HOW-TO: HDMI sound on x86 builds

RyanHardy

After having some troubles with sound in batocera myself I created a little how-to that I'd like to share.
My guide is base on the post of @wfelix75 (https://batocera-linux.xorhub.com/forum/d/40-volume-state-not-saved-when-reboot/10), so all credits should go to him.

Short summary of the problem: My Nvidia ION-based computer did not play sounds via HDMI connected monitors. If I opened Kodi and changed audio output to the correct HDMI output (#2 in my case), I had sound, even in the emulators. But I would have to do this on every reboot.
So with some simple commands I created a custom audio configuration that gets loaded upon startup. Here are the commands needed:

F4
CTRL + ALT + F2
User: root
Password: linux
(I have to input it twice, don't know why)

mount –o remount,rw /
alsamixer
-> unmute the right port (SPDIF 2 in my case), unmute with the comma key
mkdir /var/lib/alsa
alsactl store
cp /var/lib/alsa/asound.state /recalbox/share/system/asound.state
nano /etc/init.d/S99custom
-> add: alsactl restore –f /recalbox/share/system/asound.state
/recalbox/scripts/recalbox-save-overlay.sh

That's it. Now the configuration will be loaded every time and you can enjoy audio via HDMI.

jayplusone

RyanHardy I created this account just to thank you and OP! I have been looking everywhere on how to fix the Nvidia hdmi sound issue and this fixes it.

nadenislamarre

hi,
thanks a lot for this feed back.
i will add these commands automatically at boot and at shutdown to simplify the process (ie, just have to configure in alsamixer if needed)

RyanHardy

That's good to know - thank you!

gabrielferro

This tutorial works with VGA HDMi ?

RyanHardy

VGA and HDMI don't get together - either you use VGA (as in analog connector) or HDMI. I guess what you mean with VGA is the graphics card itself, right? If so then yes, this workaround should be just fine for you.

gabrielferro

My sound all time volume set to zero (0)
When i open kody sound is ok.
Whats the problem with batocera, i cant chance volume to 100.

nadenislamarre

@gabrielferro can you test this test version and tell me if the problem is fixed please : http://batocera-linux.xorhub.com/upgrades/special13
you can upgrade from command line with /recalbox/scripts/recalbox-upgrade.sh http://batocera-linux.xorhub.com/upgrades/special13
or just by unzipping the boot.tar.xz file on your sdcard from any computer.

myron

Owning an ION on my own and having the same issue.

How should the test version work?
Installed ok, reboot, no changes.
Checked alsamixer, exited, rebooted, same 😐
Other steps needed to trigger that new functionality?!?

For reference:
Here's my alsaconfig saved with above command
asound.state after start, before Kodi workaround: https://pastebin.com/Me4xRet9
asound.state after Kodi https://pastebin.com/1j0b2W2S

If you diff them, you'll see only ONE difference - there seems a mixer for PCM created, which i do not have prior!
After a fresh batocera start, i cannot "control" my PCM device in alsamixer, since it's not visible!
After Kodi workaround, it's there and everything works as expected...

hth
br
Myron

nadenislamarre

@myron nice found.
something that would be very nice : how to do the same as kodi does (add the pcm) on command line without kodi. I note to do searches, but if you found, you're welcome ;-)

nadenislamarre

@RyanHardy alsa store/restore added for batocera 5.11, thanks.

myron

some additional info:
Box has 2 sound "cards": ALC888 for Jack and optical, and NVidia for HDMI
after setting GUI, the /recalbox/share/system/.asoundrc contains correctly card=1 (nvidia) and selected device=7.
So my default alsa device has been set, "aplay some.wav" works!!

Unfortunately, this HDMI card has no mixer labelled "Master" (but some others!)
("amixer -cget Master" throws an error)
This is the problem, since ES looks especially for this name here:
https://github.com/nadenislamarre/recalbox-emulationstation/blob/batocera-5.X/es-app/src/VolumeControl.cpp#L10
(and fails with message in line 105)

So the final issue is, either to change the implementation, or to force some "Master" mixer creation?

.
.
.

But!
It seems, that i needed to unmute only the correct device!!!

amixer -c1 sset 'IEC958',1 unmute

or via alsamixer does the trick for me.
Even ES complaining about failing mixer on startup, i have immediate sound 🙂

Now we just need to unmute the correct (sub)device based on settings....awww

myron

ok, to better summarize my weird posts 😛

missing mixer seems only to be needed for GUI volume control (might not be available through HDMI)
Kodi does create a mixer, but on other card - so not relevant
Kodi DOES UNMUTE selected output <== this is the real deal

Furthermore, this "problem" is very hardware dependent, and might not be the same for other/all x86 devices!

myron

can we merge another sound related fix?
https://github.com/recalbox/recalbox-buildroot/commit/bb7e2d6b0d7a606dee5b73e3bed2756ab86f8431#diff-abc1b6e2b40fca2be8eb88e30ea7b17e
Seems to be good, to check before set, instead of letting the script die...

FerrisBueller

so, how can this issue be fixed for EVERYONE??
can anyone tell me what to do?

rdraven

Sorry new to Linux. I followed the steps but after I comma to Unmute, I don’t know how to save and continue the command lines. Could someone please explain to me those steps. Thank you

Retro-Schulzi

@myron: Sorry, the Pastebin Links are down, can you please reupload them?

GameCast

on batocera interface, just press STRL+F5 or F4 not sure, you will enter on your sound devices press f6 for choose sound driver, choose your HD driver sound wich you ussing on pc, after that activate from M to 00 ..
before exit just increase the volume on the devices list ..exit, activate HDMI0, restart and sound will works greate .

Gonzalitro

Press ctrl+Alt+F6, activate sounds with M key..