Re: [fluid-dev] Patch for bad MIDI timing (with large buffer sizes)

[Bernat Arlandis i Mañó]

Pedro Lopez-Cabanillas escrigué:
> The patch is not yet ready. Right. But it is an obvious way to solve two very 
> important goals:
>   
I'm not trying to make a judgement, I just want to better understand the 
issues and proposed solutions.
> * MIDI rendering faster than wall clock (ticket #15)
> * Predictable output. Rendering a MIDI sequence several times, to produce  
> exactly the same frame values each time.
>
> I don't agree with you about the locks. In the current implementation, when 
> you render a MIDI file there are two main threads involved:
> * A thread from the audio driver, sending output frames to the audio device. 
> * The timer thread that triggers MIDI events in the Synthesizer.
> Using David' solution, we are eliminating the second thread. There is only one  
> now, so there shouldn't be any locking problems between threads.
>
> About the time resolution, it depends only on FLUID_BUFSIZE (=64 frames), 
> because the timer is triggered in fluid_synth_one_block(). For a sample rate 
> = 44100 Hz the resolution is .68 milliseconds, which is enough for me.
>   
The last three lines explain everything. Thank you, I didn't catch it.

I see the problem just when using OSS, I guess Alsa and Jack override 
the period-size setting.

--
Bernat Arlandis i Mañó