On Wed, 07 Nov 2007 16:44:52 +0100 Krzysztof Duchnowski <amidk75 at gmail.com> wrote: > Maybe don't use "-ac mp3lib" but "-ac mp3" instead? There is no -ac mp3lib. mp3lib is used via -ac mp3, and is the default. The others are -ac mad and -ac ffmp3. In this case, though, the container is the problem, and -demuxer lavf fixes it nicely.