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 7 ; x86 SIMD extension for IJG JPEG library 8 ; Copyright (C) 1999-2006, MIYASAKA Masaru. 9 ; For conditions of distribution and use, see copyright notice in jsimdext.inc 10 ; 11 ; [TAB8] 12 13 ; Each IDCT routine is responsible for range-limiting its results and 14 ; converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could 15 ; be quite far out of range if the input data is corrupt, so a bulletproof 16 ; range-limiting step is required. We use a mask-and-table-lookup method 17 ; to do the combined operations quickly. 18 ; 19 %define RANGE_MASK (MAXJSAMPLE * 4 + 3) ; 2 bits wider than legal samples 20 21 %define ROW(n,b,s) ((b)+(n)*(s)) 22 %define COL(n,b,s) ((b)+(n)*(s)*DCTSIZE) 23 24 %define DWBLOCK(m,n,b,s) ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_DWORD) 25 %define MMBLOCK(m,n,b,s) ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_MMWORD) 26 %define XMMBLOCK(m,n,b,s) ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_XMMWORD) 27 28 ; -------------------------------------------------------------------------- 29
