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• Receiving UDP streams on my web server

  25 novembre 2013, par user3032143

  I have a Winform C# Desktop application.

  This is my overall aim :

  I have a constant stream of images from which I acquire using a VLC wrapper receiving a RTSP stream from my IP camera.

  I am doing image processing on these separate jpegs and at the same time I am wanting to upload these jpegs to my web server so my User can view these streaming jpegs live a video.

  Now, I have accomplished this so far by uploading each jpeg to my server using a [Web method]. But, I am trying to push my knowledge to make it more efficient.

  Now, i know if I use a video encoder - like OGG (used because it is Open Source) I can use ffmpeg called from my client code using the Process class so to convert images to that video format.

  Doing this saves a lot of memory when comparing that 1 ogg file to the separate bytes added up in total from all the individual jpegs.

  These are the arguments I pass to ffmpeg to achieve that :

  -f image2 -r 10 -i {location of jpegs}+"\img%05d.jpg -crf 23  -y -r 10 -f outputfile.ogg

  Now, I could take this a step further and not output to a physical file but instead to the base stream of the Process class. I would use these arguments to accomplish that :

  -f image2 -r 10 -i {location of jpegs}+"\img%05d.jpg -crf 23  -y -r 10 -f ogg -

  and in my code I would get the memory stream like so :

  mStandardOutput = serverBuild.StandardOutput.BaseStream;
  
  mStandardOutput.BeginRead(mReadBuffer, 0, mReadBuffer.Length, StandardOutputReadCallback, null);
  
  serverBuild.WaitForExit();
  
  data = mStandardOutputMs.ToArray();
  
  mStandardOutput.Close();

  Now ultimately, I would like to replace :

  -i {location of jpegs}+"\img%05d.jpg

  with a constant flow of jpegs in a memory stream like so :

  ffmpeg -f mjpeg -i - -r 10 -c:v libtheora -q:v 7 -f ogg -

  .. by over-writing the stdin...

  But I have not done this yet because I want to 1st try getting the ogg to be received within my web server.

  From there I would extract the jpegs to be accessible somehow via my web application written in asp.net 4.0.

  But first thing is first I want to just see if I can receive the UDP stream from my client.
  So, I create a test C# application to open and listen write from the client stream..
  this is my code :

  Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
  
  public Form1()
  
  {
  
     InitializeComponent();
  
  
  
     socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
  
     string ip = "My Server IP Address";
  
     int port = 3000;
  
     socket.Bind(new IPEndPoint(IPAddress.Parse(ip), port));
  
  }
  
  
  
  private void button1_Click(object sender, EventArgs e)
  
  {
  
     try
  
     {
  
        var buffer = new byte[1024];
  
        while (true)
  
        {
  
           Application.DoEvents();
  
           int numBytesReceived = socket.Receive(buffer);
  
           if (numBytesReceived > 0)
  
           {
  
              File.WriteAllBytes("c:\\udp\\test.ogg", buffer);
  
           }
  
        }
  
     }
  
     catch (Exception _ex)
  
     {
  
        MessageBox.Show(_ex.ToString());
  
     }
  
  }

  But, I get this error :

  A message sent on a datagram socket was larger than the internal message buffer or some other network limit, or the buffer used to receive a datagram into was smaller than the datagram itself.

  What am I doing wrong please ?

  Thanks

• ffmpeg is dropping frames and only using 1/10 cpu [on hold]

  7 décembre 2013, par wlraider70

  I have some old hardware so I'm not expecting miracles. I want to stream from a webcam to ustream at standard quality.

  I'm using a code like

  sudo ffmpeg -re -f v4l2 -i /dev/video1 -f flv "rtmp://1.16543hvtJ6aU flashver=FME/2.5\20(compatible;\20FMSc\201.0)"

  or

     sudo ffmpeg -re -f v4l2 -r 25 -s 640x480 -i /dev/video1 -f flv "rtmp://1.166aU flashver=FME/2.5\20(compatible;\20FMSc\201.0)

  I'm getting results like

  Tasks: 102 total,   1 running,  99 sleeping,   2 stopped,   0 zombie
  
  Cpu(s):  5.7%us,  0.7%sy,  0.0%ni, 93.6%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
  
  Mem:   1920560k total,   339028k used,  1581532k free,    19112k buffers
  
  Swap:  1963004k total,        0k used,  1963004k free,   129300k cached
  
  
  
    PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  
   3176 root      20   0  222m  31m  24m S  5.0  1.7   0:01.60 ffmpeg

  and

    Metadata:
  
      encoder         : Lavf53.32.100
  
      Stream #0:0: Video: flv1 ([2][0][0][0] / 0x0002), yuv420p, 640x480, q=2-31, 200 kb/s, 1k tbn, 30 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo -> flv)
  
  Press [q] to stop, [?] for help
  
  frame=  330 fps=  5 q=2.5 size=     808kB time=00:01:02.70 bitrate= 105.5kbits/s dup=0 drop=137

  How can I push the system harder or figure out where my bottleneck is ?

• Android FFmpeg : get frame count from video

  17 août 2017, par Tix

  I only want to filter out 20% of frames from the start of the video and the end of the video, but i cant do that if i dont have total frame count.

  I alr know how to filter out frames, i just need to know how to get total frame count of a video.

  I’ve looked this up, and there was answers saying use ffprobe to fetch total number of frames in a video. However ffmpeg for android doesnt have it.. is there another way to get the frame count from a video ?

  Compiled ffmpeg for android using :

  compile ’com.writingminds:FFmpegAndroid:0.3.2’