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• Which is the better way to use ffmpeg ?

  11 mai 2016, par seaguest

  We need ffmpeg to do some video processing, like video format conversion, live stream snapshot..., we won’t go deep in ffmpeg.

  Now I am wondering what would be the better way to use ffmpeg, we are developping in Golang, either we call ffmpeg like shell command line, or we use libav* library of ffmpeg.

  command line:
  
      Pros: 
  
          easy to use, reliable (I got a quality loss problem with library mode), many tutorials
  
      Cons:
  
          the is is a separate process, out of our control, we can't get detailed information of the process, like the video conversion progressing data
  
          the command line way seems not so cool, this is not well integrated in the whole project.
  
  
  
  libav* library:
  
      Pros:
  
          we can have the process detailed data, progressing status....
  
          ...
  
  
  
      Cons:
  
          difficult to use, much less materials

  Could anyone give your idea which is the better way to use ffmpeg ?

  Before this question, I have asked another two questions :

  One is regarding calling libav* library caused the qulity loss problem :
  Why calling libav* library doesn’t have same quality as ffmpeg command line ?

  One is for command line progressing status retrieving problem :
  How to get the realtime output for a shell command in golang ?

• Cutting and fading ts segment with ffmpeg ?

  6 juillet 2017, par Matt W

  I’m trying to cut a ts segment and apply a fade from white at the initial point of the cut segment. This is used in a situation where I need to "crop" some material from the beginning of a video and apply a fade for a smoother entry. In my test, I am cutting an 8 second segment at the 5.5s mark to yield a 2.5 second segment that will fade from white over the first second.

  The cut command by itself works fine :

  ffmpeg  -i test.ts  -ss 5.5 -c:v libx264 -profile:v baseline -c:a aac -map 0 -mpegts_copyts 1  -preset ultrafast -f ssegment -initial_offset 5.5 -segment_format mpegts   ~/Desktop/cut%d.ts

  I’ve successfully used this fade filter syntax before :

  -filter:v fade=t=in:st=0:d=1:color=0xffffff

  But I can’t seem to make the whole thing work :

  ffmpeg  -i test.ts  -filter:v fade=t=in:st=5.5:d=1:color=0xffffff  -ss 5.5 -c:v libx264 -profile:v baseline -c:a aac -map 0 -mpegts_copyts 1  -preset ultrafast -f ssegment -initial_offset 5.5 -segment_format mpegts   ~/Desktop/cut%d.ts

  I’m getting the following error :

  x264 [error] : baseline profile doesn’t support 4:4:4

  [libx264 @ 0x7fd9db002400] Error setting profile baseline.

  [libx264 @ 0x7fd9db002400] Possible profiles : baseline main high high10
  high422 high444

  Error initializing output stream 0:1 — Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height

  [aac @ 0x7fd9db001200] Qavg : nan

  Conversion failed !

  My knowledge of ffmpeg just isn’t deep enough to figure out why this is happening. Any thoughts ?

  Thanks,
  Matt

• ffmpeg video unable to play properly in most video players

  7 septembre 2022, par Lars

  I'm trying to set up a node.js app that allows me to download files from a web interface.
I'm using yt-dl to get the video and audio stream and ffmpeg to pipe those streams into an mp4. This works and returns a mp4 file.

  


  Now the only issue I have is that when I play the file through most video players, the video player is unable to seek, or skip through the song. I found somewhere deep down on a forum that means that that means the mp4 headers are not working but that is all I could find.
Here is my code, almost unchanged from this response on another thread.

  


  Can anyone provide a solution for this issue.

  


  ytdl.getInfo(link, options).then(info => {
        audioStream = ytdl.downloadFromInfo(info, { ...options, quality: 'highestaudio' });
        videoStream = ytdl.downloadFromInfo(info, { ...options, quality: 'highestvideo' });
        // create the ffmpeg process for muxing
        ffmpegProcess = cp.spawn(ffmpegPath, [
            // supress non-crucial messages
            '-loglevel', '8', '-hide_banner',
            // input audio and video by pipe
            '-i', 'pipe:3', '-i', 'pipe:4',
            // map audio and video correspondingly
            '-map', '0:a', '-map', '1:v',
            // no need to change the codec
            '-c', 'copy',
            // output mp4 and pipe
            '-f', 'matroska', 'pipe:5'
        ], {
            // no popup window for Windows users
            windowsHide: true,
            stdio: [
                // silence stdin/out, forward stderr,
                'inherit', 'inherit', 'inherit',
                // and pipe audio, video, output
                'pipe', 'pipe', 'pipe'
            ]
        });
        audioStream.pipe(ffmpegProcess.stdio[3]);
        videoStream.pipe(ffmpegProcess.stdio[4]);
        ffmpegProcess.stdio[5].pipe(result);
    });