/*
* copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#ifndef FFMPEG_MATHEMATICS_H
-#define FFMPEG_MATHEMATICS_H
+#ifndef AVUTIL_MATHEMATICS_H
+#define AVUTIL_MATHEMATICS_H
#include <stdint.h>
+#include <math.h>
+#include "attributes.h"
#include "rational.h"
+#include "intfloat.h"
+
+#ifndef M_LOG2_10
+#define M_LOG2_10 3.32192809488736234787 /* log_2 10 */
+#endif
+#ifndef M_PHI
+#define M_PHI 1.61803398874989484820 /* phi / golden ratio */
+#endif
+#ifndef NAN
+#define NAN av_int2float(0x7fc00000)
+#endif
+#ifndef INFINITY
+#define INFINITY av_int2float(0x7f800000)
+#endif
+
+/**
+ * @addtogroup lavu_math
+ * @{
+ */
+
enum AVRounding {
- AV_ROUND_ZERO = 0, ///< round toward zero
- AV_ROUND_INF = 1, ///< round away from zero
- AV_ROUND_DOWN = 2, ///< round toward -infinity
- AV_ROUND_UP = 3, ///< round toward +infinity
- AV_ROUND_NEAR_INF = 5, ///< round to nearest and halfway cases away from zero
+ AV_ROUND_ZERO = 0, ///< Round toward zero.
+ AV_ROUND_INF = 1, ///< Round away from zero.
+ AV_ROUND_DOWN = 2, ///< Round toward -infinity.
+ AV_ROUND_UP = 3, ///< Round toward +infinity.
+ AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero.
};
/**
- * rescale a 64bit integer with rounding to nearest.
- * a simple a*b/c isn't possible as it can overflow
+ * Return the greatest common divisor of a and b.
+ * If both a and b are 0 or either or both are <0 then behavior is
+ * undefined.
+ */
+int64_t av_const av_gcd(int64_t a, int64_t b);
+
+/**
+ * Rescale a 64-bit integer with rounding to nearest.
+ * A simple a*b/c isn't possible as it can overflow.
+ */
+int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
+
+/**
+ * Rescale a 64-bit integer with specified rounding.
+ * A simple a*b/c isn't possible as it can overflow.
*/
-int64_t av_rescale(int64_t a, int64_t b, int64_t c);
+int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
/**
- * rescale a 64bit integer with specified rounding.
- * a simple a*b/c isn't possible as it can overflow
+ * Rescale a 64-bit integer by 2 rational numbers.
+ */
+int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
+
+/**
+ * Rescale a 64-bit integer by 2 rational numbers with specified rounding.
+ */
+int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,
+ enum AVRounding) av_const;
+
+/**
+ * Compare 2 timestamps each in its own timebases.
+ * The result of the function is undefined if one of the timestamps
+ * is outside the int64_t range when represented in the others timebase.
+ * @return -1 if ts_a is before ts_b, 1 if ts_a is after ts_b or 0 if they represent the same position
+ */
+int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b);
+
+/**
+ * Compare 2 integers modulo mod.
+ * That is we compare integers a and b for which only the least
+ * significant log2(mod) bits are known.
+ *
+ * @param mod must be a power of 2
+ * @return a negative value if a is smaller than b
+ * a positive value if a is greater than b
+ * 0 if a equals b
*/
-int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding);
+int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod);
/**
- * rescale a 64bit integer by 2 rational numbers.
+ * @}
*/
-int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq);
-#endif /* FFMPEG_MATHEMATICS_H */
+#endif /* AVUTIL_MATHEMATICS_H */
projects / ffmpeg / blobdiff