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Published 20 hours ago • verified publisher icon schellingb

Convert attenuation from centibels to decibels

Open spazzylemons opened this issue 1 year ago • 0 comments

Attenuation is currently used as a decibel value. However, the SoundFont Technical Specification describes initialAttenuation as being in centibels. Due to this, regions with a nonzero attenuation value are much quieter than they should be. This simple fix divides the attenuation by 10 when calculating note gain to perform the conversion.

Note how the lead organ in this MIDI (about 20 seconds in) is far quieter before the change, but after the change, it much more closely resembles FluidSynth's output.

Before fix:

https://github.com/schellingb/TinySoundFont/assets/25674682/2851a4cd-eeea-44b2-a0bb-c11af4cbc8eb

After fix:

https://github.com/schellingb/TinySoundFont/assets/25674682/6277b128-fb02-4e28-b452-48d0fc46b7f8

FluidSynth for reference:

https://github.com/schellingb/TinySoundFont/assets/25674682/eeeb8753-4b5a-4e01-a617-81aae3241e9e

spazzylemons avatar Feb 13 '24 20:02 spazzylemons