[FFmpeg-devel] [PATCH]Flip zerocodec

[Reimar Döffinger]

On Sat, Dec 01, 2012 at 08:32:51AM -0500, Derek Buitenhuis wrote:
> On 30/11/2012 8:47 PM, Carl Eugen Hoyos wrote:
> > Hi!
> > 
> > Attached patch fixes ticket #1218 for me.
> 
> Patch is wrong. The problem has nothing to do with ZeroCodec really.
> 
> The way several VFW codecs signal bottup-up RGB is to use a negative height.

No, bottom-up is the default Windows bitmap format.
It signals usage of non-default layout (i.e. not bottom-up) by negative
height.

> This is handled incorrectly/insanely (read: extradata hacks for specific a codec)
> in our AVI demuxer, AFAIK.

It adds BottomUp at the end of extradata for RAW formats.
I would guess there is no real reason this check couldn't be extended to
cover ZeroCodec.
It's line 640 in avidec.c

> Furthermore, depending on which OS is used to decode or encode ZeroCodec, it
> will be flagged correctly or incorrectly, and may or may not be bottum-up RGB.

For AVI we generally consider whatever WMP does as correct...