Something MPEG2 has that VC1 does not

[Category 5]

...at least in my current experience. I am very excited to have gotten a PS3 to go along with my HD-A2, but I am having a hard time finding superlative titles to go with it. I have rented Ice Age, Ultraviolet, Talladega Nights, Fifth Element, and have just bought Pearl Harbor and Black Hawk Down (still in the mail! ugh!). I will rent Kingdom of Heaven next, but I honestly expected Pearl Harbor to dazzle me. the reviews have been pretty great.

Well, I still see MPEG block in this one. BAD in some places. I have yet to see this problem with any HD-DVD transfer. I am going to rent some VC-1 Blu-Rays next to see if it's the codec or the player...but I already know it's the codec. Well, dual layer BD-50 "should" be able to avoid this. Bit rate seems to hover around 25 most of the time, and hits the 30s during some scenes. Maybe the grain is what killed it...IDK. Just so you BR Fanboys don't flame me with suggestions about how it's my display, my eyes, or some HD-DVD love affair I took some pics at random parts of the film. These are shot close enough to show the detail of what I'm talking about. they are by NO means the worst cases of it in this film. I have yet to find a BR title that doesn't have this artifact. It's not as bad as HD cable, but it's enough that for these expensive players and movies it shouldn't be happening. The sound is unreal however, but why is BR still not matching the PQ of HD-DVDs, even with the extra space? i think it's time to stop defending MPEG2 and move on to the advanced codecs.

The pics are JPG, but I made sure to use a large enough file size to avoid adding additional artifacts (at least noticable ones). Ever see this on a VC-1 encode?

[Capek]

Wow. That last one looks horrible! I can safely say, on my 10' wide screen, I've yet to see a block with HD-DVD, for what that's worth.

[Rob Zuber]

No more codec threads, please. Codecs are not the issue.

[Grandmaster]

Let's be honest Rob, anything that criticises anything to do with BD appears to be "not the issue" for you. The OP's topic is obviously of interest.

[benwaggoner]

Originally Posted by Category 5

The pics are JPG, but I made sure to use a large enough file size to avoid adding additional artifacts (at least noticable ones). Ever see this on a VC-1 encode?

Yep, those are classic MPEG-2 block artifacts. MPEG-2 encodes everything in 8x8 blocks, and if individual blocks don't get enough bits to encode the high frequency data in them, they can wind up looking quite different from their neigbors. This becomes a bigger problem when you have two adjoining blocks with the same problem, since the errors won't match, and the underlying 8x8 block pattern pops out at you.

You're not going to see VC-1 look that bad in that way, even at insanely low data rates, since we have a "loop filter" that smooths out those harsh right-angle artifacts between 8x8 blocks. Of course, HD DVD uses higher VC-1 bitrates where the blocks don't get overly compressed to that degree anyway. But we degrade more smoothly than MPEG-2 under bandwidth stress.

Sony talks about the speed of their MPEG-2 encoder more than they talk about how good an MPEG-2 encoder it is. These are pretty dramatic problems for a title using BD-50.

[Capek]

Originally Posted by benwaggoner

Yep, those are classic MPEG-2 block artifacts. MPEG-2 encodes everything in 8x8 blocks, and if individual blocks don't get enough bits to encode the high frequency data in them, they can wind up looking quite different from their neigbors. This becomes a bigger problem when you have two adjoining blocks with the same problem, since the errors won't match, and the underlying 8x8 block pattern pops out at you.

You're not going to see VC-1 look that bad in that way, even at insanely low data rates, since we have a "loop filter" that smooths out those harsh right-angle artifacts between 8x8 blocks. Of course, HD DVD uses higher VC-1 bitrates where the blocks don't get overly compressed to that degree anyway. But we degrade more smoothly than MPEG-2 under bandwidth stress.

Sony talks about the speed of their MPEG-2 encoder more than they talk about how good an MPEG-2 encoder it is. These are pretty dramatic problems for a title using BD-50.

^^Ya, but what about the JELLY FISH!!

HAHA, sorry, that comment made by, who was it, some Sony exec still cracks me up, even if there is some artifact that could be described in that was that pops up at some stage of the VC-1 encoding process. I've never seen anything like that on any of the HD-DVDs I watch at home, while the reported blockiness of even the best looking titles of BD mare the final product. That is one thing that has allowed me to hold off on shelling out the expense of getting a BD player. I get all the blockiness I need with HD cable.

[MidnightWatcher]

I've read this disc has issues with chroma noise as well. What really gets me is that the Blu-Ray folks believe that this is a Tier 1 title with "No visible compression, sharp image with many examples of 3D." Blu-Ray must have very low standards if this is Tier 1.

[diddlyd]

hah, i don't think 15 year old worn out VHS tapes look that bad on my 60" sxrd screen. I guess blu-ray users should all sell their players and buy VHS players then, right?

[Category 5]

I thought MPEG2 was limited to 16x16 blocks. ??? At any rate, keep in mind that the playing movie doesn't look like this. These are detail shots just to show the effect. They demonstrate a 10-15% image crop.

But what's the deal with this? I expect a BD50 disc to have enough space to avoid this. I read so many messages about people defending MPEG2 (even saying at 25+ mbps it is better than VC1), so why this?

What's a good BD VC1 encoded disc to try out?

[Capek]

Originally Posted by Category 5

I thought MPEG2 was limited to 16x16 blocks. ??? At any rate, keep in mind that the playing movie doesn't look like this. These are detail shots just to show the effect. They demonstrate a 10-15% image crop.

But what's the deal with this? I expect a BD50 disc to have enough space to avoid this. I read so many messages about people defending MPEG2 (even saying at 25+ mbps it is better than VC1), so why this?

What's a good BD VC1 encoded disc to try out?

On my 10' wide screen, I'm sure they'd be visible enough.

The only VC-1 encoded BDs are from Warner, who simply port over their HD-DVD encodes. So if there are no blocks in the HD-DVDs, which there aren't, there won't be any in their BD counterparts.

I have to say it's a little disheartening to know that BD exclusive studios feel that encodes with even a little bit of blockiness is acceptable, and that they apparently don't feel the need to go with VC-1, or at least AVC for all their titles.

[BuGsArEtAsTy]

What bitrate is this, and how much motion is there?

[tkmedia2]

Yeah nice! Would love some time codes!

[BuGsArEtAsTy]

Originally Posted by tkmedia2

Yeah nice! Would love some time codes!

Heh. I was going to ask that, but decided it was moot for me, since I hate that movie anyway and wouldn't bother ever watching it again.

However, it would be interesting if someone could post the timecodes, so someone could verify the bitrates at those times.

[Category 5]

Originally Posted by Rob Zuber

No more codec threads, please. Codecs are not the issue.

Codec is certainly responsible for the issue I've illustrated above.

[tkmedia2]

With time codes you would not have to watch the entire thing over again! That's why I asked!

[Category 5]

Originally Posted by BuGsArEtAsTy

Heh. I was going to ask that, but decided it was moot for me, since I hate that movie anyway and wouldn't bother ever watching it again.

However, it would be interesting if someone could post the timecodes, so someone could verify the bitrates at those times.

No need for timecodes. Any time there is fast motion you can pause the frame and find this. If you don't want to get too far into this movie though, pause on the wide shot of the plane landing in the wheatfield as it pans right at the very beginning. It's about 1:35 into the film. PS3 reports the bitrate as 24mbps here. Half the screen will be filled with blocks.

How about 2:53 as the plane is turning around. Bitrate is 26.4 and again squares throughout the grass and bushes.

Just about anywhere there is action you can pause and find this artifact. Bitrates go over 30 at some points.

They are indeed 8x8 squares BTW. They are discernable enough that I can count their pixel dimensions.

[LynxFX]

If mpeg2 really is that bad, then why are iRobot and U-571 on DVHS still considered some of the best looking HD of any format? Are these blocking artifacts present there as well?

[MidnightWatcher]

Originally Posted by LynxFX

If mpeg2 really is that bad, then why are iRobot and U-571 on DVHS still considered some of the best looking HD of any format? Are these blocking artifacts present there as well?

Maybe for the same reason that Pearl Harbor is considered a "Tier 1" Blu-Ray release.

[vsv]

Originally Posted by LynxFX

If mpeg2 really is that bad, then why are iRobot and U-571 on DVHS still considered some of the best looking HD of any format? Are these blocking artifacts present there as well?

Just my speculation: better source and better mpeg2 encoder from JVC.
Need to ask dr1394...

[mhafner]

Originally Posted by Category 5

No need for timecodes. Any time there is fast motion you can pause the frame and find this. If you don't want to get too far into this movie though, pause on the wide shot of the plane landing in the wheatfield as it pans right at the very beginning. It's about 1:35 into the film. PS3 reports the bitrate as 24mbps here. Half the screen will be filled with blocks.
How about 2:53 as the plane is turning around. Bitrate is 26.4 and again squares throughout the grass and bushes.
Just about anywhere there is action you can pause and find this artifact. Bitrates go over 30 at some points.

Can you see blocks in real time? Are you sure the blocks are not an artifact of the pause function (incomplete decoding)? There should be no blocking at these rates unless the encoding was sloppy.

[unsigner]

Originally Posted by mhafner

Can you see blocks in real time? Are you sure the blocks are not an artifact of the pause function (incomplete decoding)? There should be no blocking at these rates unless the encoding was sloppy.

That's what I was thinking too... this can't be "real", nobody in their mind would ship a movie with such artefacts. You get artefacts such as this with JPEG if you turn the usual 0-100% quality parameter to something like 10-15. It's quite possible to be a problem with the pause function (stupid, stupid Sony - many users are likely to be comparing/examining paused frames, even though nobody watches paused movies), or something is wrong with your particular PS3.

[JeffY]

Not all video decoders are the same, it looks like the PS3 software decoders aren't up to scratch.

[Jeff Lampert]

Why does this one persons experience take precedent over everyone else? Oh I forgot. Because Blu-ray is evil and will eat our children.

This exact same thing has happened to HD DVD. I recall a thread analyzing Phantom Of The Opera practically on the pixel level looking for "jellyfish". Stop the partisan BS and get used to it. If there are no issues with PH, then there will be plenty of objective AVSer's who will offer their support. And if there are issues, then you take it from there.

[Likvid]

Originally Posted by Grandmaster

Let's be honest Rob, anything that criticises anything to do with BD appears to be "not the issue" for you. The OP's topic is obviously of interest.

I have to agree with Rob, codec is not the issue here..

This is just another desperate trick from HD-DVD campers which really starts to get boring.

[amirm]

Originally Posted by benes

Sorry but I see no such thing on my end. I went thru frame-by-frame on both of those timecodes you mentioned. And I looked at a lot of other scenes too. I'm using PC-based playback with PowerDVD Ultra 7.2. If other people give their reports with different setups then we can safely say this is something down to your setup.

It is possible the PC player employs MPEG-2 noise filter, ala Samsung in the old firmware. Such a filter is designed to smear the block edges.

My main suspect would be the PS3 obviously. You mentioned that you don't see this when the movie is playing so I would say that the PS3 pause function is not up to snuff.

No Pause function explains what is posted here. It would explain jaggies but not obvious compression artifacts.

I can pause on any frame in PowerDVD and can do perfect frame-advance and the image never falls apart.

Assuming your PC display is 1920x1080 and not some other resolution. Most PC displays are 16:10 and if you run them full screen, you get filtering/interpolation which softens the video. So be sure to run 1:1 and report back. Also look in the player to see if there is an advanced setting for noise reduction and turn that off and report what you see.

Don't you think all the reviewers and regular users who have watched this movie would have seen such huge defects? Why does this one persons experience take precedent over everyone else? Oh I forgot. Because Blu-ray is evil and will eat our children.

To be honest, this is a torture test. This was a movie that Disney picked as their test clip in DVD Forum codec shoot out for HD DVD. So if there is a movie that is going to show problems from their portfolio, this is probably it.

And yes, I agree it is pushing it to claim that every frame of a movie must be perfect. They never will be. The question is though, now that you have seen the artifact, whether you can spot it in normal viewing.

BTW, I don't agree that professional viewers have not seen this artifact. When MPEG-2 becomes mildly blocky, it can give a hard-edge look to the video with the blocks being readily visible (well, to folks who don’t do compression for a living). All of those sharp edges as they come and go rapidly in the 8x8 blocks, increase the high frequency component of the video, getting rid of the smooth "film look" we all want. You can perhaps see this in Peter Bracke's review: http://bluray.highdefdigest.com/pearlharbor.html

"Unfortunately, chroma noise can be a glaring irritant. It is especially evident on primary colors, and combined with the harsh quality I generally find with MPEG-2 transfers, the image often has an unappealing hardness."

Although he does go on to say that he doesn't see blocking artifacts during fast motion which tells me the artifacts are not as visible in full motion, but cause the harshness I talk about.

[HD-DVDwonder]

I can see this thread going on for 10-12 pages

[amirm]

Originally Posted by benes

If the blocks looked that bad then I don't think any amount of smearing could fix it. I don't see anything near that bad of an image. I don't see anything wrong with it at all in fact. No blocking, no smearing, no noise filtering that I can see.

Actually, deblocking filters are very effective in hiding such artifacts at the cost of reducing resolution. If you don't mind, please check the advanced settings in your player.

We can't rule out that the PS3 decoder is not up to par either as someone already mentioned.

I don't see any flaws in the decoder that can cause such an artifact. There can be decoder issues at all, but this is such an obvious artifact of bit started MPEG-2 that it is hard to put blame anywhere else in the decoder.

The only possibility that could point the finger at PS3 is if it sharpens the video on the way out. Doing so really highlights blocking artifacts. I don't have a PS3 yet unfortunately so don't know if there is a setting for sharpness in it. I think Stacey tested the PS3 and found it to not have any ringing problems so I am not sure there is a lot of blame to go there. BTW, trust me, I love to see something wrong in PS3 . But I just don't think that is the burning bush here.

I've seen plenty of other defects from both formats for me to complain about but not blocking. And certainly nothing to this degree.

I see blocking artifacts frequently in BD titles. The early launch titles are good examples as are the demo loops in stores/shows. But that is neither here nor there wrt to the specific title here.

My display is a 4:3 CRT and it is set to 1920x1440.

Ah, that explains it . I love CRTs and they provide an excellent picture. Alas, they lack the resolution and sharpness of a fixed pixel display. Indeed, if I want to find blocking artifacts, I always play things on a 1080p LCD with 1:1 pixel mapping, not a CRT. The CRT softens the edges automatically because there is no such thing as a pulse going from zero to max in an analog device whereas a digital display happily goes from black to full white in one pixel.

Alas, I can't find my copy of Pearl Harbor either. When I do, I will give it a try on the Ruby and report back if there is interest.

[benwaggoner]

Originally Posted by Category 5

I thought MPEG2 was limited to 16x16 blocks. ??? At any rate, keep in mind that the playing movie doesn't look like this. These are detail shots just to show the effect. They demonstrate a 10-15% image crop.

It uses 8x8 blocks. But color is only sampled once every 2x2 block, so one 8x8 block of chroma covers 16x16 pixels. That's called a macroblock.

But what's the deal with this? I expect a BD50 disc to have enough space to avoid this. I read so many messages about people defending MPEG2 (even saying at 25+ mbps it is better than VC1), so why this?

Yeah, those are pretty bad artifacts. I'm not sure how much of it is the content's unsuitbiility to MPEG-2, and how much on Sony's emphasis on fast encoding over video quality.

What's a good BD VC1 encoded disc to try out?

Check out any of the recent Warner titles - they use VC-1.

[Josh Z]

Originally Posted by unsigner

That's what I was thinking too... this can't be "real", nobody in their mind would ship a movie with such artefacts.

While not a High Definition release, the recent Sony DVD for "Transformers: The Movie - 20th Anniversary Special Edition" is plagued by horrible blocking artifacts of the type we're discussing here during any fast motion, some of the worst I've ever seen on DVD. I'd post some screen caps, but the damned thing won't load in my PC.

So yes, discs do still get released with such terrible encoding.

[BuGsArEtAsTy]

It looks sort of like a few of those lower bitrate downloadable WMV HD trailers that were posted a while back. Miami Vice:



I wonder how much of it is due to the decoder though, as this was captured on my Mac with QuickTime and the Flip4Mac plug-in. Flip4Mac is distributed by Microsoft though.

Originally Posted by amirm

if there is interest.

Of course.