Re: [fluid-dev] FluidSynth backend for SDL_mixer

[James Le Cuirot]

Just want to give an update and new patch for this SDL_mixer backend.
The tempo issue has now been ironed out. Using the sample timer instead
of the system timer (which I should have done in the first place)
allows me to call fluid_sequencer_set_time_scale from within a callback.

Matt Giuca said he'd look into making FluidSynth read MIDI from a
buffer, rendering half my code redundant (yay!) but I haven't heard
back from him yet.

I now use SDL's own audio conversion functions, which should be fine,
but there's still something very wrong with the sample rate and it
looks like FluidSynth is at least part of the problem.

When I made the adjustment to 1.1.1 to allow sample rates as low as
11025Hz, Rise of the Triad sounded correct. However, I have since tried
making the same adjustment to 1.1.2 and also tried 1.1.3 where David
has committed the change upstream (to 8000Hz) and it's back to playing
at half speed/pitch again. I tested against the patch I originally sent
here in case one my own changes were to blame. I also went back to
1.1.1 just to double check.

If you try this latest patch against 1.1.1, you'll also notice that
everything is a piano! This is probably some other FluidSynth bug
that's already been fixed. I've seen this happen intermittently with
the command line player.

I have tried to adjust the sample rate using SDL's audio conversion
functions instead of FluidSynth but this just seems to make it even
slower! At least I think that's what's happening, it's barely
recognisable by that point. It's possible that I haven't got that stuff
quite right but this is a separate issue. No conversion happens
normally because it isn't necessary.

The pitch on D1X-Rebirth is also still slightly out with all the
FluidSynth versions I've mentioned above. I'm not sure whether this is
related to the other sample rate problem. It's worth mentioning that
the command line player does play the MIDI files I have from this game
at the right pitch.

James

sdl-mixer-fluidsynth.patch
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