CDinteractive.co.uk - Home of the CD-i Forum

On a demo discs there's a demo of Choas Control (really a short video) with Dolby surround. So has anyone seen this or any other CD-i game with Dolby Surround?

The 7th Guest has Dolby Surround... I've never noticed this with Chaos Control, however. It's not indicated on the box.

But is real dobly sorround, or false (sorround in stereo)?


Are you

i have asked myself the same question, because on 'modest' cd-i players the only audio output is analogue in two channels. But some also have digital output, but I thought this was only for audio cd's. No clue at the moment

Ruekov wrote:But is real dobly sorround, or false (sorround in stereo)?


Are you

All dolby surround is based on stereo or 2 channel input only if you got an amplifier supporting Dolby Surround you will able to hear all input in a false simulated (by the amp) surround sound. I will show you how it works:

Dolby surround is based upon the (semi)quadrophonic technique.

the left and right channel are divided with each other so the back speaker will only give a sound that's harder on one of the channels:



So in my opinion all the games if played on a Dolby Amp will (if they have some kind of stereo effects) will give the full Dolby Surround sound.....

Maybe the CD-i titles that have the Dolby Surround logo on it were special designed for use with a Dolby system so the effects are more realistic.

Example of a special Dolby Surround effect: when you quickly switch a sound from the left to the right and back repeating you get the idea the sound is on top of you.....

I hope I gave you enough information...

TerraTron

Thanks for that Arno; Good to see you around again.

Good old ICDIA also has something to say about it:

"3.12.1 Does CD-i support Dolby Surround, Dolby Digital or MPEG Multichannel?

Dolby Surround is an analogue encoding technique that allows for the storage or center and rear audio in addition to the normal left and right stereo signal. Every stereo audio carrier that provides for a high frequency audio reproduction can use Dolby Surround encoding. In CD-i, Dolby Surround can only be used for MPEG audio, since ADPCM does not offer the dynamic range that is necesary for the encoding of the additional channels. Most movies use Dolby Surround, as do several games such as Seventh Guest. Please be aware of the fact that Dolby Surround is an analogue matrixing technique, which does not add extra discrete audio channels.

Dolby Digital and MPEG Multichannel are audio encoding techniques that allow for discrete surround channels to be encoded individually. Ususally, this includes two front signals, two back signals, a center signal and a low-frequency subwoofer signal. Both techniques are widely used in DVD-Video. CD-i does not support either of them."

Thanks for the information, TerraTron.

Exists other surrond? for example in 4, 5 chanels. But I never see a CDi player with digital out (or 4/5 channels out).

First there was Dolby surround:

Dolby used the same techniques as shown above, a simple decoder only filtering and deviding 2 stereo channels to one (2 speaker) mono back channel.


Then there was Dolby Prologic:

Used Almost the same techniques as Dolby surround but the decoder is more complexed resulting in 2 channel (stereo) back channels.


Then came Dolby Prologic 2.0:

The same but more secure decoder as Prologic (1)

All these systems above used analog 2 channel input.


The CD-i player can only support Dolby Surround so the 2 channel stereo signal is used to filter out the surround sound and give you 4 channels (2 stereo front and 2 mono back)

TerraTron