Something VC1 has that MPEG-2 does not... - Page 24 - AVS Forum
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post #691 of 711 Old 03-17-2007, 01:59 PM
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Originally Posted by TrevorS View Post

I just leaned back and took a slow scan around my room -- quite frankly, I could easily consider what I see to have a somewhat "soft" appearance. Not a single coarse or hard edge anywhere (except perhaps on my monitor screen )!

Perchance, have you recently "celebrated" a round number birthday? Everything gets softer after the big 4 O.
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post #692 of 711 Old 03-17-2007, 02:17 PM
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Originally Posted by rto View Post

Perchance, have you recently "celebrated" a round number birthday? Everything gets softer after the big 4 O.

Actually, I've been wearing glasses since the age of seven. Vision correction is an innate part of my existence.
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post #693 of 711 Old 03-17-2007, 02:23 PM
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Dang, and here I am creeping up on the big 5 0.

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post #694 of 711 Old 03-17-2007, 02:29 PM
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Originally Posted by jsaliga View Post

Dang, and here I am creeping up on the big 5 0.

--Jerome

Hmmm. Unfortunately, spectacles only address flaccid vision:

http://www.thecanadianmeds.com/group.php?id=131&aid=123
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post #695 of 711 Old 03-17-2007, 02:31 PM
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post #696 of 711 Old 03-17-2007, 05:35 PM - Thread Starter
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Another interesting review:
http://www.***************.com/htsth...?sequence=1873

"Fortunately, grain appears impeccably preserved by the AVC codec, not tarnished or processed in fidelity like so many low bitrate VC1 encodes."
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post #697 of 711 Old 03-17-2007, 05:42 PM
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Quote:
Originally Posted by benes View Post

Another interesting review:
http://www.***************.com/htsth...?sequence=1873

"Fortunately, grain appears impeccably preserved by the AVC codec, not tarnished or processed in fidelity like so many low bitrate VC1 encodes."


"The Spot"? Oh yeah, benes, "The Spot" is an impeccable source for objective, unbiased HD-DVD/Blu-ray software evaluations. Not!
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post #698 of 711 Old 03-17-2007, 06:10 PM
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Originally Posted by batmanbegan View Post

On the 2nd statement, do you want to qualify it or are you saying AVC cannot preserve grain per se? I dont have any AVC movies at home but perhaps someone who does could comment on this issue.

"Tends to" is my qualification. Corser grain will survive more than finer grain, and there's less of an effect at high bitrates.

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Plenty of really smart people worked on both AVC and VC1. One of them got the grain-preservation a bit wrong. I am curious as to which group OR is it neither-is-wrong and only a matter of simple case-by-case comparison?

Grain preservation simply wasn't a major design goal of AVC. Video conferencing was a much higher priority than HD movie delivery, for example. The High Profile had to be added after the initial spec was done to get it even in the ballpark of VC-1 for HD film reproduction.

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Q: Btw, Ben, was this issue considered by VC1 engineers when creating VC1? That people may respond -ively to a codec that does not treat grain the same (exaggerated, as stated) way that MPEG2 does?

I wasn't at Microsoft then, but yes, this was definitely something I remember folks at Microsoft being proud about circa 2003.

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Was it considered by AVC engineers (if you know about it)?

Less so. They were focused on other scenarios. I'm sure some thought about it, but it wasn't something I remember being talked a lot about at MPEG events and such.

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post #699 of 711 Old 03-17-2007, 07:46 PM
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Quote:
Originally Posted by Josh Z View Post

Not to mention that Kong is literally twice as long as Kung Fu Hustle, and yet differs only within 1Mbps of disc space. We're supposed to read into this that VC-1 is not more efficient? How absurd.

"Hustle" has lossless audio in PCM format and several extras, none of which "Kong" has.

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post #700 of 711 Old 03-17-2007, 08:36 PM
 
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...1Mbps of disc space.

Eh?
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post #701 of 711 Old 03-17-2007, 08:41 PM
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Quote:
Originally Posted by benwaggoner View Post

"Tends to" is my qualification. Corser grain will survive more than finer grain, and there's less of an effect at high bitrates.


Grain preservation simply wasn't a major design goal of AVC. Video conferencing was a much higher priority than HD movie delivery, for example. The High Profile had to be added after the initial spec was done to get it even in the ballpark of VC-1 for HD film reproduction.


I wasn't at Microsoft then, but yes, this was definitely something I remember folks at Microsoft being proud about circa 2003.


Less so. They were focused on other scenarios. I'm sure some thought about it, but it wasn't something I remember being talked a lot about at MPEG events and such.

thanks for the answers, man

So, when creating VC1, it was a conscious decision to treat grain differently from how MPEG2 did. Is there an effort underway, or planned for, to educate early adopters and reviewers about this difference? That this is not a flaw of VC1, but rather a strong point, one that should be welcomed by those who want a transparent encode?

I really think some consumer-education would help VC1's cause (assuming, of course, that VC1 is the most accurate at grain-encoding). I say this cos its gonna take a bit of visual evidence wrt the film-master to convince people (like me) who have watched nothing but MPEG2 for HT.


Btw (if you know), when creating the AVC HP, what design choices led to bad grain preservation at bitrates lower than what VC1 would need for a proper grain-encode? (If I understand you correctly, you are syaing that at higher than VC1 bitrates, AVC HP is fine with grain.)

Also, does MPEG2 Ever do a non-exaggerated grain-encode, say at high enough bitrates? Or are you syaing that MPEG2 is incapable of accurate grain preservation?

thanks again
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post #702 of 711 Old 03-17-2007, 10:39 PM
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Quote:
Originally Posted by Josh Z View Post

Not to mention that Kong is literally twice as long as Kung Fu Hustle, and yet differs only within 1Mbps of disc space. We're supposed to read into this that VC-1 is not more efficient? How absurd.

Huh?

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post #703 of 711 Old 03-17-2007, 10:53 PM
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Quote:
Originally Posted by batmanbegan View Post

So, when creating VC1, it was a conscious decision to treat grain differently from how MPEG2 did. Is there an effort underway, or planned for, to educate early adopters and reviewers about this difference? That this is not a flaw of VC1, but rather a strong point, one that should be welcomed by those who want a transparent encode?

That's why I'm here on AVS .

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I really think some consumer-education would help VC1's cause (assuming, of course, that VC1 is the most accurate at grain-encoding). I say this cos its gonna take a bit of visual evidence wrt the film-master to convince people (like me) who have watched nothing but MPEG2 for HT.

Yes. I've asked a number of times what kind of evidence that people who don't believe me would find convincing, but haven't heard much of a clear reply yet. Obviously we can't actually share our work with particular titles or anything.

Quote:
Btw (if you know), when creating the AVC HP, what design choices led to bad grain preservation at bitrates lower than what VC1 would need for a proper grain-encode? (If I understand you correctly, you are syaing that at higher than VC1 bitrates, AVC HP is fine with grain.)

Probably from focusing more on not artifacting over accuracy. AVC can be pushed to very low rates without blocking, or neccessarily looking "compressed" - it just that it's much softer compared to its source, but it's a natural-looking softness mostly.

Quote:
Also, does MPEG2 Ever do a non-exaggerated grain-encode, say at high enough bitrates? Or are you syaing that MPEG2 is incapable of accurate grain preservation?

At really high rates, maybe, but it's definitely a challenge. I've never done real-world MPEG-2 with grainy source I was satisfied with.

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post #704 of 711 Old 03-17-2007, 11:04 PM
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Originally Posted by benwaggoner View Post

Yes. I've asked a number of times what kind of evidence that people who don't believe me would find convincing, but haven't heard much of a clear reply yet.

As I've mentioned before, if "Babel" comes out in VC-1 (Studio Canal announced the title, but not the codec) you can point out places where the AVC/MPEG-4 does an inferior job with the film grain, if what you said before is true and it does do an inferior job with it.

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post #705 of 711 Old 03-17-2007, 11:12 PM
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At least for my eyes, AVC version of "Babel" looked slightly less grainy and less texture than MPEG2 version.
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post #706 of 711 Old 03-18-2007, 03:11 AM
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Originally Posted by cyberbri View Post

Why would you say that?
Because his face is out of focus?
If you look at the shirt, the seam on the right side (left shoulder) is very much in focus - as is the skin on his neck. That would put the focus distance from the lens around his ears, which appear to be a little more in focus.

You don't need to educate me about depth of field, I'm well aware.

Compare this shot to the Casino Royale shreenshots in this thread:
http://www.avsforum.com/avs-vb/showt...5#post10052305

The difference in quality is insane, that's why I asked.
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post #707 of 711 Old 03-18-2007, 03:16 AM
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Originally Posted by Josh Z View Post

I think it would benefit you greatly to read Trevor's post immediately above yours.

Huh? The guy edited his post.
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post #708 of 711 Old 03-18-2007, 03:17 AM
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Quote:
Originally Posted by benes View Post

Another interesting review:
http://www.***************.com/htsth...?sequence=1873

"Fortunately, grain appears impeccably preserved by the AVC codec, not tarnished or processed in fidelity like so many low bitrate VC1 encodes."

Quoting Chad Varnadore comments about VC1 makes as much sense as quoting rdjam comments about Blu-Ray...
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post #709 of 711 Old 03-18-2007, 03:57 AM
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Quote:
Originally Posted by batmanbegan View Post

Also, does MPEG2 Ever do a non-exaggerated grain-encode, say at high enough bitrates? Or are you syaing that MPEG2 is incapable of accurate grain preservation?
thanks again

Of course not. It all depends on the bit rate, quality of the encoder/compressionist and entropy of the source. So the question is which sources are too random to get right even at BR bit rates for MPEG2 as high as 40 Mbit/s.
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post #710 of 711 Old 03-18-2007, 07:56 AM
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Quote:
Originally Posted by Rob Tomlin View Post

Huh?


Alright, fine, I misspoke and retract the point.

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post #711 of 711 Old 03-18-2007, 08:26 AM
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Enough.

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