VDub2 Fast recompress Limitation ?

[Hotte]

Hi,

with 32-bit VDub I could use "Fast Recompress" when I used my Canopus HQX codec to output files that where input and filtered by Avisynth.

Doing the same with VDub2 a message appears "Video format negotiation failed: use normal recompress or full mode".

If I go for Normal recompress or Full mode it works, however, there is a slight color shift in the resulting AVI: Red and Orange appear weaker, Yellows and skintones get some Magenta influence. I did not have this with Fast recompress.

Any ideas ? Thanks.

[StainlessS]

Was gonna post this in other thread, then I thought I better do it here.

I'm assuming [new install] 64 bit VD2, might want to say so. Also, probably would have been better to post in VD forum,
although Shekh will probably see it here anyway. It's a terrific bit of kit is VD2, perhaps the negotiation thing fails due to
colorspace conversion in the system (used to have probs many years ago on 32 bit, where had to install either DIVX or
XVID or HuffYUV to do proper YUV conversion, and sometimes hack the registry, maybe 64 bit [I'm assuming] is missing
some [EDIT: 64 bit] codecs or something).

The negotiation will I think have nothing to do with VD2. (although what do I know, Shekh seems to be doing it all nowadays).

EDIT:
proper YUV conversion
I think eg YUY2 <===> YV12.

[Hotte]

Yeah you are right. It should be in the VDub forum.

Meanwhile I found the answer myself: With VDub2 and x64 Avisynth I have to add "ConvertToYUY2" at the end of the Avisynth script, which was not necessary with Avisynth x.86 and old VDub 10.4.

[StainlessS]

which was not necessary with Avisynth x.86 and old VDub 10.4.

I think that orig VD used to force conversion [EDIT: via RGB] if negotiation failed, Shekh probably would like you to know about the problem, both ways have pros and cons.

EDIT: Also take a look in Menu/Video/ 'Decode Format', and all of the stuff in same menu 'Compression'.
Fast ReCompress is/was intended for nearly compatible colorspaces eg YUY2 ==> YV12 aint much of a conversion (both YUV),
RGB ==> YV12, is a big conversion with losses, (colorspace and pixel format).

I know that Fast Recompress changed exactly how it worked a few years back, somebody (maybe Manolito) explained it to me,
but I forget exactly how it works right now.

EDIT: Something here bout Fast Recompress (how it used to work at least):- https://forum.doom9.org/showthread.php?p=1518374#post1518374

EDIT: Could not find link I was looking for, but this popped up:- https://forum.doom9.org/showthread.php?p=1791391#post1791391