Recherche avancée

Sur d’autres sites (4871)

• Building A livestreaming server like youtube from scratch

  9 décembre 2022, par Dipo Ahmed

  I am trying to build a live streaming server like youtube where I can watch the video live or if I want to I can play the video from any duration I want.

  


  What I have tried so far.
I have built a node js WebSocket server where I push the video blob that I receive from the browser via MediaRecorder API every 2 seconds. This blob is then getting converted to hls by a ffmpeg process which generates 2 seconds *.ts files and a .m3u8 file which I am playing with video.js in browser.

  


  This is my ffmpeg command

  


   spawn('ffmpeg', [
        '-i', '-',
        // '-re',
        '-fflags', '+igndts',

        '-vcodec', 'h264',
        '-acodec', 'aac',

        '-preset', 'slow',
        '-crf', '22',
        // You can also use QP value to adjust output stream quality, e.g.: 
        // '-qp', '0',
        // You can also specify output target bitrate directly, e.g.:
        '-b:v', '1500K',
        '-b:a', '128K', // Audio bitrate

        '-f', 'hls',
        '-hls_time', '1',
        // '-hls_playlist_type', 'vod',
        '-hls_list_size', '2',
        '-hls_flags', 'independent_segments',
        '-hls_segment_type', 'mpegts',
        '-hls_segment_filename', `${path}/stream%02d.ts`, `${path}/stream.m3u8`,
    ]);


  


  The problem is that the video js player duration is not updating like in youtube where the video duration increases every second.

  


  Any direction will be appreciated. Please tell me if my approach is wrong and what needs to be learned for me to build this system.

  


• Download a part of youtube video using a powershell script

  26 octobre 2024, par Nguyễn Đức Minh

  I'm writing this Powershell script :

  


  $URL = "https://www.youtube.com/watch?v=KbuwueqEJL0"
$from = 00:06:15
$to = 00:09:17

$cmdOutput = (youtube-dl --get-url $URL) 

ffmpeg -ss $from -to $to -i  -ss $from -to $to -i  output.mkv


  


  This script's purpose is to download a part of a Youtube video. I've set the variable $URL to specify the Youtube URL, while $from and $to is the start and end time of the part I want to download.

  


  $cmdOutput is used to output the stream URL. The output would have two lines : the first one is the URL for the video stream, while the second one is the audio stream URL.

  


  Currently, I don't know how to use the output as a variable and specify the line number of $cmdOutput to put it into the correct stream. I guess and would be replaced by something like $cmdOutput[line 1], and $cmdOutput[line 2], though I know that those are incorrect.

  


  I've consulted this answer, and it is handy for me to write this script. I've also read Boris Lipschitz's answer on how to do the same thing with Python, but his answer does not work.

  


  In that script, the -ss flag inputs the seeking point, and the -t <duration></duration> flag tells FFmpeg to stop encoding after the specified duration. For example, if the start time is 00:02:00 and the duration is 00:03:00, FFmpeg would download from 00:02:00 to 00:05:00, which is not the expected outcome. For some reason, his Python script skips the first 5 seconds of output, even if I replace the -t flag with -to . I've tried to edit his script, but it does not work unless you explicitly specify the time for both video and audio stream, as well as their respective stream URL.

  


• Capture Thumbnail Whilte Downloading Youtube Video

  31 décembre 2012, par Minime

  I want to capture a thumbnail of Youtube video on certain timeline. (e.g. 3.2sec)
  I used ytdl and fluent-ffmpeg with node.js to implement it.
  It was possible to capture a thumbnail when the downloading has finished.

  var fs = require('fs');
  
  var ytdl = require('ytdl');
  
  var ffmpeg = require('fluent-ffmpeg');
  
  var videostream = fs.createWriteStream('video.flv');
  
  var myytdl = ytdl('http://www.youtube.com/watch?v=A02s8omM_hI');
  
  myytdl.pipe(videostream);
  
  videostream.on('close',function() {
  
    console.log('Downloading complete...');
  
    var proc = new ffmpeg({ source: 'video.flv', nolog: true })
  
    .withSize('150x100')
  
    .takeScreenshots(1, '/home/test', function(err) {
  
      console.log(err || 'Screenshots were saved');
  
    });
  
  });

  However, I couldn't implement to capture a thumbnail while downloading. Basic idea of what I want to do is as below.

  1. Download Youtube video starting at X sec. (Worked)
  2. Pipe it to Readable/Writable(Duplex) Memory Stream (Need Advise)
  3. During downloading, check if stream has enough data to capture the first frame, which is at X sec. (Need Advise)
  4. Capture the first frame, then stop downloading

  For 2, I've realized that node.js will have Duplex Stream on coming v0.9.x, but it seems not working properly. Anyone who has good idea to implement bullet 2,3 ?