GZDoom: Reports about sounds being muffled with 1.24.1

[madame-rachelle]

For Windows, OpenAL 1.24.1 was bundled with the GZDoom 4.14.0 release. I am getting reports about sounds being more muffled and people are saying multiple people are experiencing this issue.

Original issue: ZDoom/gzdoom#2865

Original binary bundle that was previously uploaded:gzdoom-4-14-0-windows.zip

[Doom2fan]

Seems like something happened that changed GZDoom's default resampler, it sounds the same as it always did if you set it to Nearest or Linear resampling, and the "Default" and "4-Point Gaussian" options sound the same.

[kcat]

It's probably the effect of the new gaussian resampler that was added and made the default with 1.24. It has slightly more high-frequency attenuation to combat aliasing distortion compared to the previous default, which is more pronounced with lower quality (lower sample rate) sounds since it has a more limited frequency range to work with.

The previous default, "Cubic Spline", should still be selectable with GZDoom's resampler option. As well as the Linear resampler that was the default before that, and the Nearest resampler that doesn't even try to deal with the aliasing noise and results in more "bright" sounds (reminiscent of old games with software mixing on weak CPUs). Alternatively, the BSinc resamplers are there also, which better removes aliasing noise with a tighter transition band, at the cost of more CPU use.

[QmwJlHuSg9pa]

Just adding my observation that the new default (gaussian) makes Halo CE perceivably muffled, from voice-overs to gun shots (as compared to the old default, spline). How either option compares to the game on original PC hardware I do not know, though I am of the opinion that, relatively speaking, spline more accurately reflects what is occurring on the Xbox version (sample).

[kcat]

Compared to hardware, I wager 23rd order Sinc (or 23rd order Sinc (fast)) would be closer. At least, I remember reading some years ago of a Creative engineer mention some hardware using 22-point resampling, where both spline and gaussian are 4-point, and 23rd order Sinc is 24-point (which can increase up to 48-point when down-sampling).

Given the number of reports I've received about sounds being noticeably muffled for some people with games that use lower sample rate sounds, I'll likely revert it back to Cubic Spline (Gaussian will still be there as an option, and still be used in places where high-frequency attenuation will happen anyway and aliasing distortion is more likely to be audible).

[NOOTLORD]

I want to report that UT2004 also suffers from the same issue, lower sample rate sounds sound really muffled with 1.24.0 and 1.24.1. The issue is fixed in 1.24.1-530aee88

[mirh]

Fixed by 745d221 then I guess

[kcat]

1.24.2 has been released now, with Cubic Spline as the default resampler.