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In Reply to: No they can't do 192/24 DTS - but... posted by michi on January 27, 2003 at 10:58:38:
"It covers sampling rates up to 192kHz and has a lossless mode as well." -- John Kirchner of DTS on the codec's capabilities.
Follow Ups:
as far as I know there is nothing on the consumer market that can decode 192khz DTS, nor lossless DTS. That's saved for the theatres.
...be obtainable in theory by setting compression rate to zero.
But as NotMe points out it's propably not supported by the majority of DTS decoders (if any at all), not to mention problems with bit-rate restriction.
1) 24/96k/5.1 is beyond spec for DVD-A, so some compression is required, certainly zero doesn't cut it.2) WG-4, which is the governing body of DVD-Audio within the DVD Forum, held an open competition for lossless compression codecs. DTS was one of the entrants, and failed on at least one track, as did all other entrants save Meridian and their Meridian Lossless Packing.
3) Max bit rate for DTS is about 6mb/sec if I remember my discussion with Lorr Kramer correctly.
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An HD-DVD spec.It simply will never be part of the current DVD-VIdeo specification.
Widescreen Review is the ultimate shill for DTS. Everything DTS does is great, their technologies have Gary Reber wetting his pants and everything else is worthless.DTS is lossy, DTS 96/24 is lossy and worse quality than regular DTS (because data is taken from the audible region to deliver inaudible content). Sure, there is loss-less DTS (always has been) but that would require the replacement of every DTS decoder already sold.
Never believe anything written in Widescreen Review, you get more accurate reporting from AudioRevolution and that's saying something.
I was just quibling about whether to purchase some of the key artists on DVD-A incase the format was ever dropped.Whilst going DTS/DG route with more video content isn't dropping it.... well, Verence + Lossy Compression is just pushing it a bit calling it Hires.
1) I do not consider DTS to be a HI-REZ format. Any material where the music information has been compromised -- poisoned with watermarking such as Verance or by throwing away bits -- cannot be considered HI-REZ.2) The quote was in WR, but WR (Editor Gary Reber) wasn't quoted -- Kirchner from DTS was. Are you saying that DTS doesn't know the limits of its own codec?
3) Most of what WR "promotes" for DTS is for the DVD-V format -- not the DVD-A format. WidescreenReview, in their opinion and mine, supports the best codec currently available for that format -- DTS. The only other alternative lossy codec (remember, DVD-V is a video format first -- not audio) is Dolby Digital. Is "that" your choice regarding the two options? By the way, if you promote DVD-A over SACD, does that make you a "shill" for DVD-A?
4) I stated that DTS has 24/192 capability because Michi -- who, in my opinion, usually adds valuable discussion and thought provoking comments anytime she posts -- posted that it wasn't available. Well, it is available. Whether or not it will work with the decoder in everyone's processor/receiver may or may not be possible. However, keep in mind that DTS-ES is backwards compatible and DTS 24/96 is also backwards compatible. While neither will allow you to take advantage of its features unless you have a DTS-ES or DTS 24/96 capable chip, the new format can still be used with your current decoder. When, or if, you upgrade later on, you will be able to take advantage of what these new formats offer. Sounds like the similar benefit that DD/DTS/MLP DVD-As and hybrid SACDs have to me. Is that such a bad thing?
5) DTS can have a bit rate over 6 Mbs. As a lossy compression codec, I think that's a good deal of information and far more than what's used now (for lossy codecs). Will we ever go to 10.2 channels like TH the ex-THX guru wants? I can't answer that. They can't answer that. Neither can you. The fact is, they have this capability.
6) The sound quality is subjective. There are some people that think DVD-As and SACDs sound no better than CDs and those CDs can be matched by "CD-quality" MP3s! There are even people that think their format of choice, with its added sounds of Rice Krispys, is better than the master tape that it was produced from! Are you going to tell any of them that their "subjective" opinion is wrong?
7) All I know is that DTS makes a lot more people happy than you do by pissing with your pants still on. I see what they are doing to further people's enjoyment of DVD-As and DVD-Vs. Just what are you doing?
that it wasn't available to the consumer... Which it isn't. (24/192 no, 24/96 yes.)The lossless version is also not available for HT or to consumers.
(The information I get comes from whitepapers delivered by DTS when I was doing encoding professionally.)
I see people asking if 24/192 DTS is available, and then answering "Yes, 24/96 DTS is available."
//""It covers sampling rates up to 192kHz and has a lossless mode as well." -- John Kirchner of DTS on the codec's capabilities. "//
Yes, the CODEC ITSELF does. But *no* current consumer implementations can understand it.
"DTS" isn't really a single codec, more like a suite of algorithms, as most lossy codecs are. (AAC for example: AAC Main, LC, and SSR.)
However a good portion of these algorithms are not implemented _at all_ in consumer products.
What Kirchner probably meant was that in house, yes, they can make their (DTS's algorithms) do lossless 192. It was probably developed for the DVD-A forum.
DTS's current "bitrate ceiling" is determined by the DVD-V spec's bitrate limit. (~6mbps for DVD-V, ~9mbps for DVD-A.)
I just think people are getting confused as to what 'DTS' means. Their 'codec' can be used to refer to all of their algorithms in one package.
But I challenge anyone to find a single piece of consumer gear that can do lossless DTS at 192khz.
Sorry, couldn't resist. It sucks, Nonesuch is owned by Warner... so I've got a choice of1) New CD releases
2) Lossy Watermarked DVD-A if it even gets a DVD-A release
3) Original Vinyl pressings...
I'm debating the fact that WSR always promotes DTS and gives them an open forum to wax lyrical about their latest and greatest format without ever being taken to task. DTS engineers know the limits of their formats, but I'm not so sure about their marketing people or Widescreen Review. And if you think Reber wasn't involved, wake up, he's the editor/owner/publisher.I'm not sure who the remainder of your ramble is aimed at, there was no mention of anything other than the dubious merits of DTS 96/24 in my post, so I can only assume you're addressing someone else with the remainder.
And as for point seven, resorting to the schoolyard name-calling only serves to devalue anything sensible you may have had to say.
Your post came off, to me at least, that DTS is just a marketing game and holds no value in audio/video. That's what I was addressing with the reply. "Pissing with your pants up" is an expression -- not name-calling. I believe it does apply in regards to "my" impression of your post. Perhaps this was not your post's intent, but that's how I took it. As to the name-calling and having ones contribution "devalued", I don't believe I've met anyone whose given name was "shill" -- have you? WR is not perfect and I never said that they were. But if you think that these guys are bad, just wait until you read the "high end" mags...
By a substantial margin ? I guess using a mega DTS stream will give better performance to more people and leave more room for Video clips.
***DTS is lossy, DTS 96/24 is lossy and worse quality than regular DTS (because data is taken from the audible region to deliver inaudible content). ***Did you ever really hear it ?
Yes, I've heard DTS 96/24, at home and at shows. If you think it's superior to regular DTS, you fell for the marketing hype or are hearing a souped-up mix.You need to read "Backward Compatible Enhancement of DTS Multi-Channel Audio Coding That Delivers 96-kHz / 24-Bit Audio Quality" by Zoran Fejzo, Stephen Smyth, Keith McDowell, Yu-Li You, and Paul Smith - Digital Theater Systems, Inc. AES Pre-print 5259, presented at the 109th Convention.
It was written by DTS themselves and explains, in a nutshell, that a DTS 96/24 encoder splits the incoming data into two halves; one half contains the legacy backward compatible core data, whereas the other carries the extension data. In a 96/24 decoder, the 48kHz portion of the signal is upsampled to 96kHz, then combined with the true 96kHz element.
The entire audible frequency range, 20Hz - 24kHz, is carried by the core encoder, but the available data is split between the two encoder halves. In a regular 48kHz DTS system the 20Hz - 24kHz range is delivered at 1,536kb/s, in a DTS 96/24 system that same area of the spectrum is delivered at 1,152kb/s since 384kb/s is dedicated to the utterly pointless, inaudible extension data.
As I said, read the document. If you think DTS 96/24 sounds better, then fine, but don't try to say it is superior to any other form of DTS, it isn't.
The 1.5 kbs is not always used on a 'regular' DTS encoded disc.Also 'normal' DTS doesn't have a frequency range up to 24kHz. One of te losses in the lossy coding scheme is that hf above 20kHz is filtered to save bitspace. I doubt that the DTS9624 encoding extends the frequency range to a 'useless' 48kHz frequency range.
You forget that there are twice as many samples available in the 20-24kHz range with DTS9624.
Like John said win some loose some but in general DTS9624 is just slightly better.
> The 1.5 kbs is not always used on a 'regular' DTS encoded disc. <Half-rate DTS is known as just that, half-rate, so "regular" DTS is 1.5Mb/s. That is what my reference intended. Sorry for any confusion caused.
> Also 'normal' DTS doesn't have a frequency range up to 24kHz. One of te losses in the lossy coding scheme is that hf above 20kHz is filtered to save bitspace. <
No. From DTS' own literature (this particular example from http://www.dtsonline.com/dtsposition.pdf): "For 48 kHz sampling, DTS has response to 24 kHz at 1.5 Mbit/s and response to 19 kHz at 754 kbit/s."
> You forget that there are twice as many samples available in the 20-24kHz range with DTS9624. <
Wrong again. There aren't. The frequency range up to 24kHz is delivered by the core data, to remain backward compatible it has to be sampled at 48kHz. In a DTS 96/24 decoder, the 48kHz data is upsampled, so the actual content has no more samples. From the document previously referenced:
"The input digital audio signal with a sampling frequency up to 96 kHz and a word length up to 24 bits is processed in the core branch and extension branch. In the core branch input audio is low-pass filtered to reduce its bandwidth to below 24 kHz, and then decimated by a factor of two, resulting in a 48 kHz sampled audio signal. The purpose of this LPF decimation is to remove signal components that cannot be represented by the core algorithm."
> I doubt that the DTS9624 encoding extends the frequency range to a 'useless' 48kHz frequency range. <
Nope (I thought you were the tech guy around here?). The same AES document contains two graphs, the first shows uncompressed 96kHz PCM with a frequency response extending to 48kHz. The second shows the behaviour of the two DTS encoder halves, the core data, which rolls of steeply just before 24kHz and the residual component which mirrors the response of the uncompressed PCM right out to 48kHz.
As I said, try to get hold of some DTS technical documents, the 96/24 example in particular, prior to jumping the gun about the system's operation.
"The input digital audio signal with a sampling frequency up to 96 kHz and a word length up to 24 bits is processed in the core branch and extension branch. In the core branch input audio is low-pass filtered to reduce its bandwidth to below 24 kHz, and then decimated by a factor of two, resulting in a 48 kHz sampled audio signal. The purpose of this LPF decimation is to remove signal components that cannot be represented by the core algorithm."This doesn't say anything about upsampling the core data. It's just explaining how the core data is derived so it will be compatible.
As I understood it the missing samples are reconstructed by information contained in the extension data.
> This doesn't say anything about upsampling the core data. <Not this particular passage, but it demonstrates that the data is indeed separated into two halves, with the core data carrying everything up to 24kHz. The extension data, specified as "above 24kHz" carries the higher frequencies. There's nothing in the document about the extension data carrying frequencies below 24kHz sampled at a higher rate.
And just to revisit your assumption that a lossy CODEC wouldn't bother reproducing 48kHz signals, I've just spotted the following paragraph on a page fold:
"The graph in Figure 8 illustrates the capability of coding system to cover the entire bandwidth from 0-48kHz at a combined bit rate of 1536 kbps. As before 1152kbps is allocated to the core stream and 384kbps is allocated to the extension stream."
I don't know about you, but I think that's utterly pointless. Dedicating valuable data to inaudible content in a lossy coder makes no sense at all, unless one considers the marketing potential of the term "96/24" amongst those who don't appreciate how the technology works.
And, something we've not re-visited is the quality issue. I still maintain DTS 96/24 will and does sound worse than regular DTS because of the reduced data dedicated to the audible content, but whether that is a correct assumption or not, I know that anyone listening to a DTS 96/24 track on non-DTS 96/24 hardware will suffer, they're only getting 1,152kb/s.
Bits are dynamically allocated to signal content. If little signal content is availaible beyond 20kHz little bit space is used and the remaining bits get allocated to signals having a higher 'priority'.
The encoder selects different algorithms by analyzing the signals content.
The extension stream is additional data the term extension doesn't imply that it's used for the upper frequency range only.
> Bits are dynamically allocated to signal content. If little signal content is availaible beyond 20kHz little bit space is used and the remaining bits get allocated to signals having a higher 'priority'. <Thank you for agreeing with my point - a lossy coder with 48kHz response is pointless - being able to assign bits as required only underlines that point.
> The extension stream is additional data the term extension doesn't imply that it's used for the upper frequency range only. <
No - the DTS 96/24 is split in half as I explained at least once already.
Oh, and if you're still in doubt about upsampling:
"To decode a core+extension bit-stream, Figure 1 B), the unpacker first separates the stream into the core and extension data. The core decoder decodes the core data and produces the core LPCM audio that is next up-sampled to 96kHz using the 48-to-96kHz interpolator. The core decoding and interpolation are both performed in the “Reconstruct Core Audio Components” block."
What part of this do you not understand? Sheesh...
And here I thought that you were referring to Dolby Digital.:-)
DTS 24/96 -- pointless? Maybe "give and take". Marketing job? I'd agree with that (below).
I have, and I find it no better or worse than the previous codec.Trade something here, get something back there.
than substance. As you say, get something here -- give something there. But I tend to look at DTS as a "for movies" format, rather than a "for music" format. I'd take DTS-ES 6.1 Discrete (at 1.5 Mbs) over any of the other available movie formats (be they DTS or Dolby) any day. Notice I said 1.5 Mbs and not "just" the ES format. I've heard too many higher bitrate movies to say that 768kbs in 6.1 ES is as good as 1.5Mbs 5.1 (which is smoother to my ears).
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