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Diffstat (limited to 'kviewshell/plugins/djvu/libdjvu/MMRDecoder.cpp')
| -rw-r--r-- | kviewshell/plugins/djvu/libdjvu/MMRDecoder.cpp | 961 |
1 files changed, 961 insertions, 0 deletions
diff --git a/kviewshell/plugins/djvu/libdjvu/MMRDecoder.cpp b/kviewshell/plugins/djvu/libdjvu/MMRDecoder.cpp new file mode 100644 index 00000000..b14220d1 --- /dev/null +++ b/kviewshell/plugins/djvu/libdjvu/MMRDecoder.cpp @@ -0,0 +1,961 @@ +//C- -*- C++ -*- +//C- ------------------------------------------------------------------- +//C- DjVuLibre-3.5 +//C- Copyright (c) 2002 Leon Bottou and Yann Le Cun. +//C- Copyright (c) 2001 AT&T +//C- +//C- This software is subject to, and may be distributed under, the +//C- GNU General Public License, Version 2. The license should have +//C- accompanied the software or you may obtain a copy of the license +//C- from the Free Software Foundation at http://www.fsf.org . +//C- +//C- This program is distributed in the hope that it will be useful, +//C- but WITHOUT ANY WARRANTY; without even the implied warranty of +//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +//C- GNU General Public License for more details. +//C- +//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library +//C- distributed by Lizardtech Software. On July 19th 2002, Lizardtech +//C- Software authorized us to replace the original DjVu(r) Reference +//C- Library notice by the following text (see doc/lizard2002.djvu): +//C- +//C- ------------------------------------------------------------------ +//C- | DjVu (r) Reference Library (v. 3.5) +//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved. +//C- | The DjVu Reference Library is protected by U.S. Pat. No. +//C- | 6,058,214 and patents pending. +//C- | +//C- | This software is subject to, and may be distributed under, the +//C- | GNU General Public License, Version 2. The license should have +//C- | accompanied the software or you may obtain a copy of the license +//C- | from the Free Software Foundation at http://www.fsf.org . +//C- | +//C- | The computer code originally released by LizardTech under this +//C- | license and unmodified by other parties is deemed "the LIZARDTECH +//C- | ORIGINAL CODE." Subject to any third party intellectual property +//C- | claims, LizardTech grants recipient a worldwide, royalty-free, +//C- | non-exclusive license to make, use, sell, or otherwise dispose of +//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the +//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU +//C- | General Public License. This grant only confers the right to +//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to +//C- | the extent such infringement is reasonably necessary to enable +//C- | recipient to make, have made, practice, sell, or otherwise dispose +//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to +//C- | any greater extent that may be necessary to utilize further +//C- | modifications or combinations. +//C- | +//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY +//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED +//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF +//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. +//C- +------------------------------------------------------------------ +// +// $Id: MMRDecoder.cpp,v 1.8 2003/11/07 22:08:22 leonb Exp $ +// $Name: release_3_5_15 $ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif +#if NEED_GNUG_PRAGMAS +# pragma implementation +#endif + +#include "MMRDecoder.h" +#include "JB2Image.h" +#include "ByteStream.h" +#include "GBitmap.h" + + +#ifdef HAVE_NAMESPACES +namespace DJVU { +# ifdef NOT_DEFINED // Just to fool emacs c++ mode +} +#endif +#endif + + +// ---------------------------------------- +// MMR CODEBOOKS + +static const char invalid_mmr_data[]= ERR_MSG("MMRDecoder.bad_data"); + +struct VLCode +{ + unsigned short code; + short codelen; + short value; +}; + +enum MMRMode +{ + P=0, H=1, V0=2, VR1=3, VR2=4, VR3=5, VL1=6, VL2=7, VL3=8 +}; + +static const VLCode mrcodes[] = +{ // Codes on 7 bits + // 7 bit codes + { 0x08, 4, P }, // 0001 + { 0x10, 3, H }, // 001 + { 0x40, 1, V0 }, // 1 + { 0x30, 3, VR1 }, // 011 + { 0x06, 6, VR2 }, // 000011 + { 0x03, 7, VR3 }, // 0000011 + { 0x20, 3, VL1 }, // 010 + { 0x04, 6, VL2 }, // 000010 + { 0x02, 7, VL3 }, // 0000010 + { 0x00, 0, -1 } // Illegal entry +}; + + +static const VLCode wcodes[] = { + // 13 bit codes + { 0x06a0, 8, 0 }, // 00110101 + { 0x0380, 6, 1 }, // 000111 + { 0x0e00, 4, 2 }, // 0111 + { 0x1000, 4, 3 }, // 1000 + { 0x1600, 4, 4 }, // 1011 + { 0x1800, 4, 5 }, // 1100 + { 0x1c00, 4, 6 }, // 1110 + { 0x1e00, 4, 7 }, // 1111 + { 0x1300, 5, 8 }, // 10011 + { 0x1400, 5, 9 }, // 10100 + { 0x0700, 5, 10 }, // 00111 + { 0x0800, 5, 11 }, // 01000 + { 0x0400, 6, 12 }, // 001000 + { 0x0180, 6, 13 }, // 000011 + { 0x1a00, 6, 14 }, // 110100 + { 0x1a80, 6, 15 }, // 110101 + { 0x1500, 6, 16 }, // 101010 + { 0x1580, 6, 17 }, // 101011 + { 0x09c0, 7, 18 }, // 0100111 + { 0x0300, 7, 19 }, // 0001100 + { 0x0200, 7, 20 }, // 0001000 + { 0x05c0, 7, 21 }, // 0010111 + { 0x00c0, 7, 22 }, // 0000011 + { 0x0100, 7, 23 }, // 0000100 + { 0x0a00, 7, 24 }, // 0101000 + { 0x0ac0, 7, 25 }, // 0101011 + { 0x04c0, 7, 26 }, // 0010011 + { 0x0900, 7, 27 }, // 0100100 + { 0x0600, 7, 28 }, // 0011000 + { 0x0040, 8, 29 }, // 00000010 + { 0x0060, 8, 30 }, // 00000011 + { 0x0340, 8, 31 }, // 00011010 + { 0x0360, 8, 32 }, // 00011011 + { 0x0240, 8, 33 }, // 00010010 + { 0x0260, 8, 34 }, // 00010011 + { 0x0280, 8, 35 }, // 00010100 + { 0x02a0, 8, 36 }, // 00010101 + { 0x02c0, 8, 37 }, // 00010110 + { 0x02e0, 8, 38 }, // 00010111 + { 0x0500, 8, 39 }, // 00101000 + { 0x0520, 8, 40 }, // 00101001 + { 0x0540, 8, 41 }, // 00101010 + { 0x0560, 8, 42 }, // 00101011 + { 0x0580, 8, 43 }, // 00101100 + { 0x05a0, 8, 44 }, // 00101101 + { 0x0080, 8, 45 }, // 00000100 + { 0x00a0, 8, 46 }, // 00000101 + { 0x0140, 8, 47 }, // 00001010 + { 0x0160, 8, 48 }, // 00001011 + { 0x0a40, 8, 49 }, // 01010010 + { 0x0a60, 8, 50 }, // 01010011 + { 0x0a80, 8, 51 }, // 01010100 + { 0x0aa0, 8, 52 }, // 01010101 + { 0x0480, 8, 53 }, // 00100100 + { 0x04a0, 8, 54 }, // 00100101 + { 0x0b00, 8, 55 }, // 01011000 + { 0x0b20, 8, 56 }, // 01011001 + { 0x0b40, 8, 57 }, // 01011010 + { 0x0b60, 8, 58 }, // 01011011 + { 0x0940, 8, 59 }, // 01001010 + { 0x0960, 8, 60 }, // 01001011 + { 0x0640, 8, 61 }, // 00110010 + { 0x0660, 8, 62 }, // 00110011 + { 0x0680, 8, 63 }, // 00110100 + { 0x1b00, 5, 64 }, // 11011 + { 0x1200, 5, 128 }, // 10010 + { 0x0b80, 6, 192 }, // 010111 + { 0x0dc0, 7, 256 }, // 0110111 + { 0x06c0, 8, 320 }, // 00110110 + { 0x06e0, 8, 384 }, // 00110111 + { 0x0c80, 8, 448 }, // 01100100 + { 0x0ca0, 8, 512 }, // 01100101 + { 0x0d00, 8, 576 }, // 01101000 + { 0x0ce0, 8, 640 }, // 01100111 + { 0x0cc0, 9, 704 }, // 011001100 + { 0x0cd0, 9, 768 }, // 011001101 + { 0x0d20, 9, 832 }, // 011010010 + { 0x0d30, 9, 896 }, // 011010011 + { 0x0d40, 9, 960 }, // 011010100 + { 0x0d50, 9, 1024 }, // 011010101 + { 0x0d60, 9, 1088 }, // 011010110 + { 0x0d70, 9, 1152 }, // 011010111 + { 0x0d80, 9, 1216 }, // 011011000 + { 0x0d90, 9, 1280 }, // 011011001 + { 0x0da0, 9, 1344 }, // 011011010 + { 0x0db0, 9, 1408 }, // 011011011 + { 0x0980, 9, 1472 }, // 010011000 + { 0x0990, 9, 1536 }, // 010011001 + { 0x09a0, 9, 1600 }, // 010011010 + { 0x0c00, 6, 1664 }, // 011000 (what did they think?) + { 0x09b0, 9, 1728 }, // 010011011 + { 0x0020, 11, 1792 }, // 00000001000 + { 0x0030, 11, 1856 }, // 00000001100 + { 0x0034, 11, 1920 }, // 00000001101 + { 0x0024, 12, 1984 }, // 000000010010 + { 0x0026, 12, 2048 }, // 000000010011 + { 0x0028, 12, 2112 }, // 000000010100 + { 0x002a, 12, 2176 }, // 000000010101 + { 0x002c, 12, 2240 }, // 000000010110 + { 0x002e, 12, 2304 }, // 000000010111 + { 0x0038, 12, 2368 }, // 000000011100 + { 0x003a, 12, 2432 }, // 000000011101 + { 0x003c, 12, 2496 }, // 000000011110 + { 0x003e, 12, 2560 }, // 000000011111 + { 0x0000, 0, -1 } // Illegal entry +}; + + +static const VLCode bcodes[] = { + // 13 bit codes + { 0x01b8, 10, 0 }, // 0000110111 + { 0x0800, 3, 1 }, // 010 + { 0x1800, 2, 2 }, // 11 + { 0x1000, 2, 3 }, // 10 + { 0x0c00, 3, 4 }, // 011 + { 0x0600, 4, 5 }, // 0011 + { 0x0400, 4, 6 }, // 0010 + { 0x0300, 5, 7 }, // 00011 + { 0x0280, 6, 8 }, // 000101 + { 0x0200, 6, 9 }, // 000100 + { 0x0100, 7, 10 }, // 0000100 + { 0x0140, 7, 11 }, // 0000101 + { 0x01c0, 7, 12 }, // 0000111 + { 0x0080, 8, 13 }, // 00000100 + { 0x00e0, 8, 14 }, // 00000111 + { 0x0180, 9, 15 }, // 000011000 + { 0x00b8, 10, 16 }, // 0000010111 + { 0x00c0, 10, 17 }, // 0000011000 + { 0x0040, 10, 18 }, // 0000001000 + { 0x019c, 11, 19 }, // 00001100111 + { 0x01a0, 11, 20 }, // 00001101000 + { 0x01b0, 11, 21 }, // 00001101100 + { 0x00dc, 11, 22 }, // 00000110111 + { 0x00a0, 11, 23 }, // 00000101000 + { 0x005c, 11, 24 }, // 00000010111 + { 0x0060, 11, 25 }, // 00000011000 + { 0x0194, 12, 26 }, // 000011001010 + { 0x0196, 12, 27 }, // 000011001011 + { 0x0198, 12, 28 }, // 000011001100 + { 0x019a, 12, 29 }, // 000011001101 + { 0x00d0, 12, 30 }, // 000001101000 + { 0x00d2, 12, 31 }, // 000001101001 + { 0x00d4, 12, 32 }, // 000001101010 + { 0x00d6, 12, 33 }, // 000001101011 + { 0x01a4, 12, 34 }, // 000011010010 + { 0x01a6, 12, 35 }, // 000011010011 + { 0x01a8, 12, 36 }, // 000011010100 + { 0x01aa, 12, 37 }, // 000011010101 + { 0x01ac, 12, 38 }, // 000011010110 + { 0x01ae, 12, 39 }, // 000011010111 + { 0x00d8, 12, 40 }, // 000001101100 + { 0x00da, 12, 41 }, // 000001101101 + { 0x01b4, 12, 42 }, // 000011011010 + { 0x01b6, 12, 43 }, // 000011011011 + { 0x00a8, 12, 44 }, // 000001010100 + { 0x00aa, 12, 45 }, // 000001010101 + { 0x00ac, 12, 46 }, // 000001010110 + { 0x00ae, 12, 47 }, // 000001010111 + { 0x00c8, 12, 48 }, // 000001100100 + { 0x00ca, 12, 49 }, // 000001100101 + { 0x00a4, 12, 50 }, // 000001010010 + { 0x00a6, 12, 51 }, // 000001010011 + { 0x0048, 12, 52 }, // 000000100100 + { 0x006e, 12, 53 }, // 000000110111 + { 0x0070, 12, 54 }, // 000000111000 + { 0x004e, 12, 55 }, // 000000100111 + { 0x0050, 12, 56 }, // 000000101000 + { 0x00b0, 12, 57 }, // 000001011000 + { 0x00b2, 12, 58 }, // 000001011001 + { 0x0056, 12, 59 }, // 000000101011 + { 0x0058, 12, 60 }, // 000000101100 + { 0x00b4, 12, 61 }, // 000001011010 + { 0x00cc, 12, 62 }, // 000001100110 + { 0x00ce, 12, 63 }, // 000001100111 + { 0x0078, 10, 64 }, // 0000001111 + { 0x0190, 12, 128 }, // 000011001000 + { 0x0192, 12, 192 }, // 000011001001 + { 0x00b6, 12, 256 }, // 000001011011 + { 0x0066, 12, 320 }, // 000000110011 + { 0x0068, 12, 384 }, // 000000110100 + { 0x006a, 12, 448 }, // 000000110101 + { 0x006c, 13, 512 }, // 0000001101100 + { 0x006d, 13, 576 }, // 0000001101101 + { 0x004a, 13, 640 }, // 0000001001010 + { 0x004b, 13, 704 }, // 0000001001011 + { 0x004c, 13, 768 }, // 0000001001100 + { 0x004d, 13, 832 }, // 0000001001101 + { 0x0072, 13, 896 }, // 0000001110010 + { 0x0073, 13, 960 }, // 0000001110011 + { 0x0074, 13, 1024 }, // 0000001110100 + { 0x0075, 13, 1088 }, // 0000001110101 + { 0x0076, 13, 1152 }, // 0000001110110 + { 0x0077, 13, 1216 }, // 0000001110111 + { 0x0052, 13, 1280 }, // 0000001010010 + { 0x0053, 13, 1344 }, // 0000001010011 + { 0x0054, 13, 1408 }, // 0000001010100 + { 0x0055, 13, 1472 }, // 0000001010101 + { 0x005a, 13, 1536 }, // 0000001011010 + { 0x005b, 13, 1600 }, // 0000001011011 + { 0x0064, 13, 1664 }, // 0000001100100 + { 0x0065, 13, 1728 }, // 0000001100101 + { 0x0020, 11, 1792 }, // 00000001000 + { 0x0030, 11, 1856 }, // 00000001100 + { 0x0034, 11, 1920 }, // 00000001101 + { 0x0024, 12, 1984 }, // 000000010010 + { 0x0026, 12, 2048 }, // 000000010011 + { 0x0028, 12, 2112 }, // 000000010100 + { 0x002a, 12, 2176 }, // 000000010101 + { 0x002c, 12, 2240 }, // 000000010110 + { 0x002e, 12, 2304 }, // 000000010111 + { 0x0038, 12, 2368 }, // 000000011100 + { 0x003a, 12, 2432 }, // 000000011101 + { 0x003c, 12, 2496 }, // 000000011110 + { 0x003e, 12, 2560 }, // 000000011111 + { 0x0000, 0, -1 } // Illegal entry +}; + + + + +// ---------------------------------------- +// SOURCE OF BITS + +#define VLSBUFSIZE 64 + +class MMRDecoder::VLSource : public GPEnabled +{ +protected: + VLSource(GP<ByteStream> &inp); + void init(const bool striped); +public: + // Initializes a bit source on a bytestream + static GP<VLSource> create(GP<ByteStream> &inp, const bool striped); + + // Synchronize on the next stripe + void nextstripe(void); + // Returns a 32 bits integer with at least the + // next sixteen code bits in the high order bits. + inline unsigned int peek(void); + // Ensures that next #peek()# contains at least + // the next 24 code bits. + void preload(void); + // Consumes #n# bits. + void shift(const int n); +private: + GP<ByteStream> ginp; + ByteStream &inp; + unsigned char buffer[ VLSBUFSIZE ]; + unsigned int codeword; + int lowbits; + int bufpos; + int bufmax; + int readmax; +}; + +MMRDecoder::VLSource::VLSource(GP<ByteStream> &xinp) +: ginp(xinp), inp(*ginp), codeword(0), + lowbits(0), bufpos(0), bufmax(0), + readmax(-1) +{} + +void +MMRDecoder::VLSource::init(const bool striped) +{ + if (striped) + readmax = inp.read32(); + lowbits = 32; + preload(); +} + +GP<MMRDecoder::VLSource> +MMRDecoder::VLSource::create(GP<ByteStream> &inp, const bool striped) +{ + VLSource *src=new VLSource(inp); + GP<VLSource> retval=src; + src->init(striped); + return retval; +} + +void +MMRDecoder::VLSource::shift(const int n) +{ + codeword<<=n; + lowbits+=n; + if (lowbits>=16) + preload(); +} + +inline unsigned int +MMRDecoder::VLSource::peek(void) +{ + return codeword; +} + + +void +MMRDecoder::VLSource::nextstripe(void) +{ + while (readmax>0) + { + int size = sizeof(buffer); + if (readmax < size) + size = readmax; + inp.readall(buffer, size); + readmax -= size; + } + bufpos = bufmax = 0; + memset(buffer,0,sizeof(buffer)); + readmax = inp.read32(); + codeword = 0; + lowbits = 32; + preload(); +} + +void +MMRDecoder::VLSource::preload(void) +{ + while (lowbits>=8) + { + if (bufpos >= bufmax) + { + // Refill buffer + bufpos = bufmax = 0; + int size = sizeof(buffer); + if (readmax>=0 && readmax<size) + size = readmax; + if (size>0) + bufmax = inp.read((void*)buffer, size); + readmax -= bufmax; + if (bufmax <= 0) + return; + } + lowbits -= 8; + codeword |= buffer[bufpos++] << lowbits; + } +} + + + +// ---------------------------------------- +// VARIABLE LENGTH CODES + + + +class MMRDecoder::VLTable : public GPEnabled +{ +protected: + VLTable(const VLCode *codes); + void init(const int nbits); +public: + // Construct a VLTable given a codebook with #nbits# long codes. + static GP<VLTable> create(VLCode const * const codes, const int nbits); + + // Reads one symbol from a VLSource + int decode(MMRDecoder::VLSource *src); + + const VLCode *code; + int codewordshift; + unsigned char *index; + GPBuffer<unsigned char> gindex; +}; + +GP<MMRDecoder::VLTable> +MMRDecoder::VLTable::create(VLCode const * const codes, const int nbits) +{ + VLTable *table=new VLTable(codes); + GP<VLTable> retval=table; + table->init(nbits); + return retval; +} + +inline int +MMRDecoder::VLTable::decode(MMRDecoder::VLSource *src) +{ + const VLCode &c = code[ index[ src->peek() >> codewordshift ] ]; + src->shift(c.codelen); + return c.value; +} + +MMRDecoder::VLTable::VLTable(const VLCode *codes) +: code(codes), codewordshift(0), gindex(index,0) +{} + +void +MMRDecoder::VLTable::init(const int nbits) +{ + // count entries + int ncodes = 0; + while (code[ncodes].codelen) + ncodes++; + // check arguments + if (nbits<=1 || nbits>16) + G_THROW(invalid_mmr_data); + if (ncodes>=256) + G_THROW(invalid_mmr_data); + codewordshift = 32 - nbits; + // allocate table + int size = (1<<nbits); + gindex.resize(size); + gindex.set(ncodes); + // process codes + for (int i=0; i<ncodes; i++) { + const int c = code[i].code; + const int b = code[i].codelen; + if(b<=0 || b>nbits) + { + G_THROW(invalid_mmr_data); + } + // fill table entries whose index high bits are code. + int n = c + (1<<(nbits-b)); + while ( --n >= c ) { + if(index[n] != ncodes) + G_THROW( ERR_MSG("MMRDecoder.bad_codebook") ); + index[n] = i; + } + } +} + +// ---------------------------------------- +// MMR DECODER + + + +MMRDecoder::~MMRDecoder() {} + +MMRDecoder::MMRDecoder( const int xwidth, const int xheight ) +: width(xwidth), height(xheight), lineno(0), + striplineno(0), rowsperstrip(0), gline(line,width+8), + glineruns(lineruns,width+4), gprevruns(prevruns,width+4) +{ + gline.clear(); + glineruns.clear(); + gprevruns.clear(); + lineruns[0] = width; + prevruns[0] = width; +} + +void +MMRDecoder::init(GP<ByteStream> gbs, const bool striped) +{ + rowsperstrip = (striped ? gbs->read16() : height); + src = VLSource::create(gbs, striped); + mrtable = VLTable::create(mrcodes, 7); + btable = VLTable::create(bcodes, 13); + wtable = VLTable::create(wcodes, 13); +} + +GP<MMRDecoder> +MMRDecoder::create( GP<ByteStream> gbs, const int width, + const int height, const bool striped ) +{ + MMRDecoder *mmr=new MMRDecoder(width,height); + GP<MMRDecoder> retval=mmr; + mmr->init(gbs,striped); + return retval; +} + +const unsigned short * +MMRDecoder::scanruns(const unsigned short **endptr) +{ + // Check if all lines have been returned + if (lineno >= height) + return 0; + // Check end of stripe + if ( striplineno == rowsperstrip ) + { + striplineno=0; + lineruns[0] = prevruns[0] = width; + src->nextstripe(); + } + // Swap run buffers + unsigned short *pr = lineruns; + unsigned short *xr = prevruns; + prevruns = pr; + lineruns = xr; + // Loop until scanline is complete + bool a0color = false; + int a0,rle,b1; + for(a0=0,rle=0,b1=*pr++;a0 < width;) + { + // Process MMR codes + const int c=mrtable->decode(src); + switch ( c ) + { + /* Pass Mode */ + case P: + { + b1 += *pr++; + rle += b1 - a0; + a0 = b1; + b1 += *pr++; + break; + } + /* Horizontal Mode */ + case H: + { + // First run + VLTable &table1 = *(a0color ? btable : wtable); + int inc; + do { inc=table1.decode(src); a0+=inc; rle+=inc; } while (inc>=64); + *xr = rle; xr++; rle = 0; + // Second run + VLTable &table2 = *(!a0color ? btable : wtable); + do { inc=table2.decode(src); a0+=inc; rle+=inc; } while (inc>=64); + *xr = rle; xr++; rle = 0; + break; + } + /* Vertical Modes */ + case V0: + case VR3: + case VR2: + case VR1: + case VL3: + case VL2: + case VL1: + { + int inc=b1; + switch ( c ) + { + case V0: + inc = b1; + b1 += *pr++; + break; + case VR3: + inc = b1+3; + b1 += *pr++; + break; + case VR2: + inc = b1+2; + b1 += *pr++; + break; + case VR1: + inc = b1+1; + b1 += *pr++; + break; + case VL3: + inc = b1-3; + b1 -= *--pr; + break; + case VL2: + inc = b1-2; + b1 -= *--pr; + break; + case VL1: + inc = b1-1; + b1 -= *--pr; + break; + } + *xr = inc+rle-a0; + xr++; + a0 = inc; + rle = 0; + a0color = !a0color; + break; + } + /* Uncommon modes */ + default: + { + src->preload(); + unsigned int m = src->peek(); + // -- Could be EOFB ``000000000001000000000001'' + // TIFF6 says that all remaining lines are white + if ((m & 0xffffff00) == 0x00100100) + { + lineno = height; + return 0; + } + // -- Could be UNCOMPRESSED ``0000001111'' + // TIFF6 says people should not do this. + // RFC1314 says people should do this. + else if ((m & 0xffc00000) == 0x03c00000) + { +#ifdef MMRDECODER_REFUSES_UNCOMPRESSED + G_THROW( ERR_MSG("MMRDecoder.cant_process") ); +#else + // ---THE-FOLLOWING-CODE-IS-POORLY-TESTED--- + src->shift(10); + while ((m = (src->peek() & 0xfc000000))) + { + if (m == 0x04000000) // 000001 + { + src->shift(6); + if (a0color) + { + *xr = rle; + xr++; + rle = 0; + a0color = !a0color; + } + rle += 5; + a0 += 5; + } + else // 000010 to 111111 + { + src->shift(1); + if (a0color == !(m & 0x80000000)) + { + *xr = rle; + xr++; + rle = 0; + a0color = !a0color; + } + rle++; + a0++; + } + if (a0 > width) + G_THROW(invalid_mmr_data); + } + // Analyze uncompressed termination code. + m = src->peek() & 0xff000000; + src->shift(8); + if ( (m & 0xfe000000) != 0x02000000 ) + G_THROW(invalid_mmr_data); + if (rle) + { + *xr = rle; + xr++; + rle = 0; + a0color = !a0color; + } + if (a0color == !(m & 0x01000000)) + { + *xr = rle; + xr++; + rle = 0; + a0color = !a0color; + } + // Cross fingers and proceed ... + break; +#endif + } + // -- Unknown MMR code. + G_THROW(invalid_mmr_data); + } + } + // Next reference run + for(;b1<=a0 && b1<width;pr+=2) + { + b1 += pr[0]+pr[1]; + } + } + // Final P must be followed by V0 (they say!) + if (rle > 0) + { + if (mrtable->decode(src) != V0) + { + G_THROW(invalid_mmr_data); + } + } + if (rle > 0) + { + *xr = rle; + xr++; + } + // At this point we should have A0 equal to WIDTH + // But there are buggy files around (Kofax!) + // and we are not the CCITT police. + if (a0 > width) + { + while (a0 > width && xr > lineruns) + a0 -= *--xr; + if (a0 < width) + { + *xr = width-a0; + xr++; + } + } + /* Increment and return */ + if (endptr) + *endptr = xr; + xr[0] = 0; + xr[1] = 0; + lineno ++; + striplineno ++; + return lineruns; +} + + + +const unsigned char * +MMRDecoder::scanrle(const bool invert, const unsigned char **endptr) +{ + // Obtain run lengths + const unsigned short *xr = scanruns(); + if (!xr) return 0; + unsigned char *p=line; + // Process inversion + if (invert) + { + if (! *xr) + { + xr++; + }else + { + *p = 0; p++; + } + } + // Encode lenghts using the RLE format + for(int a0=0;a0 < width;) + { + int count = *xr++; + a0 += count; + GBitmap::append_run(p, count); + } + if (endptr) + *endptr = p; + p[0] = 0; + p[1] = 0; + return line; +} + + +#if 0 +const unsigned char * +MMRDecoder::scanline(void) +{ + // Obtain run lengths + const unsigned short *xr = scanruns(); + if (!xr) return 0; + // Allocate data buffer if needed + unsigned char *p = line; + // Decode run lengths + int a0 = 0; + int a0color = 0; + while (a0 < width) + { + int a1 = a0 + *xr++; + while (a0<a1 && a0<width) + line[a0++] = a0color; + a0color = !a0color; + } + return line; +} +#endif + + + + +// ---------------------------------------- +// MAIN DECODING ROUTINE + +bool +MMRDecoder::decode_header( + ByteStream &inp, int &width, int &height, int &invert) +{ + unsigned long int magic = inp.read32(); + if((magic&0xfffffffc) != 0x4d4d5200) + G_THROW( ERR_MSG("MMRDecoder.unrecog_header") ); + invert = ((magic & 0x1) ? 1 : 0); + const bool strip = ((magic & 0x2) ? 1 : 0); + width = inp.read16(); + height = inp.read16(); + if (width<=0 || height<=0) + G_THROW( ERR_MSG("MMRDecoder.bad_header") ); + return strip; +} + +static inline int MAX(int a, int b) { return a>b ? a : b; } +static inline int MIN(int a, int b) { return a<b ? a : b; } + +GP<JB2Image> +MMRDecoder::decode(GP<ByteStream> gbs) +{ + ByteStream &inp=*gbs; + // Read header + int width, height, invert; + const bool striped=decode_header(inp, width, height, invert); + // Prepare image + GP<JB2Image> jimg = JB2Image::create(); + jimg->set_dimension(width, height); + // Choose pertinent blocksize + int blocksize = MIN(500,MAX(64,MAX(width/17,height/22))); + int blocksperline = (width+blocksize-1)/blocksize; + // Prepare decoder + GP<MMRDecoder> gdcd=MMRDecoder::create(gbs, width, height, striped); + MMRDecoder &dcd=*gdcd; + // Loop on JB2 bands + int line = height-1; + while (line >= 0) + { + int bandline = MIN(blocksize-1,line); + GPArray<GBitmap> blocks(0,blocksperline-1); + // Loop on scanlines + for(; bandline >= 0; bandline--,line--) + { + // Decode one scanline + const unsigned short *s = dcd.scanruns(); + if (s) + { + // Loop on blocks + int x = 0; + int b = 0; + int firstx = 0; + bool c = !!invert; + while (x < width) + { + int xend = x + *s++; + while (b<blocksperline) + { + int lastx = MIN(firstx+blocksize,width); + if (c) + { + if (!blocks[b]) + blocks[b] = GBitmap::create(bandline+1, lastx-firstx); + unsigned char *bptr = (*blocks[b])[bandline] - firstx; + int x1 = MAX(x,firstx); + int x2 = MIN(xend,lastx); + while (x1 < x2) + bptr[x1++] = 1; + } + if (xend < lastx) + break; + firstx = lastx; + b ++; + } + x = xend; + c = !c; + } + } + } + // Insert blocks into JB2Image + for (int b=0; b<blocksperline; b++) + { + JB2Shape shape; + shape.bits = blocks[b]; + if (shape.bits) + { + shape.parent = -1; + shape.bits->compress(); + JB2Blit blit; + blit.left = b*blocksize; + blit.bottom = line+1; + blit.shapeno = jimg->add_shape(shape); + jimg->add_blit(blit); + } + } + } + // Return + return jimg; +} + + + +#ifdef HAVE_NAMESPACES +} +# ifndef NOT_USING_DJVU_NAMESPACE +using namespace DJVU; +# endif +#endif |