/* tick.h - Compute successive integer multiples of a rational * number without long-term rounding error. * (c)2002 by Lennert Buytenhek * File licensed under the GPL, see http://www.fsf.org/ for more info. * Dedicated to Marija Kulikova. */ #include "avcodec.h" typedef struct Ticker { int value; int inrate; int outrate; int div; int mod; } Ticker; extern void ticker_init(Ticker *tick, INT64 inrate, INT64 outrate); static inline int ticker_tick(Ticker *tick, int num) { int n = num * tick->div; tick->value += num * tick->mod; #if 1 if (tick->value > 0) { n += (tick->value / tick->inrate); tick->value = tick->value % tick->inrate; if (tick->value > 0) { tick->value -= tick->inrate; n++; } } #else while (tick->value > 0) { tick->value -= tick->inrate; n++; } #endif return n; } static inline INT64 ticker_abs(Ticker *tick, int num) { INT64 n = (INT64) num * tick->div; INT64 value = (INT64) num * tick->mod; if (value > 0) { n += (value / tick->inrate); value = value % tick->inrate; if (value > 0) { /* value -= tick->inrate; */ n++; } } return n; }