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