DemoCoder said:
Bullshit this is true :
"Total bitrate including video, audio and subs can be max 10.08 Mbps"
http://www.videohelp.com/dvd
The max bitrate is fixed, no Profesional DVD software can use an higer bitrare and be compatible with all the dvd player on the market.
Profesional DVD software works by two-pass encoding.
The first pass is a CBR (onstant) pass which gathers statistics on the input stream, the second pass uses the statistics gathered to maximize quality by varying the bitrate. Then professional engineers observe the output, and make tweaks to the decisions of the automatic "draft" VBR pass to fix some scenes that exhibit artifacts.
It all depende in what encoding condition you are
How much bandwitch you get use for the video ?
If you are not bitrare limited you wont have need to use a VBR .
if you econding with a bit rate of the video of 8.99mbit/sec. you dont have need use
a VBR , you can use a single CBR encoding pass.
If you are bitrate limited is better to use a VBR to decide where use an higer bitrate and where you can use a lower bitrare.
Btw Constant and variable bit have have nothing to do with the fact that the dvd can have a max bitrate of 10.08 Mbps"
You pretend as if you have industry insider experience, but you sound clueless. Well, who do you work for and what movies have you authored, Mr Expert?
See my previous post
Maybe you meant to claim that DVDs have a maximum bitrate (9.8mbps effectively) but that is different than trying to claim that MPEG-2 doesn't have variable compression ratios. Most DVDs with all of the junk extras on the disc, actually use quite low MPEG-2 bitrates, that's why SuperBit exists.
You can't read can you ?
I never said that MPEG-2 doesn't have variable compression ratios.
I said that in real word situation you can't use all the same compression ratio that you can use with mpeg4
This is what i said :
"No one encoder can encode in mpeg2 with a 1mbps bitrate without having a video full of artifact.
This is a limitation so don't make sense to say that you can use every type of compression if the codec was not made for that.
there is a limitation, and this limitation is not an hardware limitation, it is a software limitation ."
Mpeg2 codec look like shit at 1mbps where mpeg4 codec at the same bit rate work better,
and this is a limitation for mpeg2 , so don't make sense to say that you can use every type of compression if in real word situation the codec was not made for that.
there is a limitation, and this limitation is not an hardware limitation, it is a software limitation .
No, maximum bitrate in DVD software is to make sure you are compatible with all DVD players. Newer players can handle higher bitrates in theory, higher than the max 10mbps rate, but you'll break on 10 year old DVD players with 1xDVD read and slow decoding.
No, maximum bitrate in DVD software follow the dvd standard with have maxim bitrare, if you go out of the standard you can have an incompatible dvd.
It is a feature of DVD compatibility and has nothing to do with the MPEG-2 algorithm itself.
Bullshit , the fact that you have a minimim bitrate limit is due to the fact that if you use a lower bitrate the video look like shit.
This have evetything to do with the MPEG-2 algorithm itself.
I never talked about the max bitrate encoding limit like an mpeg2 limit .
You really need to learn to read better, because everything stated by the original poster that you were responding to is completely correct.
You really need to read better also : "When the compressors are done, they then review the actual result and tweak where needed."
You can't tweak where needed with mpeg2 gop compression scheme.
This is pure Bullshit , you can't tweak anything with an alredy compressed mpeg2 video.
If you do every recompression make a loss of quality.
This dont make sense at all.
Let my know what studios you know do this.
True, video is something that you can see
Humans tolerate errors and noise in visual perception much more gracefully than audio.
Not in a big therater screen, where you can easly see every effect of the compression.
If a frame or a block is dropped, we still recognize what's going on. Hiccups in audio streams are much much more disconcerting. The loss of even a few milliseconds of audio leads to the ability to misunderstand a conversation. If I shift music off pitch, human beings will instantly recognize the error. If I take a video signal, and shift the color temperature, far less people will detect it.
Video artifact make the video spixellated and with blockiness , you easly see this type of artifact.
Most people sitting at normal viewing distances can't even discern artifacts, if they did, they'd throw out their digital satellite and cable along time ago and clamor for analog cable to return.
If you project the video in a theater you can easly see the artifact that you can't see with a small screen.
This is what i said " If you project the video in a large screen you will see all the mpeg2 video artifact that you dont have if you project the video from the digibeta tape."
Complete and utter horseshit. I have a 120inch WXGA HD display hooked up to an HTPC and I have personally compared MPEG-2 to VC-1 and H.264 samples prepared by professionals at the same bitrates (taken from AVSFORUM members), and H.264/VC-1 has far less artifacts at a given bitrate.
H.264 and VC-1 simply not not gain their compression ratios from being "more lossy"
Bullshit. I am talking about projecting the video in a digital theater.
You did not projected an hd master in a dcinema theater.
I did so i know with such a big screen how much better look mpeg2 hd with the dcinema encoding.
The process is not automatic.
What you mean by the process is not automatic ?
If i want to make a blur ray disk movie, and i have an hd-d5 master i just send the tape
to the post production studio that make all the ecoding operation.
It is not a complicated process.
And most of your responses about using an "mpeg-2 master" is irrelevent.
No one ever claimed that studios use mpeg-2 "masters".
Yes aaronspink claimed here that :
"Most studios have done a significant amount of work to move back library and current libraries over to digital medium using MPEG2"
you wont use mpeg2 to get you library over to the digital medium.
You use another format like hd-d5 to move your work to the digital format.
Mpeg2 is only a delivery format, you wont make a "significant amount of work" to move your work to a delivery format.
The concept of a lossy compressed master is a contradiction, and a lame strawman.
Is English your first language?
No it is not. If he say that he move the library over a digital medium with mpeg2
this make me think he mean digitalizing your work using mpeg2.
And the fact that he act like you can edit mpeg2 make me think this also :
"When the compressors are done, they then review the actual result and tweak where needed."
You dont tweak anything, once the compression is done if where is something wrong you have to redone all the work again.
Neither, since the target spec for first generation BRDVD movies is single-layer 25Gb disks, not 50Gb DL discs. Everyone knows Sony pictures is targeting MPEG-2 on 25Gb disks, so this throws all of your arguments into the toilet.
Wrong, Dysney want the 50hb blu ray disk :
"Disney is unhappy with 50GB Blu-ray Disc delay"
At a Blu-ray Disc press demo held on November 29th, Andy Parsons, senior VP advanced product development for Pioneer announced the delayed readiness of the 50GB disc but downplayed it saying that it was something the industry would grow into over time. However, Buena Vista Home Entertainment president Bob Chapek said Disney was expecting the 50GB disc "from the get-go." The 25GB standard single layer Blu-Ray discs will be launched in the first half of 2006.
It is believed however that the 50GB disc will not be available until late in 2006. Chapek's reason for discomfort is understandable; he envisions packing a disc completely with high definition movies and extra features, which would require the bigger 50GB disc. He also envisions releasing Blu-ray/DVD hybrid discs for consumers who want to buy a movie but wont have a Blu-ray player for some time - another possibility that will probably need a lot more time to be available.
http://www.afterdawn.com/news/archive/7099.cfm
Sony want to use mpeg2
Sony Pictures senior vice president of advanced technology Don Eklund apparently said, “Advanced (formats) don’t necessarily improve picture quality. Our goal is to present the best picture quality for Blu-ray. Right now, and for the foreseeable future, that’s with MPEG-2.”
This throws all of your arguments into the toilet.
VC-1 and H.264 will give far better results on 25gb BRDVD discs. More over, it's doubly hilarious since you don't even seem to know that many studios want to ship HD movies on HD-DVD9 or BD-DVD9 (9Gb discs, essentially DVD-ROM)
Why you say me that "VC-1 and H.264 will give far better results on 25gb BRDVD discs "
then my post was about Dcinema not about 25gb blu ray disk ?
This is my oroginal post :
"it use mpeg2 because it is the codec that give you the best result in this situation.
Microsoft is trying to convince to use vc1 for the dcinema mastering but no one want to use it. "
What have 25gb blu ray disk to do with dcinema mastering ?
My post was this :
"they are worthless if they will never be used from the bigger major like lucas film and sony "
If no major will use them they will be worthless. I never stated that no one will use those codec i said IF no one use them they are wotrhless.
Warners? Fox? Disney? Universal? Paramount? All of which are not using MPEG-2 for HD-DVD or Blu-Ray.
Sony Pictures’ senior vice president of advanced technology Don Eklund apparently said, “Advanced (formats) don’t necessarily improve picture quality. Our goal is to present the best picture quality for Blu-ray. Right now, and for the foreseeable future, that’s with MPEG-2.”
I mean like Sony for the start.
With the 50bg blu ray disk they will use mpeg2.
Encoding hw is one of the cheapes thing for a movie company, the cost to encode a movie with mpeg2 aganist mpeg4 is a nothing for a movie company. 
