[McPatrickClan]

Today is my 25th birthday and my wife bought me the DVD I have on my list, The Usual Suspects: SE. Well, she explains to me that she almost bought Memento: SE as well because it is also a "hi-def transfer". I look at her in bewilderment and say, "Huh?". I explain to her that it is not possible and that it would take a different DVD player to watch HD-DVD. She then shows me the packaging. Lo and behold, it says "New 16x9 Hi-Definition Transfer" on the first line of the packaging.


Now according to DVDMG, the transfer is very good, but hey, MGM, cut out the dishonest claims. This is not 1080i.

 

[Matt_Stevens]

I think it's dishonest too. Anyone that doesn't know about this stuff (99% of the consumers) will be fooled.

 

[chap]

Its not what you think. It basically means that it was mastered from the HD transfer of the flick.

 

[Bjoern Roy]

Its neither dishonest, nor incorrect. I agree with Matt, though, that some consumers might get fooled. But most regular consumers probably don't care or know what it means anyway, and those that are into this hobby shouldn't be confused.


The term 'transfer' is used (misused) for quite a few things in regard to DVD, but the basis meaning in the industry is the 'transfer' from film to a HD master (D5, 1920x1080), the digitalization.


The D5 HD master is than either encoded for HD broadcast, or:


- downconverted to 720x480 and 'transfered' to D1 (uncompressed)

- D1 is then 'transfered' to Digibeta (approx. 2,4:1 compression ratio)

- Digibeta tape to the authoring house for MPEG encoding

- MPEG stream stored on DVD


The term 'transfered' in these 2 intermediate steps above is valid and not a mis-nomer, but a bit confusing. Whenever 'a new transfer', 'new 16x9 HD transfer' etc. is mentioned on a DVD or a press release, the actual film-to-HD transfer is meant.


The biggest confusion comes from the fact that the term 'transfer' is usually (mis-)used in DVD reviews when describing the picture of the DVD.


"The transfer on this DVD is great..."

"The new superbit transfer of XYZ is much better than the old non-SB transfer"


Basically everyone uses the word 'transfer' in this context, including me, because its convenient and its difficult to find a better suiting word instead. "The authoring of the disc is great..." doesn't fit because it also includes the navigational component of the DVD. "The compression of the disc is great..." is a proper term, but it implies that only the 'compression' of the disc (meaning blocking artefacts and the like) is meant. But the term 'transfer' usually means PQ in general in DVD reviews, thus including any step that are done before the actual compression. Low-pass filtering, aperture correction (EE), DNR, etc...


So the term 'transfer' is used to describe the whole pipeline. From the film to the DVD. Its much more convenient for the DVD reviewer.


A good example is the SuperBit line:


"The new superbit transfer of XYZ is much better than the old non-SB one."


That would be a good and easy description. In reality, the actual 'transfer' (film-to-HD) was the same for the SB titles, the same D5 HD master was used to produce both versions (except for Desperado, where a new HD transfer was done). Only the pre-processing (filtering, etc) and the compression differs on the SB titles.


Anyway, the point is, MGM is not 'dishonest'. They use the proper term. CTHV and others use similar keylines since the very beginning and rightly so.


Yes, it could confuse a few. But again, there are those who don't care and those who do. Those who DO care should know or learn about the (mis-)nomer 'transfer'.


Regards

Bjoern

 

[morganholly]

Just to clarify a few things:


D1 is uncompressed 8bit


Digital BetaCam is compressed 10bit but the compression ratio is not 4:1 it's variable DCT 1.8:1 to 2.2:1 (could be 2.4:1, it's been a while since I quoted this).


HD D5 is 4:1 compressed. The format was developed for uncompressed 10bit SD images and adapted for HD.


Digital BetaCam conforms to the SMPTE 259 spec of 720x486 (active picture) in NTSC.


D1 conforms to the CCIR 601 spec of 720x486 pixels in NTSC.


MPEG-2 for DVD can be a variety of resolutions but generally 720x480 is used. The extra six pixels are cropped by the MPEG encoder.


Usually downcoversions for DVD mastering is done directly to Digital BetaCam these day since it can hold up to 124 minutes per load as opposed to D1s max load of 76 minutes. DBteta is also less expensive and more robust. Although MGM still uses D1 for compression masters sometimes.


MH

 

[Jim Boden]

This sounds similar to "Dolby Digital", which a lot of people think means they're getting 5.1 surround. Of course, this isn't necessarily true. A Dolby Digital disc can also be mono or 2.0. I remember buying a mono copy of The Terminator, without realizing my mistake. To put it mildly, I was not impressed.


Caveat emptor when it comes to reading the fine print on the packaging and actually understanding what all the terms mean. The list of things to read seems to be getting longer all the time, too.

 

[Bjoern Roy]

Morgan,


welcome to the forum!

Quote:

Digital BetaCam is compressed 10bit but the compression ratio is not 4:1 it's variable DCT 1.8:1 to 2.2:1 (could be 2.4:1, it's been a while since I quoted this).

2.2:1 if i recall correctly (I thought of the D5 ratio when i wrote 4:1).

Quote:

HD D5 is 4:1 compressed. The format was developed for uncompressed 10bit SD images and adapted for HD.

The 4:1 ratio is for 10 bit. But there is also a 5:1 ratio for 8bit. Is the latter used at all for HD transfers or is it always 10bit? Is the telecine output usually 10bit or does that depend on the machine?

Quote:

MPEG-2 for DVD can be a variety of resolutions but generally 720x480 is used. The extra six pixels are cropped by the MPEG encoder.

Yes. D1, Digital Betacam, D5 and other CCIR-601/656/SMPTE-259 compliant devices store 486 lines. The exclusion of the extra 6 lines allows even division into the 16 pixel macroblocks. Do you know why 486 lines where chosen in the first place?

Quote:

Usually downcoversions for DVD mastering is done directly to Digital BetaCam these day since it can hold up to 124 minutes per load as opposed to D1s max load of 76 minutes. DBteta is also less expensive and more robust. Although MGM still uses D1 for compression masters sometimes.

I thought D1 is still widely used. At least one major studio uses it on basically everything. Its obvious that the usual way of both Digibeta and D1 as intermediate steps is one step too much.


Skipping D1 might be more convenient due to the runtime benefit of DB, but from a purist point of view, skipping DB would mean one useless compression/decompression step less in the chain. Although the benefit will only be slight due to the very mild compression of DB, of course. But still, I predict that the best transfer this year will have been done this way (wink, wink).


Regards

Bjoern

 

[hob]

In March of this year I cross posted the same question over all of webtv alt discuss, which can't be accessed by computer users. The question How many in this group have a wide screen HDTV hooked to your WebTV unit. The unbelievable answer was *no* on every group after 1 week exposure to all groups, which took me hours using cut, copy and paste!



I can't believe I am the only one using a wide screen HDTV on the whole subscriber list. In March it was cold and people would be home staying warm while on their webtv sets. Watching the Thomas Alva Edison 4:3 format. Guys some of these people are still playing records and 8 track tape players. Quite a few have DVD players who would buy MGM HD-transfer in a minute IMHO!

 

[morganholly]

Thanks for the welcome Bjoern,


I don't have a D5 at my facility, although there are many in our company. So I haven't had a chance to fool around with it much. From my understanding it is strictly a 10bit recorder. As with other 10bit machines I'm sure you can force 8bit on the output. Regarding compression; if there was an 8bit option it would certainly be a lower, not higher compression ratio as 8bits take up less space than 10bits.


Some telecine machines can scan at higher bit depths than 10, but I believe the HD outputs are always 10. Of course older SD telecine machines are limited to 8.


I think 486 is the number left over when you remove the lines reserved for other information. And of course 525 was decided on years ago.


Sony and MGM are both still fond of D1. We prefer Dbeta since our DVNR is 10bit and we hate changing reels

 

[Bjoern Roy]

Hi Morgan,


the 4:1, 5:1 thing was from (not loss-less ) memory. You are right, the compression would have to be lower with 8bit. Doh!


Just checked an excerpt of the spec sheet of a Panasonic's D5 deck AJ-HD2700 and it says:


"Intra-field compression (approx. 4:1/8-bits, 5:1/10-bits)"


I don't know when the 8bit mode is used. From that quote above, it seems as if D5 compression is 5:1 on the commonly used 10bit data, though. Hm.


I am sure most/all telecine machines scan much higher than 10bit and some fine dithering algorightms are used to downconvert to 10bit HD.


Which manchine is used for the HD to SD downconvertion at your facility/company? And do you happen to know which algorithm is used?

Quote:

Sony and MGM are both still fond of D1.

The studio i was thinking of is not that list

Quote:

We prefer Dbeta since our DVNR is 10bit and we hate changing reels

Aha, there we go

 

[morganholly]

I assume the Panasonic downcoverter is used, but I know Sony makes a good one. Again, I don't deal with HD material that much since I run a DVD facility. As we all know, or some of us depending on how much we believe in verbage on packaging, that DVD is SD for the moment.


I just got a 50" Panasonic plasma so I'm venturing into the world of home HD for the first time. But I won't get into that nightmare here!


MH

 

[P.Milnes]

I am interested in Jim Boden's comment that just because it says "Dolby Digital" on the package, it may not be 5.1.


I was not aware of this. I have purchased a few DVD's that advertise DD on the package only to find out that my receiver decodes them in Dolby Prologic. Needless to say, we were quite disappointed.


Is this mis-leading? I would not have purchased the DVD having known that it was not in DD 5.1. So, was I mis-lead or ignorant?



Paul

 

[snowmoon]

I always check the back of the disk carefully and the only disk I have ever been fooled on was the 2010 that claims it's anamorphic when it's not.


I think the bigger scam is Dolby Sourround = Pro logic and Dolby Digital often referes to 5.1... can someone explain THAT to me. I am careful to always check the audio options/spoken languages on a disk before starting. I often need to do that anyways for the DTS track.


I think we need a panasonic rp56 ( quality progressive ) with auto audio prefrence and memory that does not pause for the layer change.

 

[Dan Hitchman]

It was Sony that released the Memento Special Limited Edition.


Yes, the use of "New High Def. transfer" can be misleading (it's supposed to be as it may sell more copies to the unsuspecting).


From what I understand, Memento, at least, did have a new 1080p transfer made under the supervision of Director Nolan (he didn't supervise the first bare-bones release and was given the green light for this one probably because his remake of Insomnia is another big studio film and Sony could cash in on it by releasing another version of Memento, and his prominance in the industry is growing). The audio was also tweaked as well.


So, in some ways it's not dishonesty as the DVD was mastered from the HD source.


Dan

 

[coug7669]

Quote:

Originally posted by P.Milnes I am interested in Jim Boden's comment that just because it says "Dolby Digital" on the package, it may not be 5.1. I was not aware of this. I have purchased a few DVD's that advertise DD on the package only to find out that my receiver decodes them in Dolby Prologic. Needless to say, we were quite disappointed. Is this mis-leading? I would not have purchased the DVD having known that it was not in DD 5.1. So, was I mis-lead or ignorant? Paul

Not mislead just !?! . Dolby digital can have up to 5.1 channels which includes mono. I always read to see if the info states whether it says mono for older movies and surround for early 80 films. Heres the official Dolby FAQ .