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