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