From e2de64d6f1beb9e492daf5b886e19933c1fa41dd Mon Sep 17 00:00:00 2001 From: toma Date: Wed, 25 Nov 2009 17:56:58 +0000 Subject: Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features. BUG:215923 git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdemultimedia@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da --- mpeglib/lib/splay/huffmanlookup.h | 57 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 mpeglib/lib/splay/huffmanlookup.h (limited to 'mpeglib/lib/splay/huffmanlookup.h') diff --git a/mpeglib/lib/splay/huffmanlookup.h b/mpeglib/lib/splay/huffmanlookup.h new file mode 100644 index 00000000..a5bdb26c --- /dev/null +++ b/mpeglib/lib/splay/huffmanlookup.h @@ -0,0 +1,57 @@ + /* + + Copyright (C) 2000 Stefan Westerfeld + stefan@space.twc.de + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public License + along with this library; see the file COPYING.LIB. If not, write to + the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. + + */ + +#ifndef __HUFFMANLOOKUP_H +#define __HUFFMANLOOKUP_H +#include "mpegsound.h" + +/* + * This class speeds up the huffman table decoding by largely replacing it + * by a table lookup. It uses the fact that the huffman tables don't change, + * and that given a byte of the bitstream, we can predict what the result + * will be (without reading it bit by bit). + */ + +class HuffmanLookup { +private: + long pattern, bits; + int wgetbit(); + int wgetbits (int b); + void huffmandecoder_1(const HUFFMANCODETABLE *h,int *x, int *y); + + ATTR_ALIGN(64) static struct decodeData { + int x : 8; + int y : 8; + int skip : 16; + } qdecode[32][256]; +public: + HuffmanLookup(); + + static int decode(int table, int pattern, int* x, int* y) + { + *x = qdecode[table][pattern].x; + *y = qdecode[table][pattern].y; + return qdecode[table][pattern].skip; + } +}; + +#endif -- cgit v1.2.1