libavcodec/cbrt_tablegen.h

   1 /*
   2  * Header file for hardcoded AAC cube-root table
   3  *
   4  * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #ifndef AVCODEC_CBRT_TABLEGEN_H
  24 #define AVCODEC_CBRT_TABLEGEN_H
  25
  26 #include <stdint.h>
  27 #include <math.h>
  28
  29 #if CONFIG_HARDCODED_TABLES
  30 #define cbrt_tableinit()
  31 #include "libavcodec/cbrt_tables.h"
  32 #else
  33 static uint32_t cbrt_tab[1 << 13];
  34
  35 static void cbrt_tableinit(void)
  36 {
  37     if (!cbrt_tab[(1<<13) - 1]) {
  38         int i;
  39         for (i = 0; i < 1<<13; i++) {
  40             union {
  41                 float f;
  42                 uint32_t i;
  43             } f;
  44             f.f = cbrtf(i) * i;
  45             cbrt_tab[i] = f.i;
  46         }
  47     }
  48 }
  49 #endif /* CONFIG_HARDCODED_TABLES */
  50
  51 #endif /* AVCODEC_CBRT_TABLEGEN_H */