I'm not saying sample-accurate, because it turns out, Fluidsynth has an internal buffer size and thus timing granularity of 64 frames. So 64 frames is the max. accuracy attainable for SF2. But it's better than nothing. Big thanks to David Henningsson of the Fluidsynth dev team, who very helpfully answered questions. A great guy.
In addition, there are some fixes to earlier commits here, which I ran into while working on the SF2 timing.
- Remove the redundant hasSampleExactData() function. Instead, signal lack of s.ex.data by returning a NULL in valueBuffer()
- Cache s.ex.buffers and only update them once per period
- Make valueBuffer() in AutomatableModel threadsafe so that it can be used for NPH's sharing the same model
- Add sample-exactness to instrumenttrack's vol & pan knobs
Change in handling of frameoffset for multistreamed instruments and sampletracks.
- Instead of holding the offset for the lifetime of the playhandle, negate the offset in the first period
- Multistream-instruments require some small changes: they have to now check for the offset and accordingly leave empty space in the start of the period (already done in this commit)
- There are possibly optimizations that can be done later
- This change is necessary so that we can have sample-exact models, and sample-exact vol/pan knobs for all instruments. Earlier multistream instruments were always rendering some frames ahead-of-time, so applying sample-exact data for them would have been impossible, since we don't have the future-values yet...
Changing the velocity after noteon doesn't really seem to work on fluidsynth (may be dependent on soundfont file) - seems like the panning changes when velocity is changed.
So I disabled that, after which everything works fine.
Issue: Currently, we use threads to process all PlayHandles, so there's no guarantee of the order they are processed in. This causes timing inaccuracy and jitter: notes of instruments that use both NPH's and IPH's can get randomly delayed by one entire period.
The issue is solved thusly:
- When processing an IPH, we check if the instrument is midi-based. If yes, we just process it normally (no NPH's to worry about).
- If it's not, then it also uses NPH's, so we'll have the IPH wait until all NPH's belonging to same instrument have been processed. There's some similar code in the new FX mixer, I pretty much just copied how we do it there.
- currently only affects Vestige
- no idea whether this can also be used for Zyn and OpulenZ, I'm not sure if Zyn has any kind of mechanism for communicating frame offset to the synth, as for OpulenZ, @softrabbit would know the answer better
- basically, I made it happen by simply adding an extra parameter in the processMidi{In|Out} functions, which is 0 by default, and made the necessary changes in instrumentTrack and nph to utilize it
- I based this against 1.1 because I didn't think it's a very big change, and I don't see much possibility for things going wrong here, since we're basically just using the existing functionality in Vestige (there already was a frame offset being communicated to the remote plugin, just that it was always set to 0). However, if @tobydox thinks this is better to bump up to 1.2, I can rebase it for master...
Also featuring a very efficient buffer-based system for transporting sample-exact control data
Also interpolation for automations
The native Amplifier is a reference implementation for taking advantage of sample-exact data and is currently
the only one that does so, it can be used to test things out, and as documentation/example for implementing the
same elsewhere
