--- /dev/null
+/*
+ * 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;
+ }
+}
projects / 16.git / blobdiff