ejarosek
Posts: 29
Joined: Mon Aug 27, 2012 6:39 pm

RPi4: 4k60 video on one hdmi, audio pass through on other?

Sat Jun 29, 2019 1:42 pm

So, I ran out and grabbed the new Raspberry PI 4 when they came into stock at Microcenter to enable 4k HEVC content on my 4k TV. In the process of setting it up I ran into an issue. Apparently my receiver, even though it will output 4k, will not allow a 4k input. If I plug the RPi directly into the TV the 4k works great but the ARC only support PCM PII so I lose my surround.

So, the question: would it be possible to have the PI push the video through one HDMI port (maintaining 4kp60) to the TV directly and the audio through the other port directly to the receiver?

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Sun Jun 30, 2019 8:55 am

This is on my list of things to look at. It's a useful use case. Cannot give any schedule though.
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cocodude
Posts: 3
Joined: Thu Sep 26, 2019 9:15 pm

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Thu Sep 26, 2019 9:18 pm

I've been trying to do exactly this.

It does seem to work in general; I can quite easily get 4kp60 video out on HDMI 0 and some sound out on HDMI 1 (if I right click on the speaker icon on the desktop and change the output to HDMI 1). However, whatever I try, I think I can only send two channel PCM to this. I can't passthrough any other sources like Dolby Digital using Kodi, VLC or anything really.

Passthrough appears to work just fine when both video and sound are going through HDMI 0.

armyofme
Posts: 45
Joined: Sat Jan 12, 2013 11:28 am

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Thu Nov 21, 2019 9:05 pm

Does anyone know if there has been any progress on this issue? Would be great to have passthrough on hdmi 1.

vazma
Posts: 2
Joined: Mon Dec 16, 2019 2:00 pm

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Mon Dec 16, 2019 2:05 pm

I am very interested also in order to forward video to an output (projector) and the sound to another rpi with hifiberry and from there to my sound system. Lets see if there is any similar case..

Cheers,

Vasilis

vazma
Posts: 2
Joined: Mon Dec 16, 2019 2:00 pm

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Mon Dec 16, 2019 6:05 pm

I am very interested also in order to forward video to an output (projector) and the sound to another rpi with hifiberry and from there to my sound system. Lets see if there is any similar case..

Cheers,

Vasilis

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Mon Dec 16, 2019 8:21 pm

You can set the audio out to which ever HDMI port you want, even if video goes to the other one. Just select the required port from the audio option on the task bar.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
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armyofme
Posts: 45
Joined: Sat Jan 12, 2013 11:28 am

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Mon Dec 23, 2019 7:19 pm

But it doesn't work for pass through :( Passthrough only works when video and audio are both on hdmi0.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 26695
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Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Mon Dec 23, 2019 9:43 pm

armyofme wrote:
Mon Dec 23, 2019 7:19 pm
But it doesn't work for pass through :( Passthrough only works when video and audio are both on hdmi0.
Ah, that sounds likely. Not quite sure how passthrough works.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

sking
Posts: 1
Joined: Fri Dec 20, 2019 9:07 am

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Sun Dec 29, 2019 4:11 am

cocodude wrote:
Thu Sep 26, 2019 9:18 pm
I've been trying to do exactly this.

It does seem to work in general; I can quite easily get 4kp60 video out on HDMI 0 and some sound out on HDMI 1 (if I right click on the speaker icon on the desktop and change the output to HDMI 1). However, whatever I try, I think I can only send two channel PCM to this. I can't passthrough any other sources like Dolby Digital using Kodi, VLC or anything really.

Passthrough appears to work just fine when both video and sound are going through HDMI 0.
i have the same result,HDMI 1can hear,but only two channel

croft
Posts: 55
Joined: Fri Dec 13, 2019 4:58 pm

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Fri Feb 07, 2020 4:19 pm

hi
can vlc be set to send sound through av sound output

i have not found a anser yet

thanks

croft

dorian-ny
Posts: 66
Joined: Fri Nov 01, 2019 11:29 pm

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Fri Apr 17, 2020 7:53 pm

As long as your audio receiver supports surround LPCM over HDMI there is no need for passthrough. The audio signal will be decoded by the Raspberry and sent over raw LPCM multichannel.

armyofme
Posts: 45
Joined: Sat Jan 12, 2013 11:28 am

Re: RPi4: 4k60 video on one hdmi, audio pass through on other?

Sat Jul 25, 2020 10:53 am

This has now been achieved in the latest nightly of Libreelec - I now have passthrough on HDMI2! Hoping it won't be long before it's also working on the Raspberry OS too :)

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