Need help with comparing of 2 clips.

[TEB]

Hi. Im doing some research for losslessly archiving some educational content. So the other day i decided to test that recent changes in the lossless arena. The content owner sent me a 2gb avi file directly exported from the DPS velocity timeline that was digitized from Digibeta (4:2:2). I presume it was exported into uncompressed RGB in the avi container. (i checked with info() and its RGB24)

Our storage target is 4:2:2 lossless and i tested:

FFDSHOW (buld.5.12.04) FFV1:AC
FFDSHOW (buld.5.12.04) FFV1:VLC
FFDSHOW (buld.5.12.04) SNOW:@100qual
FFDSHOW (buld.5.12.04) Lossless_MJPEG
FFDSHOW (buld.5.12.04) Huffy
Logarith 1.25

I set all the codecs in 4:2:2/yuv modes.
When i tried to do a DirectShowSource("clip.avi").info it allways says yv12 and not yuv on all encoded clips?? am im missing something here? The only codec different than yv12 here is lagarith which came out as a RGB32 instead. Ive no idea how to set it to yuv2 mode..

I tried to do a avs script to do a verification test on the lossless part. I made this newbe script:

compare(DirectShowSource("d:\source.avi").ConvertToYUY2, DirectShowSource("d:\target.avi").ConvertToYUY2,"","compare.log",show_graph=yes)

And im gettting wildy different psnr results on all clips.
What should it say if its lossless 4:2:2?

ps! (if i remove the .ConvertToYUY2 im getting source and target have different colour space, then i tired removing it on the target, to no avail...


could anyone plz lend a hand ? :confused:

best regards teb

[tedkunich]

Try Avisource(you clip here).info()

I'm not sold on using DirectShow for anything yet... maybe because I hate MS so much.... ;)

[TEB]

hi. well i tried avisource first but it faild on the decompressors. would not eat anything but the source file..

[Wilbert]

I never says yuv, because yuv is a set of colorformats. It's either yv12, yuy2, rgb32 or rgb24 (others are not supported).

But, you must be confused a bit because

FFDSHOW (buld.5.12.04) FFV1:AC
FFDSHOW (buld.5.12.04) FFV1:VLC
FFDSHOW (buld.5.12.04) SNOW:@100qual
Logarith 1.25

is all stored as yv12 (4:2:0) internally. Though I'm not sure about Logarith, and am too lazy to look it up.

FFDSHOW (buld.5.12.04) Huffy
FFDSHOW (buld.5.12.04) Lossless_MJPEG

these are yuy2 (4:2:2).


compare(DirectShowSource("d:\source.avi").ConvertToYUY2, DirectShowSource("d:\target.avi").ConvertToYUY2,"","compare.log",show_graph=yes)

And im gettting wildy different psnr results on all clips.
I will pass this question to someone else :) But yes I also expect it to be the same.

[TEB]

hi. ok i meant yuv2, (im to lazy to write the 2 ;))
All the mentioned codecs can store in YUV2 mode, it says clearly in the options tab.. maybe someone can explain?

[Wilbert]

It's yuY2.

btw, I advice you to ask this in the 'New A/V Formats - Codecs' forum.

There's a post here

http://forum.doom9.org/showthread.php?s=&postid=482614#post482614

where virus claims there will be a conversion when you select 422p, because of the obtained PSNR. But looking at this thread

http://forum.doom9.org/showthread.php?s=&threadid=86148

you might be right.

Btw, I can't find anything with the Logarith codec and yuy2 (it seems it's only YV12 or RGB).