Digital Audio for Films
 

Will digital audio ever be available for NTL SKY films. To my knowledge the only audio output is the RCA audio from the STB which is stereo.

Re: Digital Audio for Films
 

It will not be possible from current boxes, but at some point I would imagine it will be available in the distant future.

Re: Digital Audio for Films
 

I don't like that word distant. If my info is correct, in the States they receive 5.1 digital from their cable networks. Why are we always so far behind?

Re: Digital Audio for Films
 

A distinct lack of money available for investment at the moment?

Re: Digital Audio for Films
 

And Sky+ boxes support 5.1 on films they broadcast with it anyway. It would take up a fair amount of extra bandwidth of course.

Re: Digital Audio for Films
 

not sure it would take up much extra bandwidth tbh

I don't know in what format the current sound is transmitted, but if you look at a dvd, the video content is several gigabytes, but the audio stream in AC3 format is only a few hundred kilobytes.

Re: Digital Audio for Films
 

Surely the entire audio content for a film is going to be a little more than a few hundred K?

Re: Digital Audio for Films
 

He means a few kb/s (kilobits per second).

Re: Digital Audio for Films
 

Not really, if you look at a DVDs composition the audio is about 10% of the total bandwidth.

IMHO digital audion will com with NTL+ and thats "coming soon..."

Re: Digital Audio for Films
 

Yeah, but that's still enough for an extra shopping channel! J/K.



Seriously, I don't think bandwidth would be a problem (I think DD5.1 on most DVDs is encoded at anywhere between 300KBps and 700KBps, DTS goes up to 1.5MBps but NTL would be unlikely to support DTS).

What, I think, might be a problem is the licencing fees Dolby would charge. IIRC, licences to use Dolby aren't cheap.

Re: Digital Audio for Films
 

DVD can use up to 8000Kbps for video and 1500Kbps for Audio. Or any other ratio maxing out at 9500 (maybe 10000Kbps). You also need some overhead for subtitles etc.

Re: Digital Audio for Films
 

MPEG limit is 15Mb/s for video bitrate, is that different for DVD? Probably is limited by the speed its possible to read from the disc.

Re: Digital Audio for Films
 

I believe the DVD spec allows burst reading of 20Mb/s but optimal disc design works on 10Mb/s At 20M/s you get a heck of a lot less on the disk and the disc / player struggle with error correction / fingerprints etc, as there is no spare overhead to keep the players buffers fed.

This is what I have read from the dvdrhelp site a good few weeks ago and is from memory.

Re: Digital Audio for Films
 

Yep, I know..

Re: Digital Audio for Films
 

This is also from Memory. I have a book called DVD demystified, which was written by one of the first DVD authors. He said that the limit as specified by the DVD Forum is 10MBps. The DVD authoring systems we have at work (one of the courses I support is in DVD authoring) will not allow you to encode above 9.99MBps.

As I understand it, the forum specified that limit because the drives available to them at the time (1994-1995) couldn't handle any higher data rates.