[MichaelHDDVD]

 In this thread


There is a claim that Happy Feet hits as low as 6 mbits in some parts of the movie

Has anyone looked into it? If this has already been discussed then delete this thread but wow. If the 6 mbits wasn't in one of the few scenes with colorbanding then I am EXTREMELY impressed! Because that would be a DVD bitrate for HD video

 

[ryoohki]

Yeah it hit 6mbits.. even 5mbits.. but those are really horriric moments. There's a scene at the start when Memphis sing and he's from the back to his mate, the bitrate hover between 5-7mbits during about 10 sec, in those, you can actually see macroblock moving in Memphis rear neck, it's my first VC1 encode that i've seen such thing. Most part it's 10-14mbits, with high a 22-25. It peak down underwater, were there's a lot of banding.


I enhanced the contrast of one shot that goes down to 4-6 mbits

This can be seen at normal playback, on DLP, LCOS, LCD and CRT's (tested most of them) and from both HD DVD and Bluray Version (same encode) even perfectly calibrated

 

[MichaelHDDVD]

ok, because I've seen it and noticed the colobanding, it seemed like such an obvious answer but I had to double check

Looks like 5 mbits as a low is a nono, lol

 

[ryoohki]



Quote:
Originally Posted by MichaelHDDVD /forum/post/0


ok, because I've seen it and noticed the colobanding, it seemed liek such an obvious answer but I had to double check

Looks like 5 mbits as a low is a nono, lol

Well 5mbits is okay for a single patch of colors with no gradiant, like maybe morning cartoon and such. Credits too and lower than that.


Happy Feet is great, but there's a couple of issues that prevent it from getting a perfect 5/5 in my book. Those moment might be only 1 minute, but they are still here none the less..

 

[MichaelHDDVD]



Quote:
Originally Posted by ryoohki /forum/post/0


Well 5mbits is okay for a single patch of colors with no gradiant, like maybe morning cartoon and such. Credits too and lower than that.


Happy Feet is great, but there's a couple of issues that prevent it from getting a perfect 5/5 in my book. Those moment might be only 1 minute, but they are still here none the less..

Credits are

 

[eapleitez]

Wow, that scene looks horrendous. Things like that should be corrected, like manually setting the bit rate for that particular scene, before the product is released. There's no excuse for that!

 

[zalahmar]



Quote:
Originally Posted by eapleitez /forum/post/0


Wow, that scene looks horrendous. Things like that should be corrected, like manually setting the bit rate for that particular scene, before the product is released. There's no excuse for that!

That's not exactly how the scene looks, the picture is altered to show the banding more clearly. The actuall original looks greats with slight banding in the gradient of the colors.

 

[MovieSwede]

Actually many BD and HD DVD have the bitrate under 1mbit/s during certain scenes. Nothing strange with that, total darkness is easy to encode.


Banding isnt really a bitrate issue. Did some test yesterday with encoding banding.

Quote:
Originally Posted by MovieSwede /forum/post/0


Just wanted to add a little of my gradient encoding tests.


I tested using three different codecs(in Vegas6). WMV, Mpeg2 advanced, Mainconcept AVC.


I did 2 encodings each of AVC and WMV, only one for Mpeg2. The clip was 10 seconds long (1920*1080/23,976P)


WMVHD(Bitrate peak encode) PeakBit:10 AvaBit:5 = 3,74mb = RealAvaBit: 2,882mbit/s

WMVHD(Bitrate peak encode) Peakbit:20 AvaBit:10 = 4,68mb = RealAvaBit: 3,774mbit/s

AVC(2passVBR) Peakbit:10 AvaBit:5 = 2,95mb = RealAvaBit: 2,36mbit/s

AVC(2passVBR) PeakBit:20 AvaBit:10 = 5,09mb = RealAvaBit: 4,07mbit/s

Mpeg2(2passVBR) Peakbit:20 Avabit:10 = 22,5mb = RealAvabit: 18mbit/s


They all looked very simular in PQ, havn´t had time to do a frame by frame comp.


But it showed very clear that AVC and WMV played a different ballgame. The Mpeg2 was forced to go all the way to its peak as avarage were the other 2 didnt even need half its avarage bitrate.

As for the screenshoot from Happy feet, it shouldnt be used because its a manipulated frame.

 

[ryoohki]



Quote:
Originally Posted by MovieSwede /forum/post/0


Actually many BD and HD DVD have the bitrate under 1mbit/s during certain scenes. Nothing strange with that, total darkness is easy to encode.


Banding isnt really a bitrate issue. Did some test yesterday with encoding banding.




As for the screenshoot from Happy feet, it shouldnt be used because its a manipulated frame.

here the original

Pretty evident around the whale and so forth. It moves too when in motion.

 

[MovieSwede]

Yes better to have the real screenshoot.


But hasnt this been discussed earlier that it could very well be on the master. VC1 dont really have any problem handling gradients. If it on the other hand is on the master VC1 can trough in as many bits you want and it will still show banding.


Going from 12bits to 8bits is problematic.

 

[ryoohki]



Quote:
Originally Posted by MovieSwede /forum/post/0


Yes better to have the real screenshoot.


But hasnt this been discussed earlier that it could very well be on the master. VC1 dont really have any problem handling gradients. If it on the other hand is on the master VC1 can trough in as many bits you want and it will still show banding.


Going from 12bits to 8bits is problematic.

that scene hover around 4-6mbits...


Well you can take the famous Planet Earth SUN banding scene.. on the BBC broadcast that scene was very very slight banding and it's 18mbits AVC (Realtime Broadcast with no optimisation), on HD DVD and Bluray and the same in VC1 is 5mbits, it slow dark blue to light blue and got about 5 very very large ban of color moving. That scene in the BBC HD broadcast is far less severe and almost not problematic to the eye


Here the shot from AVC 18mbits BBC HD Broadcast

Here the shot from the HD DVD version (Blu-Ray is the same)

Now, you can say that Low bitrate VC1 (or ANY CODEC), AVC, MPEG2 is NOT GOOD..

 

[Technicolor]



Quote:
Originally Posted by MichaelHDDVD /forum/post/0

In this thread


There is a claim that Happy Feet hits as low as 6 mbits in some parts of the movie

Has anyone looked into it? If this has already been discussed then delete this thread but wow. If the 6 mbits wasn't in one of the few scenes with colorbanding then I am EXTREMELY impressed! Because that would be a DVD bitrate for HD video

It's the movie that matters. Does it look great? Does it sound great? Numbers are quite irrelevant for me.


I can't read binary.

 

[MovieSwede]

Ryoohki


Even the BBC has been up for discussion in another thread. And if you look closely you can se colorareas in the VC1 that the broadcast version dont have. That could very well mean that the broadcast smears the banding.


Unless we have acces to the source we cant prove it one way or the other. Ben has already proven in other threads that VC1 can handle banding very well in low bitrates, but it cant take away banding that is inhearent to the master. Unless you lowers the bitrate even more.


So if we look at the facts.

We have seen lowbitrate encodings that handle banding well.

We have seen lowbitrate encodings that handle banding bad.


So then we can conclude that lowbitrate isnt a factor on its own, that create banding.

 

[MichaelHDDVD]



Quote:
Originally Posted by Technicolor /forum/post/0


It's the movie that matters. Does it look great? Does it sound great? Numbers are quite irrelevant for me.


I can't read binary.

Of course its the movie that matters, Happy Feet is very good, the PQ is outstanding with the few banding exceptions.

 

[chris062]



Quote:
Originally Posted by Technicolor /forum/post/0


It's the movie that matters. Does it look great? Does it sound great? Numbers are quite irrelevant for me.


I can't read binary.

I guess you haven't watched much broadcast HD because if you did then you would understand that compression artifacts can ruin a good movie. The issues on Happy Feet are relatively minor, but if we (educated consumers/AVS'ers) don't address the quality, then it will get worse - guaranteed.

 

[ryoohki]



Quote:
Originally Posted by MovieSwede /forum/post/0


Ryoohki


Even the BBC has been up for discussion in another thread. And if you look closely you can se colorareas in the VC1 that the broadcast version dont have. That could very well mean that the broadcast smears the banding.


Unless we have acces to the source we cant prove it one way or the other. Ben has already proven in other threads that VC1 can handle banding very well in low bitrates, but it cant take away banding that is inhearent to the master. Unless you lowers the bitrate even more.


So if we look at the facts.

We have seen lowbitrate encodings that handle banding well.

We have seen lowbitrate encodings that handle banding bad.


So then we can conclude that lowbitrate isnt a factor on its own, that create banding.

The problem with those scene is that they move, color is moving and swifting, the Banding test that the AVSFORUM member did was on a none shifting color band, color didn't moves. On all the banding i saw, MPEG2 and VC1 it was all because the bitrate gone lower than 5mbits in a moving shifting color range.


I'am pretty sure if i color color Dark Blue to light blue and i move the color, from lighter blue to even lighter blue.. or from Blue to Gray/Dark Gray, at 5mbits AVC and VC1 would have band.


I did a lot of h264 Profile 1 (AVC) encode with my HDTV TS grab in the past (last year), i did them at 7mbits VRB, and every single time the encoder saw something like this it plonge to 4 mbits and it was banding frenzy. I tried to correct it , but it would have had to be manually calibrated and i didn't have the patience.


The only way to correct that is to tell the encode not to go lower than 12mbits for example, with peak at 25, but that way you're movie is bigger.


I mean, from memory, i only see banding in Planet Earth, Happy Feet, Ant Bully, Superman return and Ice Age 2 (bluray). All those suffer from really low bitrate for their codec (Ice age 2 goes to 14mbits, for mpeg2 it's weak).. all others title, this is a none issue.

 

[Gary Murrell]

posterization sucks

-Gary

 

[MovieSwede]



Quote:
Originally Posted by ryoohki /forum/post/0



The only way to correct that is to tell the encode not to go lower than 12mbits for example, with peak at 25, but that way you're movie is bigger.

Well from my own modest test, i havnt got this severe banding on either WMV or AVC even if i did go so low as peak:10mbit and avg:5 for 1080P.


Of course this test were in the red-orange area. But i will try do some blue modification to test Banding in blue. But that will have to wait. My wife will kill me if she finds me sitting this night also watching the same 10second sequens over and over again.

 

[Matt_Stevens]

They are basically getting the bit rate as low as possible for future online distribution. There will be no more maxing the bit rate for the best PQ. Now it is lower the ****er as much as possible.


And that just sucks.

 

[Kram Sacul]



Quote:
Originally Posted by MovieSwede /forum/post/0


Even the BBC has been up for discussion in another thread. And if you look closely you can see color areas in the VC1 that the broadcast version dont have. That could very well mean that the broadcast smears the banding.

The purple/magenta part of the gradiant on the vc-1 encode looks an awful lot like what happens with jpeg compression: