gambatte-libretro/common/rateest.h
sinamas 3a66da4df8 - RateEst: Add a convenient way of filtering measures that extend beyond a buffer time, and are as such
probably invalid.
- RateEst: Allow using a custom timestamp in feed().
- RateEst: Keep a queue of the last ~100 msec worth of samples and duration, and filter out collective
  samples that give a pre-estimate that seems way off.


git-svn-id: https://gambatte.svn.sourceforge.net/svnroot/gambatte@215 9dfb2916-2d38-0410-aef4-c5fe6c9ffc24
2009-01-09 02:07:33 +00:00

74 lines
2.5 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. *
***************************************************************************/
#ifndef RATEEST_H
#define RATEEST_H
#include "usec.h"
#include <deque>
#include <utility>
class RateEst {
public:
struct Result {
long est;
long var;
};
private:
class SumQueue {
typedef std::pair<long, usec_t> pair_t;
typedef std::deque<pair_t> q_t;
q_t q;
long samples_;
usec_t usecs_;
public:
SumQueue() : samples_(0), usecs_(0) {}
void reset();
long samples() const { return samples_; }
usec_t usecs() const { return usecs_; }
void push(long samples, usec_t usecs);
void pop();
};
enum { UPSHIFT = 5 };
enum { UP = 1 << UPSHIFT };
Result srate;
SumQueue sumq;
usec_t last;
usec_t usecs;
usec_t maxPeriod;
long reference;
long samples;
public:
RateEst(long srate = 0) { init(srate); }
RateEst(long srate, long reference) { init(srate, reference); }
void init(long srate) { init(srate, srate); }
void init(long srate, long reference) { init(srate, reference, reference); }
void init(long srate, long reference, long maxSamplePeriod);
void reset() { last = 0; }
void feed(long samples, usec_t usecs = getusecs());
const Result result() const { const Result res = { (srate.est + UP / 2) >> UPSHIFT, (srate.var + UP / 2) >> UPSHIFT }; return res; }
};
#endif