Recherche avancée

Sur d’autres sites (5936)

• Correcting the variable name in an ffmpeg subtitle script

  21 juin 2017, par Steven Foong

  I have 175 mp4 video files and subtitle files with the extension .ass. Unfortunately, my smart TV is not able to read those subtitles. I plan to burn (hardcode) the subtitles into the video.

  I use this command :

  ffmpeg -i orgvideo.mp4 -vf subtitles="subtitle.ass" newvideo.mp4     <br />

  It works. So I plan to use a bash script to automate the process.

  Everything in the script is working but the ffmpeg command line isn’t able to retrieve the subtitle variable.

  After googling around, I found that my file name has special character and space, that causes my script to fail. If the video file name and the subtitle file is simple, then the script should be no problem.

  This is my script :

  for f in *.mp4
  
  do
  
      new="${f%%.mp4} (CHT).mp4"
  
      subtitle="${f%%.mp4}.chi.ass"
  
      < /dev/null ffmpeg -i "$f" -vf subtitles="$subtitle" "$new"
  
  done

  The ffmpeg line is having problems reading the subtitle file variable. Can anyone help ?

• Cloud Functions for Firebase : completing long processes without touching maximum timeout

  17 février, par Scott Ewing

  I have to transcode videos from webm to mp4 when they're uploaded to firebase storage. I have a code demo here that works, but if the uploaded video is too large, firebase functions will time out on me before the conversion is finished. I know it's possible to increase the timeout limit for the function, but that seems messy, since I can't ever confirm the process will take less time than the timeout limit.

  



  Is there some way to stop firebase from timing out without just increasing the maximum timeout limit ?

  



  If not, is there a way to complete time consuming processes (like video conversion) while still having each process start using firebase function triggers ?

  



  If even completing time consuming processes using firebase functions isn't something that really exists, is there some way to speed up the conversion of fluent-ffmpeg without touching the quality that much ? (I realize this part is a lot to ask. I plan on lowering the quality if I absolutely have to, as the reason webms are being converted to mp4 is for IOS devices)

  



  For reference, here's the main portion of the demo I mentioned. As I said before, the full code can be seen here, but this section of the code copied over is the part that creates the Promise that makes sure the transcoding finishes. The full code is only 70 something lines, so it should be relatively easy to go through if needed.

  



  const functions = require('firebase-functions');
const mkdirp = require('mkdirp-promise');
const gcs = require('@google-cloud/storage')();
const Promise = require('bluebird');
const ffmpeg = require('fluent-ffmpeg');
const ffmpeg_static = require('ffmpeg-static');


  



  (There's a bunch of text parsing code here, followed by this next chunk of code inside an onChange event)

  



  function promisifyCommand (command) {
    return new Promise( (cb) => {
        command
        .on( 'end',   ()      => { cb(null)  } )
        .on( 'error', (error) => { cb(error) } )
        .run();
    })
}
return mkdirp(tempLocalDir).then(() => {
    console.log('Directory Created')
    //Download item from bucket
    const bucket = gcs.bucket(object.bucket);
    return bucket.file(filePath).download({destination: tempLocalFile}).then(() => {
      console.log('file downloaded to convert. Location:', tempLocalFile)
      cmd = ffmpeg({source:tempLocalFile})
               .setFfmpegPath(ffmpeg_static.path)
               .inputFormat(fileExtension)
               .output(tempLocalMP4File)
      cmd = promisifyCommand(cmd)
      return cmd.then(() => {
        //Getting here takes forever, because video transcoding takes forever!
        console.log('mp4 created at ', tempLocalMP4File)
        return bucket.upload(tempLocalMP4File, {
            destination: MP4FilePath
        }).then(() => {
          console.log('mp4 uploaded at', filePath);
        });
      })
    });
  });


  


• Bash - Not able to replace the variable in ffmpeg subtitle

  20 juin 2017, par Steven Foong

  I have 175 mp4 video files and subtitle file with extension ass. Unfortunately my smart TV not able to read the subtitle title. I plan to burn (hardcode) the subtitle into the video.

  I use this command

  ffmpeg -i orgvideo.mp4 -vf subtitles="subtitle.ass" newvideo.mp4

  it work. So I plan to use bash shell script to automate the process.

  Everything is the script is working , but the ffmpeg command line wouldn’t able to retrieve the subtitle variable.

  After google around, I found that my file name has special character and space, that cause my script not working. If the video file name and the subtitle file is simple, then the script should be no problem.

  This is my script.

  for f in *.mp4
  
  do
  
  new="${f%%.mp4} (CHT).mp4"
  
  subtitle="${f%%.mp4}.chi.ass"
  
  < /dev/null ffmpeg -i "$f" -vf subtitles="$subtitle" "$new"
  
  done

  The ffmpeg having problem reading the subtitle file variable. Anyone can help ?