theora-old/lib/quant_lookup.h

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE.   *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   5  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   6  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   7  *                                                                  *
   8  * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2003                *
   9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13   function:
  14   last mod: $Id$
  15
  16  ********************************************************************/
  17
  18 #include "codec_internal.h"
  19
  20 #define MIN16 ((1<<16)-1)
  21 #define SHIFT16 (1<<16)
  22
  23 #define MIN_LEGAL_QUANT_ENTRY 8
  24 #define MIN_DEQUANT_VAL       2
  25 #define IDCT_SCALE_FACTOR     2 /* Shift left bits to improve IDCT precision */
  26 #define OLD_SCHEME            1
  27
  28 /* lookup table for DCT coefficient zig-zag ordering */
  29 static const ogg_uint32_t dezigzag_index[64] = {
  30   0,  1,  8,  16,  9,  2,  3, 10,
  31   17, 24, 32, 25, 18, 11,  4,  5,
  32   12, 19, 26, 33, 40, 48, 41, 34,
  33   27, 20, 13,  6,  7, 14, 21, 28,
  34   35, 42, 49, 56, 57, 50, 43, 36,
  35   29, 22, 15, 23, 30, 37, 44, 51,
  36   58, 59, 52, 45, 38, 31, 39, 46,
  37   53, 60, 61, 54, 47, 55, 62, 63
  38 };