Couldn't locate decompressor for YV12

[mgy999a]

I am experimenting with AVISynth (very impressive capabilities) but have run into a problem. Some filters need YV12 space to work but I can’t get ConvertToYV12 to function in my script. VirtualDubMod gives me the error “Couldn’t locate decompressor for format YV12(unknown)”. Conversions to YUY2 & RGB24 work just fine.

Searched the forums (including this one) which suggested installing ffvfw and installing YV12QTCodec10. Did both, same result. Can anyone please tell me what I am doing wrong?

I am running VirtualDubMod 1.5.10.1 build 2439, and AVISynth 2.5.4. and my captures are in VirtualVCR using the PicVideo MJPEG 3Vfw codec.

Thanks in advance. - MGY

[gastorgrab]

The simple fix looks something like this:

---------------------
Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32]
"vidc.yv12"="xvid.dll"
---------------------

but you'll have to switch "xvid.dll" with what ever MPEG-4 codec you have installed.

Are you capturing in YV12 with the PicVideo codec? Maybe the "xvid.dll" should be replaced with the PicVideo codec.

[mgy999a]

I set VirtualVCR to capture in YUY2. The other options are RGB24, RGB555 & YVU9. I'm too new to this game to know if it can be configured for YV12 or not.

In the registry keys, there is no "vidc.yv12" entry. (Gee, big surprise). The only MPEG4 codecs I have installed are ffvfw & Microsofts Video MPEG4 Codecs 1 & 2. Please feel free to recommend something.

Oh, please correct me if I am wrong but doesn't ffvfw have several codecs? If ffvfw is good enough, what dll holds the MPEG4 codec?

BTW, thanks for the quick response. -MGY

[Wilbert]

You can use ffvfw.dll to decode your YV12 stuff:

Just add the following in your registry file (like gastorgrab said):

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32]
"vidc.yv12"="ffvfw.dll"

[mgy999a]

Hmm. . .

Tried ffvfw.dll but did not work. (Though it could be my fault; not an expert with Windows Registry).

However, I downloaded XviD, installed it, modified Windows Registry as suggested and it worked like a champ.

Excellent. I thank you both very much. (Now to have some fun. . .)

-MGY

[gastorgrab]

Yup, any common MPEG-4 codec should work for this, including;

DivX, Xvid, ffvfw, etc, etc.