Recherche avancée

Sur d’autres sites (12532)

• How YouTube identifies if a movie is shaky [closed]

  28 novembre 2012, par MollyRazor

  After uploading a movie to Youtube, it analyzes the movie and if it's shaky, then it gives the option to correct it. The correction works with ffmpeg, but is there any open source method to analyze whether a movie is shaky ?

  I can't understand StackOverflow moderators. This place is full of self righteous bastards.

  Mr. Moderator says in a comment : ffmpeg is open source. O REALLY ? Then what parameters to use so ffmpeg outputs => yes, this is a shaky movie or no, this isnt. Ah, you can't answer that, so you close this question.

  Have you even read the question thoroughly ? Then do so again please. I think by the age of 50 you can correctly interpret what was written and what the question was.

  Thank you.

• 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 ?

• How to Replace Duplicate Frames in a Video with Black Frames using ffmpeg ?

  21 mars 2021, par Yam Shargil

  I'm trying to trim all "no action, no movement" frames out of my screen recording. Some of my screen recordings are really long (like 100 hours long).

  


  I found this :
How to Simply Remove Duplicate Frames from a Video using ffmpeg

  


  ffmpeg -i in.mp4 -vf
"select='if(gt(scene,0.01),st(1,t),lte(t-ld(1),1))',setpts=N/FRAME_RATE/TB"
trimmed.mp4


  


  I don't want to lose any important frames, so for testing the threshold purposes, I want to replace (not remove) all the "no action" frames with black frames.

  


  That's my best shot so far, not my proudest work :

  


  ffmpeg -i in.mp4 -vf "select='if(gt(scene,0.01),st(1,t),lte(t-ld(1),1))',drawbox=color=black:t=fill" out.mp4