Chris@0: /*
Chris@0:  * libmad - MPEG audio decoder library
Chris@0:  * Copyright (C) 2000-2004 Underbit Technologies, Inc.
Chris@0:  *
Chris@0:  * This program is free software; you can redistribute it and/or modify
Chris@0:  * it under the terms of the GNU General Public License as published by
Chris@0:  * the Free Software Foundation; either version 2 of the License, or
Chris@0:  * (at your option) any later version.
Chris@0:  *
Chris@0:  * This program is distributed in the hope that it will be useful,
Chris@0:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Chris@0:  * GNU General Public License for more details.
Chris@0:  *
Chris@0:  * You should have received a copy of the GNU General Public License
Chris@0:  * along with this program; if not, write to the Free Software
Chris@0:  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
Chris@0:  *
Chris@0:  * $Id: timer.c,v 1.18 2004/01/23 09:41:33 rob Exp $
Chris@0:  */
Chris@0: 
Chris@0: # ifdef HAVE_CONFIG_H
Chris@0: #  include "config.h"
Chris@0: # endif
Chris@0: 
Chris@0: # include "global.h"
Chris@0: 
Chris@0: # include <stdio.h>
Chris@0: 
Chris@0: # ifdef HAVE_ASSERT_H
Chris@0: #  include <assert.h>
Chris@0: # endif
Chris@0: 
Chris@0: # include "timer.h"
Chris@0: 
Chris@0: mad_timer_t const mad_timer_zero = { 0, 0 };
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->compare()
Chris@0:  * DESCRIPTION:	indicate relative order of two timers
Chris@0:  */
Chris@0: int mad_timer_compare(mad_timer_t timer1, mad_timer_t timer2)
Chris@0: {
Chris@0:   signed long diff;
Chris@0: 
Chris@0:   diff = timer1.seconds - timer2.seconds;
Chris@0:   if (diff < 0)
Chris@0:     return -1;
Chris@0:   else if (diff > 0)
Chris@0:     return +1;
Chris@0: 
Chris@0:   diff = timer1.fraction - timer2.fraction;
Chris@0:   if (diff < 0)
Chris@0:     return -1;
Chris@0:   else if (diff > 0)
Chris@0:     return +1;
Chris@0: 
Chris@0:   return 0;
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->negate()
Chris@0:  * DESCRIPTION:	invert the sign of a timer
Chris@0:  */
Chris@0: void mad_timer_negate(mad_timer_t *timer)
Chris@0: {
Chris@0:   timer->seconds = -timer->seconds;
Chris@0: 
Chris@0:   if (timer->fraction) {
Chris@0:     timer->seconds -= 1;
Chris@0:     timer->fraction = MAD_TIMER_RESOLUTION - timer->fraction;
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->abs()
Chris@0:  * DESCRIPTION:	return the absolute value of a timer
Chris@0:  */
Chris@0: mad_timer_t mad_timer_abs(mad_timer_t timer)
Chris@0: {
Chris@0:   if (timer.seconds < 0)
Chris@0:     mad_timer_negate(&timer);
Chris@0: 
Chris@0:   return timer;
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	reduce_timer()
Chris@0:  * DESCRIPTION:	carry timer fraction into seconds
Chris@0:  */
Chris@0: static
Chris@0: void reduce_timer(mad_timer_t *timer)
Chris@0: {
Chris@0:   timer->seconds  += timer->fraction / MAD_TIMER_RESOLUTION;
Chris@0:   timer->fraction %= MAD_TIMER_RESOLUTION;
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	gcd()
Chris@0:  * DESCRIPTION:	compute greatest common denominator
Chris@0:  */
Chris@0: static
Chris@0: unsigned long gcd(unsigned long num1, unsigned long num2)
Chris@0: {
Chris@0:   unsigned long tmp;
Chris@0: 
Chris@0:   while (num2) {
Chris@0:     tmp  = num2;
Chris@0:     num2 = num1 % num2;
Chris@0:     num1 = tmp;
Chris@0:   }
Chris@0: 
Chris@0:   return num1;
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	reduce_rational()
Chris@0:  * DESCRIPTION:	convert rational expression to lowest terms
Chris@0:  */
Chris@0: static
Chris@0: void reduce_rational(unsigned long *numer, unsigned long *denom)
Chris@0: {
Chris@0:   unsigned long factor;
Chris@0: 
Chris@0:   factor = gcd(*numer, *denom);
Chris@0: 
Chris@0:   assert(factor != 0);
Chris@0: 
Chris@0:   *numer /= factor;
Chris@0:   *denom /= factor;
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	scale_rational()
Chris@0:  * DESCRIPTION:	solve numer/denom == ?/scale avoiding overflowing
Chris@0:  */
Chris@0: static
Chris@0: unsigned long scale_rational(unsigned long numer, unsigned long denom,
Chris@0: 			     unsigned long scale)
Chris@0: {
Chris@0:   reduce_rational(&numer, &denom);
Chris@0:   reduce_rational(&scale, &denom);
Chris@0: 
Chris@0:   assert(denom != 0);
Chris@0: 
Chris@0:   if (denom < scale)
Chris@0:     return numer * (scale / denom) + numer * (scale % denom) / denom;
Chris@0:   if (denom < numer)
Chris@0:     return scale * (numer / denom) + scale * (numer % denom) / denom;
Chris@0: 
Chris@0:   return numer * scale / denom;
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->set()
Chris@0:  * DESCRIPTION:	set timer to specific (positive) value
Chris@0:  */
Chris@0: void mad_timer_set(mad_timer_t *timer, unsigned long seconds,
Chris@0: 		   unsigned long numer, unsigned long denom)
Chris@0: {
Chris@0:   timer->seconds = seconds;
Chris@0:   if (numer >= denom && denom > 0) {
Chris@0:     timer->seconds += numer / denom;
Chris@0:     numer %= denom;
Chris@0:   }
Chris@0: 
Chris@0:   switch (denom) {
Chris@0:   case 0:
Chris@0:   case 1:
Chris@0:     timer->fraction = 0;
Chris@0:     break;
Chris@0: 
Chris@0:   case MAD_TIMER_RESOLUTION:
Chris@0:     timer->fraction = numer;
Chris@0:     break;
Chris@0: 
Chris@0:   case 1000:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION /  1000);
Chris@0:     break;
Chris@0: 
Chris@0:   case 8000:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION /  8000);
Chris@0:     break;
Chris@0: 
Chris@0:   case 11025:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION / 11025);
Chris@0:     break;
Chris@0: 
Chris@0:   case 12000:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION / 12000);
Chris@0:     break;
Chris@0: 
Chris@0:   case 16000:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION / 16000);
Chris@0:     break;
Chris@0: 
Chris@0:   case 22050:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION / 22050);
Chris@0:     break;
Chris@0: 
Chris@0:   case 24000:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION / 24000);
Chris@0:     break;
Chris@0: 
Chris@0:   case 32000:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION / 32000);
Chris@0:     break;
Chris@0: 
Chris@0:   case 44100:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION / 44100);
Chris@0:     break;
Chris@0: 
Chris@0:   case 48000:
Chris@0:     timer->fraction = numer * (MAD_TIMER_RESOLUTION / 48000);
Chris@0:     break;
Chris@0: 
Chris@0:   default:
Chris@0:     timer->fraction = scale_rational(numer, denom, MAD_TIMER_RESOLUTION);
Chris@0:     break;
Chris@0:   }
Chris@0: 
Chris@0:   if (timer->fraction >= MAD_TIMER_RESOLUTION)
Chris@0:     reduce_timer(timer);
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->add()
Chris@0:  * DESCRIPTION:	add one timer to another
Chris@0:  */
Chris@0: void mad_timer_add(mad_timer_t *timer, mad_timer_t incr)
Chris@0: {
Chris@0:   timer->seconds  += incr.seconds;
Chris@0:   timer->fraction += incr.fraction;
Chris@0: 
Chris@0:   if (timer->fraction >= MAD_TIMER_RESOLUTION)
Chris@0:     reduce_timer(timer);
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->multiply()
Chris@0:  * DESCRIPTION:	multiply a timer by a scalar value
Chris@0:  */
Chris@0: void mad_timer_multiply(mad_timer_t *timer, signed long scalar)
Chris@0: {
Chris@0:   mad_timer_t addend;
Chris@0:   unsigned long factor;
Chris@0: 
Chris@0:   factor = scalar;
Chris@0:   if (scalar < 0) {
Chris@0:     factor = -scalar;
Chris@0:     mad_timer_negate(timer);
Chris@0:   }
Chris@0: 
Chris@0:   addend = *timer;
Chris@0:   *timer = mad_timer_zero;
Chris@0: 
Chris@0:   while (factor) {
Chris@0:     if (factor & 1)
Chris@0:       mad_timer_add(timer, addend);
Chris@0: 
Chris@0:     mad_timer_add(&addend, addend);
Chris@0:     factor >>= 1;
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->count()
Chris@0:  * DESCRIPTION:	return timer value in selected units
Chris@0:  */
Chris@0: signed long mad_timer_count(mad_timer_t timer, enum mad_units units)
Chris@0: {
Chris@0:   switch (units) {
Chris@0:   case MAD_UNITS_HOURS:
Chris@0:     return timer.seconds / 60 / 60;
Chris@0: 
Chris@0:   case MAD_UNITS_MINUTES:
Chris@0:     return timer.seconds / 60;
Chris@0: 
Chris@0:   case MAD_UNITS_SECONDS:
Chris@0:     return timer.seconds;
Chris@0: 
Chris@0:   case MAD_UNITS_DECISECONDS:
Chris@0:   case MAD_UNITS_CENTISECONDS:
Chris@0:   case MAD_UNITS_MILLISECONDS:
Chris@0: 
Chris@0:   case MAD_UNITS_8000_HZ:
Chris@0:   case MAD_UNITS_11025_HZ:
Chris@0:   case MAD_UNITS_12000_HZ:
Chris@0:   case MAD_UNITS_16000_HZ:
Chris@0:   case MAD_UNITS_22050_HZ:
Chris@0:   case MAD_UNITS_24000_HZ:
Chris@0:   case MAD_UNITS_32000_HZ:
Chris@0:   case MAD_UNITS_44100_HZ:
Chris@0:   case MAD_UNITS_48000_HZ:
Chris@0: 
Chris@0:   case MAD_UNITS_24_FPS:
Chris@0:   case MAD_UNITS_25_FPS:
Chris@0:   case MAD_UNITS_30_FPS:
Chris@0:   case MAD_UNITS_48_FPS:
Chris@0:   case MAD_UNITS_50_FPS:
Chris@0:   case MAD_UNITS_60_FPS:
Chris@0:   case MAD_UNITS_75_FPS:
Chris@0:     return timer.seconds * (signed long) units +
Chris@0:       (signed long) scale_rational(timer.fraction, MAD_TIMER_RESOLUTION,
Chris@0: 				   units);
Chris@0: 
Chris@0:   case MAD_UNITS_23_976_FPS:
Chris@0:   case MAD_UNITS_24_975_FPS:
Chris@0:   case MAD_UNITS_29_97_FPS:
Chris@0:   case MAD_UNITS_47_952_FPS:
Chris@0:   case MAD_UNITS_49_95_FPS:
Chris@0:   case MAD_UNITS_59_94_FPS:
Chris@0:     return (mad_timer_count(timer, -units) + 1) * 1000 / 1001;
Chris@0:   }
Chris@0: 
Chris@0:   /* unsupported units */
Chris@0:   return 0;
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->fraction()
Chris@0:  * DESCRIPTION:	return fractional part of timer in arbitrary terms
Chris@0:  */
Chris@0: unsigned long mad_timer_fraction(mad_timer_t timer, unsigned long denom)
Chris@0: {
Chris@0:   timer = mad_timer_abs(timer);
Chris@0: 
Chris@0:   switch (denom) {
Chris@0:   case 0:
Chris@0:     return timer.fraction ?
Chris@0:       MAD_TIMER_RESOLUTION / timer.fraction : MAD_TIMER_RESOLUTION + 1;
Chris@0: 
Chris@0:   case MAD_TIMER_RESOLUTION:
Chris@0:     return timer.fraction;
Chris@0: 
Chris@0:   default:
Chris@0:     return scale_rational(timer.fraction, MAD_TIMER_RESOLUTION, denom);
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	timer->string()
Chris@0:  * DESCRIPTION:	write a string representation of a timer using a template
Chris@0:  */
Chris@0: void mad_timer_string(mad_timer_t timer,
Chris@0: 		      char *dest, char const *format, enum mad_units units,
Chris@0: 		      enum mad_units fracunits, unsigned long subparts)
Chris@0: {
Chris@0:   unsigned long hours, minutes, seconds, sub;
Chris@0:   unsigned int frac;
Chris@0: 
Chris@0:   timer = mad_timer_abs(timer);
Chris@0: 
Chris@0:   seconds = timer.seconds;
Chris@0:   frac = sub = 0;
Chris@0: 
Chris@0:   switch (fracunits) {
Chris@0:   case MAD_UNITS_HOURS:
Chris@0:   case MAD_UNITS_MINUTES:
Chris@0:   case MAD_UNITS_SECONDS:
Chris@0:     break;
Chris@0: 
Chris@0:   case MAD_UNITS_DECISECONDS:
Chris@0:   case MAD_UNITS_CENTISECONDS:
Chris@0:   case MAD_UNITS_MILLISECONDS:
Chris@0: 
Chris@0:   case MAD_UNITS_8000_HZ:
Chris@0:   case MAD_UNITS_11025_HZ:
Chris@0:   case MAD_UNITS_12000_HZ:
Chris@0:   case MAD_UNITS_16000_HZ:
Chris@0:   case MAD_UNITS_22050_HZ:
Chris@0:   case MAD_UNITS_24000_HZ:
Chris@0:   case MAD_UNITS_32000_HZ:
Chris@0:   case MAD_UNITS_44100_HZ:
Chris@0:   case MAD_UNITS_48000_HZ:
Chris@0: 
Chris@0:   case MAD_UNITS_24_FPS:
Chris@0:   case MAD_UNITS_25_FPS:
Chris@0:   case MAD_UNITS_30_FPS:
Chris@0:   case MAD_UNITS_48_FPS:
Chris@0:   case MAD_UNITS_50_FPS:
Chris@0:   case MAD_UNITS_60_FPS:
Chris@0:   case MAD_UNITS_75_FPS:
Chris@0:     {
Chris@0:       unsigned long denom;
Chris@0: 
Chris@0:       denom = MAD_TIMER_RESOLUTION / fracunits;
Chris@0: 
Chris@0:       frac = timer.fraction / denom;
Chris@0:       sub  = scale_rational(timer.fraction % denom, denom, subparts);
Chris@0:     }
Chris@0:     break;
Chris@0: 
Chris@0:   case MAD_UNITS_23_976_FPS:
Chris@0:   case MAD_UNITS_24_975_FPS:
Chris@0:   case MAD_UNITS_29_97_FPS:
Chris@0:   case MAD_UNITS_47_952_FPS:
Chris@0:   case MAD_UNITS_49_95_FPS:
Chris@0:   case MAD_UNITS_59_94_FPS:
Chris@0:     /* drop-frame encoding */
Chris@0:     /* N.B. this is only well-defined for MAD_UNITS_29_97_FPS */
Chris@0:     {
Chris@0:       unsigned long frame, cycle, d, m;
Chris@0: 
Chris@0:       frame = mad_timer_count(timer, fracunits);
Chris@0: 
Chris@0:       cycle = -fracunits * 60 * 10 - (10 - 1) * 2;
Chris@0: 
Chris@0:       d = frame / cycle;
Chris@0:       m = frame % cycle;
Chris@0:       frame += (10 - 1) * 2 * d;
Chris@0:       if (m > 2)
Chris@0: 	frame += 2 * ((m - 2) / (cycle / 10));
Chris@0: 
Chris@0:       frac    = frame % -fracunits;
Chris@0:       seconds = frame / -fracunits;
Chris@0:     }
Chris@0:     break;
Chris@0:   }
Chris@0: 
Chris@0:   switch (units) {
Chris@0:   case MAD_UNITS_HOURS:
Chris@0:     minutes = seconds / 60;
Chris@0:     hours   = minutes / 60;
Chris@0: 
Chris@0:     sprintf(dest, format,
Chris@0: 	    hours,
Chris@0: 	    (unsigned int) (minutes % 60),
Chris@0: 	    (unsigned int) (seconds % 60),
Chris@0: 	    frac, sub);
Chris@0:     break;
Chris@0: 
Chris@0:   case MAD_UNITS_MINUTES:
Chris@0:     minutes = seconds / 60;
Chris@0: 
Chris@0:     sprintf(dest, format,
Chris@0: 	    minutes,
Chris@0: 	    (unsigned int) (seconds % 60),
Chris@0: 	    frac, sub);
Chris@0:     break;
Chris@0: 
Chris@0:   case MAD_UNITS_SECONDS:
Chris@0:     sprintf(dest, format,
Chris@0: 	    seconds,
Chris@0: 	    frac, sub);
Chris@0:     break;
Chris@0: 
Chris@0:   case MAD_UNITS_23_976_FPS:
Chris@0:   case MAD_UNITS_24_975_FPS:
Chris@0:   case MAD_UNITS_29_97_FPS:
Chris@0:   case MAD_UNITS_47_952_FPS:
Chris@0:   case MAD_UNITS_49_95_FPS:
Chris@0:   case MAD_UNITS_59_94_FPS:
Chris@0:     if (fracunits < 0) {
Chris@0:       /* not yet implemented */
Chris@0:       sub = 0;
Chris@0:     }
Chris@0: 
Chris@0:     /* fall through */
Chris@0: 
Chris@0:   case MAD_UNITS_DECISECONDS:
Chris@0:   case MAD_UNITS_CENTISECONDS:
Chris@0:   case MAD_UNITS_MILLISECONDS:
Chris@0: 
Chris@0:   case MAD_UNITS_8000_HZ:
Chris@0:   case MAD_UNITS_11025_HZ:
Chris@0:   case MAD_UNITS_12000_HZ:
Chris@0:   case MAD_UNITS_16000_HZ:
Chris@0:   case MAD_UNITS_22050_HZ:
Chris@0:   case MAD_UNITS_24000_HZ:
Chris@0:   case MAD_UNITS_32000_HZ:
Chris@0:   case MAD_UNITS_44100_HZ:
Chris@0:   case MAD_UNITS_48000_HZ:
Chris@0: 
Chris@0:   case MAD_UNITS_24_FPS:
Chris@0:   case MAD_UNITS_25_FPS:
Chris@0:   case MAD_UNITS_30_FPS:
Chris@0:   case MAD_UNITS_48_FPS:
Chris@0:   case MAD_UNITS_50_FPS:
Chris@0:   case MAD_UNITS_60_FPS:
Chris@0:   case MAD_UNITS_75_FPS:
Chris@0:     sprintf(dest, format, mad_timer_count(timer, units), sub);
Chris@0:     break;
Chris@0:   }
Chris@0: }