libavcodec/dcamath.h

   1 /*
   2  * This file is part of Libav.
   3  *
   4  * Libav is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * Libav is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with Libav; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #include "libavutil/common.h"
  20
  21
  22 // clip a signed integer into the (-2^23), (2^23-1) range
  23 static inline int dca_clip23(int a)
  24 {
  25     return av_clip_intp2(a, 23);
  26 }
  27
  28 static inline int32_t dca_norm(int64_t a, int bits)
  29 {
  30     if (bits > 0)
  31         return (int32_t)((a + (INT64_C(1) << (bits - 1))) >> bits);
  32     else
  33         return (int32_t)a;
  34 }
  35
  36 static inline int64_t dca_round(int64_t a, int bits)
  37 {
  38     if (bits > 0)
  39         return (a + (INT64_C(1) << (bits - 1))) & ~((INT64_C(1) << bits) - 1);
  40     else
  41         return a;
  42 }