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