[FFmpeg-user] -map and matroska files

Marios Titas redneb8888 at gmail.com
Fri Nov 11 03:12:04 CET 2011

Hi all,

I have a video file with multiple audio streams and I want to select
one of them. I did

    ffmpeg -i input.mkv -map 0.0 -map 0.2 -y output.avi

to select streams 0 (the video) and 2 (the desired audio stream) and
this works fine. But if I try to output to matroska, ie

    ffmpeg -i input.mkv -map 0.0 -map 0.2 -y output.mkv

this fails with the following error:

    Number of stream maps must match number of output streams

Why is this happening?

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