Avisynth 2.50 ALPHA shifts collor channel...

[vinetu]

Every new version of avisynth 2.5 since 11.04.2002 shifts collor
component 16 pixels to the left when the source is MPEG2 and you
use "DirectShowSource" and the collor space(output from DS decoder) is YV12...

You can easy confirm that if you have ffdshow installed - check to enable MPEG2 decoding
in ffdshow configuration and create a simple avs:

DirectShowSource("d:\TEMP\MPEG2.VOB",fps=200)

This is not a ffdshow bug!

Best Regards!

vinetu

[sh0dan]

What directshow filter are you using to decode the MPEG2?

Can you confirm this using other input sources?

PS. You should really use DVD2AVI and MPEG2Dec3 for MPEG 2 - much faster and much more reliable.

[vinetu]

Hi sh0dan!
It's nice you hear me finaly!

For first time I found this collor shift with
MainConcept MPEG2 DS Decoder and "avisynth_a_071102.zip" - at this times
I was not sure it's a DS decoder bug or avisynth -
today I've checked with ffdshow-20021213 and now I'm
sure it's avisynth(even with avisynth_a_291202.zip).
This is only with MPEG2 files - xvid avi files are correct
(I dont have other avi codec with YV12 capability ).

For eliminate this bug I use the next script:

Luma=DirectShowSource("T:\TEMP\VTS_17.VOB").crop(16,0,-16,-0)
Chroma=DirectShowSource("T:\TEMP\VTS_17.VOB").crop(0,0,-32,-0)
MergeChroma(Luma,Chroma,1.0)

... well I'm not 100% sure it's avisinth - may by xvid.dll ???


Currently I use gabest's D2VSource.ax which work
in YUY2 but the quality is BETTER than YV12 decoders-
try this!!!
I've maded some tests between Mark_FD mpeg2dec3 v0.94 and
MainConcept MPEG2 Decoder - they are absolutelly identical in quality(the speed is not important for encoding,but for playing I think).

BEST REGARDS!

P.S.Can you reproduce the error with the help of ffdshow MPEG2 DS decoder?

[scmccarthy]

@vinetu

How can you say the quality is better in one sentence and then say they are absolutely identical in quality in the next sentence?

Sh0dan said:
PS. You should really use DVD2AVI and MPEG2Dec3 for MPEG 2 - much faster and much more reliable.
I think you try that. Both AviSynth and Xvid have always used or been made to work with the mpeg2dec code originally found in DVD2AVI. As long as all these programs work together, any problems with another piece of software, like the one you are using, might best be described as an incompatibility rather than a bug.

It is worthwhile investigating this, but I cannot see how this would result in an AviSynth re-write.

Stephen

[vinetu]

How can you say ...

sorry - some words in my explain are missing...(bad english):o

well ,I want to say that the decoded frame by D2VSource.ax looks BETTER than that decoded by
YV12 decoder(Mainconcept,ffdshow and mpeg2dec3 v0.94 are YV12 capable decoders)
and on the other side Mainconcept is identical to Mark's mpeg2dec3 v0.94 .

this collor shift bug is missing in avisynth_250_a_041102.zip and olders
so I think it's not a compatibility(I hope!):confused:

Generally this bug is not problem for me -I just think(hope) that the avisynth must have no bugs at all :)
(or at least in import-export-collor conversion parts) !

Best Regards!
I'll be back tomorrow...

[vinetu]

The bug is gone = ("avisynth_a_180103.zip")!
Thanks sh0dan!
Thanks U-235!

Best Regards!

[sh0dan]

No problem. I just need to be able to reproduce the result - that helps :)

As for this problem it proved to be a general bug, I hope you could live with the dealy. (Believe me - the speed gain you'll get from the feature "causing" this bug will make you ahppy in the long run. But now it's fixed, so let's everybody celebrate :) :D :D

(ok, I'll return tomorrow, when I'm sober and see if this makes sense ;)