DD/DTS 5.1 specs for Laserdisc vs DVD

[Erik Saether]

Hi guys.

Maybe this has been answered before in this NG, but anyway:

Can anyone in an easy way list the specs of DD and DTS (5.1) for the
Laserdisc format.
I'm thinking of min----> max bitrate for data transfer + resolution.
A comparison to DVD-VIDEO would have been interesting, since I know most of
the DTS LDs had a higher bitrate in data transfer than the average DTS DVD
today.


Best regards
Erik

[publius]

Yes.
As follows :

Dolby Digital AC-3, on LaserDisc, fixed at 384 kbps regardless of
audio channel format, due to characteristics of QPSK RF encoding
format.

dts Zeta, on LaserDisc, fixed at 1441 kbps regardless of audio channel
format, due to characteristics of EFM (pseudo-Red Book) encoding
format.

Do note that bitrate allocation and sharing are possible between
channels in AC-3, whereas dts Zeta in this form employs a fixed
per-channel bitrate ; that is, AC-3 2.0 @ 384 kbps can allocate 196
kbps to each channel, while dts Zeta 2.0 @ 1441 can only allocate about
288 kbps to each channel.
Also note that it is possible to "pad out" an AC-3 signal with empty
bits, so that a 192 kbps 2.0 stream could be packaged as 384 kbps
without taking advantage of the full signal space. I am not aware of
this function being in use.

--publius--

Post by Erik Saether
Hi guys.
Can anyone in an easy way list the specs of DD and DTS (5.1) for the
Laserdisc format.
I'm thinking of min----> max bitrate for data transfer + resolution.
A comparison to DVD-VIDEO would have been interesting, since I know most of
the DTS LDs had a higher bitrate in data transfer than the average DTS DVD
today.
Best regards
Erik

[Erik Saether]

Thanks.

Do you have the specs for DVD for comparison ?

And, what do you mean by dts Zeta ?


Erik

Post by publius
Yes.
Dolby Digital AC-3, on LaserDisc, fixed at 384 kbps regardless of
audio channel format, due to characteristics of QPSK RF encoding
format.
dts Zeta, on LaserDisc, fixed at 1441 kbps regardless of audio channel
format, due to characteristics of EFM (pseudo-Red Book) encoding
format.
Do note that bitrate allocation and sharing are possible between
channels in AC-3, whereas dts Zeta in this form employs a fixed
288 kbps to each channel.
Also note that it is possible to "pad out" an AC-3 signal with empty
bits, so that a 192 kbps 2.0 stream could be packaged as 384 kbps
without taking advantage of the full signal space. I am not aware of
this function being in use.
--publius--

Post by Erik Saether
Hi guys.
Can anyone in an easy way list the specs of DD and DTS (5.1) for the
Laserdisc format.
I'm thinking of min----> max bitrate for data transfer + resolution.
A comparison to DVD-VIDEO would have been interesting, since I know most of
the DTS LDs had a higher bitrate in data transfer than the average DTS DVD
today.
Best regards
Erik

[Joshua Zyber]

Post by Erik Saether
Do you have the specs for DVD for comparison ?

Most DVD Dolby Digital tracks use 448 kb/s for 5.1 soundtracks (Warner
Bros. stuck with 384 kb/s for a long time, but finally switched to 448
starting with 'Matrix Reloaded') or 192 kb/s for 2.0 sountracks.

DTS on DVD came come in two varieties: 754 kb/s (most common) or 1509
kb/s (very rare).

Note that differences in sound quality between Laserdisc and DVD come
down to more than just numerical bit rate. Most laserdisc soundtracks
were untouched from the theatrical audio mix, while a great many DVD
Dolby Digital 5.1 tracks (despite the higher bit rate) are "dumbed down"
so that they will convert to basic stereo better for viewers listening
through their TV speakers. This usually entails filtering all bass out
of the main speakers and directing it exclusively to the subwoofer .1
channel. This has an audible effect on the fullness and 'body' of the
front soundstage.

DD5.1 on laserdisc could only be accessed by viewers using full surround
sound equipment. DD5.1 on DVD has to be able to downmix to stereo
without blowing out tiny TV speakers.

[Erik Saether]

Thanks Joshua !

About the higher bitrate on DD 5.1 on DVD:
When they in Japan release DVD titles as "Superbit", are they referring to
the data transfer bitrate of the DD 5.1 track ?
A DVD movie with DD at 448 kbps is a "superbit" movie ?


Erik


----- Original Message -----
From: "Joshua Zyber" <***@comcast.net>
Newsgroups: alt.video.laserdisc
Sent: Tuesday, August 01, 2006 3:41 AM
Subject: Re: DD/DTS 5.1 specs for Laserdisc vs DVD

Post by Joshua Zyber

Post by Erik Saether
Do you have the specs for DVD for comparison ?

Most DVD Dolby Digital tracks use 448 kb/s for 5.1 soundtracks (Warner
Bros. stuck with 384 kb/s for a long time, but finally switched to 448
starting with 'Matrix Reloaded') or 192 kb/s for 2.0 sountracks.
DTS on DVD came come in two varieties: 754 kb/s (most common) or 1509
kb/s (very rare).
Note that differences in sound quality between Laserdisc and DVD come
down to more than just numerical bit rate. Most laserdisc soundtracks
were untouched from the theatrical audio mix, while a great many DVD
Dolby Digital 5.1 tracks (despite the higher bit rate) are "dumbed down"
so that they will convert to basic stereo better for viewers listening
through their TV speakers. This usually entails filtering all bass out
of the main speakers and directing it exclusively to the subwoofer .1
channel. This has an audible effect on the fullness and 'body' of the
front soundstage.
DD5.1 on laserdisc could only be accessed by viewers using full surround
sound equipment. DD5.1 on DVD has to be able to downmix to stereo
without blowing out tiny TV speakers.

Post by Erik Saether
Do you have the specs for DVD for comparison ?

Most DVD Dolby Digital tracks use 448 kb/s for 5.1 soundtracks (Warner
Bros. stuck with 384 kb/s for a long time, but finally switched to 448
starting with 'Matrix Reloaded') or 192 kb/s for 2.0 sountracks.
DTS on DVD came come in two varieties: 754 kb/s (most common) or 1509
kb/s (very rare).
Note that differences in sound quality between Laserdisc and DVD come
down to more than just numerical bit rate. Most laserdisc soundtracks
were untouched from the theatrical audio mix, while a great many DVD
Dolby Digital 5.1 tracks (despite the higher bit rate) are "dumbed down"
so that they will convert to basic stereo better for viewers listening
through their TV speakers. This usually entails filtering all bass out
of the main speakers and directing it exclusively to the subwoofer .1
channel. This has an audible effect on the fullness and 'body' of the
front soundstage.
DD5.1 on laserdisc could only be accessed by viewers using full surround
sound equipment. DD5.1 on DVD has to be able to downmix to stereo
without blowing out tiny TV speakers.

[Joshua Zyber]

Post by Erik Saether
When they in Japan release DVD titles as "Superbit", are they
referring to
the data transfer bitrate of the DD 5.1 track ?
A DVD movie with DD at 448 kbps is a "superbit" movie ?

"Superbit" is a Sony (Columbia Tri-Star) marketing label that translates
to: "We didn't put any supplements on this disc, but we want to charge
the same price as our regular DVDs, so we're going to pretend it's
better quality".

Superbit DVDs include the movie soundtrack in DD5.1 (448 kb/s, the same
as most other studios) and DTS 5.1 (754 kb/s "half bit-rate"). The
bit-rate for the video transfer has supposedly been optimized by
stripping out extraneous features like supplements. However, the reality
is that other studios regularly produce DVDs with picture quality as
good or better than Superbit without a fancy marketing label.

[Nico de Vries]

Hi Group,

The Superbit approach is indeed: leave everything off, and jampack the
entire disc with just the movie and a DTS soundtrack. And it works for me.

In Europe the Superbit DTS bitrate is often the full 1536 kbps and the total
bitrate of the entire movie is usually 8 Mbps or higher, with regular peaks
at the maximum.

Whether or not this gives an edge over the standard DVD depends on a lot of
factors. Old movies for instance do not gain much as the source is often the
limiting factor, but modern ones do indeed look and sound fabulous.

Not just a marketing trick in my view.

Regards,

Nico de Vries

[Jeff Rife]

Post by Nico de Vries
Whether or not this gives an edge over the standard DVD depends on a lot of
factors. Old movies for instance do not gain much as the source is often the
limiting factor, but modern ones do indeed look and sound fabulous.
Not just a marketing trick in my view.

Well, your view is wrong, then.

There are many movies on DVD that run the video bitrate up around 7Mbps
as the minimum, with peaks at the max legal limit. These aren't called
"Superbit", but they still look just as good. And, many come with
another disc crammed full of extras, all for less than the cost of a
"Superbit" release.

[publius]

"Zeta" is the name of the audio CODEC used by Digital Theater Systems
[now dts Inc.] for home products ; I think it may now be marketed
under the name "Coherent Acoustics". It has had a number of variations
since it was first introduced, but originally it was specified to pack
5.1 audio channels into the bitstream of an industry-standard Compact
Disc, or what is the same thing, the Digital Audio channel of a
LaserDisc. It is a subband differential coder, similar in principle to
Dolby AC-3 Digital but without the psychoacoustic modelling AC-3 uses
to achieve high compression ratios. In signal processing terms it is
"nearly lossless", if that phrase means anything.
dts Zeta is NOT the same CODEC used in theatrical dts audio. That is
a straightforward ADPCM system which uses a datarate higher than CD
provides, being played back from special CD-ROMs synchronised to the
film via timecode. An early version of this system used an LD-ROM
instead. By contrast, Dolby Digital AC-3 is the same on DVD as it is
in the theatre, or broadcast DTV, or anywhere else ; it is a
development of Dolby Digital AC-2, a fixed 192 kbps stereo encoder used
for satellite TV in the early 1990s. Dolby Digital Plus, or E-AC-3, is
an extension to standard AC-3 which may or may not be directly
compatible, depending on the technical details of the coding.

On DVD, dts Zeta is nominally specified for transmission at 1536
kbps, which is the bitrate of a 16 bit, 48 kHz PCM stereo audio stream
as supported by the DVD format. In the event, however, it is generally
encoded at half this rate, 768 kbps, in order not to affect the video
bitrate ceiling too badly ; dts Inc. does not describe this
half-bitrate implementation as "audibly transparent", which it does
with full-rate Zeta. AC-3 on DVD is specified for a maximum bitrate of
448 kbps, with a choice of coding rates ; 384 is still common for 5.1,
occasionally 320 (the rate used in theatres by printing between the
sprocket holes, and the minimum Dolby recommends for 5.1), going down
to 192 as the commonest rate for stereo or "2.0 mono" (same information
L and R).

Really, none of this information is hard to find ; there are all
kinds of books on video and audio production which go into some detail.

--publius--

Post by Erik Saether
Thanks.
Do you have the specs for DVD for comparison ?
And, what do you mean by dts Zeta ?
Erik

Post by publius
Yes.
Dolby Digital AC-3, on LaserDisc, fixed at 384 kbps regardless of
audio channel format, due to characteristics of QPSK RF encoding
format.
dts Zeta, on LaserDisc, fixed at 1441 kbps regardless of audio channel
format, due to characteristics of EFM (pseudo-Red Book) encoding
format.
Do note that bitrate allocation and sharing are possible between
channels in AC-3, whereas dts Zeta in this form employs a fixed
288 kbps to each channel.
Also note that it is possible to "pad out" an AC-3 signal with empty
bits, so that a 192 kbps 2.0 stream could be packaged as 384 kbps
without taking advantage of the full signal space. I am not aware of
this function being in use.
--publius--

[Erik Saether]

Thanks for good info.

So, in short, on LD:

DTS 5.1 = 16 bit / 48 kHz resolution over 384 kbps data transfer

DD/AC3 = 16 bit / 48 kHz resolution over 1441 kbps data transfer

Am I right ?

Is it the specs on LD limited to 16 bit or would it in theory be possible to
have a DTS or DD track of 20 or 24 bit / 48 kHz resolution ?

Erik

Post by publius
"Zeta" is the name of the audio CODEC used by Digital Theater Systems
[now dts Inc.] for home products ; I think it may now be marketed
under the name "Coherent Acoustics". It has had a number of variations
since it was first introduced, but originally it was specified to pack
5.1 audio channels into the bitstream of an industry-standard Compact
Disc, or what is the same thing, the Digital Audio channel of a
LaserDisc. It is a subband differential coder, similar in principle to
Dolby AC-3 Digital but without the psychoacoustic modelling AC-3 uses
to achieve high compression ratios. In signal processing terms it is
"nearly lossless", if that phrase means anything.
dts Zeta is NOT the same CODEC used in theatrical dts audio. That is
a straightforward ADPCM system which uses a datarate higher than CD
provides, being played back from special CD-ROMs synchronised to the
film via timecode. An early version of this system used an LD-ROM
instead. By contrast, Dolby Digital AC-3 is the same on DVD as it is
in the theatre, or broadcast DTV, or anywhere else ; it is a
development of Dolby Digital AC-2, a fixed 192 kbps stereo encoder used
for satellite TV in the early 1990s. Dolby Digital Plus, or E-AC-3, is
an extension to standard AC-3 which may or may not be directly
compatible, depending on the technical details of the coding.
On DVD, dts Zeta is nominally specified for transmission at 1536
kbps, which is the bitrate of a 16 bit, 48 kHz PCM stereo audio stream
as supported by the DVD format. In the event, however, it is generally
encoded at half this rate, 768 kbps, in order not to affect the video
bitrate ceiling too badly ; dts Inc. does not describe this
half-bitrate implementation as "audibly transparent", which it does
with full-rate Zeta. AC-3 on DVD is specified for a maximum bitrate of
448 kbps, with a choice of coding rates ; 384 is still common for 5.1,
occasionally 320 (the rate used in theatres by printing between the
sprocket holes, and the minimum Dolby recommends for 5.1), going down
to 192 as the commonest rate for stereo or "2.0 mono" (same information
L and R).
Really, none of this information is hard to find ; there are all
kinds of books on video and audio production which go into some detail.
--publius--

Post by Erik Saether
Thanks.
Do you have the specs for DVD for comparison ?
And, what do you mean by dts Zeta ?
Erik

Post by publius
Yes.
Dolby Digital AC-3, on LaserDisc, fixed at 384 kbps regardless of
audio channel format, due to characteristics of QPSK RF encoding
format.
dts Zeta, on LaserDisc, fixed at 1441 kbps regardless of audio channel
format, due to characteristics of EFM (pseudo-Red Book) encoding
format.
Do note that bitrate allocation and sharing are possible between
channels in AC-3, whereas dts Zeta in this form employs a fixed
288 kbps to each channel.
Also note that it is possible to "pad out" an AC-3 signal with empty
bits, so that a 192 kbps 2.0 stream could be packaged as 384 kbps
without taking advantage of the full signal space. I am not aware of
this function being in use.
--publius--

[publius]

You have it the other way around.

On LaserDisc, DD AC-3 is 384 kbps. It can be sampled at 32, 44.1, or
48 kHz, and at 16, 20, or 24 bit depths according to the standard :
bitrate is determined by compression, and can be set independently of
source characteristics. The only AC-3 discs I have use 48 kHz. On DVD
the bitrate is variable, but the sampling parameter choices are the
same.
On LaserDisc, dts Zeta is 1441 kbps. It must be sampled at 44.1 kHz
for the packing to work, and may be sampled at depths of 16, 20, or 24
bits to my understanding. On DVD, dts Zeta must be sampled either at
48 kHz or at 96 kHz because of the way it is encoded, and may be
sampled at 16, 20, or 24 bit depth to my understanding.

Obviously, the bitrate will interact with the other parameter
choices, including various compression setting in the encoder, to
determine the actual audio output quality. A 24-bit 48 kHz sampled
AC-3 5.1 at 192 kbps, for example, could easily sound worse than a
16-bit 32-kHz version of the same soundtrack with the same bitrate. A
448-kbps DD track will probably sound better than a 768-kbps dts track
from the same master.

And no, "Superbit" is a marketing term referring to the maximisation
of the VIDEO bitrate on a DVD by various optimisations, including
cutting out un-needed extra audio tracks. It does not describe the
audio encoding itself. Anyway, that's not a topic for the LD
newsgroup.

--publius--

Post by Erik Saether
Thanks for good info.
DTS 5.1 = 16 bit / 48 kHz resolution over 384 kbps data transfer
DD/AC3 = 16 bit / 48 kHz resolution over 1441 kbps data transfer
Am I right ?
Is it the specs on LD limited to 16 bit or would it in theory be possible to
have a DTS or DD track of 20 or 24 bit / 48 kHz resolution ?
Erik

Post by publius
"Zeta" is the name of the audio CODEC used by Digital Theater Systems
[now dts Inc.] for home products ; I think it may now be marketed
under the name "Coherent Acoustics". It has had a number of variations
since it was first introduced, but originally it was specified to pack
5.1 audio channels into the bitstream of an industry-standard Compact
Disc, or what is the same thing, the Digital Audio channel of a
LaserDisc. It is a subband differential coder, similar in principle to
Dolby AC-3 Digital but without the psychoacoustic modelling AC-3 uses
to achieve high compression ratios. In signal processing terms it is
"nearly lossless", if that phrase means anything.
dts Zeta is NOT the same CODEC used in theatrical dts audio. That is
a straightforward ADPCM system which uses a datarate higher than CD
provides, being played back from special CD-ROMs synchronised to the
film via timecode. An early version of this system used an LD-ROM
instead. By contrast, Dolby Digital AC-3 is the same on DVD as it is
in the theatre, or broadcast DTV, or anywhere else ; it is a
development of Dolby Digital AC-2, a fixed 192 kbps stereo encoder used
for satellite TV in the early 1990s. Dolby Digital Plus, or E-AC-3, is
an extension to standard AC-3 which may or may not be directly
compatible, depending on the technical details of the coding.
On DVD, dts Zeta is nominally specified for transmission at 1536
kbps, which is the bitrate of a 16 bit, 48 kHz PCM stereo audio stream
as supported by the DVD format. In the event, however, it is generally
encoded at half this rate, 768 kbps, in order not to affect the video
bitrate ceiling too badly ; dts Inc. does not describe this
half-bitrate implementation as "audibly transparent", which it does
with full-rate Zeta. AC-3 on DVD is specified for a maximum bitrate of
448 kbps, with a choice of coding rates ; 384 is still common for 5.1,
occasionally 320 (the rate used in theatres by printing between the
sprocket holes, and the minimum Dolby recommends for 5.1), going down
to 192 as the commonest rate for stereo or "2.0 mono" (same information
L and R).
Really, none of this information is hard to find ; there are all
kinds of books on video and audio production which go into some detail.
--publius--

[Erik Saether]

Thanks !

One additional question:

A few LDs were released with the "DTS Stereo" encoding. I know this is
similar to "Dolby Pro Logic" as a matrix surround system, but were there
ever processors/receivers with dedicated DTS Stereo decoders ?

And further, do you get the same effect from "DTS Stereo" by using the Pro
Logic-decoder in the receiver ?


Best regards
Erik

Post by publius
You have it the other way around.
On LaserDisc, DD AC-3 is 384 kbps. It can be sampled at 32, 44.1, or
bitrate is determined by compression, and can be set independently of
source characteristics. The only AC-3 discs I have use 48 kHz. On DVD
the bitrate is variable, but the sampling parameter choices are the
same.
On LaserDisc, dts Zeta is 1441 kbps. It must be sampled at 44.1 kHz
for the packing to work, and may be sampled at depths of 16, 20, or 24
bits to my understanding. On DVD, dts Zeta must be sampled either at
48 kHz or at 96 kHz because of the way it is encoded, and may be
sampled at 16, 20, or 24 bit depth to my understanding.
Obviously, the bitrate will interact with the other parameter
choices, including various compression setting in the encoder, to
determine the actual audio output quality. A 24-bit 48 kHz sampled
AC-3 5.1 at 192 kbps, for example, could easily sound worse than a
16-bit 32-kHz version of the same soundtrack with the same bitrate. A
448-kbps DD track will probably sound better than a 768-kbps dts track
from the same master.
And no, "Superbit" is a marketing term referring to the maximisation
of the VIDEO bitrate on a DVD by various optimisations, including
cutting out un-needed extra audio tracks. It does not describe the
audio encoding itself. Anyway, that's not a topic for the LD
newsgroup.
--publius--

Post by Erik Saether
Thanks for good info.
DTS 5.1 = 16 bit / 48 kHz resolution over 384 kbps data transfer
DD/AC3 = 16 bit / 48 kHz resolution over 1441 kbps data transfer
Am I right ?
Is it the specs on LD limited to 16 bit or would it in theory be possible to
have a DTS or DD track of 20 or 24 bit / 48 kHz resolution ?
Erik

Post by publius
"Zeta" is the name of the audio CODEC used by Digital Theater Systems
[now dts Inc.] for home products ; I think it may now be marketed
under the name "Coherent Acoustics". It has had a number of variations
since it was first introduced, but originally it was specified to pack
5.1 audio channels into the bitstream of an industry-standard Compact
Disc, or what is the same thing, the Digital Audio channel of a
LaserDisc. It is a subband differential coder, similar in principle to
Dolby AC-3 Digital but without the psychoacoustic modelling AC-3 uses
to achieve high compression ratios. In signal processing terms it is
"nearly lossless", if that phrase means anything.
dts Zeta is NOT the same CODEC used in theatrical dts audio. That is
a straightforward ADPCM system which uses a datarate higher than CD
provides, being played back from special CD-ROMs synchronised to the
film via timecode. An early version of this system used an LD-ROM
instead. By contrast, Dolby Digital AC-3 is the same on DVD as it is
in the theatre, or broadcast DTV, or anywhere else ; it is a
development of Dolby Digital AC-2, a fixed 192 kbps stereo encoder used
for satellite TV in the early 1990s. Dolby Digital Plus, or E-AC-3, is
an extension to standard AC-3 which may or may not be directly
compatible, depending on the technical details of the coding.
On DVD, dts Zeta is nominally specified for transmission at 1536
kbps, which is the bitrate of a 16 bit, 48 kHz PCM stereo audio stream
as supported by the DVD format. In the event, however, it is generally
encoded at half this rate, 768 kbps, in order not to affect the video
bitrate ceiling too badly ; dts Inc. does not describe this
half-bitrate implementation as "audibly transparent", which it does
with full-rate Zeta. AC-3 on DVD is specified for a maximum bitrate of
448 kbps, with a choice of coding rates ; 384 is still common for 5.1,
occasionally 320 (the rate used in theatres by printing between the
sprocket holes, and the minimum Dolby recommends for 5.1), going down
to 192 as the commonest rate for stereo or "2.0 mono" (same information
L and R).
Really, none of this information is hard to find ; there are all
kinds of books on video and audio production which go into some detail.
--publius--

[Matthew L. Martin]

Post by publius
dts Zeta, on LaserDisc, fixed at 1441 kbps regardless of audio channel
format, due to characteristics of EFM (pseudo-Red Book) encoding
format.

It's my understanding that very few LDs with DTS had 1441kp/s of data.
Most were encoded at 1200Kb/s (14 bits of data in each 16 bit sample).
Is that understanding incorrect?

Matthew

[publius]

Actuslly, my information is that you are correct : the two MSBs were
set to 0 in order to reduce the possibility that somebody's amplifier
might be blown up by the "black noise" if he incautiously inserted a
dtsCD or dtsLD with analog outputs in use, or if the decoder failed to
lock. This can be observed by ripping a .WAV file and looking at the
peak amplitudes, which are always at 25%. The bitstream, however, is
still 1441, and the poster seemed confused enough I wasn't going to add
to the problem right away.
To the best of my knowledge, all commercial dtsCDs and dtsLDs do
this, and only the first experimental pressings use the full bitspace.

--publius--

Post by Matthew L. Martin

Post by publius
dts Zeta, on LaserDisc, fixed at 1441 kbps regardless of audio channel
format, due to characteristics of EFM (pseudo-Red Book) encoding
format.

It's my understanding that very few LDs with DTS had 1441kp/s of data.
Most were encoded at 1200Kb/s (14 bits of data in each 16 bit sample).
Is that understanding incorrect?
Matthew
--
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