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Question Virgin V6: Stereo over HDMI, Dolby Digital over Optical at the same time?

bllymcrthr

Standard Member
I'm a Home Automation programmer who is doing some work on a multi-room video system put together by another dealer. The customer is looking to add a couple of V6 boxes, but due to the way the system has been put together, this is only feasible if the box is able to output PCM stereo over HDMI and Dolby Digital over optical at the same time.

Is this possible, or does one override the other?

Thanks.
 

grahamlthompson

In memoriam
Very doubtful, the box would need twin audio decoders and a way to route each to either output. Would seem to be certain to cause lip synch issues as different delays would be required for the two seperate audio streams.
 

bllymcrthr

Standard Member
Very doubtful, the box would need twin audio decoders and a way to route each to either output. Would seem to be certain to cause lip synch issues as different delays would be required for the two seperate audio streams.

How annoying. Is this a guess, or are you sure?

The reason I ask is that this does appear to be possible on Sky boxes, where there are two separate audio settings for HDMI and Optical.
 

grahamlthompson

In memoriam
How annoying. Is this a guess, or are you sure?

The reason I ask is that this does appear to be possible on Sky boxes, where there are two separate audio settings for HDMI and Optical.

A guess but I see Joe Fernand confirms guess was correct. Can't see how it can work on a Sky box. Outputting the native soundtrack requires no processing, re-coding it will add a small delay presumably the box changes the delays to maintain lip synch dependent on the audio selected.

The sound codec varies with the programme, generally on satellite SD uses mpeg 1 layer 2 stereo audio (MP2) and HD uses Dolby Digital 2.0 or 5.1. Not sure what Virgin does as they encode the content using mpeg 2 for HD and SD (Satellite and Freeview uses the more efficient H264/AVC for HD).
 

stevelup

Distinguished Member
This does work on Sky. I have 2ch PCM via HDMI which goes off to all the other rooms via HDBaseT. There's then an optical cable from the Sky Box direct to my AVR which provides DD / whatever is being broadcast for the main room. The outputs are definitely independent and concurrent.

The old TiVo units only had one toggle 'DD > PCM' which globally converted DD to PCM on both the HDMI and Optical outputs.

I don't have first-hand knowledge of the V6 boxes as I moved to a non-cabled area, however the VM website that Joe linked to above states 'This setting applies to both HDMI and optical out.'
 

t3rr4nc3

Novice Member
I'm a Home Automation programmer who is doing some work on a multi-room video system put together by another dealer. The customer is looking to add a couple of V6 boxes, but due to the way the system has been put together, this is only feasible if the box is able to output PCM stereo over HDMI and Dolby Digital over optical at the same time.

Is this possible, or does one override the other?

Thanks.

Sorry to resurrect an old thread but I have this exact same requirement. I currently have Sky distribution over HDBaseT and some Samsung TVs that won't decode Dolby Digital... We needed to push stereo over HDMI and then Dolby Digital to the AVR, exactly as @stevelup described. Not ideal but has been working perfectly.

Did you find a solution for this with the Virgin V6 box? I'm stuggling to find any acceptable option.
 

dante01

Distinguished Member
The V6 and the TiVo both only include a universal Dolby Digital or PCM audio output setting that effects both their HDMI and optical audio output. The STBs have no ability to set their HDMI audio output differently to their optical audio output. You can only either have the audio set to stereo PCM or set to Dolby Digital. The latter option doesn't set all output to Dolby Digital and allows the STBs to output DD when and if present. THe former PCM setting converts all audio to stereo 2 channel PCM.
 

t3rr4nc3

Novice Member
Thanks for that, this was my understanding from reading the above.

I'm curious as to whether people have found creative solutions, or if it's a lost cause. I'm keen to switch my TV service to Virgin as I'm just taking their internet and phone, but if this means two of my three screens get no sound over the HDBaseT system then it's not so smart.

Sadly the Samsung TV models I bought seem to be an anomaly in the Samsung range in that they refuse to decode Dolby Digital. Apparently both earlier and later year models do this happily.

I appreciate the quick response anyhow!
 

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