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• Unable to find replacement for -vol [closed]

  21 février 2024, par Michael Benton

  I'm referring to this thread posted years ago.

  


  While I was testing Downmixing without discarding the LFE channel (Dave_750's answer) on ffmpeg, which included the formula

  


  ffmpeg -i "sourcetrack.dts" -c dca -vol 425 -af "pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" "outputstereo.dts"


  


  the cmd raised the following error :

  


  Unrecognized option 'vol'. Error splitting the argument list: Option not found


  


  The formula I put in cmd wasn't the same as the one in the thread at the beginning, because I replaced in it the attributes of my ac3 track.

  


  ffmpeg -i "inputsurround.ac3" -vol 425 -af "pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" -c:a ac3 -b:a 320k -ar 48000 "outputstereo.ac3"


  


  Through this thread, I discovered that the -vol function was deprecated years ago.

  


  I found another thread where the syntax used was

  


  -af volume=N


  


  (where N stands for a percentage or, if N is followed by "dB", a dB value).

  


  I'm not sure if -af volume behaves exactly like -vol while downmixing to stereo the ac3.

  


  I went back editing the formula :

  


  ffmpeg -i "inputsurround.ac3" -af "volume=425" -af "pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" -c:a ac3 -b:a 320k -ar 48000 "outputstereo.ac3"


  


  It raised the following warning (which didn't stop the file generation) :

  


  Multiple -filter/-af/-vf options specified for stream 0, only the last option '-filter:a pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3' will be used


  


  As I already suspected, I couldn't use two "-af" in the same command. The generated file is useless, because ffmpeg only applied one of the two commands. I also tried with N defined in dB, with no success.

  


  I continued my search and, from another thread, I learned that I could use

  


  -filter_complex "[1] formula1;[0] formula2"


  


  to resolve my issue.

  


  My formula then became :

  


  ffmpeg -i "inputsurround.ac3" -filter_complex "[1]volume=425;[0]pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" -c:a ac3 -b:a 320k -ar 48000 "outputstereo.ac3"


  


  And it still raised an error :

  


  Invalid file index 1 in filtergraph description [1]volume=425;[0]pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3.
Error initializing complex filters: Invalid argument


  


  To simplify the formula, I went back using -af with the properties of -filter_complex. And I got :

  


  ffmpeg -i "inputsurround.ac3" -af "[1]volume=425;[0]pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" -c:a ac3 -b:a 320k -ar 48000 "outputstereo.ac3"


  


  Again, another error :

  


  Simple filtergraph '[1]volume=425;[0]pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3' was expected to have exactly 1 input and 1 output. However, it had 2 input(s) and 2 output(s). Please adjust, or use a complex filtergraph (-filter_complex) instead.
[aost#0:0/ac3 @ 000001d83b4c4200] Error initializing a simple filtergraph
Error opening output file outputstereo.ac3.
Error opening output files: Invalid argument


  


  whether I used a semicolon or comma as a separator.

  


  I'm completely lost at this point as I don't have deep knowledge of the topic.

  


  


  • has -vol been deprecated or I've searched badly/it's a syntax typo ?

    


  


  • if -vol has been deprecated, is there a way to rewrite the formula such that it outputs the result intended by the original user ?

    


  


  • if I replace c0, c1, c2, c3, c4, c5 to FL, FR, FC, LF, BL, BR in the formula, would I get a different channel layout ? (my file is : L, R, C, LFE, Ls, Rs)

    


  


  


  I'll try to clear every doubt. Any help is highly appreciated !

  


• checkasm : Implement helpers for defining and checking padded rects

  21 mars, par Martin Storsjö

  checkasm : Implement helpers for defining and checking padded rects
  This backports similar functionality from dav1d, from commits
  
  35d1d011fda4a92bcaf42d30ed137583b27d7f6d and
  
  d130da9c315d5a1d3968d278bbee2238ad9051e7.
  This allows detecting writes out of bounds, on all 4 sides of
  
  the intended destination rectangle.
  The bounds checking also can optionally allow small overwrites
  
  (up to a specified alignment), while still checking for larger
  
  overwrites past the intended allowed region.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] tests/checkasm/checkasm.c
  • [DH] tests/checkasm/checkasm.h

• ffmpeg node js s3 stream screenshots qestion

  20 octobre 2015, par user3564443

  On my Node js server I need get video from s3, generate thumbnail for it, set thumbnail to s3, without saving video or thumbnail on my server. So I need to use streams for this. For thumbnail generation I use fluent-ffmpeg.

  Is it possible to get screenshots from streams using fluent-ffmpeg ?

  Is the correct way to intercept s3 getObject stream, that there was no need to download full video ?

  var config = require('../config');
  
  var AWS = require('aws-sdk');
  
  AWS.config.update({
  
    accessKeyId: config.AWS_accessKeyId,
  
    secretAccessKey: config.AWS_secretAccessKey,
  
    region: 'eu-west-1'
  
  });
  
  var s3 = new AWS.S3();
  
  var fs = require('fs');
  
  var ffmpeg = require('fluent-ffmpeg');
  
  
  
  exports.generateVideoThumbnail = function(fileId, url, done) {
  
    var params = {
  
      Bucket: config.AWS_bucket,
  
      Key: url
  
    };
  
    var input = s3.getObject(params);
  
    var stream = fs.createWriteStream('./screenshot.png');
  
    return ffmpeg(input).screenshots({
  
      timestamps: ['0.1', '0.2'],
  
      size: '200x200'
  
    }).output('./screenshot.png').output(stream).on('error', function(err) {
  
      return done(err);
  
    }).on('end', function() {
  
      input.close();
  
      var _key = "files/" + fileId + "/thumbnail.png";
  
      return s3.putObject({
  
        Bucket: config.AWS_bucket,
  
        Key: _key,
  
        Body: stream,
  
        ContentType: 'image/jpeg'
  
      }, function(err) {
  
        return done(err);
  
      });
  
    });
  
  };