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DD+ and AV32R DP

Bogi

Novice Member
Hi all,

I went over to take a look at Dolby's web site, looking for info on the DD+ format that some of the new high def discs are running.

Unfortunately, the info was a bit sketchy with regards to the DD+ format. I was more specifically looking to see if it was supported over the S/PDIF connection. Of course it's always possible to hook it up via the bypass, but then one would be missing out on TMREQ and all the other goodies.

Anyway, they say this under one of the points (here):


"Outputs a Dolby Digital bitstream for playback on existing Dolby Digital systems." (my highlight)

However, I can't find any info with regards to the bit rate that is sent over to the S/PDIF connection. DD+ is able to output up to 6 Mbps but if this is to "existing systems" or not is unclear.

They also state:

//...Dolby Digital Plus was designed for the delivery formats of the future, but remains fully compatible with all current A/V receivers.//..

Any ideas of what the "remains fully compatible with all current A/V receivers." means here?

1.
What it comes down to, is the AV32R DP able to handle DD+ in it's current state?

2.
And also, what's the highest bit rate the S/PDIF can handle?

Please note, I'm not talking about the Dolby TrueHD, which can only be run via the analogue bypass connections to a AV32R DP BP unit.

Cheers
 

Stevesky

Novice Member
Hi Bogi,

A few answers to your questions:

However, I can't find any info with regards to the bit rate that is sent over to the S/PDIF connection. DD+ is able to output up to 6 Mbps but if this is to "existing systems" or not is unclear.
Thats only to AV processors that are equipped with a HDMI 1.3 input receiver that has the audio part wired into the DSP... you can count those on 0 fingers at the moment!

Any ideas of what the "remains fully compatible with all current A/V receivers." means here?
Source components (eg. HD player / STB's) will give a SPDIF out which will be backwards compatible but will loose any benefits of DD+. This will typically be a 640kb/s Dolby Digital stream.

What it comes down to, is the AV32R DP able to handle DD+ in it's current state?
No, not natively. Only by using the compatibility stream on the SPDIF, so hardly an optimal way to appreciate DD+!


And also, what's the highest bit rate the S/PDIF can handle?
1.4Mb/Sec. Standard Consumer Dolby Decoders don't support to this maximum bit-rate, hence why they use 640kbit/sec instead for the compatibility feeds.
 

Ettepet

Novice Member
Stevesky said:
1.4Mb/Sec. Standard Consumer Dolby Decoders don't support to this maximum bit-rate, hence why they use 640kbit/sec instead for the compatibility feeds.

Steve, what are the upper limits the Tag av32dp can handle here? (DTS/DD) Might be nice to know in case these compatibility modes on some players support higher bit rates.

And, would 96/24 and other formats (6.1 discrete) work with higher than current bit rates?
 

Stevesky

Novice Member
The Dolby Decoder supports up to 640kBits/sec, The DTS decoder supports up to 1.4Mb/Sec (some people round this figure up to 1.5Mb depending how you count your numbers!).
 

Ettepet

Novice Member
Thanks. :)
 

Bogi

Novice Member
Thanks a lot Steve for the info!

I'm away for a vacation and haven't been able to hook me up until now (a quick I-net fix :) ).

Typical, lots of nice words and glossy brochures on Dolby's web page...

Cheers and thanks again.
 

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