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• Problem : av_seek_frame() always returns me the beginning of the video

  3 novembre 2020, par ZWen

  I'm currently trying to making use of FFMpeg to build a player. When I'm using av_seek_frame() to change the timestamp, it always gives me the beginning of the stream.

  


  Here is my code :

  


  bool XDemux::Seek(double pos)
{
    mux.lock();
    if (!ic)
    {
        mux.unlock();
        return false;
    }
    avformat_flush(ic);

    long long seekPos = 0;
    seekPos = ic->streams[videoStream]->duration * pos;
    int re = av_seek_frame(ic, videoStream, seekPos, AVSEEK_FLAG_BACKWARD | AVSEEK_FLAG_FRAME);
    mux.unlock();
    if (re < 0)
    {
        return false;
    }
    return true;
}


  


  Where ic and mux are defined as

  


  AVFormatContext* ic
std::mutex mux;


  


  When I'm trying to call the Seek function and print out the frame index, it will be something like :

  


  //Read() is called:
0 0 21 42 40 ...
//Then Seek(0.9) is called, should have begin with a later frame, but it also returns me:
0 0 21 42 40 ...


  


• avcodec_open2 returns Invalid Argument (errnum -22)

  7 avril 2023, par nokla

  I am trying to encode a vector of AVFrames to an MP4 file using the h264 codec.

  


  Everything seems to work fine until the avcodec_open2 function, which returns an "Invalid Argument" (-22) error.

  


  *The stream parameter is a pointer to AVStream.

  


  Here is the code that sets the stream parameters :

  


      stream->codecpar->codec_id = AV_CODEC_ID_H264;
    stream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
    stream->codecpar->width = settings.resolution[0]; // 270
    stream->codecpar->height = settings.resolution[1]; // 480
    stream->codecpar->format = AV_PIX_FMT_YUV420P;
    stream->codecpar->bit_rate = 400000;
    AVRational framerate = { 1, 30};
    stream->time_base = av_inv_q(framerate);


  


  And here is the code that opens the codec context :

  


      // Open the codec context
    AVCodecContext* codec_ctx = avcodec_alloc_context3(codec);
    if (!codec_ctx) {
        std::cout << "Error allocating codec context" << std::endl;
        avformat_free_context(format_ctx);
        return;
    }

    ret = avcodec_parameters_to_context(codec_ctx, stream->codecpar);
    if (ret < 0) {
        std::cout << "Error setting codec context parameters: " << av_err2str(ret) << std::endl;
        avcodec_free_context(&codec_ctx);
        avformat_free_context(format_ctx);
        return;
    }

    ret = avcodec_open2(codec_ctx, codec, nullptr);
    if (ret < 0) {
        wxMessageBox("Error opening codec: ");
        wxMessageBox(av_err2str(ret));
        avcodec_free_context(&codec_ctx);
        avformat_free_context(format_ctx);
        return;
    }


  


  I tried the solution that @philipp suggested in ffmpeg-avcodec-open2-returns-invalid-argument but it didn't resolve my error.

  


  I don't know what's causing this error in my code, can someone please help me ?

  


• vf_program_opencl : Add missing error code returns

  11 janvier 2018, par Mark Thompson

  vf_program_opencl : Add missing error code returns
  Fixes CID #1427285.
  

  • [DH] libavfilter/vf_program_opencl.c