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5.1 passthrough over TV without hdmi spliter

Posted: Mon May 13, 2013 3:19 pm
by ktarajano
Hello All,

I'm trying to have the most complete MC with the fewer resources, so:

Raspberry Pi + latest openelec as the MC
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HDMI Cable
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Samsung 46es8000 as Display
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Optical SPDIF Cable
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Onkyo 5.1 Receiver

The issue is that the Samsung cannot perform the Multichannel Passthrough so it downmix to 2.0 audio the 5.1 DTS/DD signal.

The issue can be solved using using a hdmi to spdif spliter, but this implies to purchase new hardware and to not have a "clean" installation.

Researching a bit, I came with a possible solution: forcing the RPI to output the 5.1 signal through the HDMI. To do so, I have added the next line to the config.txt file:

Code: Select all

hdmi_force_edid_audio=1
Then the RPI don't ask the tv what are the sound capabilities and theoretically, the TV will passthrough the DTS/DD to the 5.1 Receiver.

And then my surprise: IT WORKS! I just have to change the config in the xbmc player to 5.1 speakers.

Well, said it works is not the real truth. IT ONLY WORKS FOR Dolby Digital AUDIO. The 5.1 DTS files are always downmixed to 2.0.

┬┐Anyone know why this is happening and how to solve it?

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Tue Aug 20, 2013 12:31 am
by dracupg
I have the same issue, but my Dolby Digital (AC-3) plays as stereo.

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Wed Aug 21, 2013 1:23 pm
by masterluke
I think its unlikely you will solve this. The tv can choose to do whatever it likes to the signal as it passes through. Options are...

1) Live with 2.0 audio
2) Get a HDMI->Spdif splitter\extractor
3) Get a new tv which supports DTS passthrough
4) Get a new amp which supports HDMI

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Sun Oct 13, 2013 1:15 pm
by derartz
If you want to get DD and DTS audio output if you have a audio receiver with optical or coaxial input only.
Then buy this splitter and it will work:
http://www.ebay.co.uk/itm/HDMI-4-Ports- ... 3cd6f66456

add this line to the config of your raspberry. (I use xbmc from openelec)
hdmi_force_edid_audio=1

Now ik have PCM 2.0 stereo, Dolby Digital and DTS audio via the audio outputs of the splitter

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Tue May 06, 2014 9:06 pm
by queery
Here is my situation.

I bought a new Samsung HT-F4500 system. It has Optical Audio input.
I bought a splitter, but a different one http://bit.ly/1fRaltz
and connected the HDMI from the RBP to the splitter (IN),
another HDMI to TV (from splitter HDMI out)
and the Toslink cable from the splitter to the HT system which is set on D. IN
I also made sure the splitter has its own power source.
I added hdmi_force_edid_audio=1 , as well as hdmi_drive=2 to the config.txt file in /Flash

When the settings is on HDMI with 2.0 with nothing else selected I get audio from the TV (I thought it would just go to the Optical Audio) and NO audio from the HT system

Changing it to HDMI with 5.1 and nothing else selected gives me static on the TV and NO audio from the HT system

Changing it to HDMI with 5.1 and selecting - (AC3) capable receiver and DTS capable receiver (even if I add output stereo to all speakers), gives me static on the TV and NO audio from the HT system.

I don't know if it is the HT system or the splitter? any ideas?

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Wed May 07, 2014 10:02 am
by masterluke
Could be either your splitter or your HT system. Do you know anyone with a HT system that has an optical input?? you could bring the Pi + splitter to them to test?

What happens if you connect the Pi directly to the tv and allow 5.1 passthrough.. do you get the same static?

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Wed May 07, 2014 12:57 pm
by queery
If I set the rep to HDMI out and 5.1 and plug it into the TV, it still makes the noise when playing a 5.1 movie. Playing a 2.0 movie, it plays the sound properly. The TV is a sh*ty logik TV.

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Wed May 07, 2014 1:01 pm
by queery
I now also played the 2.0 movie going through the splitter and the sound is perfect through the TV. So it is just passing through the splitter. And seems like it's not taking the sound away from the hdmi.

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Wed May 07, 2014 1:16 pm
by masterluke
OK I think its fairly clear the TV is only capable of 2.0 over HDMI and otherwise it will give you the static.

The amplifier should be working via optical though. Either there is a problem with the splitter or a problem with the amplifier. Do you have anything else that outputs an optical signal? Xbox? satellite box? pc? Try that and see if it works. If it does the splitter isn't working. If it doesn't then its the amplifier.

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Thu May 08, 2014 6:57 am
by queery
We unfortunately don't have anything else that works via Optical. We will have to take the system to friends (On Sunday) that I know is using optical to connect their TV with a speaker tube. So can test the splitter using their speaker tune and the HT system using the TV.

Re: 5.1 passthrough over TV without hdmi spliter

Posted: Sun May 11, 2014 5:05 pm
by queery
Hmm... Okay so we took the whole system to a friend, the HT system and splitter was working fine, plugged everything back in and then it just worked.

My theory is that the config.txt was stuck in the swop through the reBoot and only after actually unplugging did the new file or settings kick in.

Will see what happens when we get home.