Very slow conversion with avconv (libav) - Trusty Tahr 14.04?

Solution 1:

So the answer is in one simple parameter -vn which disable video recording for the output which is actually unneeded when making conversion from mp4(probably every video file) to mp3.

‘-vn (output)’ Disable video recording.

In my case I'm using Download Helper for Firefox. I made custom mp3 conversion where added this parameter there and now everything is even faster than ffmpeg.

Solution 2:

It would be well worth experimenting a little with the avconv -threads option. For example when transcoding from mp4 to mp3 file, as you mentioned, try something like the following:

avconv -i input.mp4 -threads auto -vn -c:a libmp3lame -qscale:a 3 output.mp3

The -threads option also accepts an integer so you could experiment a little with this. If this makes no difference the eventual answer is probably that your copy of FFmpeg encodes faster than your copy of avconv. Try using the time utility to quantify the difference...