[theora-dev] DirectShow Theora Issue with RGB24

[ogg.k.ogg.k at googlemail.com]

> this results in the video file being
> mirrored vertically.

This wouldn't be caused by using YUV colorspace instead of RGB,
but because the Theora code stores lines in the 'reverse' order
(eg, a negative stride). If you can control the order in which lines
are processed, just reverse this order. If not, a post processing
step that flips the image should be enough, and fast.