any plans in the furture for dolby digital 5.1 sound on RTE 2

sky23

is there going be?? possibly? or can they on DTT? i guess they have to get some actual hd content first

The Cush

It's part of the Saorview specification, don't think its been tested yet

MPEG4 HD Level mandatory on all IRD which among other things include:

Audio decoding
• MPEG1 Layer II stereo audio (Musicam).
• AC 3 (Dolby digital) EAC 3 (Dolby Digital Plus) multi-channel audio.
• HEAAC multi-channel audio

watty

hardly any TV content in surround.
Hardly space till 2nd mux. The HE-AAC surround is as good as Dolby AC3 and needs less space.

John mac

Lots of stuff on bbchd have 5.1 (mostly nature stuff )

watty

But is it actually Dolby AC3 or HE-AAC surround? Some Receivers transcode to AC3 for Home Theatre Amp.

I must have a look at the TS next time it's surround sound on BBC HD.

My Home theatre Amp only does Analogue Surround. Loads and Loads of wires from the DVD Player!

I'll have to get one with Optical sometime (probably as cheap as a standalone Digital to Analogue Decoder). I've considered using my Soundblaster USB Optical in and my SoundBlaster PCI card as 5.1 Channel analogue out. I wonder if the delay would be too much!

watty

I checked a few HD channels. Most when selecting AC3 option on DVB viewer turn out to be AAC 2.0 actually. Luxe HD was showing as actually AC3 5.1, but monitoring with Virtual Audio Cable only showed Audio on L & R.

Arte HD claimed to have a AC3 track, but was actually Mono encoded as Stereo. (Old B&W film).


Indeed the TV optical Out via fibre cable to "Optical In"/SPDIF of the Soundblaster MP3 USB box via Virtual Audio Cable to Realtek AC97 does allow Analogue out to the Analogue in on Home Theater. Oddly the TV has no Analogue RCA audio out. Maybe it has Analogue Audio out from DTT tuner on SCART (But that's only 2 ch obviously).

Jpmarn

From the Sky Box I often get Dolby Pro Logic reproduction off some of the RTE programmes. Prologic is almost as good as digital 5.1. You might get it on DTT and from Nicam on anologue.

watty

"prologic" is just 2 channel. You can pass it over any stereo system.

5.1 is 5 channels and a sub bass track for Cinema. It can be totally duplicated with just four channels. "5.1" is about surround cinema effects. Of itself it says nothing about the actual sound quality. It can use HE-AAC codec, Dolby AAC or DTS codec to carry it. Stereo or "prologic" can use MP2, HE-AAC or 2 channel DD (aka Dolby AC3 2.0).

The quality depends on bitrate used.
The best quality for same bit rate is HE-AAC. The poorest for same bitrate is MP2 at lower bitrates. But you can have same quality MP2 as AAC by increasing bit Rate.

The DD 2.0 and DD 5.1 (AC3 codec) are designed for Cinema distrubution and Disk. They are much less efficienct for same quality as HE-AAC (need more bitrate). On Broadcast you pay daily for space used and on terrestrial the space is very limited, so any 5.1 (which only much exists in any sensible form on material produced for Cinema) is more likely to be using HE-AAC.