Recherche avancée

Sur d’autres sites (13264)

• FFmpeg.wasm demuxing - Get encodedChunks in Javascript

  16 mars 2023, par Kevin Baving

  I am building a video editor whose process looks like this :

  


  Demuxing -> Decoding -> Editing -> Encoding -> Muxing.

  


  The demuxing and muxing process is currently done with mp4box.js. I would like to replace mp4box.js with ffmpeg.wasm. Unfortunately, I can't get along with the process.

  


  What should FFmpeg.wasm do in the demuxing process ?

  


  

  • load a .mp4 file

  


  • extract the encodedVideoChunks and store them as EncodedVideoChunk objects in an array

  


  • extract the encodedAudioChunks and store them as EncodedAudioChunk objects in an array

  


  • get some metadata like : duration, timescale, fps, track_width, track_height, codec, audio_channel_count, sample_rate ....

  


  


  public async loadFile(file: File) {
    let data = await fetchFile(file)
    let blob = new Blob();
    await this.ffmpeg.setProgress(({ratio }) => console.log(`Extracting frames: ${Math.round(ratio * 100)}%`));
    this.ffmpeg.FS('writeFile', 'videoTest.mp4', data);
    //Here is where I am struggling
    //Should look like this: 
    //const command = '-i videoTest.mp4 -c:v copy .... '
    //await this.ffmpeg.run(command);
    //....
}


  


  Lets get deeper into my problem :

  


  Because FFmpeg.wasm is still a cli tool, I have no idea what the best way to safe the encodedChunks into a file is (and what kind of filetype I should use). Further I would like to know how to read that file propertly so that i can safe the input of the file into seperate EncodedVideo- and AudioChunks.

  


• ffmpeg is not working while uploading file using uploadify

  21 janvier 2016, par Ranjith

  for a particular video i tried like this, and it worked

  exec('/usr/bin/ffmpeg -i /home/xxxxxx/public_html/test/video1.mp4  /home/xxxxxxx/public_html/test/video1.flv');

  but for uploadify i write code like this ,

  <?php
  
  
  
  if (!empty($_FILES)) {
  
  $userId=$_SESSION["user_userid"];
  
  $filename = $_FILES['Filedata']['name'];
  
  $filetmpname = $_FILES['Filedata']['tmp_name'];
  
  $fileType = $_FILES["Filedata"]["type"];
  
  $fileSizeMB = ($_FILES["Filedata"]["size"] / 1024 / 1024);
  
  $folder=$_REQUEST['folder'];
  
  
  
  exec("/usr/bin/ffmpeg -i"."/home/xxxxxx/public_html/private/".$folder."/".$filename." "."/home/xxxxxx/public_html/private/".$folder."/".$filename.".flv");
  
  
  
  }elseif($_POST['d']){
  
  $filename = $_POST['d'];
  
  $folder=$_REQUEST['folder'];
  
  $dFile = $folder.$filename;
  
  if(file_exists($dFile)){
  
      unlink($dFile);
  
  }
  
  }
  
  ?>

  this code is not converting the uploaded file.
  help me please.

  thanks

• How to generate only 10 thumbnails irrespective of video duration with ffmpeg

  15 août 2022, par EaBengaluru

  Hi i want to generate only 10 thumbnails irrespective of video duration with ffmpeg

  


  I have followed this thread Create multiple thumbnails from a video at equal times / intervals

  


  here is the command i'm using

  


  ffmpeg -i input.mp4 -vf "select='not(mod(t,60/12))'" -vsync vfr output_%04d.jpg


  


  for 14.4 duration video it is generating only 3 thumbnails , i want always 10 with equal interval.

  


  For example if i have 120 duration video i must get thumbnails at

  


  [0 or 12, 24,36,48,60,72,84,96,108,120]


  


  Question : i want to generate always 10 thumbnails with equal interval as shown in example for duration of 120