SCVD with AC3 sound??

[SuperMario]

Is it possible to make SVCD with AC3 sound?? It works fine with mini dvd, but i'll don't get it to word with SVCD....anyone?

[adam]

Svcds cannot support ac3 sound. You can mulitplex an mpeg2 video stream and an ac3 file with TMPGenc or bbmpeg and essentially make an xsvcd but I doubt that there is a single dvd player that would be able to play it.

[mickboss]

xSVCD with 5.1 sound is possible! (not with AC3 track)

I am doing some backups of my DVDs with SVCDs at 720x576 with 5.1 MPEG-2 sound!

They play LIKE A CHARM! 8)

[patrickm]

I am doing some backups of my DVDs with SVCDs at 720x576 with 5.1 MPEG-2 sound!

They play LIKE A CHARM! 8)

on what?

[Faceman101]

xSVCD with 5.1 sound is possible! (not with AC3 track)

I am doing some backups of my DVDs with SVCDs at 720x576 with 5.1 MPEG-2 sound!

They play LIKE A CHARM! 8)

why bother making a SVCD at 720x576?

[vcd4me]

ok let me get this straight you can only put pro-logic on vcd's and you can put dd 5.1 on svcds. I've been told this cannot be done

MICKBOSS- are you sure it's 5.1 and not pro-logic

[SuperMario]

Hey Mickboss....how do you do that? Are you sure it isn't Prologic?
Supermario[/quote]

[adam]

You don't "put" prologic on a svcd, theres no way to encode in prologic. You encode in stereo and it is decoded into prologic. Maybe a minor distinction but nevertheless it prevents confusion.

You cannot put dolby digital onto a svcd but you can preserve the 5.1 signals, in fact you can even have up to 7.1, if you encode your audio using multichannel mpeg audio which I assume is what mickboss is referring to unless he is making mini-dvds.

I'm not going to explain this audio format, its literally been done dozens of times on this forum. Just do a forum search.

What I will say is that in order to use this function you have to have a Philips dvd player, you have to have a reciever capable of decoding multichannel mpeg audio, and in order for your svcd to be compliant you must author the audio in linux. With all these requirements mc mpeg audio is understandly seldom used. For the vast majority of people prologic or dolby surround is the best quality your going to get from a svcd.

mickboss, unless you are specifically making multichannel mpeg audio than you are simply hearing prologic. Just because sound comes out of each speaker that doesn't mean its discretely encoded.

[vcd4me]

Adam,
I accidently wrote put when I was typing but not all 2 channel stereo is prologic.

Also I did do a forum search and that's when the confusion all started for me.I will just expirement and if the movie ends up having some type of surround format then I'll be happy and it will be worth all the trouble I've obviously put everyone through.

Not only did I post her but Idid start my own thread.

sorry eveyone for all the confusions--VCD4ME

[adam]

Adam,
I accidently wrote put when I was typing but not all 2 channel stereo is prologic.

Yes all 2 channel stereo audio IS prologic but only when being decoded on a prologic reciever. Again, prologic is a decoding method not an encoding method, thats the distinction I am trying to make.

[vcd4me]

EVEN PRE 1977 BEFORE STAR WARS?

I UNDERSTAND THAT IT IS SOMETHING THAT THE RECIEVER DOES.
IT TAKES 2 CHANNEL STEREO AND MAKES IT INTO SURROUND SOUND
I GET IT!

THINK ABOUT WHAT I'M SAYING A CD IS 2 CHANNEL STEREO AND THAT' CAN NOT PLAY IN SURROUND SOUND WITH A PRO-LOGIC RECEIVER.

LET'S JUST DROP IT!
I'M JUST STUPID!
AND I'M SICK OF EVERYONE SLAMMING ME

[adam]

I'm slamming you at all I trying to help you understand the concept of pro logic. If you would like me to drop it then I will, although I really don't understand what is so frustrating about this discussion.

THINK ABOUT WHAT I'M SAYING A CD IS 2 CHANNEL STEREO AND THAT' CAN NOT PLAY IN SURROUND SOUND WITH A PRO-LOGIC RECEIVER.

Yes it can, that is EXACTLY what a pro logic reciever is designed to do.

[vitualis]

@ vcd4me:

The centre and surround tracks MUST still be matrixed INTO the stereo signal for Dolby Surround/Dolby ProLogic/Dolby ProLogic II decoding to work.

Just a standard stereo signal that hasn't been processed to be Dolby Surround compatible (i.e., centre and surround channels added in) will NOT be decoded to have additional centre and surround channels with a ProLogic decoder (*read caveat at bottom).

This is your example of some audio CDs. Audio CDs that are not Dolby Surround encoded won't play back with additional channels (as expected). However, Audio CDs that ARE encoded with Dolby surround information will play back with the additional channels. They are both still just two discrete channels of audio.

I reposted a method (I didn't write it) of making (sort of) your own Dolby Surround encoded tracks once. It involves something like the following:
L = L + 0.7*(C + S)
R = R + 0.7*(C - S)

L=left channel, R=right channel, C=centre, S=surround

That is, the volume of the centre and surround channels are reduced in volume by ?? 3dB and the surround channel is phase inverted (??terminology) between the left and right channels. I believe that there is also a frequence low-pass cutoff at some frequency as well as the application of some type of noise reduction (strongly suggest you read the Dolby tech. documents for details).

* the caveat I mentioned before is that the Dolby Surround encoding scheme is somewhat analogous to what happens with environmental/natural surround audio. Thus, audio that is recorded in some environments (e.g., an echoey room) may decode to have some appropriate surround channel audio even if they weren't specifically encoded to by Dolby Surround compatible. The first time you hear and realise that this is happening, you'll realise that the Dolby Surround scheme is really quite cool...

Regards.