Page 1 of 1

Unable to view a video image on YCbCr 4:2:2 video device

Posted: 30 Jul 2007 14:37
by amareshram
Hi,

I have ported the VLC-0.8.6a for TI Davinci platform. TI Davinci platform has 4 Framebuffer device (2 for Video supporting YCbCr 4:2:2 (UYVY), 1 for OSD supporting RGB and 1 for Attribute). I have added another FB module for supporting video framebuffer of Davinci.

With this ported code, I am able to view the perfect video clip on OSD FB but on video FB I can only see some colored pixel distributed across half of the screen.

As per the log input chorma FMT is I420 and output chroma format is UYVY.

Help sought to resolve the problem.

regards/Amaresh

Re: Unable to view a video image on YCbCr 4:2:2 video device

Posted: 30 Jul 2007 15:09
by Jean-Baptiste Kempf
Ask on the mailing list.

Re: Unable to view a video image on YCbCr 4:2:2 video device

Posted: 07 Aug 2007 14:48
by dionoea
Looks like we might be missing a I420 to I422 chroma conversion module. Chroma conversion modules are in modules/video_chroma/ in the source code tree. Extra chroma conversion modules are available through the ffmpeg library only if you compiled it with --disable-swscaler. If you haven't given that a try yet, I suggest that you do. If that still doesn't work, you can write a small I420 to I422 chroma conversion module (should be really easy since you're just copying the Y plane and duplicating each U and V line (Cb/Cr)).