| ; |
| ; jdct.inc - private declarations for forward & reverse DCT subsystems |
| ; |
| ; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB |
| ; Copyright (C) 2018, D. R. Commander. |
| ; |
| ; 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 |
| |
| ; 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) |
| %define YMMBLOCK(m, n, b, s) \ |
| ((b) + (m) * DCTSIZE * (s) + (n) * SIZEOF_YMMWORD) |
| |
| ; -------------------------------------------------------------------------- |
