[fluid-dev] stereo sounds and panning

[Antoine Schmitt]

Hi all,
I'm wondering about the usage of fluidsynth to pan stereo sounds.

The way I integrate sounds samples in fluidXtra (pluging for Adobe  
Director) without using sfonts is by creating a ramsfont preset which  
contains the sample. That was actually the first reason to introduce  
the ramsfont in fluidsynth.

I have a problem for panning stero sounds using this method. WHat I do  
for stereo sounds is creating a ramsfont preset with two samples  
attached to the preset, one fully pre-panned to the left and the other  
one fully pre-panned to the right, using generators :

			fluid_ramsfont_izone_set_gen(ramsf, bank, presetNum, sampleL,  
GEN_PAN, -500.);
			fluid_ramsfont_izone_set_gen(ramsf, bank, presetNum, sampleR,  
GEN_PAN, 500.);

This is fine until I try to dynamically pan the preset. If I fully pan  
it to the left for exemple, it adds -500 to the pre-pan on both  
samples, and the left sample gets panned to -1000, which gets maxed to  
-500, and the right sample gets panned to 0. This gives a preset that  
sounds 50% panned to the left, and not 100% to the left as one would  
expect.

I'm not sure, first of the right behavior for panning on stereo  
sounds, and second on the best way to do it either using fluidsynth  
API as it is, if possible, and if not how to modify fluidsynth to do  
the right thing, using for example, the FLUID_SAMPLETYPE_RIGHT and  
FLUID_SAMPLETYPE_LEFT values for the sampletype member of the  
_fluid_sample_t struct, which are not used anywhere in fluidsynth  
actually.

Any idea ?
Thanks

++ as :: Antoine Schmitt