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5bbabdcfdd
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
100 lines
3.7 KiB
C++
100 lines
3.7 KiB
C++
/***************************************************************************
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* Copyright (C) 2008 by Sindre Aamås *
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* aamas@stud.ntnu.no *
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License version 2 as *
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* published by the Free Software Foundation. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License version 2 for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* version 2 along with this program; if not, write to the *
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* Free Software Foundation, Inc., *
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* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
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***************************************************************************/
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#ifndef RECTSINC_H
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#define RECTSINC_H
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#include "convoluter.h"
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#include "subresampler.h"
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#include "makesinckernel.h"
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#include "cic2.h"
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#include <cmath>
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#include <cstdlib>
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template<unsigned channels, unsigned phases>
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class RectSinc : public SubResampler {
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PolyPhaseConvoluter<channels, phases> convoluters[channels];
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short *kernel;
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static double rectWin(const long /*i*/, const long /*M*/) {
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return 1;
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}
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void init(unsigned div, unsigned phaseLen, double fc);
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public:
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enum { MUL = phases };
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typedef Cic2<channels> Cic;
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static float cicLimit() { return 2.0f; }
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class RollOff {
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static unsigned toTaps(const float rollOffWidth) {
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static const float widthTimesTaps = 0.9f;
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return std::ceil(widthTimesTaps / rollOffWidth);
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}
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static float toFc(const float rollOffStart, const int taps) {
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static const float startToFcDeltaTimesTaps = 0.43f;
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return startToFcDeltaTimesTaps / taps + rollOffStart;
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}
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public:
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const unsigned taps;
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const float fc;
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RollOff(float rollOffStart, float rollOffWidth) : taps(toTaps(rollOffWidth)), fc(toFc(rollOffStart, taps)) {}
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};
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RectSinc(unsigned div, unsigned phaseLen, double fc) { init(div, phaseLen, fc); }
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RectSinc(unsigned div, RollOff ro) { init(div, ro.taps, ro.fc); }
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~RectSinc() { delete[] kernel; }
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std::size_t resample(short *out, const short *in, std::size_t inlen);
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void adjustDiv(unsigned div);
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unsigned mul() const { return MUL; }
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unsigned div() const { return convoluters[0].div(); }
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};
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template<const unsigned channels, const unsigned phases>
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void RectSinc<channels, phases>::init(const unsigned div, const unsigned phaseLen, const double fc) {
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kernel = new short[phaseLen * phases];
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makeSincKernel(kernel, phases, phaseLen, fc, rectWin);
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for (unsigned i = 0; i < channels; ++i)
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convoluters[i].reset(kernel, phaseLen, div);
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}
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template<const unsigned channels, const unsigned phases>
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std::size_t RectSinc<channels, phases>::resample(short *const out, const short *const in, const std::size_t inlen) {
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std::size_t samplesOut;
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for (unsigned i = 0; i < channels; ++i)
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samplesOut = convoluters[i].filter(out + i, in + i, inlen);
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return samplesOut;
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}
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template<const unsigned channels, const unsigned phases>
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void RectSinc<channels, phases>::adjustDiv(const unsigned div) {
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for (unsigned i = 0; i < channels; ++i)
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convoluters[i].adjustDiv(div);
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}
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#endif
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