Hello everyone!

Since the different flavors of soundtracks on DiscoVision/LaserVision/LaserDisc seems to be a somewhat complicated topic for new collectors or people trying to jump from/to PAL and NTSC or confused about the different soundtracks of MUSE/Hi-Vision discs, I started a draft help section here:

https://www.lddb.com/help_sound.php

For each example, I'm trying to give the earliest commercial release as possible (first stereo, first CX, first Digital, etc.).

I still have a big section on AC3 and DTS to draft, and then move to Hi-Vision (A-mode, B-mode, EFM, etc.).

Could you take a look at the draft and make some comments if I made mistakes or over-simplified things?

Julien

Well, that's pretty good actually.
Not too technical, not oversimplified either.

While I don't have as much knowledge about the technical aspect of this stuff it looks great and I can clearly understand it.

The section on RSS is incorrect. The digital tracks on the disc contain the program code so the only listenable audio is on the analog tracks. I'm basing this on the single LDRom title I have, but I can't imagine any of the others would be different.

The very early Digital Sound players could not select Digital 1/L and 2/R independently. You won't have "4 separate audio" programs until much later. I think Criterion were the only ones to actually do this in supplemental sections.

Seems a lot of early titles do not indicate any surround information on the jackets though it was present in the soundtrack, how should this type be classified?

Same for CED announced as "Stereo" but actually carrying over the surround information from the original masters.

Best way would be to ... just play the disc and turn on Prologic/Surround decoding to for sound the center/rear channels?

Julien

Would you have some more data in it?

Realizing it's not "surround" but stereo spatialisation actually.

https://segaretro.org/Roland_Sound_Space



We'll have it as an additional feature when I can find time (and internet at home, now looking at Nov 15th!) to code further the Hardware section.

Julien

AC3 and DTS added!

Julien

Nice, about ac3, there is also Judge Dredd that has been released in France as an NTSC ac3 disc.
And a question about DTS, you say that closed caption can't be contained on a disc, but why is my street fighter copy (only dts disc I have) saying that it has closed captions ? was it a lie ? (can't verify it)

Ahhh might have been my mistake.

CC is in the video signal... LD-G is in the audio signal.

Correct?

Julien

Forgot one special case of NTSC LD with Digital Audio only -> CDV and VSD (5"!)

Julien

The draft made it to "public release".

I let the HELP -> SOUNDTRACKS become a public link.

Hope it will be helpful!

Julien

Yep. CC uses two lines of the video signal (the second includes the first active half-line of the picture, so you can often see it twittering away right at the top of the display). LD+G uses the R to W subchannels of the CD-style soundtrack, like CD+G does.



The first bit there doesn't sound quite right. CX should work fine on mono soundtracks (i.e. where both channels are the same) or on stereo soundtracks. It won't sound very good when the two channels carry different material because the same gain adjustment is applied to both channels in the CX scheme - so volume variation on one channel would cause the background noise level on the other channel to vary.

Best as I can determine, the MegaLD and LD-Rom2 formats were laid out on the disc in exactly the same way. Analog audio playback, PCM tracks for game data. The difference was which game pack was required. MegaLD required the Sega pac. and LD-Rom2 required the NEC pac.

I've been backup'ing and extracting my DVDs and BDs recently to put the audio only in a form that I can audio-stream.

Only fair use, I'm allowed to do that since it's not for distribution but personal use... also extends the lifetime of the optical blocks!

Old folks here -- like me -- will remember how DVD owners would disregard Dolby Digital on LaserDisc as inferior because it was "only" 384kbps and DVD could do a lot more.

Well, it was all in the "could".

For example: X-Men Ultimate DVD Edition Japan



LD-bitrate for DD and half-bitrate for DTS. Not nearly as "ultimate" as one could expect.

Let's try Alien Resurrection Ultimate DVD Edition Japan



448kbps is the max standard DD bitrate for DVD, still half-bitrate for DTS and LD-bitrate for Japanese DD.

Kill Bill Japan DTS box is a little better:




So far the good surprise were music/live DVDs with 2.0 LPCM and 5.1 full-bitrate DTS (ex: Madonna - Confession Tour):



Metallica - Cunning Stunts tried a little harder (and split on 2 discs):



All the Peter Gabriel releases I have max out the audio bitrate for maximum quality (DD 448k / DTS 1.5M / DTS 96/24) -- a true perfectionist there.

King Crimson as well (Deja Vrooom):



... don't TELL DVD lovers they were listening to LaserDisc Dolby Digital quality for many years

Julien

Those are some interesting numbers for sure.