lr-genesisplus-gx audio problem on Retropie 4.7.1

REK607 · 17 Dec 2020, 20:13

Hello! I recently moved to lr-genesisplus-gx and I was incredibly happy on my raspberry pi 3B with retropie 4.6. I just started a new SD card with retropie 4.7.1 and had the infamous audio issues. The problem looks solved after following the steps in the linked topic as it is not showing before loading the games of my emulators. I only find that megadrive's audio is not working correctly and there's about 15 fps fall. I don't even know if these two problems are linked (?).

I'm using Alsathread (64ms audio latency) and MAME (Enhanced YM3438) on retropie 4.7.1. I also tried varying sound quality from lower to highest with no good result. Emulationstation and Retropie-setup have been updated.

Oh, and games run OK on lr-picodrive.

mitu · 18 Dec 2020, 04:52

@rek607 said in lr-genesisplus-gx audio problem on Retropie 4.7.1:

I only find that megadrive's audio is not working correctly and there's about 15 fps fall. I don't even know if these two problems are linked (?).

I don't think the issues are linked. Can you get a Verbose log from running a game with lr-genesis-plus-gx and post the log on pastebin.com ?

REK607 · 18 Dec 2020, 20:25

Thank you @mitu for your interest :-) It's my first time creating and sharing a verbose log, but I think I've done it properly as you can see here. I tried Sonic & Knuckles game for the test and it's moving at 50-60fps, audio was OK until the game started and you run for rings, jumping platforms and enemies.

mitu · 18 Dec 2020, 21:10

Try removing your shader preset for the core and see if you still get the same slowdown.

REK607 · 18 Dec 2020, 23:13

It worked! So were there many shaders then? I still preserve the content directoru ones and it's working smooth and fine.

dankcushions · 18 Dec 2020, 23:35

@rek607 we can't see what shader you have active but from the pragmas it looks like lcd_zfast. lr-genesis-plus-gx is particularly bandwidth expensive so it's unlikely to work well with any shader. if you change your genesis/megadrive emulator to lr-picodrive it should be able to handle a shader.

BuZz · 19 Dec 2020, 01:25

Can lower your output resolution also - I run at 720p on my 1080p screen and use a scanline shader. I actually think it looks better actually, with the scanlines applied at that resolution and then upscaled. This obviously depends on your screen, but it may be a good compromise.

BuZz · 19 Dec 2020, 01:27

I also wrote this before checking your log. Looks like you may already be running at a lower res - should have checked that first. Having said that I'm sure I've been running this emulator with zfast scanline shader myself without issue but will check (on RPI 3).

REK607 · 19 Dec 2020, 07:38

@buzz thing is on Retropie 4.6 I had not a single issue with shaders or even sound quality, while on 4.7.1 I had to lower these specs in order to make it run and sound smoothly. I'm now testing this on Mega CD and I had to remove shaders, bilinear filtering and put sound quality to normal (then exit the game and run it again), that solves the problem. Is there something else that can be done maybe? As I say on 4.6 I had no issue with my favourite audio and video presets.

mitu · 19 Dec 2020, 07:56

I don't think it's a RetroPie version issue - more likely an emulator update between 4.6 and now that changed the performance of lr-genesis-plus-gx. Do you have the same slowdown with lr-picodrive ?

REK607 · 19 Dec 2020, 08:04

@mitu that makes sense indeed. lr-picrodrive runs flawlessly as always and is my B plan if I can't solve the issue.

dankcushions · 19 Dec 2020, 08:49

@rek607 note that picodrive was the default genesis/megadrive emulator until February this year, so genesis-plus-gx was default in 4.6, but if you updated to 4.6 from an earlier version, you may have been using lr-picodrive.

REK607 · 19 Dec 2020, 18:28

@dankcushions yes! I did the change when I found this new emulator was ported to libretro. At the end I found that the main problem in my lr-genesis-plus-gx performance is the bilinear filter. If I turn it off it's working 58-60 fps with very good sound quality. So as I see it maybe I overloaded my raspberry pi 3B too much, if I'm correct is definitely something to have in mind if you dont have a rpi3B+ or rpi4. SegaCD is working fine too now!