[FFmpeg-user] libx264 - unknown decoder,

[Sw@g]

On 06/26/2011 03:45 AM, Lou wrote:
> 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).
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Many thanks for your reply,

I tried like your suggested:
ffmpeg -f video4linux2 -b 3000k -r 15 -crf 16 -pix_fmt yuv420p -i -vcodec libx264 /dev/video0 out.avi

but that give me an error:
[video4linux2 @ 0x9fab8e0] Cannot open video device -vcodec : No such file or directory

So I tried:
ffmpeg -f video4linux2 -b 3000k -r 15 -crf 16 -pix_fmt yuv420p -i /dev/video0 out.mkv -vcodec libx264

that work without error, but when I check mediainfo -f out.mkv then I can see the "Codec : V_MPEG4/ISO/ASP" so obviously ffmpeg hasn't encode with libx264.

What would the command be exactly?

Looking forward for your reply,

Regards,