DGindex automatically converts to YV12 - is there a way to avoid that?

[FLM]

Hi..

all my mpg files are in YUY2 colorspace, at least according to DirectShowSource(). when they are indexed via DGindex they are converted automatically to YV12.

I want to avoid conversion to YV12 and do it manually with ConvertToYV12() because there are some filters that only support YUY2, Like TemporalCleaner.

I read the Reference Manual and it says that in MPEG2Source there's a parameter called UpConv.
isn't using this parameter means there will be 2 convertions (YUY2 > YV12 > YUY2)?
I want avoid colorspace coverstions as much as possible because I learned that converting without need can be destructive.

I'd apprciate your help. :)
Thanks in advance...

[Guest]

First, DGIndex does not output any video at all. It only outputs an index file.

DGDecode, which does output video, never converts anything to YV12.

If you'd like to post a short source sample I can test whether it is really 4:2:2 rather than 4:2:0.

[FLM]

hmmmm... something is really weird here...
after I read your comment, I tried again using DirectShowSource("file.mpg).info() and avisynth reports YV12!
when I did it a week ago BEFORE I installed FFDshow, DirectShowSource reported YUY2...
I'm beginning to think that it was the decoder's "Fault" in reporting or simply upsampling to YUY2...

How can I check the real colorspace of the files?

I uploaded a rar file that contains 2 samples from 2 different clips I captured using 2 different capture programs: ChrisTV and Winfast PVR2 which is the program that is bundled with my TV Card.

I thought that TV cards only capture to YUY2... apparently not.
anyhow, neither of these program don't let the user decide which colorspace to capture with.

the samples:
http://www.fileflyer.com/view/m4cTpBM

[scharfis_brain]

analogue TV cards will output YUY2 to the capturing application.
what the app is making out of it is an completely different story.
If your capturing application will encode to MPEg2/Mpeg4 in realtime the color will be YV12


digital tv cards always will output the received bitstream.
thus the MPEG2/H.264 from the broadcaster which most likely is YV12.

[Guest]

Both the samples are 4:2:0 (YV12).

One way to tell is go here:

http://tsviatko.jongov.com

Go to Projects. Get the MPEG Video ES Utils application.

Open your file and look at the chroma_format in the sequence extension. If it is 1, you have 4:2:0. If it is 2 you have 4:2:2.

Jongov's apps are little known but useful little gems.

[FLM]

Ok. I see that it was my false assumption and misunderstanding...

Thank you both for the info and help. :)