TMPGenc blockyness problem

[Irrational Stoat]

I use TMPGenc to make M2V files that I use in DVDLab, and the results are usually excellent.

However - I recently started using AutoGourdianKnot to convert VOB files to AVI (I use the Xvid codec), and even though the resulting AVI quality is excellent, when I convert them to M2V I get blockyness on the faster-moving sections of the M2V, even if I use a high bitrate and set the motion-search precision to very high.

This is very strange, as I have been converting to M2V this way for a long time, and don't usually get any blockyness with the settings I use.

Some info on files and settings:

The source VOB is PAL, around 900mg, 21 minutes duration.
The AGKnot settings are 200mg filesize, 640px screenwidth, Xvid codec - the resulting file has a bitrate inbetween 1100 and 1200 kbits/sec, and picture quality is excellent with no blockyness.
The TMPGenc settings are PAL 352x576 screensize with fullscreen keep-aspect-ratio, 1200 kbits/sec CBR bitrate, highest motion search precision.

The AVI loads into TMPGenc as interlaced, with bottom order first.

[jimmalenko]

Why not demux your VOBs to get your M2V and audio, instead of converting twice ?

[Irrational Stoat]

Because I want to keep filesizes low while maintaining quality - that's why I convert to AVI first.

The blockyness is puzzling, as the AVI has excellent quality, and I use TMPGenc settings that normally give me excellent quality low filesize M2V's with no blockyness.

[guns1inger]

Lossy compression to lossy compression to lossy compression is going to cause some problems along the way.

You could also frameserve from the vobs to tmpgenc and not even have to have the intermediate avi. Less space required than your current method, higher quality output, and much faster.

[Irrational Stoat]

So how do I frameserve to TMPGenc?

[mats.hogberg]

mpeg video to AVI to mpeg video won't get you any advantages whatsoever over mpeg2 to mpeg2.
Only degrading the quality twice, instead of once.
Seems like you're under the misconception that the source file size is related to the final file size. Those two have no relation whatsoever.

/Mats

[mats.hogberg]

So how do I frameserve to TMPGenc?

There's a whole guide dedicated to frameserving under "how to" left.

/Mats

[Irrational Stoat]

OK, a couple of things:

1) I know that filesize isn't an issue. I'm simply puzzled why a perfectly good quality AVI converts to a bad quality M2V when I use the same settings that normally give me excellent quality M2V's.

The fact that I converted the VOB myself is beside the point. I've downloaded AVI's of a similar quality and bitrate that convert with no blockyness.

2) I did check out those frameserving guides, but I could do with others to look at. I'm Googling around as well.

[guns1inger]

Assuming, for the moment, that this process has worked flawlessly in the past, something must have changed in the environment to cause the current problem.

Have you changed versions of Xvid or tmpgenc ?
Have you changed your DVD player ?
Have you changed your TV ?

[Irrational Stoat]

Installing the AGKnot pack would have installed a new Xvid codec, I suppose - but I've converted downloaded Xvid files with no blockyness since I installed AGKnot.

I haven't installed a new TMPGenc.

And the blockyness shows up when I play the M2V on my computer as well as on a DVD.

And no, I haven't changed my DVD player or TV.

[jimmalenko]

1200kbps is very much on the low side IMO for Half D1 MPEG-2. I'm surprised that it hasn't given you substandard results before now.

[Irrational Stoat]

1200 does seem like a low bitrate, it's true - but I have had excellent results using that bitrate. Just not with these particular AVI's.

[Irrational Stoat]

I'm trying to frameserve the source VOB at the moment - I'm using VDubMod to frameserve to TMPGenc Plus. But I can't get TMPGenc to open the dummy file that the frameserver generates.....