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