H264+AC3 (MKV container) to H264+MP3 (MKV container)

[diebri]

Hi there folks!

I need your help on transcoding mkv files that i'm gonna watch on my led tv. Unfortunately, it is not able to fast forward or rewind mkv files with h264 video codec and ac3 audio codec. It only does it well when that files are encoded with h264 video codec and mp3 audio codec.

The point is that I've tried to make it, first of all using AVIMux GUI to discard or remove the audio tracks that I don't need from the mkv file, so I get a new MKV file with only a video track (h264 codec) and an audio track (ac3 codec). But the second and last step, which is, transcoding the MKV file by encoding just the audio track, it's not working at all using apps like formatfactory, vlc player and so on, because they've failed with the last 10% of the file conversion process, more or less. Then, if you try to play the resulting file, and jump forward to the last minutes, the player crashes.

Does anyone know of an app that could encode it successfully?

Thanks a lot in advance! See ya!

[Baldrick]

ffmpeg -i video.mkv -vcodec copy -acodec mp3 -ab 192k output.mkv

Or if you don't like command line tools you can try avidemux, open mkv, under video choose copy, under audio choose mp3, save as a new mkv.


And are you sure it's the ac3 audio? It might also be advanced h264 settings or hd video size/resolution.

[diebri]

Thank u, Baldrick!

You said: "ffmpeg -i video.mkv -vcodec copy -acodec mp3 -ab 192k output.mkv"
- I've tried it, but wrote libmp3lame instead of mp3, because ffmpeg didn't recognize mp3 as an audio codec. However, it didn't work, and a "non monotone timestamps" error ocurred.

You said: "Or if you don't like command line tools you can try avidemux, open mkv, under video choose copy, under audio choose mp3, save as a new mkv."
- I'll give it a try and then, post the results here, to let you know.

You said: "And are you sure it's the ac3 audio? It might also be advanced h264 settings or hd video size/resolution."
- There's something weird when transcoding audio tracks within mkv files. I made it with some files using formatfactory, and after that tried to play them on my led tv. All the functions (play, pause, fastforward and rewind) worked, but the same file with ac3 audio track didn't. So I'm pretty sure is an audio codec issue.

See ya!

[epsilonalpha]

extract the ac3 with mkvextractgui2, encode it to mp3 and then remux it back using mmg (uncheck the ac3 audio).