[fluid-dev] Fluid_synth_write and sequencer queries

[sqweek]

Hi folks,

Thanks for fluid-synth! I've been using it for the midi side of a
transcription program I'm developing. To ensure the midi notes are
synchronized with the audio stream, I'm using fluid_synth_write_s16
and mixing the streams together myself.

I have it working, but I haven't quite grasped _which_ samples the
fluid_synth_write call returns. Do they return the present state of
the synthesizer (ie. the returned samples should be played
immediately), or does it return the most recently rendered samples
that have yet to be retrieved by a _write call? (or is there some
other semantics?)

Secondly, my crude implementation results in some midi events being
triggered up to 4095 frames too early or too late; the plan is to use
fluid-synth's sequencer API to fix this. Is it reasonable to use the
frame number directly as the sequencer's 'tick' (ie.
fluid_sequencer_set_time_scale(seq, 1.0/44100.0) ) or is that too
fine?

Cheers,
-sqweek