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• I can't get bitmap from Process StandardOutput pipe ffmpeg

  7 juin 2018, par Srdjan M.

  Following article Read and Write Video Frames Using FFMPEG, I am trying to extract and process all frames from a video. The problem is that I don’t get exact same bytes in buffer and sample image.

  string Arguments = string.Format(@"-i {0} -f image2pipe -pix_fmt bgr24 -vcodec rawvideo pipe:", "output.mp4");
  
  using (Process process = new Process())
  
  {
  
      process.StartInfo.CreateNoWindow = false;
  
      process.StartInfo.UseShellExecute = false;
  
      process.StartInfo.RedirectStandardOutput = true;
  
      process.StartInfo.FileName = "ffmpeg.exe";
  
      process.StartInfo.Arguments = Arguments;
  
  
  
      process.Start();
  
  
  
      char[] buffer = new char[854 * 480 * 3];
  
  
  
      using (StreamReader reader = process.StandardOutput)
  
      {
  
          while (!reader.EndOfStream)
  
          {
  
              reader.Read(buffer, 0, buffer.Length);
  
          }
  
      }
  
  
  
      process.WaitForExit();
  
  }

• Node.js, stream pipe output data to client with socket io-stream

  22 mai 2018, par Empha

  Sorry for a repeating topic, but i’ve searched and experimented for 2 days now and i haven’t been able to solve the problem.

  I am trying to live stream pictures every 1 second to a client via socket.io-stream using the following code :

  var args = [
  
      "-i",
  
      "/dev/video0",
  
      "-s",
  
      "1280x720",
  
      "-qscale",
  
      1,
  
      "-vf",
  
      "fps=1",
  
      config.imagePath,
  
      "-s",
  
      config.imageStream.resolution[0],
  
      "-f",
  
      "image2pipe",
  
      "-qscale",
  
      1,
  
      "-vf",
  
      "fps=1",
  
      "pipe:1"
  
  ];
  
  camera = spawn("avconv", args);    // avconv = ffmpeg

  The settings are good, and the process writes to stdout successfully. I capture all outgoing image data using this simplified code :

  var ss = require("socket.io-stream");
  
  camera.stdout.on("data", function(data) {
  
      var stream = ss.createStream();
  
      ss(socket).emit("img", stream, "newImg");
  
      // how do i write the data-object to the stream?
  
      // fs.createReadStream(imagePath).pipe(stream);
  
  });

  "socket" comes from the client using the socket.io-package, no problem there. So what i am doing is that i listen to the stdout-pipe for the "data" event. That data gets passed to the function above. That means that at this stage "data" is not a stream, its a "<buffer></buffer>code>"-object, and therefore i cannot stream it like i could previously using the commented createReadStream-statement where i read the image from disk. <strong>How do i stream the data (Buffer at this stage) to the client? Can i do this differently, perhaps not using socket.io-stream?</strong> "data" is just one part of the whole image, so perhaps two or three "data"-objects need to be put together to form the complete image.

  I tried using "stream.write(data, "binary") ;" which did transfer the Buffer-objects, problem is that there is not end of stream-event and therefore i do not know when an image is complete. I tried registering to stdout.on "close", "end", "finish", nothing triggers. Am i missing something ? Am i making it overly complex ? The reasoning behind my implementation is that i need a new stream for each complete image, is that right ?

  Thanks alot !

• pipe:0 : could not find codec parameters

  10 avril 2018, par Harish

  I am trying to store streaming video as a segments of 15 min,it is working fine with gst-launch-1.0 my command is

  gst-launch-1.0 -e --gst-debug-level=2 v4l2src device=/dev/video0 ! vspmfilter outbuf-alloc=true ! \
  
  video/x-raw,width=640,height=480,framerate=15/2 ! omxh264enc target-bitrate=10485760 num-p-frames=0 ! \
  
  mpegtsmux name="muxer" ! fdsink fd=1 \
  
  alsasrc device=hw:0,0 latency-time=30000 buffer-time=800000 ! audioconvert ! audio/x-raw,format=S16LE,channel=2,rate=44100 ! \
  
  faac bitrate=128000 ! muxer. \
  
  | /usr/bin/ffmpeg -v info -i pipe:0 -map 0 -c copy -f segment \
  
  -reset_timestamps 1 -segment_atclocktime 1 -segment_time 900 \
  
  -segment_list_type csv -segment_list_size 0 \
  
  -segment_list /home/root/ContinuousCapture/CamFiles.txt
  
  -segment_list_entry_prefix /home/root/ContinuousCapture/ \
  
  -segment_format mpegts -strftime 1 /home/root/ContinuousCapture/video_%g%m%d_%H%M%S.mpegts

  I changed same command to gstd,my command is

  gstd-client pipeline_create p v4l2src device=/dev/video0 ! ${textoverlay} text=${dev0} ! ${clockoverlay} ! vspmfilter outbuf-alloc=true ! \
  
  video/x-raw,width=640,height=480,framerate=15/2 ! omxh264enc target-bitrate=10485760 num-p-frames=0 \
  
  mpegtsmux name="muxer" ! fdsink fd=1 \
  
  alsasrc device=hw:0,0 latency-time=30000 buffer-time=800000 ! audioconvert ! audio/x-raw,format=S16LE,channel=2,rate=44100 ! \
  
  faac bitrate=128000 ! muxer. \ 
  
  gstd-client pipeline_play p | /usr/bin/ffmpeg  -v info -i pipe:0 -map 0 -c copy -f segment \
  
  -reset_timestamps 1 -segment_atclocktime 1 -segment_time 900 \
  
  -segment_list_type csv -segment_list_size 0 \
  
  -segment_list /home/root/ContinuousCapture/CamFiles.txt -segment_list_entry_prefix /home/root/ContinuousCapture/ \
  
  -segment_format mpegts -strftime 1 /home/root/ContinuousCapture/video_%g%m%d_%H%M%S.mpegts

  its giving me the following error

  libdir=/usr/lib --shlibdir=/usr/lib --datadir=/usr/share/ffmpeg --disable-mipsdsp --disable-mipsdspr2 --cpu=generic --pkg-config=pkg-config --enable-avcodec --enable-avdevice --enable-avfilter --enable-avformat --disable-avresample --enable-bzlib --enable-gpl --disable-libgsm --disable-indev=jack --disable-libvorbis --disable-libmp3lame --disable-openssl --enable-postproc --disable-libschroedinger --disable-sdl2 --disable-libspeex --enable-swresample --enable-swscale --enable-libtheora --disable-vaapi --disable-vdpau --disable-libvpx --enable-libx264 --enable-outdev=xv
  
  libavutil      55. 58.100 / 55. 58.100
  
  libavcodec     57. 89.100 / 57. 89.100
  
  libavformat    57. 71.100 / 57. 71.100
  
  libavdevice    57.  6.100 / 57.  6.100
  
  libavfilter     6. 82.100 /  6. 82.100
  
  libswscale      4.  6.100 /  4.  6.100
  
  libswresample   2.  7.100 /  2.  7.100
  
  libpostproc    54.  5.100 / 54.  5.100
  
  [mpegts @ 0x49450] Format mpegts detected only with low score of 2, misdetection possible!
  
  [mpegts @ 0x49450] Could not detect TS packet size, defaulting to non-FEC/DVHS
  
  pipe:0: could not find codec parameters

  Thank you