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• How to check if client is still connected with ffmpeg

  11 décembre 2017, par Adalcar

  I am working on a live-streaming server in C++ using FFMPEG.
  I have a I have an acquisition thread which grabs the images from the cameras and I spawn a new thread on each client connexion to send them the packets.

  Here’s my "send" function :

  void Encoder::_encode()
  
  {
  
      int ret = 0;
  
      if (avcodec_send_frame(ctx, frame) < 0)
  
          throw new std::runtime_error("error sending a frame for encoding");
  
      while (ret >= 0)
  
      {
  
          ret = avcodec_receive_packet(ctx, pkt);
  
          if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
  
              return;
  
          avio_write(client, pkt->data, pkt->size);
  
          avio_flush(client);
  
          av_packet_unref(pkt);
  
      }
  
  }

  This encodes the frame and sends it to the client.

  The problem is : whenever the client exits, the thread keeps sending it data, and throws no exception, even when the same client connects again, it will spawn a new thread while the old one keeps running...
  Is there a way to "ping" the client to check whether it is still connected ?

• Extract audio from video using autogen ffmpeg C# in Unity

  5 décembre 2024, par Johan Sophie

  Hi I'm using ffmpeg autogen to extract audio from video in Unity, but when I following this code, the file write cannot write, it's 0Kb, so what's issue of this or someone have any examples for extract audio using this library, apologize for my English. This is github of library : 
https://github.com/Ruslan-B/FFmpeg.AutoGen

  



  unsafe void TestExtractAudio()
{

    string inFile = Application.streamingAssetsPath + "/" + strFileName;
    string outFile = Application.streamingAssetsPath + "/" + strFileNameAudio;

    AVOutputFormat* outFormat = null;
    AVFormatContext* inFormatContext = null;
    AVFormatContext* outFormatContext = null;
    AVPacket packet;

    ffmpeg.av_register_all();

    inFormatContext = ffmpeg.avformat_alloc_context();
    outFormatContext = ffmpeg.avformat_alloc_context();

    if (ffmpeg.avformat_open_input(&inFormatContext, inFile, null, null) < 0)
    {
        throw new ApplicationException("Could not open input file.");
    }

    if (ffmpeg.avformat_find_stream_info(inFormatContext, null) < 0)
    {
        throw new ApplicationException("Failed to retrieve input stream info.");
    }

    ffmpeg.avformat_alloc_output_context2(&outFormatContext, null, null, outFile);
    if (outFormatContext == null)
    {
        throw new ApplicationException("Could not create output context");
    }

    outFormat = outFormatContext->oformat;

    AVStream* inStream = inFormatContext->streams[1];
    AVStream* outStream = ffmpeg.avformat_new_stream(outFormatContext, inStream->codec->codec);
    if (outStream == null)
    {
        throw new ApplicationException("Failed to allocate output stream.");
    }

    if (ffmpeg.avcodec_copy_context(outStream->codec, inStream->codec) < 0)
    {
        throw new ApplicationException("Couldn't copy input stream codec context to output stream codec context");
    }

    outFormatContext->audio_codec_id = AVCodecID.AV_CODEC_ID_MP3;

    int retcode = ffmpeg.avio_open(&outFormatContext->pb, outFile, ffmpeg.AVIO_FLAG_WRITE);
    if (retcode < 0)
    {
        throw new ApplicationException("Couldn't open output file");
    }

    int returnCode = ffmpeg.avformat_write_header(outFormatContext, null);

    if (returnCode < 0)
    {
        throw new ApplicationException("Error occurred opening output file.");
    }

    while (true)
    {
        if (ffmpeg.av_read_frame(inFormatContext, &packet) < 0)
        {
            break;
        }

        if (packet.stream_index == 1)
        {

            inStream = inFormatContext->streams[1];
            outStream = outFormatContext->streams[0];

            // TODO: Replicate log packet functionality to print out what's inside the packet.

            packet.pts = ffmpeg.av_rescale_q_rnd(packet.pts, inStream->time_base, outStream->time_base,
                AVRounding.AV_ROUND_NEAR_INF | AVRounding.AV_ROUND_PASS_MINMAX);
            packet.dts = ffmpeg.av_rescale_q_rnd(packet.dts, inStream->time_base, outStream->time_base,
                AVRounding.AV_ROUND_NEAR_INF | AVRounding.AV_ROUND_PASS_MINMAX);

            packet.duration = ffmpeg.av_rescale_q(packet.duration, inStream->time_base, outStream->time_base);

            int returncode = ffmpeg.av_interleaved_write_frame(outFormatContext, &packet);

        }

        ffmpeg.av_packet_unref(&packet);
    }

    ffmpeg.av_write_trailer(outFormatContext);


    ffmpeg.avformat_close_input(&inFormatContext);

    ffmpeg.avformat_free_context(outFormatContext);

    Console.WriteLine("Press any key to continue...");

    Console.ReadKey();
}


  



  the value returnCode return less than 0, so someone can fix this, thanks so much for that

  


• avcodec/nvdec : More effort to make vp8 compile with gcc 4.6

  27 novembre 2017, par Philip Langdale

  avcodec/nvdec : More effort to make vp8 compile with gcc < 4.6
  I'm told my prefix work-around wasn't enough to make it compile,
  
  although I'm not sure why ; I did some basic testing and that
  
  approach appeared to work, but I'm not in a position to do a
  
  full compile on CentOS 6 so I can't be sure of anything.
  I have had it confirmed that the additional change to not use
  
  named initialisers is enough to make it compile, so let's
  
  throw that into the mix too.
  

  • [DH] libavcodec/nvdec_vp8.c