Consumers Must Demand an Increase in Audio Quality for 'HD-DVD', Not Just Video! (1 Viewer)

[ChrisA]

We need a new Dolby Digital format as well as a new DTS format for the upcoming 'HD-DVD' format which could utilize around somewhere around 2-4 Mbit/sec (or so)(actually, you could use 10mbit/sec if you really wanted to.. and still have 20+ Mbit sec for video, however, video is much more demanding (and would benefit greater) so realistically we should not utilize more than 4 mbit/sec for a primary multichannel audio track. Standard DD could be utilized for other languages and accessory tracks.

There is no reason to suffer with 480k, 600k, or 7XXk/s for your primary audio track when you have a format like BLU-RAY offering 34 Mbit/sec... Once you start using higher bandwidths, these DD vs. DTA battles should not be important anymore, especially if we use lossless compression.

I'm not saying we should use 10Mbit/sec to use on 24/96 MLP for Blu Ray movies: video is so much more demanding. Remember, even the digital master tapes are compressed 4X and still utilize 350-400 Mbit/sec bandwidth for video alone. While I sympathize for those who want the best, one must always remember on how best to utilize bandwidth.

20/48 MLP would be one option for an outstanding format for the consumer market as described in the petition on my signature file. With MLP you could have 24/96 for the front three speakers, and then save bandwidth by utilizing 20/48 for surround channels.

At the very least, Dolby digital needs to come out with an advanced, 'new and improved' alogrithm that is LESS HARSH and takes advantage of being able to use much more bandwidth. DTS is already SCALABLE, but DD is NOT. DD has a limit of 640k/sec which is seen on D-Theater titles.

We talk about improving the video for HD-DVD. We need to talk about our expectation for the audio improvement for the upcoming 'HD-DVD' format. We need to take advantage of the huge increase in bandwidth that BLU-RAY and similar new optical formats are offering. Warner Brothers fails to acknowledge ANY improvement in audio with their persistent pushing of current (old) DVD technology for a future HD-DVD format...

 

[Ed St. Clair]

Great!!!
DVD was supposed to surpass LD audio (as well as video, which it did).
However, because of bit space, was 'downgraded' too, "CD quality" sound.:frowning:
Let's hope the 'new' standard raises the bar for both audio & video, for HT.
I'm ready!

 

[Richard Paul]

Though it would be nice for Dolby to make a improved audio standard I've read that DTS can do up to 6.2 Mbps, and if you have a lot of room it also has a lossless mode. As such if DTS wanted to they could easily make 2-4 Mbps audio track's for Blu-ray. I am amazed that Dolby seems to be giving up on being the best audio format but at the end of the day it's their decision. Also their will never be 640 Kbps Dolby Digital audio on D-Theater since many receivers can only process DD up to 576 Kbps.

 

[Dan Hitchman]

At 50 GB storage and over 30 Megabits/sec for a dual layered Blu-Ray (their recordable format anyway) using standard MPEG-2 you would fit about 3 hours using a maxed bitrate all the way through considering the data capacities of D-VHS as a comparison.

Now, since Blu-Ray still doesn't have a spec. for pre-recorded discs, who's to say they couldn't increase the bitrate even a bit more and maybe put a little over 2 hours on one disc. That way they could have superior 1080p (24, 30, & 60 fps), and MLP 96/24 PCM, or DSD. If they used a more sophisticated video codec, then maybe increase the discrete channels to 7 or even 8?

I think some of our ideas are far superior than what they ultimately will give us as they aren't as concerned about quality as we are and politics tends to rule the day. :frowning:

Dan

 

[Rich Malloy]

I completely agree with everything written here, except Ed's comment that Dolby Digital is "CD quality sound"... it's actually quite a bit lower in resolution than a CD (the only advantage being multichannel capabilities).

I would also think that some permutation of the Meridian Lossless Packaging scheme (or whatever... you know, "MLP") would be an ideal place to start. Alternatively, even a return to full-bitrate DTS would be an improvement, but IMO a higher resolution format would be much more desireable.

Yes, count me in. Hi-def video + hi-def audio please!

 

[ChrisA]

I believe that MLP lossless running 5.1 channels at 20/48 utilizes 5.0 Mbit/sec....

DTS lossless is probably nowhere near as efficient and certainly not as powerful as MLP.

"24/96 lossy" is a questionable procedure in the first place... almost an oxymoron.

That being said, the current bitrates utilized for audio by DD and DTS are unacceptable for 'HD-DVD'. We must demand better audio. Certainly DTS utilizing 2-4 Mbit/sec would be available immediately. It owuld be difficult to justify anything above 20/48 if MLP is utilized simply because the video will benefit much more... (I'd still take 20/48 MLP lossless over anything DTS/DD)

 

[Rob Gillespie]

However, because of bit space, was 'downgraded' too, "CD quality" sound

Errm.. no. Dolby Digital on DVD runs at a higher bitrate than it did on LaserDisc. PCM uncompressed audio does also.

It's down to the mix.

 

[Richard Paul]

Chris, though I can't say that DTS in lossless mode is equal to MLP, I also don't see how anyone would know that it's worse since it's never been used. I believe that MLP would be the best lossless audio standard, but I'll be surprised if multi-channel MLP is an option on pre-recorded Blu-ray. If they did include MLP as an option on pre-recorded Blu-ray I would think it would be used rarely while 2-4 Mbps DTS could be common. This depends heavily though on whether DTS could be used as the primary audio track for pre-recorded Blu-ray.

 

[Patrick McCart]

For HD-DVD, there should be PCM 2.0 for all mono and stereo-only films. For surrounds, have full bitrate DD and DTS 3.0, 4.0, 4.1, 5.1, 6.1, etc

 

[David Susilo]

how can one lossless codec is better than another? they are both "LOSSLESS"!!!!! That means in = out without change whatsoever. If any of them degrade the sound, it's already "LOSSY"!!!!!

and I thought my English is bad

 

[Damin J Toell]

how can one lossless codec is better than another? they are both "LOSSLESS"!!!!! That means in = out without change whatsoever.

Lossless codecs can be different from one another in their sampling rates. The higher the sampling rate, the better the analog waveform is captured and digitized. Not all lossless codecs are necessarily equal.

DJ

 

[MikeMcNertney]

The trick is that people are using the term "lossless" where it doesn't really apply. No analog to digital conversion is truely "lossless" so various methods of doing this conversion will give different results. The term is meaningless in this context because there is no such thing as "lossless" ADC.

Where the term "lossless" really applies is the compression done to the digital data after the analog-digital conversion. In this case, yes all "lossless" codecs are the same, since they all preserve the original digital data exactly.

As was pointed out, different codecs may specify different ways of capturing the analog data. Specifically they may have different bitrate requirements for the input data

 

[Roogs Benoit]

I would also like to see a better quality of audio on HD-DVD but it will also have to be realistic. I see a large demand for 24/96K audio and up to 7.1 channels.It would be nice to have 24/96 available for when movies are actually made this way but for now I don't think any feature film (from a major movie studio) has been dubbed this way. Even the most recent features I have delt with have been mastered 24bit/48Khz. I have never worked with a feature soundtrack with a higher bitrate than that. I don't see the benefit of creating a 24/96 dvd with a master that is only 24/48. For the future when films are dubbed this way, and I mean recorded in the field 24/96, the music scoring recorded 24/96, the ADR,foley, effects and finally dubbed in 24/96. Then it would make sense to have the higher rate for HD-DVD.
I like the idea of MLP or a higher Dolby bit rate for the HD-DVD standard. DTS doesn't have to be part of the standard but it would be nice to have them involved and available as an option like it is now.

Roogs

From an earlier post:
DD has a limit of 640k/sec which is seen on D-Theater titles.

Dolby is not involved with D-Cinema audio as far as I know.
The Q-bit encoder/playback unit uses a 6 channel uncompressed PCM signal usually from a 16 bit master (it does have 24bit capabilities). I am unaware of any compression sceme built into the Q-bit for audio. I do know that it compresses the picture.

 

[ChrisA]

Not all lossless codecs are necessarily equal.

Absolutely. MLP packages the information differently. It is an entire 'system' for handling the data. The algorithms differ in ability to maximally compress the data as well as the way 24/96 MLP can stay within the 10 mbit/sec bandwidth limitation (current DVD). MLP offers the ability to use different bit/samplingrates for a given channel, which is a very nice feature. This means you could use 24/96 for the front three speakers, and utilize 20/48 for all surround channels, whether it be 5.1, 7.1, 8.2, 10.4, whatever... MLP is almost infintely flexible and expandable and can address up to 64 channels if so desired (or more than we would need as consumers).

Lossless compression also means that every MLP copy is the same quality as the MLP master.

I'd take 20/48 MLP for a primary audio soundtrack over any DD or DTS offering. The lossy 24/96 DTS that is currently available is a bit of a marketing gimmick. It is not like these lossy formats are offering flat signal response from 20-20,000 Hz... HA!!

 

[Ned]

I'm more concerned with how they will package the video portion. Ideally the source would be 1080p@24fps and the player itself does all of the conversion (if any).

So perhaps:

1080p @48/60/72/96/120hz
1080i @"
720p @"
480p @60hz
480i @60hz

And, AND, any pan+scan done in the player with p+s directions in the stream. We DON'T want another format with dual versions of the same damn video, slashing the bitrate in half for each. And no more of this crap with constant flagreading that has mastering errors/combed frames/dropping to 2:2 pulldown, and various other nonsense. Why the hell do they need to encode any FILM source with constant flags? Why would the stream ever stray from progressive? It came from FILM for christ's sake.

As far as audio goes, I would be fine if they just doubled/tripled the bitrate. DD/DTS tracks can already sound incredible now. If the peak bitrate for HD-DVD is 30mbit, you can't allocate 5mbit of that to audio. SD-DVD is 5-9mbit video / 448-784kbit audio (10:1 ratio). 30mbit to 5 (6:1 is too high) and video will/may suffer.

In the dreaming category, let us select in the player if we want movies to immediately play or go to the menu, and have it ALWAYS work on every disc. Audio preference would be great too, why do we always have to select DTS?

 

[ChrisA]

If the peak bitrate for HD-DVD is 30mbit, you can't allocate 5mbit of that to audio. SD-DVD is 5-9mbit video / 448-784kbit audio (10:1 ratio). 30mbit to 5 (6:1 is too high) and video will/may suffer.

Comparing the ratio of current DVD A/V bandwidth useage to that of Blu-ray is not totally off the wall, however, once you start giving 20 Mbit/sec to the video, you do have room to play with audio... I agree that people requesting 24/96 MLP in 7.1 channels for movies are not being realistic and are really underestimating the need for the majority of bandwidth to go to video. I believe that 2-4 Mbit/sec for a single primary audio track would be ideal.. If you want to use 'your' ratio, then 3.4 Mbit/sec would be 10:1 to the total bandwidth of 34 MBit/sec. Although I don't think it is apples to apples.

 

[Dan Hitchman]

Why are we even considering MLP anyway (although a good lossless codec)??

The major players with Blu-Ray are still Sony & Royal Philips. They own the CD patents and the SACD patents (which include DSD and their proprietary lossless codec for DSD). If they used MLP then they would be paying someone else royalties... namely Dolby Labs since they own the licensing to Meridian Lossless Packing. If they added a Dolby Digital backup track then that would be paying them twice.

I would think if there was to be high resolution audio on Blu-Ray it would be lossless compressed DSD, which would be a-ok in my book.

At the very, very least 8 channel discrete DTS running at 3-5 Megabits/sec. That way we don't get any more of this "discrete + matrix" crap like Dolby Digital EX (a half-assed attempt IMHO). Surround should be completely discrete at this stage of the game.

Dan

 

[ChrisA]

At the very, very least 8 channel discrete DTS running at 3-5 Megabits/sec. That way we don't get any more of this "discrete + matrix" crap like Dolby Digital EX (a half-assed attempt IMHO). Surround should be completely discrete at this stage of the game.

I certainly would agree with that statement. Discrete channels only. I would still say 2-4 Mbit/sec, leaning more towards 4 Mbit/sec if for some reason they are brilliant enough to come out with a couple more useful discrete channels, such as discrete side/height channels. DTS has certainly shown the ability to release new formats and they seem to be the only format that is in commercial theaters and home video besides Dolby Digital. I'm not sure why a home format would also have to be a commercial theater format, but so far that seems to be the case... This is the time to release a new audio format and quite frankly I don't care who or how it is released as long as it is a significant improvement as we have been describing.

I'd certainly also like to see a dedicated tactile transducer channel. A limited bandwidth tactile transducer channel would take up negligible bandwidth, absolutely negligible, yet provide true tactile feedback. Commercial theaters are really the weakest link to what we get in the home. If commercial theaters had tactile capability, would would already have a 0.1 tactile tract on DVD (and we wouldn't have to rely on the audio soundtrack/LFE track to derive tactile information which is innacurate/crude).

 

[Dan Hitchman]

ChrisA,

Great idea about tactile transducers. I don't even think taking up space for a specific channel would be necessary as long as they remembered sub 20 Hz signals in the LFE channel and all processors had a specification for the proper 20 Hz and under filter for a tactile transducer output. The Parasound Halo C2 and C1 processors are the first of their kind to offer this feature.

DTS has commercially released a new encoder and theatrical decoder that is scalable to multiple bitrates, bit depths, sampling rates, and up to 10 channel discrete surround, so they can be flexible if they want to be (I bet they want one product for multiple venues from the local multiplex up to IMAX quality sound).

If they're smart, DTS will be in talks with the Blu-Ray group pronto!

Dan

 

[Ned]

We should really start a thread that discusses all of the aspects of HD-DVD and come to some kind of consensus on all of the issues. As is, we are just letting/hoping the manufacturers will do it right without any input from us.