One thing that keeps annoying me about Soundfonts is that there is no way to specify the initial pitch of an instrument in the instrument itself. The spec defines generators for an "initial attenuation", "initial filter Q and FC", and many more. But there is no such thing when it comes to the initial pitch wheel sensitivity or pitch bend range. Everything completely relies on the default initialization of MIDI RPN0, which is defined to be 2 semitones.
Yet, in order to override it in the soundfont itself, people recommend that one should override the default pitch modulator. This is not an adequate solution! For example, if we have an instrument that should have an initial pitch bend range of +- 4 semitones (rather than the +-2 default), we should go ahead, overriding the default pitch modulator in the instrument's global zone, by doubling its original amount, i.e. giving it an amount of 25400 cents. This works great, as long as there is no MIDI that overrides the default value of RPN0 with anything but 2. Overriding RPN0, in this case, would not lead to overriding the pitch bend range. No, it would lead to a new, most likely bigger pitch bend range. What's a possible solution to this? The soundfont spec has many unused generators. Just take one of them, let's say "unused1", and use it for storing the initial pitch bend range of that particular instrument - relative cents should be used as units, stored as signed int16. Every time when fluidsynth would change the program of a channel, it would read that value and update the fluid_chan::pitch_wheel_sensitivity accordingly. But why is that value signed? To keep backward compatibility with the default value of RPN0 in sync. I.e. To set a default pitch bend range of 5 semitones, the value stored would be 500 cents - 200 cents = 300 cents. Likewise, when there should only be 1 semitone initial bend range, the value stored would be 100 - 200 = -100 cents. Note how nicely this solution would be backward compatible: Soundfonts that do not use this technique would just continue to keep this field 0. Reading back this value and adding 2 semitones would magically result in the default RPN0 initialization as per MIDI spec. Any opinions or comments? Tom _______________________________________________ fluid-dev mailing list fluid-dev@nongnu.org https://lists.nongnu.org/mailman/listinfo/fluid-dev
