[FFmpeg-user] libx264 - unknown decoder,

[Lou]

On Sun, Jun 26, 2011 at 03:28:48AM +0100, Sw at g wrote:
> Hi all,
>
> I am recording a webcam using ffmpeg (ideally to replace mencoder) on  
> archlinux (the latest package has been updated on 7th of June) and when  
> running the following command I run into the "Unknown decoder 'libx264'"
>
> But as you can see from the error ffmpeg has been build with the  
> --enable-libx264 options.
>
> Any suggestions?
>
> Looking forward for your reply,
>
> Regards,
>
> $ ffmpeg -f video4linux2 -vcodec libx264 -b 3000k -r 15 -crf 16 -pix_fmt  
> yuv420p -i /dev/video0 out.avi
> ffmpeg version git-N-30610-g1929807, Copyright (c) 2000-2011 the FFmpeg  
> developers
>   built on Jun  7 2011 19:14:56 with gcc 4.6.0 20110513 (prerelease)
>   configuration: --enable-gpl --enable-libx264 --enable-x11grab
>   libavutil    51.  6. 1 / 51.  6. 1
>   libavcodec   53.  6. 1 / 53.  6. 1
>   libavformat  53.  2. 0 / 53.  2. 0
>   libavdevice  53.  1. 1 / 53.  1. 1
>   libavfilter   2. 14. 0 /  2. 14. 0
>   libswscale    0. 14. 1 /  0. 14. 1
>   libpostproc  51.  2. 0 / 51.  2. 0
> Unknown decoder 'libx264'

You're applying '-vcodec libx264' as an input option, and your input is
being decoded, so FFmpeg is expecting a decoder called libx264 but there
is no such thing.

If you want to encode with libx264 then use it as an output option (after
-i foo).