Using Avisynth with MPEG Video Wizard DVD

[robjv1]

I was previously having a problem with VFAPI making my videos too dark (see this post) and it was suggested that I use Avisynth instead since VFAPI is limited to uncompressed RGB data (I assume this is why video run through VFAPI --> Procoder looks different than the same video run straight through Procoder -- it is slightly increasing contrast of the original video).

The closest solution I could find for my issue using AVISynth was in this post but it uses a VFAPI plugin to accomplish it. I tried it out with the requisite modifications for use with Procoder instead of HCenc, and Procoder keeps crashing when I try to feed it the AVS file.

Here is the script I am using:

LoadVFAPIPlugin("C:\Program Files\Womble Multimedia\MPEG Video Wizard DVD 5.0\WbpVFAPI.vfp", "womble")
womble("M:\testing.wbp")
flipvertical
Lancszosresize(720,480)
converttoyv12

What Avisynth plug-in (if not VFAPI) would I use to accomplish getting my MPEG Video Wizard project file into Procoder?

Basically here is what I am trying to do:

I'm working with several different MPEG2 video sources that need to be combined to make a good master source. This involves replacing bad frames of one source with good frames of another.

They are matched up color-wise, but they don't quite line-up visually (considering one copy as having the correct orientation, then another one is off a few pixels to the left and bottom, another is slightly up and to the right, etc). Thus, I am using MPEG Video Wizard's translation filter to get them lined up perfectly, and it works like a charm. Then I save all my changed segments to a .wbp project file.

Since MPEG Video Wizard has a terrible encoder, I don't encode my project file to an MPEG2 file from MPEG Video Wizard. I am frameserving these segments that are saved in the project file (ie project.wbp) into Procoder for re-encoding. This applies the internal translation filter of MPEG Video Wizard, but encodes it with Procoder. This works great via VFAPI, except for the contrasted/dark video problem as previously mentioned.

[poisondeathray]

I believe these are well known issues with procoder. I can't recall the exact details, but there are some specific workarounds you have to do to get it to work with procoder without the contrast issues

For example, what happens when you use HCEnc with that same script listed above?


http://forum.doom9.org/showthread.php?p=1281938#post1281938

Another question is you forgot to add "601 Correction - Shrink Color Space" filter in ProCoder, or you have to add ConvertToYUY2() at the last line of your avs script. ProCoder can only be fed with YUY2/RGB, not YV12. If you feed ProCoder with YV12, it will find the YV12 Decoder on your system to decode from YV12 to RGB. Strangely, ProCoder doesn't do the shrinking color space job when converting from RGB to YUV, which means it assumes limited RGB16~235 as input by default, not normal RGB0~255. Therefore RGB0~255 will be converted to YUV0~255, not YUV16~235.

ProCoder never changes Brigthness and Contrast, if you feed it properly with YUY2 Video.
If you feed it with YV12 video then it will rely on a system-decoder that may break things up.
so redo the test for procoder with YUY2 input and you'll see that it will behave much better.

So try feeding it YUY2

ie. use convertoyuy2() in the script instead of converttoyv12()

if it's interlaced, use converttoyuy2(interlaced=true)

also if you don't specify a matrix, it will be rec.601 (which is usually ok for MPEG2/DVD)

[robjv1]

You're fantastic! Good call, it's for sure a Procoder issue and not a VFAPI issue.

I went ahead and dropped the script into VirtualDub and saved it as an uncompressed AVI and dropped it on my MPEG Video Wizard time line and it looks fine. After I run that .AVI through virtualdub, the resulting MPEG2 file has the color issue.

Applying the 601 Correction - Shrink Color Space filter does the trick. Thanks so much.