1 ; 2 ; jdct.inc - private declarations for forward & reverse DCT subsystems 3 ; 4 ; Copyright 2009 Pierre Ossman <ossman (a] 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
