This adds new LFO modulators:
- these modulators are computed on the fly, instead of using lfo lookup table. Advantages:
- Avoiding a lost of 608272 memory bytes when lfo speed is low (0.3Hz).
- Allows to diminish the lfo speed lower limit to 0.1Hz instead of 0.3Hz.
A speed of 0.1 is interesting for chorus. Using a lookup table for 0.1Hz
would require too much memory (1824816 bytes).
- Make use of first-order all-pass interpolator instead of bandlimited interpolation.
- Although lfo modulator is computed on the fly, cpu load is lower than using
lfo lookup table with bandlimited interpolator.
Also adds a stereo unit controlled by WIDTH macro. WIDTH [0..10] value define a stereo separation between left and right.
- When 0, the output is monophonic.
- When > 0 , the output is stereophonic.
WIDTH is currently fixed to maximum value to provide maximum stereo effect.
`GTimeVal` has been deprecated in glib 2.62 . While switching to `g_get_monotonic_time()`, I realized that we could simply reuse `fluid_utime()` for that purpose.
This provides a less branchy and therefore more instruction-cache-friendly version of fluid_ct2hz(), which also significantly reduces the number of floating-point comparisons.
- memset should clear all the memory
- end position should be at the end of sample data
Closes#576
Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>
The synthesizer is using stdint types for a long time, perhaps for consistency, it would be worth to get rid of the GLIB macros for integer to pointer conversion and viceversa, and use just a type cast for that purpose.
The parameters (roomsize, level, etc.) of the reverb effects unit are initialized at the very end of `new_fluid_synth()` with `fluid_synth_set_reverb_full_LOCAL()`.
This however only adds an update-event to the `rvoice_mixer` queue.
The call to `fluid_synth_process_event_queue()` in `new_fluid_synth()` should make sure, that this event is dispatched and triggers the actual update.
However, the event is not dispatched immediately, because the rvoice event queue has not been committed yet, that is, a call to `fluid_rvoice_eventhandler_flush()` is missing.
So, although a reverb param initialization event has been queued, the reverb params still are garbage initialized (on Windows to some `-6.2774385622041925e+66`).
The next call to through the synth's public API will flush the queue and finally dispatch the update event, but when will it happen?
1. If the soundfont is specified as command-line argument, this call will happen before the audio driver starts rendering.
2. If the soundfont is loaded via shell command `load`, the audio driver will first start rendering audio, after updating the reverb.
Case 1. is trivial, everything works as it should.
Case 2. is interesting. Since the synth already started rendering audio by using that uninitialized reverb unit, the reverb engine's internal buffer is completely filled up with noise. Before outputting that signal to sound card, the sound is clipped to `1.0f`. That's the click we hear at the beginning. And because the reverb is so loud, the rendered audio signal stays 1.0f for quite a long time (...or always, can't tell).
Why is it not reproducible on Linux? Because GCC and Clang (AFAIK) leave all values uninitialized after allocating memory. And because malloc() often return zero-initialized memory, the reverb params seem to be nicely zero-initialized. MSVC however, always initializes memory with garbage, which is why we "hear" this resonance disaster.
Solution: Just update the reverb params via public API, which implicitly calls `fluid_rvoice_eventhandler_flush()`.
Fixes#563.
