[FFmpeg-user] to .mkv conversion fails.

Rodney Baker rodney.baker at iinet.net.au
Mon May 2 17:24:03 CEST 2011

On Mon, 2 May 2011 23:45:18 ranjini raguu wrote:
> Hello im using ffmpeg for conversions... my prob is whn ever i try to
> convert any video files to .mkv it fails.... this is the parameter im
> passing for the conversion.
> -vcodec libx264 -b 1250kb -acodec libmp3lame -ar 44100 -ab 160kb -ac 2  is
> there any prob with this conversion in default???? thanks for any
> replies....
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> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user

I use ffmpeg with libx264 for converting m2t to mkc regularly and it works 
fine. You need to post your full command line and full output from ffmpeg 
(with whatever error messages you're getting). "It fails" does not help anyone 
diagnose the problem.

My guess, though, is that you're getting an "invalid size or bitrate" message 
because you're not passing any presets to libx264 (and the ffmpeg default 
parameters for libx264 are badly broken, apparently). 

After -vcodec libx264 add -preset <preset> [-profile <profile>] [-tune <tune>]

The parameters in <> you can find by doing x264 --help (or x264 --fullhelp for 
more detail). The parameters in [] are optional. You need at least the preset, 
and you will probably want the profile too.

If you need more help than that, like I said, post your full command line 
along with the full output.

Rodney Baker VK5ZTV
rodney.baker at iinet.net.au

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