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• Révision 108131 : [ux] Placer la prévisualisation du forum sous le forum (au lieu de dessus)

  20 décembre 2017, par erational@erational.org

  https://core.spip.net/issues/4063

• 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 !

• ffmpeg : can't loop over files in folder error : f was unexpected at this time

  17 février 2021, par parsecer

  I have a folder with .avi files :

  


  dogs
  dog1.avi
  dog2.avi
  ...


  


  Each .avi file has 2 audio tracks. I want to remove the first track.

  


  I can do if for one file like this :

  


  ffmpeg -i dog1.avi -map 0 -map -0:a:0 -c copy dog1-changed.avi


  


  However I need to do it for all files.

  


  I tried (after cd dogs) :

  


  for f in *avi; do ffmpeg -i "$f" -map 0 -map -0:a:0 -c copy "${f/%.avi/-changed.mkv}"; done


  


  However it gives

  


  f was unexpected at this time


  


  error.

  


  How do I fix it ?