gambatte-libretro/common/adaptivesleep.cpp
sinamas 5bbabdcfdd - Real-time, sophisticated resampling framework with several performance/quality profiles for dynamically generated windowed sinc and CIC chains based on analysis of
fourier transforms and optimal cost equations. Fast 2-tap linear as a low quality alternative.
- libgambatte: Use deltas and a running sum to decrease buffer writes in sound emulation sample generation.
- libgambatte: Rearrange sound emulation event loop to optimize for high-frequency event units.
- libgambatte: Initialize palette arrays to avoid valgrind noise.
- Don't do resampling in libgambatte. Update API to reflect this.
- Move non-emulation common code to a common directory to avoid duplication.
- Update front-ends to new libgambatte API.
- Utilize resampling framework in front-ends. Selectable resamplers.
- Improved adaptive sleep class that estimates oversleep.
- Gambatte SDL: Estimate actual output sample rate in terms of OS timers and derive frame rate from it.
- Gambatte SDL: Move AudioData and RingBuffer classes to separate files.
- Gambatte SDL: Make underruns slightly less painful, by resetting buffer positions.
- Gambatte Qt: Update AudioEngine to support sample rate estimation in terms of OS timers.
- Gambatte Qt: Implement sample rate estimation in ALSA and OSS audio engines.
- Gambatte Qt: AlsaEngine: Revert to using snd_pcm_avail_update for buffer status since snd_pcm_delay may consider external latencies.
- Gambatte Qt: AlsaEngine: Use snd_pcm_hw_params_set_buffer_time_near. Don't request a particular number of periods per buffer.
- Gambatte Qt: AlsaEngine: Use hw as default custom device string, rather than hw:0,0.
- Gambatte Qt: OssEngine: Don't trust GETOSPACE fragment info.
- Gambatte Qt: Estimate optimal frame rate based on sample rate estimations.
- Gambatte Qt: Extend BlitterWidget to support estimation of vsynced frame rate in terms of OS timers.
- Gambatte Qt: Implement vsync frame rate estimation in QGlBlitter, Direct3DBlitter and DirectDrawBlitter.
- Gambatte Qt: Use a combination of OS timer sample rate estimation and vsync frame rate estimation to derive resampling ratio for no-frame-duplication vsync.
- Gambatte Qt: Change API to reflect MediaSources not being responsible for resampling.
- Gambatte Qt: Make sure to parent PaletteDialog list model, so it gets deleted properly.
- Various refactoring, small changes and stuff I forgot.


git-svn-id: https://gambatte.svn.sourceforge.net/svnroot/gambatte@165 9dfb2916-2d38-0410-aef4-c5fe6c9ffc24
2008-10-13 21:08:08 +00:00

57 lines
2.2 KiB
C++

/***************************************************************************
* Copyright (C) 2008 by Sindre Aamås *
* aamas@stud.ntnu.no *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License version 2 as *
* published by the Free Software Foundation. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License version 2 for more details. *
* *
* You should have received a copy of the GNU General Public License *
* version 2 along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#include "adaptivesleep.h"
usec_t AdaptiveSleep::sleepUntil(usec_t base, usec_t inc) {
usec_t now = getusecs();
usec_t diff = now - base;
if (diff >= inc)
return diff - inc;
diff = inc - diff;
if (diff > oversleep + oversleepVar) {
diff -= oversleep + oversleepVar;
usecsleep(diff);
const usec_t ideal = now + diff;
now = getusecs();
{
usec_t curOversleep = now - ideal;
if (negate(curOversleep) < curOversleep)
curOversleep = 0;
oversleepVar = (oversleepVar * 15 + (curOversleep < oversleep ? oversleep - curOversleep : curOversleep - oversleep)) >> 4;
oversleep = (oversleep * 15 + curOversleep) >> 4;
}
noSleep = 60;
} else if (--noSleep == 0) {
noSleep = 60;
oversleep = oversleepVar = 0;
}
while (now - base < inc)
now = getusecs();
return 0;
}