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Garbled Audio when crt shaders enabled



  • I just discovered that there are a ton of existing shaders already installed with RetroPie and I was playing around with them for my nes system roms.

    These look amazing and work great! Looks just like you are playing on an old tv.

    However, when they are enabled the audio is all garbled like it is having trouble mixing or maybe not getting enough cpu time or the frequency of update is wrong or something.

    Has anyone else run into this? I am running on a Pi 3.

    The specific shader combinations I was trying were:
    system: nes
    crt-pi.glslp
    crt-pi-curvature.glslp

    Both demonstrate the same garbled audio problem when active.
    Audio returns to normal immediately if i disable the shader and apply right in the in-game menus.

    Side Note: Man I had never seen that in-game menu for the nes emulator before. Its amazing! Just like a ps3 or something.



  • Also this only seems to be an issue with that new fancy RetroArch that looks like a ps3 os menu system when you use the in-game menus.

    Basically gb, gba, gbc, nes, snes all demonstrate this issue. But I am able to use shaders without any audio issues on all other systems (that use that older RetroArch with the ugly green menus)



  • Update on this. So not sure why but it appears that this is mainly only an issue if you USE the in-game menus to load a pre-defined shader and enable it. Furthermore, if you save the setting for the current system core it will persist.

    However, if you roll all that back and instead set up your system retroarch.cfg manually like my example here, it appears to work fine:

    Not sure what the dealio is. It also seems like some shaders do cause slowdowns that are noticeable. But again it seems that this is inconsistent and somehow depends on if you had done it via the menus or manually.

    ~/.configs/nes/retroarch.cfg

    # Settings made here will only override settings in the global retroarch.cfg if placed above the #include line
    
    video_fullscreen_x = "1920"
    video_fullscreen_y = "1080"
    custom_viewport_width = "1356"
    custom_viewport_height = "1012"
    custom_viewport_x = "281"
    custom_viewport_y = "27"
    aspect_ratio_index = "22"
    integer_scale = "off"
    window_scale = "5"
    
    input_overlay = "/opt/retropie/emulators/retroarch/overlays/arcade-bezels/tv_80s.cfg"
    input_overlay_enable = "true"
    input_overlay_opacity = "0.900000"
    input_overlay_scale = "1.000000"
    input_remapping_directory = "/opt/retropie/configs/nes/"
    
    video_shader_enable = "true"
    video_shader = "~/.config/retroarch/shaders/crt-pi-curvature.glslp"
    
    #include "/opt/retropie/configs/all/retroarch.cfg"
    

    Edit: Update - Actually it appears that somehow I wiped out some retroarch settings i had for the console such that now the retroarch version that is in use for gb, gba, nes, snes is the old style green menu system. So I think the issue is tied to the updated newer ps3 style menu retroarch. When using that retroarch, audio is garbled when you have shaders enabled.


  • Global Moderator

    the ‘new style’ xmb menu is not enabled in retropie by default. we use the old green menu for these kind of reasons. i guess your configs are all messed up and it’s using default retroarch settings, so all bets are off.



  • @dankcushions said in Garbled Audio when crt shaders enabled:

    the ‘new style’ xmb menu is not enabled in retropie by default. we use the old green menu for these kind of reasons. i guess your configs are all messed up and it’s using default retroarch settings, so all bets are off.

    Yep. I got it fixed now. Not even sure how exactly but I noticed that my nes and gb system cfg files had a ton of stuff in there copied from the default retroarch. I just rebuilt them by hand and all is well now.



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