/usr/include/wvstreams/wvrateadjust.h is in libwvstreams-dev 4.6.1-12~deb9u1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | /* -*- Mode: C++ -*-
* Worldvisions Weaver Software:
* Copyright (C) 1997-2002 Net Integration Technologies, Inc.
*
* WvRateAdjust is a WvEncoder that makes sure data comes out of it at a
* given average rate. It adds duplicate samples or removes extra samples
* from the input in order to achieve this.
*
* The current version doesn't do anything fancy like linear or spline
* interpolation, since it's being built mainly for minor rate adjustments
* like 8000 Hz to 8020 Hz, and interpolation probably doesn't help too
* much there. It's also nicer to not have to worry explicitly about the
* number format, which you would have to do if you were doing actual math.
*
* You can also use this as a slightly (not terribly) inefficient rate
* *estimator* for the input stream.
*
* NOTE: Time is of the essence of this encoder.
*/
#ifndef __WVRATEADJUST_H
#define __WVRATEADJUST_H
#include "wvencoder.h"
#include "wvtimeutils.h"
class WvRateAdjust : public WvEncoder
{
public:
WvRateAdjust *match_rate;
int sampsize, irate_n, irate_d, orate_n, orate_d;
WvTime epoch; // the time when sampling started
// the token bucket holds the "remainder" of our fake integer division
// operation. With this, we can make sure we always average out to
// exactly the right rate.
//
// Basically:
// bucket = ((orate*insamps) - (irate*outsamps)) * irate_d * orate_d
//
// ...but with some care thrown in to prevent overflows.
int bucket;
WvRateAdjust(int _sampsize, int _irate_base, int _orate);
WvRateAdjust(int _sampsize, int _irate_base, WvRateAdjust *_match_rate);
int getirate()
{ return irate_n / irate_d; }
int getorate()
{ return orate_n / orate_d; }
protected:
void init(int _sampsize, int _irate_base);
virtual bool _encode(WvBuf &inbuf, WvBuf &outbuf, bool flush);
};
#endif // __WVRATEADJUST_H
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