X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Fmathematics.h;h=043dd0fafea85034edef9079c8662f815409ab48;hb=73f5e17a203713c4ac4e5a821809823b383b195f;hp=fa407b61116c87cea02f71db5dbc410170794bdc;hpb=2119bb8f51d5cbf946d8e87974a2d95016133942;p=ffmpeg

diff --git a/libavutil/mathematics.h b/libavutil/mathematics.h
index fa407b61116..043dd0fafea 100644
--- a/libavutil/mathematics.h
+++ b/libavutil/mathematics.h
@@ -1,52 +1,111 @@
 /*
  * 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 */