Recherche avancée

Sur d’autres sites (12219)

• 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 !

• How to compress video applying even blur effect

  17 octobre 2016, par Kukuster

  How to compress video applying well-looking apportioned blur effect, like in JPG image ?

  I tried some ffmpeg postprocesing libraries, they are fspp, spp, uspp (takes really long time to render), etc. I almost reached the goal using fspp with parameters 5:60:15 . But blur was stronger than needed, and it’s leave bad artifacts when i try to use less compression. Also uspp is does beautiful and compresses enough, but it’s leave about 50% of video unblured. I also haven’t much time to try all uspp features. Is there resolution special for this purpose ?

  The point is to implement video compression with the only side effect of compression approaches jpeg-compression-like blur or blur-mask-like. Also it would be very good if there is a simple option to choose between :
  1) more compress, less pretty blur / more strong blur ; and 2) less compress, prettier blur / less strong blur.

  I am used to use ffmpeg and i’m running linux, so it would be so nice if there is a way to solve this with ffmpeg.
  Here is my ffmpeg input data about the video streams :

    Duration : 00:01:03.02, start : 0.000000, bitrate : 4010 kb/s
      Stream #0:0(und) : Video : h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 3870 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
      Metadata :
        handler_name : VideoHandler
      Stream #0:1(eng) : Audio : aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 133 kb/s (default)
      Metadata :
        handler_name : SoundHandler
  

  Edit : attaching jpeg pictured as example of desired output :
  
  

• ffprobe not showing language tag for ASS files in Ubuntu

  9 juillet 2023, par Efraín

  This is something that has me totally lost, because I'm not sure what could I have done, but from one week to another, "language" stopped appearing in the tags of an ASS track on a MKV. I know this just started to appear, because just last week I ended working on an script to detect the language of tracks, and today that I decided to test it again, I noted that it started to fail, and from my debug it's because ffprobe is now printing this

  


  {
    "index": 2,
    "codec_name": "ass",
    "codec_long_name": "ASS (Advanced SSA) subtitle",
    "codec_type": "subtitle",
    "codec_tag_string": "[0][0][0][0]",
    "codec_tag": "0x0000",
    "r_frame_rate": "0/0",
    "avg_frame_rate": "0/0",
    "time_base": "1/1000",
    "start_pts": 0,
    "start_time": "0.000000",
    "duration_ts": 1430816,
    "duration": "1430.816000",
    "disposition": {
        "default": 1,
        "dub": 0,
        "original": 0,
        "comment": 0,
        "lyrics": 0,
        "karaoke": 0,
        "forced": 0,
        "hearing_impaired": 0,
        "visual_impaired": 0,
        "clean_effects": 0,
        "attached_pic": 0,
        "timed_thumbnails": 0
    },
    "tags": {
        "BPS-eng": "85",
        "DURATION-eng": "00:23:34.830000000",
        "NUMBER_OF_FRAMES-eng": "262",
        "NUMBER_OF_BYTES-eng": "15128",
        "_STATISTICS_WRITING_APP-eng": "mkvmerge v40.0.0 ('Old Town Road + Pony') 32-bit",
        "_STATISTICS_WRITING_DATE_UTC-eng": "2023-07-02 11:29:54",
        "_STATISTICS_TAGS-eng": "BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES"
    }
}


  


  Where it should be a field called "language" in the "tags", like this(Note that other file types, like SRT, or audio tracks show it correctly)

  


  "tags": {
    "language": "eng",
    "BPS-eng": "128000",
    "DURATION-eng": "00:23:50.813000000",
    "NUMBER_OF_FRAMES-eng": "61620",
    "NUMBER_OF_BYTES-eng": "22893018",
    "_STATISTICS_WRITING_APP-eng": "mkvmerge v40.0.0 ('Old Town Road + Pony') 32-bit",
    "_STATISTICS_WRITING_DATE_UTC-eng": "2023-07-02 11:29:54",
    "_STATISTICS_TAGS-eng": "BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES"
}


  


  The weird part is that is the same file I used for testing(And it worked), and I haven't edited it, so I'm not sure why is this happening, Does someone knows if I might have messed up something installing a library for another thing that might have caused it ?

  


  Just in case is necessary, this is the command I use : ffprobe -v quiet -print_format json -show_streams <file></file>