Change audio in mkv from mp3 to ac3

[gauche]

Hi,

I've got a couple of MKVs that I'm trying to watch on my PS3 via ps3mediaserver. They currently play without sound and I believe that's because the audio stream is MP3 rather than AC3 or AAC (they both play fine on my laptop). Therefore, I thought I'd use ffmpeg to change the audio stream to AC3. I thought this would do it:

ffmpeg -i input.mkv -vcodec copy -acodec ac3 output.mkv

However, that gives me an error:

[matroska @ 0x9ca0a0]st:0 error, non monotone timestamps 200 >= 40

I have no idea what the heck that means or whether I'm just making some noob mistake here. Can anyone offer any advice?

Thanks

[Baldrick]

You could just try another tool like avidemux, under audio change too aac or ac3. But I think mp3 should work fine ps3mediaserver...

[gauche]

You're right - I'm an idiot. I was getting mixed up with another video that plays without sound.

These particular videos don't play at all (invalid data or some-such) so the video stream is likely the issue. Copying the video stream will just give me the same issue.

I tried re-encoding with Handbrake but the quality seemed to really suffer (despite using the same target size with a two-pass encoding). Oh well, at least I can watch them now.