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Diffstat (limited to 'kviewshell/plugins/djvu/libdjvu/MMRDecoder.h')
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diff --git a/kviewshell/plugins/djvu/libdjvu/MMRDecoder.h b/kviewshell/plugins/djvu/libdjvu/MMRDecoder.h new file mode 100644 index 00000000..6516b4cd --- /dev/null +++ b/kviewshell/plugins/djvu/libdjvu/MMRDecoder.h @@ -0,0 +1,238 @@ +//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.h,v 1.9 2003/11/07 22:08:22 leonb Exp $ +// $Name: release_3_5_15 $ + +#ifndef _MMRDECODER_H_ +#define _MMRDECODER_H_ +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif +#if NEED_GNUG_PRAGMAS +# pragma interface +#endif + + +#include "GSmartPointer.h" + +#ifdef HAVE_NAMESPACES +namespace DJVU { +# ifdef NOT_DEFINED // Just to fool emacs c++ mode +} +#endif +#endif + +class ByteStream; +class JB2Image; + +/** @name MMRDecoder.h + Files #"MMRDecoder.h"# and #"MMRDecoder.cpp"# implement a + CCITT-G4/MMR decoder suitable for use in DjVu. The main + entry point is function \Ref{MMRDecoder::decode}. + + The foreground mask layer of a DjVu file is usually encoded with a + #"Sjbz"# chunk containing JB2 encoded data (cf. \Ref{JB2Image.h}). + Alternatively, the qmask layer may be encoded with a #"Smmr"# + chunk containing a small header followed by MMR encoded data. + This encoding scheme produces significantly larger files. On the + other hand, many scanners a printers talk MMR using very efficient + hardware components. This is the reason behind the introduction + of #"Smmr"# chunks. + + The #Smmr# chunk starts by a header containing the following data: + \begin{verbatim} + BYTE*3 : 'M' 'M' 'R' + BYTE : 0xb000000<s><i> + INT16 : <width> (MSB first) + INT16 : <height> (MSB first) + \end{verbatim} + + The header is followed by the encoded data. Bit 0 of the fourth header + byte (#<i>#) is similar to TIFF's ``min-is-black'' tag. This bit is set + for a reverse video image. The encoded data can be in either ``regular'' + MMR form or ``striped'' MMR form. This is indicated by bit 1 of the + fourth header byte (#<s>#). This bit is set to indicate ``striped'' + data. The ``regular'' data format consists of ordinary MMR encoded data. + The ``striped'' data format consists of one sixteen bit integer (msb + first) containing the number of rows per stripe, followed by data for each + stripe as follows. + \begin{verbatim} + INT16 : <rowsperstripe> (MSB first) + INT32 : <nbytes1> + BYTE*<nbytes1> : <mmrdata1> + INT32 : <nbytes2> + BYTE*<nbytes2> : <mmrdata2> + ... + \end{verbatim} + Static function \Ref{MMRDecoder::decode_header} decodes the header. You + can then create a \Ref{MMRDecoder} object with the flags #inverted# and + #striped# as obtained when decoding the header. One can also decode raw + MMR data by simply initialising a \Ref{MMRDecoder} object with flag + #striped# unset. Each call to \Ref{MMRDecoder::scanruns}, + \Ref{MMRDecoder::scanrle} or \Ref{MMRDecoder::scanline} will then decode a + row of the MMR encoded image. + + Function \Ref{MMRDecoder::decode} is a convenience function for decoding + the contents of a #"Smmr"# chunk. It returns a \Ref{JB2Image} divided + into manageable blocks in order to provide the zooming and panning + features implemented by class \Ref{JB2Image}. + + @memo + CCITT-G4/MMR decoder. + @version + #$Id: MMRDecoder.h,v 1.9 2003/11/07 22:08:22 leonb Exp $# + @author + Parag Deshmukh <parag@sanskrit.lz.att.com> \\ + Leon Bottou <leonb@research.att.com> */ +//@{ + + + +#define MMRDECODER_HAS_SCANRUNS 1 +#define MMRDECODER_HAS_SCANRLE 1 + + + +/** Class for G4/MMR decoding. The simplest way to use this class is + the static member function \Ref{MMRDecoder::decode}. This + function internally creates an instance of #MMRDecoder# which + processes the MMR data scanline by scanline. */ +class MMRDecoder : public GPEnabled +{ +protected: + MMRDecoder(const int width, const int height); + void init(GP<ByteStream> gbs, const bool striped=false); +public: + /** Main decoding routine that (a) decodes the header using + #decode_header#, (b) decodes the MMR data using an instance of + #MMRDecoder#, and returns a new \Ref{JB2Image} composed of tiles + whose maximal width and height is derived from the size of the + image. */ + static GP<JB2Image> decode(GP<ByteStream> gbs); + + /// Only decode the header. + static bool decode_header(ByteStream &inp, + int &width, int &height, int &invert); + +public: + /// Non-virtual destructor. + ~MMRDecoder(); + /** Create a MMRDecoder object for decoding an image + of size #width# by #height#. Flag $striped# must be set + if the image is composed of multiple stripes. */ + static GP<MMRDecoder> create(GP<ByteStream> gbs, + const int width, const int height, + const bool striped=false ); + + /** Decodes a scanline and returns a pointer to an array of run lengths. + The returned buffer contains the length of alternative white and black + runs. These run lengths sum to the image width. They are followed by + two zeroes. The position of these two zeroes is stored in the pointer + specified by the optional argument #endptr#. The buffer data should be + processed before calling this function again. */ + const unsigned short *scanruns(const unsigned short **endptr=0); + /** Decodes a scanline and returns a pointer to RLE encoded data. The + buffer contains the length of the runs for the current line encoded as + described in \Ref{PNM and RLE file formats}.) The flag #invert# can be + used to indicate that the MMR data is encoded in reverse video. The RLE + data is followed by two zero bytes. The position of these two zeroes is + stored in the pointer specified by the optional argument #endptr#. The + buffer data should be processed before calling this function again. This + is implemented by calling \Ref{MMRDecoder::scanruns}. */ + const unsigned char *scanrle(const bool invert, + const unsigned char **endptr=0); +#if 0 + /** Decodes a scanline and returns a pointer to an array of #0# or #1# bytes. + Returns a pointer to the scanline buffer containing one byte per pixel. + The buffer data should be processed before calling this function again. + This is implemented by calling \Ref{MMRDecoder::scanruns}. */ + const unsigned char *scanline(); +#endif + private: + int width; + int height; + int lineno; + int striplineno; + int rowsperstrip; + unsigned char *line; + GPBuffer<unsigned char> gline; + unsigned short *lineruns; + GPBuffer<unsigned short> glineruns; + unsigned short *prevruns; + GPBuffer<unsigned short> gprevruns; +public: + class VLSource; + class VLTable; +private: + GP<VLSource> src; + GP<VLTable> mrtable; + GP<VLTable> wtable; + GP<VLTable> btable; + friend class VLSource; + friend class VLTable; +}; + + +//@} + + +// ----------- + +#ifdef HAVE_NAMESPACES +} +# ifndef NOT_USING_DJVU_NAMESPACE +using namespace DJVU; +# endif +#endif +#endif |