x001B), yuv420p, 640x480, 30 fps, 30 tbr, 90k tbn, 60 tbc

Stream #0.1[0x101]: Audio: aac ([6][0][0][0] / 0x0006), 96000 Hz, 4.0, s16, 9 kb/s

Answer 1

不久前我也玩过。我发现：-蓝光只支持48000采样率-我总是使用大端而不是小端。

我认为ffmpeg将使用蓝光设置mpeg2_ts。

Answer 2

根据SMPTE 302M的规定，MPEG-TS似乎支持将AES3格式的PCM音频作为私有数据。

目前，ffmpeg中有一个s302m编码器/解码器，可以让您轻松实现目标。

Answer 3

我想我怀疑MEPG2 TS是否允许PCM音频。它可以占用MPI、MP2或AAC。AAC更多地被视为一种默认选择，而不是身份识别。

此外，与视频不同，音频标题的描述性不强。i、 e.没有开始代码和其他东西，所以除了PES头，通常没有办法找出它是什么类型的音频。

如果可能，对音频进行编码。

尝试Gspot应用程序进行交叉检查。