[FFmpeg-devel] video corruption using h264 hw decoders

Rainer Hochecker fernetmenta at xboxmediacenter.com
Sat Oct 29 11:40:16 CEST 2011

>Iam not sure what statement from whom you refer to, but the sizes
>must be large enough to cover all writes to the surface and the
>linesizes must be sufficiently aligned to allow SIMD code to function
>at full speed. That is not just SIMD from the software decoder when
>used but also possible filters a user application might want to
>apply to the output afterwards

>If you need some croping details exported, this can be done though i
>do not understand why you have this need and everyone else seems not
>to have it.

>Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

We see this problem mainly on BBC channels which broadcast additional lines
at the bottom of a frame. So far I have not seen any material which had
set crop_right. I would be interested in trying such a movie.

Looking at the vdpau decoder API it does not take paramters like linesize
or mb_width so I guess it assumes that the alloceted video surface has to
match the encoded frame size.

dxva allows bumping video surface by a couple of macroblocks. This is work
around as long crop_top or crop_left are not used.

Exposing the original size and cropping parameters in the future would be


More information about the ffmpeg-devel mailing list