Sound issues over HDMI (works fine using analogue out)

[J.Beau]

Hey guys!

First of all, I would like to thank you guys for your hard work. I'm having a blast with RetroPie and the various games I can play with it! There's lots of information in the wiki of the forums that makes it even better. However, I have not been able to solve this one:

I was running RetroPie on an old CRT tv and everything worked well. Yesterday I switched over to an HD tv. All the emulators and games work, except for the Vectrex. The screen flickers a lot and the sound is almost completely gone. I hear some 'bleeps', but there's no startup chime for example. What could have caused this? I haven't changed anything (except an overscan setting in the /boot/config.txt).

I'm using the lr-vecx emulator for the Vectrex. I have a Raspberry Pi 3B with Raspberry Pi powersupply.
I run RetroPie 4.1 downloaded from RetroPie website. There are no USB devices connected, only an 8bitdo SNES30 bluetooth controller. I can't find an error message.

Any ideas?

Thanks!

[J.Beau]

I ran it on a fresh RetroPie installation (image from the website) yesterday. Problem is still there. Maybe it has something to do with the tv?

[J.Beau]

This is what's in the runcommand.log:

Parameters: 
Executing: /opt/retropie/emulators/retroarch/bin/retroarch -L /opt/retropie/libretrocores/lr-vecx/vecx_libretro.so --config /opt/retropie/configs/vectrex/retroarch.cfg "/home/pi/RetroPie/roms/vectrex/Spinball.vec" --appendconfig /dev/shm/retroarch.cfg

Nothing special right?

[J.Beau]

Okay. I kind of fixed it. Turns out NES audio was choppy too. Since I switched from an SD tv to HDMI, I thought of disabling sound from the HDMI and switching to the analogue audio out. To do this, I had to input the following line into the /boot/config.txt:

hdmi_drive=1

This forces DVI mode, so my tv will read the audio from the analogue in. I had to boost the audio signal quite a lot, but... this worked perfectly! NES audio was smooth, Vectrex audio works fine now and even the Atari 2600 emulator makes sounds I haven't heard before! I also put in:

disable_audio_dither=1

I was hearing some white noise, but this fixed it.

Question is: why does the audio from the Genesis emulator work fine over HDMI, but the rest of them have issues? Is there a way to make them all work over HDMI?

[edmaul69]

@J.Beau you dont need hdmi_drive=1. Switch it back to 2. Then when emulationstation boots, go into the retropie menu and go into audio setting. Switch the audio there. You can swap back and forth that way.

[J.Beau]

@edmaul69 It needs drive=1, because otherwise my tv won't read the audio signal from the analogue in. That port only works when HDMI in in DVI mode.

[edmaul69]

@J.Beau i know it wont recognize normally from analog while hdmi is on without a setting. But the audio configuration lets you enable it without the need to change the config.txt so you can switch back and forth without the need to change the code.

[J.Beau]

@edmaul69 That didn't work for me. That only works when I connect external speakers or headphones. If the signal to the the tv is not in DVI mode, the tv itself does nothing with audio received on other ports. I hope you understand what I mean. English is not my first language. The other question remains. Why does the sound work without a problem over analogue but does it have troubles with some emulators over HDMI?

[edmaul69]

@J.Beau when you were on hdmi audio did you try hdmi_drive=2 before doing 1? Also you could put a hashtag # in front of that line to disable it and try to see if this works on hdmi mode:

hdmi_force_edid_audio=1

[edmaul69]

@J.Beau also just realized something. Did you try setting your tv into game mode? That can cause this too. And a good chance it is the problem.

[J.Beau]

@edmaul69 Yes, tried them both. Was trying everything to get sound working over HDMI for the last 3 days, before I came up with the idea of using an extra cable. Used this page a lot: http://elinux.org/RPiconfig.

[J.Beau]

Can I change the topic title? It wasn't really a Vectrex issue, but a sound over HDMI issue.

[edmaul69]

@J.Beau did you see my last post about setting your tv's game mode on? Not sure if you tried that or not?

[edmaul69]

@J.Beau yes you can change the title

[J.Beau]

@edmaul69 Yes, tried the game mode. Thanks!