rgvolume does'nt apply gain using fallback-gain (without Track and Album tags)

Submitted by anthony

Link to original bug (#673970)

Description

Created attachment 211909
rgvolume does'nt apply gain using fallback-gain (without Track and Album tags)

When trying to apply the advised gain (that is the result of rganalysis) by using the fallback-gain property (no ReplayGain tags), the result gain is always near 0 and no normalization is being applied.

The reason is that in this case, the plugin assumes a peak value of 1.0, which makes the clipping prevention mecanism prevent any normalization (because gain + linear_to_db(peak) is always > headroom, in fact in our case here, linear_to_db(1.0) is 0 every time), so as long as the gain is positive, the result gain will always be reduced.

To sum up, the anti-clipping mecanism is counter-productive when the media has no ReplayGain tags: assuming a peak of 1.0 means that the track has full volume, therefore normalization cannot be safely applied (according to the anti-clipping feature).

I propose a patch to change peak value from 1.0 to 0.000001 (linear_to_db(0.000001) = -120, which equals to the maximum appliable gain, i.e. pre-amp + fallback-gain), so that in the case of using fallback-gain, the gain will always be applied.

Patch 211909, "rgvolume does'nt apply gain using fallback-gain (without Track and Album tags)":
0001-BugFix-Change-peak-value-to-normalize-audio-file-wit.patch