Audio Channel

[biferi]

I know if a DVD Says the Audio is AC3 5.1 Channel this Tells me the Audio is Made of Five Audio Channels and One Subwoofer Channel.

I have the DVD of Robocop 1987.

I use Win10 and DVDShrink to Rip the DVD to my Hard Drive.

It Shows me 2. Audio Channels I can pick to Rip.

AC3 4.1 this Tells me it is Made of Four Channels and One Subwoofer Channel.

Then the other Audio Channel Says DTS 5.1 this Tells me the Audio is Made of Five Audio Channels and One Subwoofer Channel.

Now this you would Say pick the DTS 5.1 because this is the Surround Sound.

But I know DTS is the Competitor of Dolby.

So why is the 4.1 Audio Channel not AC3?

Was Robocop 1987 not in AC3 5.1 when it came out?

[Cornucopia]

No it was not.
If it was surround at all (and you could look that up on IMDB, Wikipedia, etc), it would have been "Dolby Surround", which is a matrixed and (at the time) analog format (think: 4ch -> 2ch -> 4ch). Dolby ProLogic is a newer variation of this.

AC3 came out in the early 90s and is digital only, and - not counting the odd EX variations - is discreet only, not matrixed.
The master tracks at the studio may have been multitrack, or maybe not. If they were, that would have been possible to later remix down to various forms of surround (4.1, 5.1, 7.1...).

On the dvd, main formats for audio would be ac3, dts, lpcm. So very likely that ON THE DISC it is ac3, as that is the prime format for dvd and would have been encoded by the mastering house for that disc.

And to be clear, you are given a choice of 2 STREAMS (aka files, when extracted), not channels, on that disc.

Scott

[biferi]

So if I Understand you Right the Robocop 1987 Movie was Made in 4.1 Channel Audio.

And DTS Made the Audio as 5.1 for the DVD?

[Cornucopia]

Who knows.

Look it up.

Could have been mono for all I know, but I have many other things to do and Robocop is NOT in my top 100, so I'll leave that to others to work out. I just know it didn't ORIGINATE as AC3 or (the consumer version of) DTS. And very few movies in the 80's (or earlier) were surround, and when they were >3ch they were almost always Dolby Surround matrixed analog. Equivalent to 4.0 (or perhaps 3 1/2.0, since the back channel was poor then, and there was much crosstalk).

Scott