The gain should be positive for an upward compressor. Initially, the
gain would be zeroe'd below -60 dB to ensure noise is not amplified by
the upward compressor. This created a discontinuity at -60 dB since
just above -60 dB, the audio is boosted by +20 dB (at default
settings). This was fixed in commit 50db097 which decreased smoothly
the gain so that it's 0 dB at -60 dB. However that commit forgot to
limit the gain decrease which was negative below -60 dB.
This is fixed by the current commit.
Additionally initialization allowed -inf gain. We hard limit to positive
gains only as they should be for an upward compressor.
The bugfix was found by R1ch and put in form by pkv.
Co-authored-by: pkv <pkv@obsproject.com>
Signed-off-by: pkv <pkv@obsproject.com>