http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/wvstreams/wvrateadjust.h

/* -*- 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