From 2ab3d99967d68c79351fe2a3df22c445447e3010 Mon Sep 17 00:00:00 2001 From: Michał Cichoń Date: Tue, 15 Nov 2011 22:28:48 +0100 Subject: Initial import. --- libmad/src/timer.c | 485 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 485 insertions(+) create mode 100644 libmad/src/timer.c (limited to 'libmad/src/timer.c') diff --git a/libmad/src/timer.c b/libmad/src/timer.c new file mode 100644 index 0000000..4b909ab --- /dev/null +++ b/libmad/src/timer.c @@ -0,0 +1,485 @@ +/* + * 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 + +# ifdef HAVE_ASSERT_H +# include +# 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; + } +} -- cgit v1.2.3