Effect level clip

[derselbst]

Original email to fluid-dev list by David Hilvert:
http://lists.nongnu.org/archive/html/fluid-dev/2007-07/msg00007.html

The following patch moves effect level adjustments prior to the send clip, and
reduces the chorus effect linearly with the number of voices. These changes
seem to make output (volume) levels more uniform; in particular, the phenomenon
of certain instruments with high choral component being several times louder
than those with low choral component seems to be mitigated across a variety of
synthesizer parameter settings.

Notes

- The magnitude of the choral effect for large N is reduced by this patch; some

reduction is also present at smaller N.

- Effect level defaults have been adjusted so that qsynth's center is neutral.

Better might be to balance the scale around 0, with 0 neutral.

- The patch is against version 1.0.7a.

Reported by: elementgreen

Original Ticket: fluidsynth/tickets/2

[derselbst]

Calls to fluid_voice_set_param() in fluid_synth_one_block() should probably be called when reverb/chorus levels are changed. Causes a significant decrease in performance. Currently checked in, but should be modified to update those parameters in a less intrusive manner.

Original comment by: elementgreen

[derselbst]

Reverted this patch since it seemed to make the chorus number parameter have a lessor effect. Leaving open, since something should probably done about the change in chorus volume when modifying parameters.

Original comment by: elementgreen