]> git.sesse.net Git - ffmpeg/blobdiff - libavutil/mathematics.c
mem: introduce av_malloc_array and av_mallocz_array
[ffmpeg] / libavutil / mathematics.c
index 91ade22571a881155f609275325aad97a6ff4894..e2f06eda296b750f39a7e0e68c0c7b969f092391 100644 (file)
@@ -1,31 +1,31 @@
 /*
  * 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
  */
 
 /**
- * @file mathematics.c
- * Miscellaneous math routines and tables.
+ * @file
+ * miscellaneous math routines and tables
  */
 
 #include <assert.h>
-#include "avutil.h"
-#include "common.h"
+#include <stdint.h>
+#include <limits.h>
 #include "mathematics.h"
 
 const uint8_t ff_sqrt_tab[256]={
@@ -50,22 +50,35 @@ const uint8_t ff_log2_tab[256]={
         7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
 };
 
+const uint8_t av_reverse[256]={
+0x00,0x80,0x40,0xC0,0x20,0xA0,0x60,0xE0,0x10,0x90,0x50,0xD0,0x30,0xB0,0x70,0xF0,
+0x08,0x88,0x48,0xC8,0x28,0xA8,0x68,0xE8,0x18,0x98,0x58,0xD8,0x38,0xB8,0x78,0xF8,
+0x04,0x84,0x44,0xC4,0x24,0xA4,0x64,0xE4,0x14,0x94,0x54,0xD4,0x34,0xB4,0x74,0xF4,
+0x0C,0x8C,0x4C,0xCC,0x2C,0xAC,0x6C,0xEC,0x1C,0x9C,0x5C,0xDC,0x3C,0xBC,0x7C,0xFC,
+0x02,0x82,0x42,0xC2,0x22,0xA2,0x62,0xE2,0x12,0x92,0x52,0xD2,0x32,0xB2,0x72,0xF2,
+0x0A,0x8A,0x4A,0xCA,0x2A,0xAA,0x6A,0xEA,0x1A,0x9A,0x5A,0xDA,0x3A,0xBA,0x7A,0xFA,
+0x06,0x86,0x46,0xC6,0x26,0xA6,0x66,0xE6,0x16,0x96,0x56,0xD6,0x36,0xB6,0x76,0xF6,
+0x0E,0x8E,0x4E,0xCE,0x2E,0xAE,0x6E,0xEE,0x1E,0x9E,0x5E,0xDE,0x3E,0xBE,0x7E,0xFE,
+0x01,0x81,0x41,0xC1,0x21,0xA1,0x61,0xE1,0x11,0x91,0x51,0xD1,0x31,0xB1,0x71,0xF1,
+0x09,0x89,0x49,0xC9,0x29,0xA9,0x69,0xE9,0x19,0x99,0x59,0xD9,0x39,0xB9,0x79,0xF9,
+0x05,0x85,0x45,0xC5,0x25,0xA5,0x65,0xE5,0x15,0x95,0x55,0xD5,0x35,0xB5,0x75,0xF5,
+0x0D,0x8D,0x4D,0xCD,0x2D,0xAD,0x6D,0xED,0x1D,0x9D,0x5D,0xDD,0x3D,0xBD,0x7D,0xFD,
+0x03,0x83,0x43,0xC3,0x23,0xA3,0x63,0xE3,0x13,0x93,0x53,0xD3,0x33,0xB3,0x73,0xF3,
+0x0B,0x8B,0x4B,0xCB,0x2B,0xAB,0x6B,0xEB,0x1B,0x9B,0x5B,0xDB,0x3B,0xBB,0x7B,0xFB,
+0x07,0x87,0x47,0xC7,0x27,0xA7,0x67,0xE7,0x17,0x97,0x57,0xD7,0x37,0xB7,0x77,0xF7,
+0x0F,0x8F,0x4F,0xCF,0x2F,0xAF,0x6F,0xEF,0x1F,0x9F,0x5F,0xDF,0x3F,0xBF,0x7F,0xFF,
+};
+
 int64_t av_gcd(int64_t a, int64_t b){
     if(b) return av_gcd(b, a%b);
     else  return a;
 }
 
-#if LIBAVUTIL_VERSION_MAJOR < 50
-int64_t ff_gcd(int64_t a, int64_t b){
-    return av_gcd(a, b);
-}
-#endif
-
 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
     int64_t r=0;
     assert(c > 0);
     assert(b >=0);
-    assert(rnd >=0 && rnd<=5 && rnd!=4);
+    assert((unsigned)rnd<=5 && rnd!=4);
 
     if(a<0 && a != INT64_MIN) return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd>>1)&1));
 
@@ -117,37 +130,30 @@ int64_t av_rescale(int64_t a, int64_t b, int64_t c){
     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
 }
 
-int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
+int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,
+                         enum AVRounding rnd)
+{
     int64_t b= bq.num * (int64_t)cq.den;
     int64_t c= cq.num * (int64_t)bq.den;
-    return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
+    return av_rescale_rnd(a, b, c, rnd);
 }
 
-#ifdef TEST
-#include "integer.h"
-#undef printf
-int main(void){
-    int64_t a,b,c,d,e;
-
-    for(a=7; a<(1LL<<62); a+=a/3+1){
-        for(b=3; b<(1LL<<62); b+=b/4+1){
-            for(c=9; c<(1LL<<62); c+=(c*2)/5+3){
-                int64_t r= c/2;
-                AVInteger ai;
-                ai= av_mul_i(av_int2i(a), av_int2i(b));
-                ai= av_add_i(ai, av_int2i(r));
-
-                d= av_i2int(av_div_i(ai, av_int2i(c)));
-
-                e= av_rescale(a,b,c);
-
-                if((double)a * (double)b / (double)c > (1LL<<63))
-                    continue;
+int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
+{
+    return av_rescale_q_rnd(a, bq, cq, AV_ROUND_NEAR_INF);
+}
 
-                if(d!=e) printf("%"PRId64"*%"PRId64"/%"PRId64"= %"PRId64"=%"PRId64"\n", a, b, c, d, e);
-            }
-        }
-    }
+int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b){
+    int64_t a= tb_a.num * (int64_t)tb_b.den;
+    int64_t b= tb_b.num * (int64_t)tb_a.den;
+    if (av_rescale_rnd(ts_a, a, b, AV_ROUND_DOWN) < ts_b) return -1;
+    if (av_rescale_rnd(ts_b, b, a, AV_ROUND_DOWN) < ts_a) return  1;
     return 0;
 }
-#endif
+
+int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod){
+    int64_t c= (a-b) & (mod-1);
+    if(c > (mod>>1))
+        c-= mod;
+    return c;
+}