zeez

Hey All,

THis is my first post here, though I have been reading and benefiting from the reviews for quite some time (I am particularly grateful for the reviews on all the different "Time Bandits" versions!).

After reading all these reviews I began to ponder why some movies seem to not fill up an entire DVD. I have used an application to peer into my films and I have found that the video component size is not very regular between different films. Some films surprised me by not even being dual layer discs, despite looking pretty good.

I have seen video components the size of 6.5gb, and video components the size of 3.8gb! Mind you, the 3.8gb was my LotR Two Towers: Extended (disc 1), and that blew my mind. There seemed to be plenty of space left on the disc even after the DTS and dolby tracks, so I am puzzled as to why this space was not used for a larger video file size.

Although I realise that there is a lot more to transfer quality than filesize, am I incorrect in assuming that in general a larger video file size would mean improved quality? Many reviews I have read here praise 2-disc dvds for giving the transfer greater breathing room, so I would assume that larger video component = better quality. I am a bit disappointed when I want to order a DVD but see that it is only 1 disc and has a lot of special features on it.. makes me afraid that I'm not getting the best possible image.

It also makes me wonder why they don't expand the video component and either use 2-discs or fill up the one disc to the brim (the latter is sometimes the case).

Possible explanations?

- Extra space is left for international distributors to slap on additional audio tracks instead of replacing them

- Diminishing marginal returns and/or DVD player output hard caps.

- (Paranoia) video quality is deliberately capped so that HD/Blu-Ray versions look even better ;p

I would appreciate hearing other theories and actual known reasons.

milo bloom

A lot of it depends on how well the compression program works, plus how good the human overseeing it is also.

If you'll recall the Superbit line of DVDs, this was pretty much their schtick: take away everything unnecessary (extras, audio tracks), and let the movie have as much space as possible.

It wasn't a perfect system as I seem to recall people checking the disc space of Panic Room and Punch Drunk Love, and there being tons of space leftover.


This is one of those things I've always been a little puzzled about not hearing more about from insiders. I suppose they're just too afraid of getting in trouble to discusse the issue at all.

Edit to add: and I wouldn't be surprised to find out titles in the past year or two were intentionally nerfed to make the HD/BR look even better in comparison.

zeez

Me either, but I think it also might have something to do with the limitations of older tvs/players.. perhaps they figured there was a limit to what could be displayed, so they didn't bother to try improve the quality... however, now many more people have better tvs and players and I don't know if this 'cap' would still apply. It's possible that they are still creating these newer dvds with only older tvs in mind (which would also keep the barrier between the formats wide).

zyzzle

zeez,

Your post is one of the most intelligent and most insightful I've read on this forum... You raise some excellent, difficult, and quite embarrassing questions that need some answers, specificially by many of the DVD authoring houses out there that seem to not utilize the format to its best end...

There are times when I've been so infuriated when a film IS given an RSDL treatment, but when I looked at the video component, the film was only from 3 to 4 GB in size, while the extras, menus and "fluff" took up 4 to 5 GB which could have gone to improve the bitrate of the movie itself!

I wouldn't place much credance in your suggestion that it may be due to international distributors' needs, as these release are probably re-authored in their entirity. Have you ever noticed how the VAST MAJORITY of Region 2 releases do fill the DVD up and utilitze the maximum bitrate for the feature? Most Region 2 counterparts totally blow away the US release in video quality and bitrate.

The dimishing returns claim is doubtful as well. Each DVD is authored ONCE and it is telecined, and run through the MPEG2 encoding program of choice depending on the DVD authoring house... How much more time can it take to specify an average VBR of 6.5 or 7 MBits/sec for the video component than specifiying one of only 3.5 to 4 Mbits? Not too much, right? So, it is either laziness, an idiot setting the encoding parameters, or simply being far, FAR too conservative in specifiying bitrate averages.

The paranoia angle is interesting and the most malevolent and scary of all. The studios and MPAA are probably bribing and/or paying off the authoring houses to intentionally author a poor DVD, with a low average video bitrate for the feature. If so, this is totally unforgivable and somebody inside the industry needs to blow the whistle... These days, with inferior quality of so many other things in the US, it would not shock me in the least if this turns out to be true... Pure corporate greed as usual. Business as usual, right?

zeez

Thanks for the vote of confidence (must be because we are both Z's)!

I went through my DVD collection and pulled a few to test on. I'll list the results I found below:

Das Boot - Director's cut (flipper disc)
Disk 1
-Video = 3,071mb (1:48.07)
-5.1 German = 319mb
-5.1 English = 319mb
-2ch English = 159mb
-2ch Spanish = 159mb
-2ch English = 159mb
-Menu = 242mb
TOTAL = 4,464mb
Disk 2
-Video = 2,807mb (1:39.53)
-5.1 German = 300mb
-5.1 English = 300mb
-2ch English = 150mb
-2ch Spanish = 150mb
-2ch English = 150mb
-Menu = 289mb
TOTAL = 4,177mb

Das Boot - Superbit
Disk 1
-Video = 4,951mb (1:48.04)
-5.1 German = 373mb
-DTS German = 629mb
-2ch English = 160mb
-Menu = 49mb
TOTAL = 6,209mb
Disk 2
-Video = 4,583mb (1:41.04)
-5.1 German = 343mb
-DTS German = 577mb
-2ch English = 146mb
-Menu = 49mb
TOTAL = 5,740mb

Equilibrium
-Video = 4,739mb (1:46.43)
-5.1 English = 347mb
-2ch English = 150mb
-2ch English = 150mb
-Menu = 1mb
-Extra = 247mb (unspecified by me)
TOTAL = 5,665

Once Upon a Time in the West - Collector's Edition
Disk 1 (movie)
-Video = 6,556 (2:45:10)
-5.1 English = 551mb
-2ch English = 236mb
-2ch French = 236mb
-2ch English = 236mb
-Menu = 82mb
-Extra = 10mb (unspecified by me)
TOTAL = 7,952mb

Platoon 20th Anniversary Edition
Disk 1 (movie)
-Video = 4,238mb (1:59.28)
-5.1ch English = 335mb
-DTS English = 657mb
-2ch French = 166mb
-2ch Spanish = 166mb
-2ch English = 166mb
-2ch English = 166mb
-Menu =7mb
-Extras = 24mb (unspecified by me)
TOTAL = 6,068mb

Predator SE
Disk 1 (movie)
-Video = 5,197mb (1:46.28)
-5.1 English = 351mb
-DTS English = 592mb
-2ch Spanish =150mb
-2ch French = 151mb
-2ch English = 151mb
-Menu = 23mb
-Extras = 252mb (unspecified by me)
TOTAL = 6,926mb

Robocop 20th Anniversary Edition
Disk1 (movie)
-Video = 4,019mb (1:42.40)
-4ch English = 338mb
-5.1 English = 337mb
-DTS English = 571mb
-2ch French = 144mb
-2ch English = 144mb
-Menu = 79mb
-Extras = 1,161mb (unspecified by me)
TOTAL = 6,840mb

Star Trek First Contact SE
Disk 1 (movie)
-Video = 5,347mb (1:50.34)
-5.1 English = 346mb
-DTS English = 585mb
-5.1 French = 345mb
-2ch English = 148mb
-2ch English = 148mb
-2ch English = 148mb
-Menu = 63mb
TOTAL = 7,197mb

Starship Trooprs SE
Disk 1 (movie)
-Video = 4,254mb (2:09.19)
-5.1 English = 374mb
-5.1 English = 437mb (.. one of these is probably French)
-2ch French = 186mb
-2ch English = 186mb
-2ch English = 186mb
-Menu = 105mb
-Extras = 94mb
TOTAL = 5,867mb

V for Vendetta Special Edition
Disk 1 (movie)
-Video = 5,543mb (2:12.23)
-5.1 English = 436mb
-5.1 French = 436mb
-Menu = 39mb
-Extras = 279mb
TOTAL = 6,799mb

War and Peace
Disk 1
-Video = 5,979mb (2:20.02)
-5.1 Russian = 462mb
-5.1 English = 462mb
-5.1 French = 464mb
-Menu = 212mb
-Extras = 16mb
TOTAL = 7,702mb
Disk 2
-Video = 5,410mb (1:33.11)
-5.1 Russian = 310mb
-5.1 English = 309mb
-5.1 French = 310mb
-Menu = 193mb
-Extras = 16mb
TOTAL = 6,599mb
Disk 3
-Video = 4,506mb (1:17.42)
-5.1 Russian = 258mb
-5.1 English = 258mb
-5.1 French = 258mb
-Menu = 218mb
-Extras = 16mb
TOTAL = 5,569mb
Disk 4
-Video = 5,352mb (1:32.13)
-5.1 Russian = 308mb
-5.1 English = 307mb
-5.1 French = 307mb
-Menu = 206mb
-Extras = 16mb
TOTAL = 6,539mb


I realise this is not very clear, and it may not be a perfect sample of DVDs from different printing dates, production dates and 'clean up' dates, but I just grabbed an assortment rather quickly to give some indication of what I've found.

Is it a case of a hard limit imposed by the source material? Some of these films are old, yes.. and I will try get more new films (rather than cleaned up releases of old films) in my next batch of tests.

All these films are Region 1 NTSC releases.. if someone has other region releases it might be beneficial to do direct comparisons to see if (in some cases) the extra space is left for other languages fill in the empty areas.

milo bloom

Now I have heard of older films sometimes being harder to compress because of print damage, extra grain, or just differences in emulsion and whatnot. So that's one possible answer there.

zyzzle

The examples you give actually show fairly good video component size. At least a significant portion of the 8.5 GB of the RSDL capacity is used. What is most surprising to me is just how much space is devoted to AUDIO. Especially on some of those older movies, which ARE harder to compress, why take 500 to 600 MB for a fake 5.1 track? This is not how the film originally was shown in the theatres (most had just mono tracks, some were stereo). Also, all the foreign language tracks / dubs seem dubious at best, UNLESS they are targeting a Region 1 release for an International market, which doesn't really make sense, because of the whole region-coding mess to begin with. So, why waste that space when the Region 2 populace would make better use those tracks?

My main point is that we seem to be seeing this lack of capacity utilization on the more modern releases. The source may be "easier" to compress, being that it has less film noise, etc, but that still isn't any excuse for intentionally reducing the bitrate by a factor or 30 to 40%. So much depends on the *quality* of the MPEG2 video encoder used. I will readilly admit that the best ones out there will produce a better, sharper picture at 4 Mbits/sec than the mediocre ones will at 6 Mbits/sec.

You've set a good precident by listing some raw numbers... I'll post some of my findings to update this. I have found Criterion to be the best optimizer of bit rate... The care they put in really shows, especially on a large screen. Is it any surprise that their DVDs cost the most? Also Dark Sky Films seems to release all their DVDs with excellent utilization of bitrate (Read: using the maximum possible for the feature to fill out ALL the DVD capacity). Their titles cost the same as mainstream releases, yet they put in that little extra in optimization, and it really shows onscreen.

zeez

It's part of the new trend to change everythign to 5.1, and I'm not certain if I like or dislike, it myself. Until very recently I never had a 5.1 system (i never had a separate subwoofer, either) so it was tv speakers or stereo speakers most of my life. Because of that, I find that everything sounds very, very very different even when I compare remastered dvds to vhs tapes of, say, Conan the Barbarian (they are both in mono, i think). People expect that if they buy an old movie re-released on DVD that it should have something new to it... so they split the sound to 5.1 even though it rarely is fully utilised. On that note, if I play a 5.1 track in Stereo mode on my receiver, will it sound like a proper Stereo track? Wait.. nm.. my receiver might automatically fudge the 2.1 into 5.1 ...but we're getting off topic.

As far as the audio languages.. well, that is because Canada/USA are both region 1, and I'm not certain about south of the US but it's possible it's region 1 down there as well, so that would account for Spanish. I used to try not to buy DVDs in Canada that had french & english script on the covers (because I didn't like how the covers looked!) but if the audio tracks are still there then it doesn't really matter, I suppose.

I'm still shocked that some of these DVDs have so much space left for video.. especially Das Boot -Superbit. It's a bit depressing, but at the same time I wonder if they truly maxed out what can be displayed given the source material. That's why I'm going to check some newer dvds, like RotS, Pirates of the Caribbean and etc. I have some criterion discs as well, so I will check on those.

As for Dark Sky Films, i'm not familiar with the name at all. I"ll have to do some research.

Drexl

When the compressionist is given a "budget" to work with, I wonder if there are cases where a certain amount of space is set aside for special features that never materialize, cannot be cleared, or are just dropped. They may not plan everything that will be on the disc ahead of time. That obviously doesn't explain why Superbit titles have extra space though.

Zyzzle, you want to talk about a waste of space? The Blu-ray Disc of Identity has a German dubbed track in 5.1 PCM, which takes up 3-4GB of space.

zeez

Citizen Kane (from Essential Classics - Drama)
-Video = 5,188mb (1:59.20)
-Mono English= 167mb
-2ch English= 168mb
-2ch English = 167mb
-menu = 66mb
-extras = 275mb
TOTAL = 6,075mb

Creature from the Black Lagoon
Disc 1 (movie)
-Video = 4,861mb (1:19.10)
-2ch English = 110mb
-2ch English = 110mb
-Menu = 7mb
-Extras = 1,124mb (video +audio)
TOTAL = 6,237mb

Kagemusha - Criterion
-Video = 6,880mb (3:00.23)
-4ch Japanese = 512mb
-2ch English = 256mb
-Menu = 26mb
-Extras = 149mb
TOTAL = 7,876

Kingdom of Heaven - Director's Cut
Disc 1
-Video = 4,640mb (1:39.09)
-5.1 English = 328mb
-dts english = 554mb
-2ch english = 140mb
-2ch english = 141mb
-2ch english = 140mb
-Menu = 68mb
-Extras = 60mb
TOTAL = 6,133mb
Disc 2
-Video = 4,340mb (1:34.35)
-5.1 English = 311mb
-DTS english = 521mb
-2ch english = 133mb
-2ch english =132mb
-2ch english = 132mb
-Menu = 51mb
-Extras = 7mb
TOTAL = 5,679mb

Planet of the Apes (can't remember.. maybe the newest edition of the classic)
-Video = 5,579mb (1:51.55)
-5.1 English = 353mb
-DTS english = 597mb
-2ch Spanish = 151mb
-2ch French = 150mb
-2ch English = 150mb
-2ch English = 151mb
-Menu = 119mb
-Extras = 8mb
TOTAL = 7,313mb

Star Wars - Revenge of the Sith
-Video = 5,733mb (2:20.47)
-5.1 English = 464mb
-2ch english = 198mb
-2ch Spanish = 198mb
-2ch French = 199mb
-2ch English = 200mb
-Menu = 274mb
-Extras = 47mb
TOTAL = 7,401mb

Seven Samurai - Criterion
Disc 1
-Video = 6,129mb (1:51.53)
-1ch Japanese = 158mb
-2ch Japanese = 158mb
-1ch English = 158mb
-1ch English = 158mb
-Menu = 36mb
-Extras = 244mb
TOTAL = 7,075mb


I'm pretty disappointed in my Kingdom of Heaven dvds.. so much leftover space for no good reason.. and a blu-ray released around the same time, which means they had the ability to add quality to this dvd, perhaps.

I'm not sure if this is an accurate measure of anything, but if you divide the mb of video by minutes of video you get numbers ranging from 31-42.5 or etc.. does this measure of 31mb/min mean anything about the encoding quality? If so, Planet of the Apes and Seven Samurai have the highest values, with Citizen Kane and others following.

zeez

Ok, I've updated the list to include the video bitrate calculated in the following way:

(Megabytes of video) x (8 Megabits/Megabyte)
---------------------------------------------
(Minutes of video) x (60 seconds/minute)


I'm not certain if I should be adding the largest audio track to the video size, since people say dvds have a playback limitation of 10Mbps.. let me know what you think.

Das Boot - Director's cut (flipper disc)
Disk 1
-Video = 3,071mb (1:48.07)
-5.1 German = 319mb
-5.1 English = 319mb
-2ch English = 159mb
-2ch Spanish = 159mb
-2ch English = 159mb
-Menu = 242mb
TOTAL = 4,464mb
Video bitrate = 3.7914 Mbps
Disk 2
-Video = 2,807mb (1:39.53)
-5.1 German = 300mb
-5.1 English = 300mb
-2ch English = 150mb
-2ch Spanish = 150mb
-2ch English = 150mb
-Menu = 289mb
TOTAL = 4,177mb
Video bitrate = 3.7427 Mbps

Das Boot - Superbit
Disk 1
-Video = 4,951mb (1:48.04)
-5.1 German = 373mb
-DTS German = 629mb
-2ch English = 160mb
-Menu = 49mb
TOTAL = 6,209mb
Video bitrate = 6.1123 Mbps
Disk 2
-Video = 4,583mb (1:41.04)
-5.1 German = 343mb
-DTS German = 577mb
-2ch English = 146mb
-Menu = 49mb
TOTAL = 5,740mb
Video Bitrate = 6.0502 Mbps

Equilibrium
-Video = 4,739mb (1:46.43)
-5.1 English = 347mb
-2ch English = 150mb
-2ch English = 150mb
-Menu = 1mb
-Extra = 247mb (unspecified by me)
TOTAL = 5,665
Video Bitrate = 5.961 Mbps

Once Upon a Time in the West - Collector's Edition
Disk 1 (movie)
-Video = 6,556 (2:45:10)
-5.1 English = 551mb
-2ch English = 236mb
-2ch French = 236mb
-2ch English = 236mb
-Menu = 82mb
-Extra = 10mb (unspecified by me)
TOTAL = 7,952mb
Video bitrate = 5.2978 Mbps

Platoon 20th Anniversary Edition
Disk 1 (movie)
-Video = 4,238mb (1:59.28)
-5.1ch English = 335mb
-DTS English = 657mb
-2ch French = 166mb
-2ch Spanish = 166mb
-2ch English = 166mb
-2ch English = 166mb
-Menu =7mb
-Extras = 24mb (unspecified by me)
TOTAL = 6,068mb
Video Bitrate = 4.7286 Mbps

Predator SE
Disk 1 (movie)
-Video = 5,197mb (1:46.28)
-5.1 English = 351mb
-DTS English = 592mb
-2ch Spanish =150mb
-2ch French = 151mb
-2ch English = 151mb
-Menu = 23mb
-Extras = 252mb (unspecified by me)
TOTAL = 6,926mb
Video Bitrate = 6.5064 Mbps

Robocop 20th Anniversary Edition
Disk1 (movie)
-Video = 4,019mb (1:42.40)
-4ch English = 338mb
-5.1 English = 337mb
-DTS English = 571mb
-2ch French = 144mb
-2ch English = 144mb
-Menu = 79mb
-Extras = 1,161mb (unspecified by me)
TOTAL = 6,840mb
Video Bitrate = 5.2198 Mbps

Star Trek First Contact SE
Disk 1 (movie)
-Video = 5,347mb (1:50.34)
-5.1 English = 346mb
-DTS English = 585mb
-5.1 French = 345mb
-2ch English = 148mb
-2ch English = 148mb
-2ch English = 148mb
-Menu = 63mb
TOTAL = 7,197mb
Video Bitrate = 6.4519 Mbps

Starship Trooprs SE
Disk 1 (movie)
-Video = 4,254mb (2:09.19)
-5.1 English = 374mb
-5.1 English = 437mb (.. one of these is probably French)
-2ch French = 186mb
-2ch English = 186mb
-2ch English = 186mb
-Menu = 105mb
-Extras = 94mb
TOTAL = 5,867mb
Video Bitrate = 4.3969 Mbps

V for Vendetta Special Edition
Disk 1 (movie)
-Video = 5,543mb (2:12.23)
-5.1 English = 436mb
-5.1 French = 436mb
-Menu = 39mb
-Extras = 279mb
TOTAL = 6,799mb
Video Bitrate = 5.599 Mbps

War and Peace
Disk 1
-Video = 5,979mb (2:20.02)
-5.1 Russian = 462mb
-5.1 English = 462mb
-5.1 French = 464mb
-Menu = 212mb
-Extras = 16mb
TOTAL = 7,702mb
Video Bitrate = 5.6943 Mbps
Disk 2
-Video = 5,410mb (1:33.11)
-5.1 Russian = 310mb
-5.1 English = 309mb
-5.1 French = 310mb
-Menu = 193mb
-Extras = 16mb
TOTAL = 6,599mb
Video Bitrate = 7.7563 Mbps
Disk 3
-Video = 4,506mb (1:17.42)
-5.1 Russian = 258mb
-5.1 English = 258mb
-5.1 French = 258mb
-Menu = 218mb
-Extras = 16mb
TOTAL = 5,569mb
Video Bitrate = 7.8026 Mbps
Disk 4
-Video = 5,352mb (1:32.13)
-5.1 Russian = 308mb
-5.1 English = 307mb
-5.1 French = 307mb
-Menu = 206mb
-Extras = 16mb
TOTAL = 6,539mb
Video Bitrate = 7.7565 Mbps

Citizen Kane (from Essential Classics - Drama)
-Video = 5,188mb (1:59.20)
-Mono English= 167mb
-2ch English= 168mb
-2ch English = 167mb
-menu = 66mb
-extras = 275mb
TOTAL = 6,075mb
Video Bitrate = 5.7968 Mbps

Creature from the Black Lagoon
Disc 1 (movie)
-Video = 4,861mb (1:19.10)
-2ch English = 110mb
-2ch English = 110mb
-Menu = 7mb
-Extras = 1,124mb (video +audio)
TOTAL = 6,237mb
Video Bitrate = 5.4465 Mbps

Kagemusha - Criterion
-Video = 6,880mb (3:00.23)
-4ch Japanese = 512mb
-2ch English = 256mb
-Menu = 26mb
-Extras = 149mb
TOTAL = 7,876
Video Bitrate = 5.0870 Mbps

Kingdom of Heaven - Director's Cut
Disc 1
-Video = 4,640mb (1:39.09)
-5.1 English = 328mb
-dts english = 554mb
-2ch english = 140mb
-2ch english = 141mb
-2ch english = 140mb
-Menu = 68mb
-Extras = 60mb
TOTAL = 6,133mb
Video Bitrate = 6.2492
Disc 2
-Video = 4,340mb (1:34.35)
-5.1 English = 311mb
-DTS english = 521mb
-2ch english = 133mb
-2ch english =132mb
-2ch english = 132mb
-Menu = 51mb
-Extras = 7mb
TOTAL = 5,679mb
Video Bitrate = 6.1235 Mbps

Planet of the Apes (can't remember.. maybe the newest edition of the classic)
-Video = 5,579mb (1:51.55)
-5.1 English = 353mb
-DTS english = 597mb
-2ch Spanish = 151mb
-2ch French = 150mb
-2ch English = 150mb
-2ch English = 151mb
-Menu = 119mb
-Extras = 8mb
TOTAL = 7,313mb
Video Bitrate = 6.6417 Mbps

Star Wars - Revenge of the Sith
-Video = 5,733mb (2:20.47)
-5.1 English = 464mb
-2ch english = 198mb
-2ch Spanish = 198mb
-2ch French = 199mb
-2ch English = 200mb
-Menu = 274mb
-Extras = 47mb
TOTAL = 7,401mb
Video Bitrate = 5.429 Mbps

Seven Samurai - Criterion
Disc 1
-Video = 6,129mb (1:51.53)
-1ch Japanese = 158mb
-2ch Japanese = 158mb
-1ch English = 158mb
-1ch English = 158mb
-Menu = 36mb
-Extras = 244mb
TOTAL = 7,075mb
Video Bitrate = 7.2964

There may be a few calculation errors in there, I did it rather quickly.

An example of video + audio bitrate would be the following:

Star Trek First Contact SE
Disk 1 (movie)
-Video = 5,347mb (1:50.34)
-5.1 English = 346mb
-DTS English = 585mb
-5.1 French = 345mb
-2ch English = 148mb
-2ch English = 148mb
-2ch English = 148mb
-Menu = 63mb
TOTAL = 7,197mb
Video Bitrate = 6.4519 Mbps
Video + DTS = 7.1903 Mbps
Video + all audio = 8.5273 Mbps


I've posted the same type of thread on Avsforum.com, and received some interesting answers over there. Below is the link to that thread

http://www.avsforum.com/avs-vb/showthread.php?t=931475