A few questions regarding Macroblocking.

Willen · Post by **Willen** » Tue May 16, 2006 6:04 pm

I believe Funi's older DBZ DVDs are infamous for the bad quality. Not always their fault since they sometimes only had crappy masters to work with, but this one is probably a bad encode by Funi.

Hellmaster Inu · Post by **Hellmaster Inu** » Tue May 16, 2006 7:49 pm

DJ_Izumi wrote:Who ever encoded that DVD should be fired. Chinese pirates could do better.

I'd have to agree. Before I started buying the DVDs and watching DBZ subbed, I had seen said episode on TV and it didn't have any macroblocking. While it does hold true that Funimation's masters for DBZ aren't of the best quality, it's definitely the encoder's fault on this one.

bulmafox · Post by **bulmafox** » Wed May 17, 2006 5:24 pm

When you watch the DVD, do you notice the color fluctuating from very dark to very light and back again, in a cycle? If so, it may have Macrovision (anti-piracy) protection enabled.

Zero1 · Post by **Zero1** » Wed May 17, 2006 5:42 pm

Macroblocking is kinda a bad term for this, even though it's written in the guides. Basically it's caused by aggressive rounding of the co-efficients (which is caused by high quantizers). You usually get high quantizers when the CODEC does not react fast enough to a change (they vary the bitrate over an averaging period usually), or there is not enough bitrate to code that high complexity area/frame (a combination of both is what makes this frame look so shitty).

There are a few ways round this.
1) Omit the frame (if it's just a single frame, it might not notice).
2) Recreate the frame. If the difference from the last frame is only lighting, colour or something along those lines, grab the previous/future frame and edit it in photoshop and create an artificial replacement.
3) You can replace the bad frame with the previous or next frame (if it is similar enough)
4) You can take the previous and next frame and motion compensate/morph/interpolate them to get an "inbetween" frame.
5) You can blast it with filters/effects and hope that since it's just 1 frame, no one will notice

Now as for 5)... I was originally going to post this as a bit of humour, but I realised that if you was really desperate, or clever, you could actually put this to use.
http://img67.imageshack.us/img67/5039/pdvd018as5es.jpg

Gaussian blur. It's big, it's blurry, it's ugly, but it's hidden that blocking enough to not be so noticable. Now I said clever. You might be able to integrate a gaussian blur of varying strength over a few frames, kind of like an aftershock (if he's fires some energy there).

Qyot27 · Post by **Qyot27** » Wed May 17, 2006 6:32 pm

Hellmaster Inu wrote:
DJ_Izumi wrote:Who ever encoded that DVD should be fired. Chinese pirates could do better.
I'd have to agree. Before I started buying the DVDs and watching DBZ subbed, I had seen said episode on TV and it didn't have any macroblocking. While it does hold true that Funimation's masters for DBZ aren't of the best quality, it's definitely the encoder's fault on this one.

While it's out of most people's price ranges (and the episode in question hasn't been released yet) a remastered edition of DBZ is in the process of being released in Japan. The DVDs are available from CDJapan. That's about the only thing I could possibly suggest if you don't want to compensate with the advice Zero1 gave.

Melanchthon · Post by **Melanchthon** » Wed May 17, 2006 7:17 pm

Zero1 wrote:Now as for 5)... I was originally going to post this as a bit of humour, but I realised that if you was really desperate, or clever, you could actually put this to use.
http://img67.imageshack.us/img67/5039/pdvd018as5es.jpg

At least I can tell it's a front view of his face now.

The doom9.org forums have a bunch of deblocking filters available, but I really don't know which would be the most effective. If this happens on only a single frame at a time, then replacement would work unless the affected section was drawn at 24fps.

DJ_Izumi · Post by **DJ_Izumi** » Wed May 17, 2006 7:37 pm

I think the issue here is quite simple.

There are no filters for fucked up blocks. Removing blocking and such, sure. This is isn't that. This is what you see when you try to play a DVD after sneezing on the disc or digital video broadcasts being screwed up by weather and signal problems.

Zero1 · Post by **Zero1** » Thu May 18, 2006 12:09 pm

Yes, apart from the gaussian blur, that image is pretty much unsalvageable.

All filters are made to takle average blocking, the steps between the blocks are too high to be able to do it effectively.

I personally wouldn't waste my time, but you might find a nice comprimise.