suggestions for low bandwidth MPEG artifact removal?

[FredThompson]

I've got a larger TV now and the effects of relatively low bandwdith on my MPEG2 satellite receiver are quite obvious now. I'm wondering what filters people have found helpful to reduce some of the color swim in non-anime source. I see it most in almost smooth surfaces. It's almost like a pulsing effect. There's also the obvious unwanted smoothing of large ares into an irregular single-color mass.

[PowerMacG4]

Try Blockbuster (http://www.avisynth.org/users/warpenterprises/files/blockbuster_25_dll_20030204.zip)

[FredThompson]

Blockbuster might be a little help in the overly flat areas. I didn't see much improvement last time but the source was better.

The other effect is hard to explain. It's almost a false motion created by the compression. Think of a surface like a door or tabletop which should be static. Well, it sort of swims a little bit. Really sucks.

[Si]

Can you post a sample avi so we can see how bad "bad" is?

regards
Simon

[FredThompson]

sure. I had a good one but deleted the recording because the effect made it really annoying. Give me a couple of days and I'll get one. Need to pull from the less popular channels and it needs to be something with low motion, like an old movie.

[Kika]

@FredThompson

The effect you descripe is the result of high quantisation in the low motion part. Maybe because of a low bitrate and/or a wrong quantisation matrix.

Blockbuster might help a little. But i suggest you to try a resizing to prevent the same macroblocks from being quantisized and compressed again.
Also it might help to use a matrix with a lower quantisation.

[FredThompson]

@Kika, I somewhat follow your explanation.

FWIW, I'm fully prepared to re-encode to a higher bitrate, say, double the source rate. What I'm looking for is a way to filter out some of the visual effect.

I don't mind re-sizing down then back up if that's what it takes to help with the chroma. Hadn't thought of that until just now. It helps with NTSC DV.

The source is 480x480 DirecTV MPEG2 satellite and I'd prefer to keep that size and burn to DVDR.

My understanding of BlockBuster is it adds noise to help prevent blockiness in nearly-identical colors. I've tried it before with almost no visible result, probably because that I'm describing is the other side of the issue BlockBuster is supposed to help with.

Is there a technique to help reduce this less-than-proper-quantization used to make the source?

[Kika]

The source is 480x480 DirecTV MPEG2 satellite and I'd prefer to keep that size and burn to DVDR.

I guess you know that 480x480 isn't a valid DVD-Resolution?
Um, you can try the following: Use Blockbuster and resize it to 448x448.

My understanding of BlockBuster is it adds noise to help prevent blockiness in nearly-identical colors.

It's the same trick DivX uses to hide the blockyness of some Movies (some DivX-Animes i've seen are looking awefull without the option of including artificial Noise while Playback).
Yes, it helps - if you are using high Bitrates at low quantisation levels for re-encoding.
Set the Min-Bitrate of the highest Level possible to prevent blockyness at high action parts.

[FredThompson]

I use DVDlab and DVDPatcher to put the 480x480 on DVDR.

448x448 will be a complete no-go but I guess it could be used to downsize then enlarge. If the edge-aware resizing gets out of the development stage, maybe this is a solution.

[Kika]

OK, i meant resize it to 448x448 and letterbox to 480x480. ;)

The adcantage of this way is: The "old" Macroblocks do not longer exist, you can spare some bitrate, and you can see more of the Video on the TV, because the Picture is smaler and the additional black bars are into the Overscan-Area of the TV.

I use DVDlab and DVDPatcher to put the 480x480 on DVDR.

If you are using DVDLab, you don't need DVDPatcher. DVDLab can handle this by itself.

[FredThompson]

Hmmm...I'll test 448x448 later tonight. That might be a good idea.

DVDLab or DVDPatcher with Nero (because it does Optorite 1400M/CDR.) Guess I should have been more explicit.

[FredThompson]

Well, I've done some searching as a new version of my links list is almost done and found this:

http://www11.brinkster.com/poptones/newcleus/ow.asp?SomeSurprises

Unfortunately, the images aren't there and WayBack doesn't have them. I seem to recall they were available a few days ago but maybe I'm hallucinating about that.

Is this site dead? Is poptones still around? Is there any work on this?

[Si]

Unfortunately Poptones and a ex-moderator of this forum had a bit of a falling out and some marbles were taken home :(

regards
Simon