YV12 FAQ

[Wilbert]

The YV12 FAQ is moved to avisynth.org.

[Koepi]

Very nice FAQ, finally all links and necessary information collected!

EDIT: edited out the points, they made it into the FAQ Thanks Wilbert for assembling and maintaining it!

Best regards
Koepi

[Wilbert]

@Koepi,

I will remove vdub-mpg2 if vdub-mod comes with a first release. I have added your other point.

[iago]

Thanks Wilbert! Great collection of information and necessary tools!

[droolian01]

Really excellent guide and link resource - obviously needs to be made a sticky!

WARNING - DUMB QUESTION ALERT ! ! !

I can see (i think) how YV12 will be quicker to process than YUY2 (working with 12 bits/pixel instead of 18 bits/pixel) but (now this MAY be the dumb part) will this mean that the same 'data' can be stored in 3/4 of the file space compared to YUY2? Because if this is the case quality should increase too on a 'same filesize' basis.

Could anyone confirm that this is the case?

[sh0dan]

Originally posted by droolian01
I can see (i think) how YV12 will be quicker to process than YUY2 (working with 12 bits/pixel instead of 18 bits/pixel) but (now this MAY be the dumb part) will this mean that the same 'data' can be stored in 3/4 of the file space compared to YUY2?

Only when dealing with uncompressed data. DivX/Xvid and other MPEG4 formats already store in YV12 format. So when you pass 16 bit/pixel YUY2 it is converted to YV12 before it is compressed. Skipping this is what's giving you the speed increase.

@Wilbert: Couldn't you make an "alpha notice" in the top of the FAQ. Many functions are quite badly tested, and some may even return bad data or crash. Most Doom9 users are pros, but I don't see the program fit for everyone (yet).

[droolian01]

@ shOdan

Thanks for clearing this up for me.

What with the developments in XVID and avisynth2/vdub using YV12 these are very exciting times indeed!

Great work - and i'll try and do some testing if i can.

Thanks again.

[sh0dan]

Originally posted by droolian01
What with the developments in XVID and avisynth2/vdub using YV12 these are very exciting times indeed!

I haven't heard anything specific - VdubMod hasn't had the YV12 fix committed (even though I posted it in the development thread) - Belgabor?

I don't know how Xvid is coming along - I'm still using DivX, but I'm actually quite tired of it (it gives me a bunch of internal access violation, making debugging very tiresome). Is the newest XVID capable of decoding YV12 to other formats (Koepi?)

[Koepi]

It claims to decode YV12 but just spits out a black picture - but it works for encoding purposes, if that suffices for your needs.

Regards,
Koepi

[JohnMK]

What I'm basically wondering is, and it may be answered above but in language I can't understand, is this new YV12 support in VDub/Avisynth something I can begin using immediately, given the fact that I use the DVD2AVI & GordianKnot, etc.?

[vlad59]

As it's explained, it's in an alpha stage and
as stated in Sh0dan web page all external filter need a new compile before being usable with avisynth 2.5. So Decomb, TemporalSmoother, TomsMoComp, ...... are not usable at all now.

So I'm afraid it's not ready for today's use .

EDIT : I think that YV12 has so many advantages that it shouldn't be too long. all avisynth filters developpers really owe a lot to Sh0dan.

[hakko504]

@JohnMK

Yes, as long as you only uses the internal filters stated on sh0dan's alpha page. the only external plugin that works is the YV12 version of MPEG3DEC, but given that you edit the GKnot script to use this .d2v import function it will work.

[JohnMK]

Thank you vlad59, hakko. Appreciated your comments. This should be added to the FAQ. It will be a frequently asked question, I'm sure . . .

[sh0dan]

OK - I spend a few hours converting (and debugging) milan's YV12 optimized version of WarpSharp. It's quite fast aleady. I made a few adjustments to it, but nothing major.
Be very careful - you cannot use it after a crop, since ffdshow assumes that input pitch = output pitch! This will give the wellknown distorted pictures! I hope someone else has the time to take up the challenge?

I also have a ColorYUV lying at home, so people shouldn't bother converting it - it's already done!

Edit: It's on the alpha page - forgot to tell ya

[Wilbert]

I added the plugins WarpSharp and Undot. For JohnMK I changed Q10 a bit

[JohnMK]

What is WarpSharp? Forum search turned up no definition, and indeed downloading WarpSharp . . . tells me nothing as there's no "Here's what this is" section, probably because there's no readme whatsoever.

[MaTTeR]

Quick Google search shows-

http://www.virtualdub.org/virtualdub_filters
http://web.syr.edu/~tjmyers/both_filters.html

Lots more too.

[JohnMK]

Ahhh excellent, the one source I forgot to consult. Thank you for your kind and generous assistance.

[HarryM]

@Wilbert, @Koepi:

Do exists any MJPEG codec (for TV grabbing) with native YV12 support?

I use morgan-multimedia's MJPEG (v3.0) and this have only 4:2:2 (YUY2) or 4:1:1 support.
4:2:0 (YV12 for Avisynth 2.5) don't...

[sh0dan]

When I open MJPEG files with YV12, using Morgan, it has swapped the UV channels (giving me I420 instead of YV12). I'll do a SwapUV function shortly. I'm using an older version of Morgan, so it might be fixed in the latest version.