/*
* Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
*
- * 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 AVUTIL_INTMATH_H
#define AVUTIL_INTMATH_H
+#include <stdint.h>
#include "config.h"
-#include "common.h"
-
-#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
+#include "attributes.h"
-#ifndef av_log2
+/**
+ * @addtogroup lavu_internal
+ * @{
+ */
-#define av_log2(x) (31 - __builtin_clz((x)|1))
+extern const uint32_t ff_inverse[257];
-#ifndef av_log2_16bit
-#define av_log2_16bit av_log2
+#if ARCH_ARM
+# include "arm/intmath.h"
+#elif ARCH_X86
+# include "x86/intmath.h"
#endif
+#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
+
+#ifndef av_log2
+# define av_log2(x) (31 - __builtin_clz((x)|1))
+# ifndef av_log2_16bit
+# define av_log2_16bit av_log2
+# endif
#endif /* av_log2 */
#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */
+#ifndef FASTDIV
+# if CONFIG_FASTDIV
+# define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32))
+# else
+# define FASTDIV(a,b) ((a) / (b))
+# endif
+#endif /* FASTDIV */
+
+#include "common.h"
+
+extern const uint8_t ff_sqrt_tab[256];
+
+static inline av_const unsigned int ff_sqrt(unsigned int a)
+{
+ unsigned int b;
+
+ if (a < 255) return (ff_sqrt_tab[a + 1] - 1) >> 4;
+ else if (a < (1 << 12)) b = ff_sqrt_tab[a >> 4] >> 2;
+#if !CONFIG_SMALL
+ else if (a < (1 << 14)) b = ff_sqrt_tab[a >> 6] >> 1;
+ else if (a < (1 << 16)) b = ff_sqrt_tab[a >> 8] ;
+#endif
+ else {
+ int s = av_log2_16bit(a >> 16) >> 1;
+ unsigned int c = a >> (s + 2);
+ b = ff_sqrt_tab[c >> (s + 8)];
+ b = FASTDIV(c,b) + (b << s);
+ }
+
+ return b - (a < b * b);
+}
+
+/**
+ * @}
+ */
#endif /* AVUTIL_INTMATH_H */