YUV from AVISynth sometimes faulty?

[Xesdeeni]

I'm frameserving a VOB from AVISynth through D2V and MPEG2DEC.dll. If I leave the format in YUV, I get faulty video in TMPGEnc and in MediaPlayer. The problem looks like over-quantization, where bad banding occurs. But if I load the same script into VirtualDub, it looks fine. Also, if I add ConvertToRGB() into the script, it then looks OK in TMPGEnc and MediaPlayer.

Has anyone else seen this? I would like to frameserve in YUV, since this would eliminate the YUV->RGB->YUV conversion (and speed things up a bit), but my encodes look bad. Any ideas?

Xesdeeni

[vhelp]

xesdeeni,

Yes, on mine. I heard lots of people complaining of this phenominon but did
not believe - hogwash, I said, while reading their posts.
Then, just last week, I decided to try it the same way (I had thought that
I did this before w/out problems) and guess what? I was eating my own words...
hogwash! It was happening to me too.

I think it has to do w/ a combination of what's installed PROPERLY and in the
correct ORDER in TMPG and VFAPI plug-in and I think it also has something to
do with the VFAPI.exe app or whatever it's called not being installed properly
or in the proper installation ORDER of things and maybe your graphics
card driver setup etc.

But, as for me, I don't feed the *.AVS scripts directly into TMPG anyways.
I was just testing this out. Anyways, I don't think that there is a solution,
other than to continue feeding into VDUB and then to TMPG. However, as far
as the speed "supposively" being faster by feeding *.AVS scripts directly
into tmpg, I saw no diference. So, if speed was your concirn, don't bother
pulling your hair out. stick w/ feeding your *.AVS into VDUB and then TMPG.

Oh, yes, I've tried ass the convertToRGB() at the end of script, but that did
not really clear up the color issue, though it made it look a tad bit better.

-vhelp

[vcd4ever]

Xesdeeni,

Yes, i have also seen this problem with avisynth. I't happend when encoding a captured avifile to mpeg with tmpgenc from a avisynth script.

The problem is also affected by the codec used in the avifile.

Therefore i'm not using avisynth anymore, i only framserve from
virtualdub to tmpgenc.

[Xesdeeni]

Well unfortunately, VirtualDub cannot do what I need. I am doing a high quality standards conversion from PAL video to NTSC video. It involves these steps:

1. Convert 50 fields/sec to 50 frames/sec, using a smart deinterlacer.
2. Scale to NTSC resolution
3. Change frame rate to 59.94 frames/sec by replicating frames
4. Convert 59.94 frames/sec to 59.94 fields/sec

[Believe it or not, the results are outstanding! The replicated frame becomes only a replicated field, and I cannot see the stutter, even on a horizontal pan!]

VirtualDub cannot do 1 or 4, and only appears to do 3 in the input or output, rather than in the middle of the process.

Also, ConvertToRGB() doesn't appear to slow the process measurably, but does correct the problem, so that's my solution for now.

Xesdeeni

[vhelp]

Xesdeeni,

No, what I was saying is that you CAN feed your *.AVS script into VDUB
w/out the ...toRGB() command in your script, and then frameserve THAT
into TMPG. The quality of the color in your final encode will be outstanding.

Yes, continue using your *.AVS script commands etc.

-vhelp

[Xesdeeni]

I don't understand why I need to frameserve from AVISynth through VirtualDub, if I can frameserve directly from AVISynth just by adding ConvertToRGB(). Did I miss a trick here?

Xesdeeni

[vhelp]

X,

on my system, I have a color banding issue of some sort - hard to explain.
But, there is a limit of colors or hatches or something like that.

On others' there claim is a good one. I just happen to be the one suffering
this issue, as well as some other's here too.

If you see no quality issues in your process, then I would not change a
thing. If it ain't broke, don't fix it!!

-vhelp