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• stream flv over tcp using ffmpeg

  16 août 2017, par Naseeb Panghal

  I am using FC23 machine and FFMPEG version is 2.8.10

  Using below command, I can stream flv over tcp successfully and able to receive it successfully at receiver side as well. I play it using vlc player. Both audio and video are played well.

  ./ffmpeg -f x11grab -s 1920x1080 -framerate 15 -i :0.0 -f alsa -ac 2 -i hw:1 -vcodec libx264 -r 30 -pix_fmt yuv420p -tune zerolatency -preset ultrafast -acodec aac -strict -2 -ar 48000 -ab 96k -f flv -metadata streamName=naseeb.sdp tcp ://127.0.0.1:6666

  But in actually i need to do this using an application. So i wrote an application in ’C’ language.
  I have done following things in the application.

  1. open `AVOutputFormat` using below API
  
      fmt = av_guess_format("flv", NULL , NULL);
  
   2. Get `AVFormatContext` using below API
  
      avformat_alloc_output_context2(&oc, fmt, NULL, NULL);
  
   3. Then added streams(audio and video) using required APIs
  
   4. Then open codecs using required APIs
  
   5. Then set the output using below API
  
      ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);

  When i need to write flv into a file on system then i provide filename in step 5 as muxer.flv.
  When i need to stream flv over tcp then i provide filename as tcp://127.0.0.1:6666.

  when i play muxer.flv using vlc player both video and audio are played well but when it is streamed over network then Green frames are shown for video and audio works very well. I am wondering what extra setting is required when i need to stream it over network ?

  I have no doubt on Receiver side as it works very well with ffmpeg utility(command mentioned above).
  Currently i have downloaded ffmpeg 2.8.10 source code and looking into ffmpeg.c file for some extra setting. Till now i have not found anything helpful. Please suggest something why Green frames shown when flv is sent on network where it works well when dump on system hard disk.

• TCP or UDP ? Delays building up on production for video stream

  31 janvier 2020, par Ben Beri

  I am creating a video stream from a camera with FFMPEG and nodejs stream Duplex class.

  this.ffmpegProcess = spawn('"ffmpeg"', [
  
  
  
    '-i', '-',
  
    '-loglevel', 'info',
  
  
  
    /**
  
     * MJPEG Stream
  
     */
  
  
  
    '-map', '0:v',
  
    '-c:v', 'mjpeg',
  
    '-thread_type', 'frame', // suggested for performance on StackOverflow.
  
    '-q:v', '20', // force quality of image. 2-31 when 2=best, 31=worst
  
    '-r', '25', // force framerate
  
    '-f', 'mjpeg',
  
    `-`,
  
  
  
  ], {
  
    shell: true,
  
    detached: false,
  
  });

  On local network, we are testing it with a few computers and every thing works very stable with latency of maximum 2 seconds.

  However, we have imported the service to AWS production, when we connect the first computer we have a latency of around 2 seconds, but if another client connects to the stream, they both start delaying a lot, where the latency builds up to 10+ seconds, and in addition the video is very slow, as in the motion between frames.

  Now I asked about TCP or UDP is because we are using TCP for the stream, which means that every packet that is sent is implementing the TCP syn-ack-synack protocol and sequence.

  My question is, could TCP really be causing such an issue that the delays get up to 10 seconds with very slow motion ? because on local network it works very just fine.

• Encoding Android Camera Frames h263/h264 [closed]

  29 décembre 2015, par Another Guy

  I want to implement a Video Chatting app on Android . I created a SurfaceView , get Camera preview and captured the frame as a byte[ ] using Camera.PreviewCallback.onPreviewFrame( ) method . Now I want to encode that byte[ ] to a h263 frame , pass over the network . Also get similar type of frame over network , decode it to a byte[ ] ( or a displayable format ) , and show it in a View . I want to do it at least 15 FPS rate . I am asking help for the encoding/decoding part .

  For that purpose , which library would be suitable for me ? From where I should start ? Is my starting point wrong ? Is there any support on SDK or would I have to use NDK ? I have heard about FFMpeg/x264 library , but I could not figure out how I can use them in my purpose . It’s highly appreciated If you name any library , any reference , learning path , link or code snippet . Can you help me saying any workflow I should follow ? What if I want to use h264 encoding ? I just want to get it done , GPL/LGPL license of library would not matter a lot .

  I am a beginner in Android development . Any kind of assistance would be highly appreciated . Thanks in advance .