Retroarch: (Audio) Reverb-related audio filters are broken

[ghost]

First and foremost consider this:
Only RetroArch bugs should be filed here. Not core bugs or game bugs
This is not a forum or a help section, this is strictly developer oriented
Description
Using audio filters that uses reverb (reverb, echoreverb, chiptuneenhanced) sound is really distorted and not right.

Expected behavior
should cool, warm reverb sounds

Actual behavior
sounds are distorted and unlistenable (is this a word?) @orbea corfims the issue in #retroarch iirc

Steps to reproduce the bug
*play a game
*load any of those 3 filters
*get ready to scream

Bisect Results
[Try to bisect and tell us when this started happening]

Version/Commit
You can find this information under Information/System Information

RetroArch: 1.7.3
Environment information
OS: Arch Linux
Compiler: gcc version 8.1.1 20180531 (GCC)

[orbea]

My issue is a little bit different, these three audio filters do not have sound at all or one time reverb had sound only in the right speaker, but I could not reproduce this behavior.

I tried bisecting to v1.3.6 without finding a good commit, but I did not try to rebuild the filters. I will retry the bisect later.

The log prints this which seems relevant.

[ERROR] Softfilter does not support input format.
[ERROR] [SoftFitler]: Failed to create softfilter graph...
[ERROR] [Video]: Failed to load filter.

[orbea]

Can you please not close valid issue reports?

[hizzlekizzle]

It's usually not a matter of coding skill/experience, but rather having the time and inclination to look into something and pin it down. Most bug-fixes are just a few lines or less.

[orbea]

@retro-wertz fwiw, my collaborator status is just to help maintain the source release tarballs. :)

[ghost]

@orbea 1st bad commit: https://github.com/libretro/libretro-common/commit/8ecf19887a035853e8cb173b3a297b114de3455c#diff-4df94854f253a1fbcbabf6e890064c3a

in default pulse audio, sounds are totally wrong. other audio drivers does not even output sound when an audio filter that uses reverb is used.

@twinaphex @mudlord can please check this? thanks.

[ghost]

Thanks for the precise report of where it went wrong.

I should look into this on Sunday.

[ghost]

thanks.

not sure why this is tagged only as linux issue but this should be an issue in windows as well...

[ghost]

https://github.com/libretro/libretro-common/pull/84

I looked into this a bit earlier. Was quite an adventure into learning more about Linux devel, too.

[ghost]

thanks. should be working now as of 7c22f265

[orbea]

@mudlord This does not appear to work here, instead there is no sound with reverb now and I will hear a single pop when toggling the RetroArch menu.

[ghost]

@orbea sorry to ask, but did you recompile libretro-common/audio/dsp_filters and used those new ones for audio filters? i have tested this on linux arch and debian

[orbea]

No, I didn't! Sorry for the noise and thanks for pointing out the obvious which I missed, it all works now...

[ghost]

Thanks dudes, I'm happy a fix of mine is now working.