1; 2; jdct.inc - private declarations for forward & reverse DCT subsystems 3; 4; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB 5; 6; Based on the x86 SIMD extension for IJG JPEG library 7; Copyright (C) 1999-2006, MIYASAKA Masaru. 8; For conditions of distribution and use, see copyright notice in jsimdext.inc 9; 10; [TAB8] 11 12; Each IDCT routine is responsible for range-limiting its results and 13; converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could 14; be quite far out of range if the input data is corrupt, so a bulletproof 15; range-limiting step is required. We use a mask-and-table-lookup method 16; to do the combined operations quickly. 17; 18%define RANGE_MASK (MAXJSAMPLE * 4 + 3) ; 2 bits wider than legal samples 19 20%define ROW(n,b,s) ((b)+(n)*(s)) 21%define COL(n,b,s) ((b)+(n)*(s)*DCTSIZE) 22 23%define DWBLOCK(m,n,b,s) ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_DWORD) 24%define MMBLOCK(m,n,b,s) ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_MMWORD) 25%define XMMBLOCK(m,n,b,s) ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_XMMWORD) 26 27; -------------------------------------------------------------------------- 28