Bug(?): ConvertToYV12 gives green frames on big input [Archive]

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25th March 2003, 19:58

# (source is RGB32)
PointResize(1440, 960)
ConvertToYV12()
PointResize(720, 480)
Gives this:
http://mf.onthanet.com/greenconvertyv12.png

sh0dan

25th March 2003, 19:59

.. under investigation... :)

25th March 2003, 20:07

Originally posted by sh0dan
.. under investigation... :)
Wha that was quick :). As a note: I encountered the problem once before (also on big input, where I had to do a convert in the middle of a supersample chain), and now that I found the problem a second time I tested all other relevant filter combinations and isolated the problem to the script posted above. So I know it's not PointResize's fault, for instance :p. Might save you some time testing. Thanks :).

Edit: I forgot something, which I just tested. If the source is YUY2 it doesn't happen.
Edit2: ConvertToYUY2 doesn't have the problem. Do they share code? If so, it's probably not the problem of that shared code ;). Might save some time ;).
Edit3: Since it doesn't happen on YUY2, does it hurt to do ConvertToYUY2.ConvertToYV12 (afaik only the subsampling is different between YUY2 and YV12, and when your source isn't subsampled, you have no problem, right)?

sh0dan

25th March 2003, 20:28

The YV12 <-> RGB conversions are the ones from XviD, but due to differences there might be some differences. All conversions involving YUY2 are written specially for AviSynth.

sh0dan

25th March 2003, 20:33

Confirmed - strange bug. Seems like there are distortions when h>512.

(Completely offtopic - are you interested in a zoomby2() funtion?)

25th March 2003, 20:47

Originally posted by sh0dan
(Completely offtopic - are you interested in a zoomby2() funtion?)
I'd be more interested in a YUV colorspace that doesn't do chroma subsampling. Because Merge*ma() only eats YUV, I have to blow up the image to keep the chroma intact.

Bidoche

25th March 2003, 20:47

I would say yes for zoomby2

sh0dan

25th March 2003, 21:40

MASM assembler error - nice ;)

Fixed in CVS.

When we got YV12 stable well have a look at a YUV 4:4:4 format :)

25th March 2003, 22:54

Originally posted by sh0dan
MASM assembler error - nice ;)

Fixed in CVS.

When we got YV12 stable well have a look at a YUV 4:4:4 format :)
Thanks alot :). Now I still have two problems left from the script that generated this error, which you can find in the AVISynth usage forum :p.

sh0dan

26th March 2003, 15:01

New binary put up.