DD passthrough on phono out?

[Skywatch]

HI,

Is it possible to pass dolby digital out on the phono of the pi? If so how is it done?

Thanks

Skywatch

[rikardo1979]

nope
you can only downmix to stereo and than out over analog

[Skywatch]

Wow! - That was *fast* :-)

But it's not the answer I had hoped for.

TBH I am begining to wonder if the pi is really what I was in need of. I have 3 of them now and they are great little boards, but networking is slow and this latest revelation is a real blow to the HTPC set up I was aiming for.

Still, might be able to find a way around it, but it will be yet more expense.

Thanks for letting me know, I appreciate it!

Skywatch

[rikardo1979]

what you trying to do? what is your plan???

[Dave400]

Dolby digital would be via hdmi out only, hardware couldn't support it from the 3.5mm jack, would be fantastic if it could though.

[Skywatch]

Yes it would be fantastic. ;-)

The plan is needed as the amps and projector don't have HDMI inputs (too old) and I can't afford new ones.

So, I have a HDMI to VGA + Audio splitter to get sound into the system and VGA to the projector. This also gives me better quality audio as the phono out on the pi is not so good quality. So far so good.

But, I can't get DD this way as the audio from the converter has to be connected to the analogue inputs on the amp. If HDMI DD passthrough worked I would still have to unplug the cables from the amp and reconnect them to the DD decoder box each time I wanted to go from film to music. This is not an attractive option! Nor, it seems is a USB DAC a viable solution. :-(

So I was hoping to leave the HDMI audio as stereo analogue and use the phono ouput to connect to the DD decoder and just use the remote to switch between the two. But as Rikardo pointed out this won't work.

I am now wondering if there is another way, maybe I could use a small relay board connected to the pi gpio and have that switch the HDMI out to phono or DD inputs on the amp/decoder. I don't know if the HDMI splitter will allow passthrough of DD. How would I test this?

With the above there is the danger of 'poping' on the audio when the relays operate, but if I ever get the IR control working as well I could mute the amp, then switch, then unmute the amp. But I am months away from getting near to that.

Cheers,

Skywatch.

[rikardo1979]

I was discussing this splitter or switching in one or two threads here on forum some time ago so you may search and look into.
To be honest you have not much choice with your settup im afraid.
Splitter/extractor should be able to extract DD or even DTS but the price of these devices go way about the cist of RPi with all accessories ...

[Skywatch]

Hi Rikardo,

Well the splitter cost me about £25 last year and works well (once you throw away the crappy power supply it came with) so I might give this a go and see.

But I have a question.

DD would be only on 1 channel, right? I only think there's the one input on the decoder so would the pi put an identical signal on both output cables meaning I could use either one? - I am not sure on this.

Cheers!

Skywatch

[mk01]

(30th Jun, 2013 07:42 PM)Skywatch Wrote:  But, I can't get DD this way as the audio from the converter has to be connected to the analogue inputs on the amp. If HDMI DD passthrough worked I would still have to unplug the cables from the amp and reconnect them to the DD decoder box each time I wanted to go from film to music. This is not an attractive option! Nor, it seems is a USB DAC a viable solution. :-(

if you have amplifier with HDMI input, it has video in any form for sure. this is how the AV inbetween source and TV are working as amplifiers, or DD home cinema audio devices.

USB DAC should work, but system level only. XBMC does not support this.

[rikardo1979]

not sure what is your setup like...
Most of the HDMI extractors can pass the A/V out to HDMI and extract the sound from HDMI input and than pass this out over TOSLINK, COAX or 2CH RCA Analog.
Not sure what is your like.
If you want to get the DD sound from extractor into your AV this is possible only in digital form so over Coax or Toslink, not over RCA Analog.
If you go over analog than this is and always will be stereo!
Also Im not sure why would you need to change the cables, or switching the cables when you want to chose between movie and music???
It all depends on the connection basicaly. So if you play a movie with DD soun and your extractor works, and you have digital connection into your AV than you will have a DD sound. If you have only analog RCA than you will have a stereo sound. Music is usually just a stereo so doesnt really matter.

[Skywatch]

Hmmm.....I wonder about this little box......

http://www.ebay.co.uk/itm/Digital-audio-decoder-1-4b-HDMI-Conveters-1080P-HDMI-to-VGA-SPDIF-audio-NEW-/111078943803?pt=US_Video_Cables_Adapt...19dcd22c3b

Has anyone tried one of these with a pi?

Skywatch

[mk01]

(4th Jul, 2013 08:02 AM)Skywatch Wrote:  Has anyone tried one of these with a pi?

Skywatch

should work, why not. but I would not be very optimistic about the D/A quality for VGA output. for 25$ ? )