[FFmpeg-user] Blue images from raw capture

Yan Seiner yan at seiner.com
Tue Nov 20 03:41:10 CET 2012

Carl Eugen Hoyos wrote:
> Yan Seiner <yan <at> seiner.com> writes:
>> ffmpeg -f rawvideo -pix_fmt yuyv422 -s $SIZE 
>> -i /tmp/video.raw -vf yadif -f image2 /tmp/road%02d.png
>> ffmpeg version 0.11.2
> This is old.
It's the newest I can build for the embedded system.  :-(

> Since the png encoder does not support yuyv422, you 
> have to give a hint which colourspace it should use.
> (But that is not necessarily related to "blue", why 
> do you think that the v4l2 input is yuyv422? 
> Consider trying uyvy.)
OK, some testing....

Using the raw video I grabbed, ffplay plays it perfectly.

ffplay -f rawvideo -pix_fmt yuyv422 -s 512x384 -i anchor

If I try

ffplay -f rawvideo -pix_fmt uyvy422 -s 512x384 -i anchor

it looks like one of those postarized images.

However, ffmpeg fails no matter what I use for pix_fmt

ffmpeg -f video4linux2 -s $SIZE -i /dev/video0 -vframes $NFRAMES -f 
rawvideo /tmp/video.raw
ffmpeg -f rawvideo -pix_fmt yuyv422 -s $SIZE -i /tmp/video.raw -f image2 
-pix_fmt rgb24 /tmp/road%02d.png

At least this version of ffmpeg wants you to specify both input and 
output pixel formats to work right.


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