examples/input-stream.js fails with Node 6.8.0 on Ubuntu 16.04

[stephenwithav]

The following code, slightly modified from https://github.com/fluent-ffmpeg/node-fluent-ffmpeg/blob/master/examples/input-stream.js , hangs when using Node 6.8.0 on Ubuntu 16.04.

Generally, any code that passes a readable stream to ffmpeg() hangs.

The code was modified to 1) show the command line; 2) show progress; and 3) provide specific paths.

The output is:

ffmpeg:start ffmpeg -i pipe:0 -y -b:a 96k -acodec aac -ar 22050 -ac 2 -b:v 512k -vcodec libx264 -r 24 -filter:v scale=w=320:h=trunc(ow/a/2)*2 -f flv ./out.mp4

The input file is http://www.dvdloc8.com/clip.php?movieid=12167&clipid=3 <-- with the media renamed to in.mp4.

If I run the following command from the cli--or change infs to './in.mp4' in the code--it works:

ffmpeg -i pipe:0 -y -b:a 96k -acodec aac -ar 22050 -ac 2 -b:v 512k -vcodec libx264 -r 24 -filter:v scale=w=320:h=trunc(ow/a/2)*2 -f flv ./out.mp4 < in.mp4

The modified code:

var fs = require('fs'),
    ffmpeg = require('fluent-ffmpeg');

// open input stream
var infs = fs.createReadStream('./in.mp4');

infs.on('error', function(err) {
    console.log(err);
});

// create new ffmpeg processor instance using input stream
// instead of file path (can be any ReadableStream)
var proc = ffmpeg(infs)
	.preset('flashvideo')
// setup event handlers
        .on('start', function(data) {
	    console.log('\nffmpeg:start', data);
	})
        .on('progress', function(data) {
	    console.log('\nffmpeg:progress', data);
	})
	.on('end', function() {
	    console.log('done processing input stream');
	})
	.on('error', function(err) {
	    console.log('an error happened: ' + err.message);
	})
// save to file
	.save('./out.mp4');

Should I try something else?

[stephenwithav]

I upgraded to 6.9.1 and the code now returns the following error:

ffmpeg:start ffmpeg -i pipe:0 -y -b:a 96k -acodec aac -ar 22050 -ac 2 -b:v 512k -vcodec libx264 -r 24 -filter:v scale=w=320:h=trunc(ow/a/2)*2 -f flv ./out.mp4
an error happened: ffmpeg exited with code 1: pipe:0: Invalid data found when processing input

[stephenwithav]

The error appears to occur due to the progress event handler. See here:

      if (this.listeners('progress').length > 0) {
        // Read metadata in parallel
        runFfprobe(this);
      } else {
        // Read metadata as soon as the first 'progress' listener is added
        this.once('newListener', function(event) {
          if (event === 'progress') {
            runFfprobe(this);
          }
        });
      }

When the input is a stream, ffprobe and ffmpeg are both told to read from it, which is why the data on pipe:0 is considered invalid.

[njoyard]

Yeah examples are not up to date. I maintained them for compatibility's sake for a while, but some of them are plain outdated (who still does divx or flashvideo anyway).

Feel free to submit a PR to fix them !

[jrogozen]

@stephenwithav how did you fix the error?

[stephenwithav]

@jrogozen I removed the .on('progress', ...) handler.

@njoyard I'll submit a PR once my project is finished. Deadlines are fun. :D

[jrogozen]

any idea on how to fix this while maintaining the progress handler? possible to run probe first?

[stephenwithav]

@jrogozen if your output stream is a file, eliminate the progress handler and run ffprobe yourself. That's pretty much the only way at the moment.

[stephenwithav]

It's going to be a while before I'm able to write/submit the promised PR due to a seizure two weeks ago, as my memories are still returning.

If anyone's up for pushing a solution, I won't complain. At all.