diff options
Diffstat (limited to 'kviewshell/plugins/djvu/libdjvu/JB2Image.h')
| -rw-r--r-- | kviewshell/plugins/djvu/libdjvu/JB2Image.h | 805 |
1 files changed, 805 insertions, 0 deletions
diff --git a/kviewshell/plugins/djvu/libdjvu/JB2Image.h b/kviewshell/plugins/djvu/libdjvu/JB2Image.h new file mode 100644 index 00000000..f55ae451 --- /dev/null +++ b/kviewshell/plugins/djvu/libdjvu/JB2Image.h @@ -0,0 +1,805 @@ +//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: JB2Image.h,v 1.9 2003/11/07 22:08:22 leonb Exp $ +// $Name: release_3_5_15 $ + +#ifndef _JB2IMAGE_H +#define _JB2IMAGE_H +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif +#if NEED_GNUG_PRAGMAS +# pragma interface +#endif + +/** @name JB2Image.h + + Files #"JB2Image.h"# and #"JB2Image.cpp"# address the compression of + bilevel images using the JB2 soft pattern matching scheme. These files + provide the complete decoder and the decoder back-end. The JB2 scheme is + optimized for images containing a large number of self-similar small + components such as characters. Typical text images can be compressed into + files 3 to 5 times smaller than with G4/MMR and 2 to 4 times smaller than + with JBIG1. + + {\bf JB2 and JBIG2} --- JB2 has strong similarities with the forthcoming + JBIG2 standard developed by the "ISO/IEC JTC1 SC29 Working Group 1" which + is responsible for both the JPEG and JBIG standards. This is hardly + surprising since JB2 was our own proposal for the JBIG2 standard + and remained the only proposal for years. The full JBIG2 standard however + is significantly more complex and slighlty less efficient than JB2 because + it addresses a broader range of applications. Full JBIG2 compliance may + be implemented in the future. + + {\bf JB2 Images} --- Class \Ref{JB2Image} is the central data structure + implemented here. A #JB2Image# is composed of an array of shapes + and an array of blits. Each shape contains a small bitmap representing an + elementary blob of ink, such as a character or a segment of line art. + Each blit instructs the decoder to render a particular shape at a + specified position in the image. Some compression is already achieved + because several blits can refer to the same shape. A shape can also + contain a pointer to a parent shape. Additional compression is achieved + when both shapes are similar because each shape is encoded using the + parent shape as a model. A #"O"# shape for instance could be a parent for + both a #"C"# shape and a #"Q"# shape. + + {\bf JB2 Dictionary} --- Class \Ref{JB2Dict} is a peculiar kind of + JB2Image which only contains an array of shapes. These shapes can be + referenced from another JB2Dict/JB2Image. This is arranged by setting the + ``inherited dictionary'' of a JB2Dict/JB2Image using function + \Ref{JB2Dict::set_inherited_dict}. Several JB2Images can use shapes from a + same JB2Dict encoded separately. This is how several pages of a same + document can share information. + + {\bf Decoding JB2 data} --- The first step for decoding JB2 data consists of + creating an empty #JB2Image# object. Function \Ref{JB2Image::decode} then + reads the data and populates the #JB2Image# with the shapes and the blits. + Function \Ref{JB2Image::get_bitmap} finally produces an anti-aliased image. + + {\bf Encoding JB2 data} --- The first step for decoding JB2 data also + consists of creating an empty #JB2Image# object. You must then use + functions \Ref{JB2Image::add_shape} and \Ref{JB2Image::add_blit} to + populate the #JB2Image# object. Function \Ref{JB2Image::encode} finally + produces the JB2 data. Function #encode# sequentially encodes the blits + and the necessary shapes. The compression ratio depends on several + factors: + \begin{itemize} + \item Blits should reuse shapes as often as possible. + \item Blits should be sorted in reading order because this facilitates + the prediction of the blit coordinates. + \item Shapes should be sorted according to the order of first appearance + in the sequence of blits because this facilitates the prediction of the + shape indices. + \item Shapes should be compared to all previous shapes in the shape array. + The shape parent pointer should be set to a suitable parent shape if + such a parent shape exists. The parent shape should have almost the + same size and the same pixels. + \end{itemize} + All this is quite easy to achieve in the case of an electronically + produced document such as a DVI file or a PS file: we know what the + characters are and where they are located. If you only have a scanned + image however you must first locate the characters (connected component + analysis) and cut the remaining pieces of ink into smaller blobs. + Ordering the blits and matching the shapes is then an essentially + heuristic process. Although the quality of the heuristics substantially + effects the file size, misordering blits or mismatching shapes never + effects the quality of the image. The last refinement consists in + smoothing the shapes in order to reduce the noise and maximize the + similarities between shapes. + + {\bf JB2 extensions} --- Two extensions of the JB2 + encoding format have been introduced with DjVu files version 21. The first + extension addresses the shared shape dictionaries. The second extension + bounds the number of probability contexts used for coding numbers. + Both extensions maintain backward compatibility with JB2 as + described in the ICFDD proposal. A more complete discussion + can be found in section \Ref{JB2 extensions for version 21.}. + + {\bf References} + \begin{itemize} + \item Paul G. Howard : {\em Text image compression using soft + pattern matching}, Computer Journal, volume 40:2/3, 1997. + \item JBIG1 : \URL{http://www.jpeg.org/public/jbighomepage.htm}. + \item JBIG2 draft : \URL{http://www.jpeg.org/public/jbigpt2.htm}. + \item ICFDD Draft Proposed American National Standard, 1999-08-26. + \end{itemize} + + @version + #$Id: JB2Image.h,v 1.9 2003/11/07 22:08:22 leonb Exp $# + @memo + Coding bilevel images with JB2. + @author + Paul Howard <[email protected]> -- JB2 design\\ + L\'eon Bottou <[email protected]> -- this implementation + +// From: Leon Bottou, 1/31/2002 +// Lizardtech has split the corresponding cpp file into a decoder and an encoder. +// Only superficial changes. The meat is mine. + +*/ +//@{ + + +#include "GString.h" +#include "ZPCodec.h" + + +#ifdef HAVE_NAMESPACES +namespace DJVU { +# ifdef NOT_DEFINED // Just to fool emacs c++ mode +} +#endif +#endif + +class JB2Dict; +class JB2Image; +class GRect; +class GBitmap; +class ByteStream; + +/** Blit data structure. A #JB2Image# contains an array of #JB2Blit# data + structures. Each array entry instructs the decoder to render a particular + shape at a particular location. Members #left# and #bottom# specify the + coordinates of the bottom left corner of the shape bitmap. All + coordinates are relative to the bottom left corner of the image. Member + #shapeno# is the subscript of the shape to be rendered. */ + +class JB2Blit { +public: + /** Horizontal coordinate of the blit. */ + unsigned short left; + /** Vertical coordinate of the blit. */ + unsigned short bottom; + /** Index of the shape to blit. */ + unsigned int shapeno; +}; + + +/** Shape data structure. A #JB2Image# contains an array of #JB2Shape# data + structures. Each array entry represents an elementary blob of ink such as + a character or a segment of line art. Member #bits# points to a bilevel + image representing the shape pixels. Member #parent# is the subscript of + the parent shape. */ + +class JB2Shape +{ +public: + /** Subscript of the parent shape. The parent shape must always be located + before the current shape in the shape array. A negative value indicates + that this shape has no parent. Any negative values smaller than #-1# + further indicates that this shape does not look like a character. This + is used to enable a few internal optimizations. This information is + saved into the JB2 file, but the actual value of the #parent# variable + is not. */ + int parent; + /** Bilevel image of the shape pixels. This must be a pointer to a bilevel + #GBitmap# image. This pointer can also be null. The encoder will just + silently discard all blits referring to a shape containing a null + bitmap. */ + GP<GBitmap> bits; + /** Private user data. This long word is provided as a convenience for users + of the JB2Image data structures. Neither the rendering functions nor + the coding functions ever access this value. */ + long userdata; +}; + + + +/** JB2 Dictionary callback. + The decoding function call this callback function when they discover that + the current JB2Image or JB2Dict needs a pre-existing shape dictionary. + The callback function must return a pointer to the dictionary or NULL + if none is found. */ + +typedef GP<JB2Dict> JB2DecoderCallback ( void* ); + + +/** Dictionary of JB2 shapes. */ + +class JB2Dict : public GPEnabled +{ +protected: + JB2Dict(void); +public: + class JB2Codec; + + // CONSTRUCTION + /** Default creator. Constructs an empty #JB2Dict# object. You can then + call the decoding function #decode#. You can also manually set the + image size using #add_shape#. */ + static GP<JB2Dict> create(void); + + // INITIALIZATION + /** Resets the #JB2Image# object. This function reinitializes both the shape + and the blit arrays. All allocated memory is freed. */ + void init(void); + + // INHERITED + /** Returns the inherited dictionary. */ + GP<JB2Dict> get_inherited_dict(void) const; + /** Returns the number of inherited shapes. */ + int get_inherited_shape_count(void) const; + /** Sets the inherited dictionary. */ + void set_inherited_dict(const GP<JB2Dict> &dict); + + // ACCESSING THE SHAPE LIBRARY + /** Returns the total number of shapes. + Shape indices range from #0# to #get_shape_count()-1#. */ + int get_shape_count(void) const; + /** Returns a pointer to shape #shapeno#. + The returned pointer directly points into the shape array. + This pointer can be used for reading or writing the shape data. */ + JB2Shape &get_shape(const int shapeno); + /** Returns a constant pointer to shape #shapeno#. + The returned pointer directly points into the shape array. + This pointer can only be used for reading the shape data. */ + const JB2Shape &get_shape(const int shapeno) const; + /** Appends a shape to the shape array. This function appends a copy of + shape #shape# to the shape array and returns the subscript of the new + shape. The subscript of the parent shape #shape.parent# must + actually designate an already existing shape. */ + int add_shape(const JB2Shape &shape); + + // MEMORY OPTIMIZATION + /** Compresses all shape bitmaps. This function reduces the memory required + by the #JB2Image# by calling \Ref{GBitmap::compress} on all shapes + bitmaps. This function is best called after decoding a #JB2Image#, + because function \Ref{get_bitmap} can directly use the compressed + bitmaps. */ + void compress(void); + /** Returns the total memory used by the JB2Image. + The returned value is expressed in bytes. */ + unsigned int get_memory_usage(void) const; + + // CODING + /** Encodes the JB2Dict into ByteStream #bs#. + This function generates the JB2 data stream without any header. */ + void encode(const GP<ByteStream> &gbs) const; + /** Decodes JB2 data from ByteStream #bs#. This function decodes the image + size and populates the shape and blit arrays. The callback function + #cb# is called when the decoder determines that the ByteStream data + requires a shape dictionary which has not been set with + \Ref{JB2Dict::set_inherited_dict}. The callback receives argument #arg# + and must return a suitable dictionary which will be installed as the + inherited dictionary. The callback should return null if no such + dictionary is found. */ + void decode(const GP<ByteStream> &gbs, JB2DecoderCallback *cb=0, void *arg=0); + + +public: + /** Comment string coded by JB2 file. */ + GUTF8String comment; + +private: + int inherited_shapes; + GP<JB2Dict> inherited_dict; + GArray<JB2Shape> shapes; + +}; + +/** Main JB2 data structure. Each #JB2Image# consists of an array of shapes + and an array of blits. These arrays can be populated by hand using + functions \Ref{add_shape} and \Ref{add_blit}, or by decoding JB2 data + using function \Ref{decode}. You can then use function \Ref{get_bitmap} + to render anti-aliased images, or use function \Ref{encode} to generate + JB2 data. */ + +class JB2Image : public JB2Dict +{ +protected: + JB2Image(void); +public: + + /** Creates an empty #JB2Image# object. You can then + call the decoding function #decode#. You can also manually set the + image size using #set_dimension# and populate the shape and blit arrays + using #add_shape# and #add_blit#. */ + static GP<JB2Image> create(void) { return new JB2Image(); } + + // INITIALIZATION + /** Resets the #JB2Image# object. This function reinitializes both the shape + and the blit arrays. All allocated memory is freed. */ + void init(void); + + // DIMENSION + /** Returns the width of the image. + This is the width value previously set with #set_dimension#. */ + int get_width(void) const; + /** Returns the height of the image. + This is the height value previously set with #set_dimension#. */ + int get_height(void) const; + /** Sets the size of the JB2Image. + This function can be called at any time. + The corresponding #width# and the #height# are stored + in the JB2 file. */ + void set_dimension(int width, int height); + + // RENDERING + /** Renders an anti-aliased gray level image. This function renders the + JB2Image as a bilevel or gray level image. Argument #subsample# + specifies the desired subsampling ratio in range #1# to #15#. The + returned image uses #1+subsample^2# gray levels for representing + anti-aliased edges. Argument #align# specified the alignment of the + rows of the returned images. Setting #align# to #4#, for instance, will + adjust the bitmap border in order to make sure that each row of the + returned image starts on a word (four byte) boundary. */ + GP<GBitmap> get_bitmap(int subsample = 1, int align = 1) const; + /** Renders an anti-aliased gray level sub-image. This function renders a + segment of the JB2Image as a bilevel or gray level image. Conceptually, + this function first renders the full JB2Image with subsampling ratio + #subsample# and then extracts rectangle #rect# in the subsampled image. + Both operations of course are efficiently performed simultaneously. + Argument #align# specified the alignment of the rows of the returned + images, as explained above. Argument #dispy# should remain null. */ + GP<GBitmap> get_bitmap(const GRect &rect, int subsample=1, int align=1, int dispy=0) const; + + // ACCESSING THE BLIT LIBRARY + /** Returns the total number of blits. + Blit indices range from #0# to #get_blit_count(void)-1#. */ + int get_blit_count(void) const; + /** Returns a pointer to blit #blitno#. + The returned pointer directly points into the blit array. + This pointer can be used for reading or writing the blit data. */ + JB2Blit *get_blit(int blitno); + /** Returns a constant pointer to blit #blitno#. + The returned pointer directly points into the shape array. + This pointer can only be used for reading the shape data. */ + const JB2Blit *get_blit(int blitno) const; + /** Appends a blit to the blit array. This function appends a copy of blit + #blit# to the blit array and returns the subscript of the new blit. The + shape subscript #blit.shapeno# must actually designate an already + existing shape. */ + int add_blit(const JB2Blit &blit); + + // MEMORY OPTIMIZATION + /** Returns the total memory used by the JB2Image. + The returned value is expressed in bytes. */ + unsigned int get_memory_usage(void) const; + + // CODING + /** Encodes the JB2Image into ByteStream #bs#. + This function generates the JB2 data stream without any header. */ + void encode(const GP<ByteStream> &gbs) const; + /** Decodes JB2 data from ByteStream #bs#. This function decodes the image + size and populates the shape and blit arrays. The callback function + #cb# is called when the decoder determines that the ByteStream data + requires a shape dictionary which has not been set with + \Ref{JB2Dict::set_inherited_dict}. The callback receives argument #arg# + and must return a suitable dictionary which will be installed as the + inherited dictionary. The callback should return null if no such + dictionary is found. */ + void decode(const GP<ByteStream> &gbs, JB2DecoderCallback *cb=0, void *arg=0); + +private: + // Implementation + int width; + int height; + GTArray<JB2Blit> blits; +public: + /** Reproduces a old bug. Setting this flag may be necessary for accurately + decoding DjVu files with version smaller than #18#. The default value + is of couse #false#. */ + bool reproduce_old_bug; +}; + + + +// JB2DICT INLINE FUNCTIONS + +inline int +JB2Dict::get_shape_count(void) const +{ + return inherited_shapes + shapes.size(); +} + +inline int +JB2Dict::get_inherited_shape_count(void) const +{ + return inherited_shapes; +} + +inline GP<JB2Dict> +JB2Dict::get_inherited_dict(void) const +{ + return inherited_dict; +} + +// JB2IMAGE INLINE FUNCTIONS + +inline int +JB2Image::get_width(void) const +{ + return width; +} + +inline int +JB2Image::get_height(void) const +{ + return height; +} + + +inline int +JB2Image::get_blit_count(void) const +{ + return blits.size(); +} + + +inline JB2Blit * +JB2Image::get_blit(int blitno) +{ + return & blits[blitno]; +} + +inline const JB2Blit * +JB2Image::get_blit(int blitno) const +{ + return & blits[blitno]; +} + + + + + +/** @name JB2 extensions for version 21. + + Two extensions of the JB2 encoding format have been introduced + with DjVu files version 21. Both extensions maintain significant + backward compatibility with previous version of the JB2 format. + These extensions are described below by reference to the ICFDD + proposal dated August 1999. Both extension make use of the unused + record type value #9# (cf. ICFDD page 24) which has been renamed + #REQUIRED_DICT_OR_RESET#. + + {\bf Shared Shape Dictionaries} --- This extension provides + support for sharing symbol definitions between the pages of a + document. To achieve this objective, the JB2 image data chunk + must be able to address symbols defined elsewhere by a JB2 + dictionary data chunk shared by all the pages of a document. + + The arithmetically encoded JB2 image data logically consist of a + sequence of records. The decoder processes these records in + sequence and maintains a library of symbols which can be addressed + by the following records. The first record usually is a ``Start + Of Image'' record describing the size of the image. + + Starting with version 21, a #REQUIRED_DICT_OR_RESET# (9) record + type can appear {\em before} the #START_OF_DATA# (0) record. The + record type field is followed by a single number arithmetically + encoded (cf. ICFDD page 26) using a sixteenth context (cf. ICFDD + page 25). This record appears when the JB2 data chunk requires + symbols encoded in a separate JB2 dictionary data chunk. The + number (the {\bf dictionary size}) indicates how many symbols + should have been defined by the JB2 dictionary data chunk. The + decoder should simply load these symbols in the symbol library and + proceed as usual. New symbols potentially defined by the + subsequent JB2 image data records will therefore be numbered with + integers greater or equal than the dictionary size. + + The JB2 dictionary data format is a pure subset of the JB2 image + data format. The #START_OF_DATA# (0) record always specifies an + image width of zero and an image height of zero. The only allowed + record types are those defining library symbols only + (#NEW_SYMBOL_LIBRARY_ONLY# (2) and #MATCHED_REFINE_LIBRARY_ONLY# + (5) cf. ICFDD page 24) followed by a final #END_OF_DATA# (11) + record. + + The JB2 dictionary data is usually located in an {\bf Djbz} chunk. + Each page {\bf FORM:DJVU} may directly contain a {\bf Djbz} chunk, + or may indirectly point to such a chunk using an {\bf INCL} chunk + (cf. \Ref{Multipage DjVu documents.}). + + + {\bf Numcoder Reset} --- This extension addresses a problem for + hardware implementations. The encoding of numbers (cf. ICFDD page + 26) potentially uses an unbounded number of binary coding + contexts. These contexts are normally allocated when they are used + for the first time (cf. ICFDD informative note, page 27). + + Starting with version 21, a #REQUIRED_DICT_OR_RESET# (9) record + type can appear {\em after} the #START_OF_DATA# (0) record. The + decoder should proceed with the next record after {\em clearing + all binary contexts used for coding numbers}. This operation + implies that all binary contexts previously allocated for coding + numbers can be deallocated. + + Starting with version 21, the JB2 encoder should insert a + #REQUIRED_DICT_OR_RESET# record type whenever the number of these + allocated binary contexts exceeds #20000#. Only very large + documents ever reach such a large number of allocated binary + contexts (e.g large maps). Hardware implementation however can + benefit greatly from a hard bound on the total number of binary + coding contexts. Old JB2 decoders will treat this record type as + an #END_OF_DATA# record and cleanly stop decoding (cf. ICFDD page + 30, Image refinement data). + + + {\bf References} --- + \begin{itemize} + \item ICFDD Draft Proposed American National Standard, 1999-08-26. + \item DjVu Specification, \URL{http://www.lizardtech.com/djvu/sci/djvuspec}. + \end{itemize} + + @memo Extensions to the JB2 format introduced in version 21. */ + +//@} + +//////////////////////////////////////// +//// CLASS JB2CODEC: DECLARATION +//////////////////////////////////////// + +// This class is accessed via the encode and decode +// functions of class JB2Image + + +//**** Class JB2Codec +// This class implements the base class for both the JB2 coder and decoder. +// The JB2Codec's Contains all contextual information for encoding/decoding +// a JB2Image. + +class JB2Dict::JB2Codec +{ +public: + class Decode; + class Encode; + typedef unsigned int NumContext; + struct LibRect + { + int top,left,right,bottom; + void compute_bounding_box(const GBitmap &cbm); + }; + virtual ~JB2Codec(); +protected: + // Constructors + JB2Codec(const bool xencoding=false); + // Forbidden assignment + JB2Codec(const JB2Codec &ref); + JB2Codec& operator=(const JB2Codec &ref); + + int CodeNum(int lo, int hi, NumContext *pctx,int v); + void reset_numcoder(void); + inline void code_eventual_lossless_refinement(void); + void init_library(JB2Dict &jim); + int add_library(const int shapeno, JB2Shape &jshp); + void code_relative_location(JB2Blit *jblt, int rows, int columns); + void code_bitmap_directly (GBitmap &bm); + void code_bitmap_by_cross_coding (GBitmap &bm, GP<GBitmap> &cbm, const int libno); + void code_record(int &rectype, const GP<JB2Dict> &jim, JB2Shape *jshp); + void code_record(int &rectype, const GP<JB2Image> &jim, JB2Shape *jshp, JB2Blit *jblt); + static void compute_bounding_box(GBitmap &cbm, LibRect &lrect); + static int get_direct_context( unsigned char const * const up2, + unsigned char const * const up1, unsigned char const * const up0, + const int column); + static int shift_direct_context ( const int context, + const int next, unsigned char const * const up2, + unsigned char const * const up1, unsigned char const * const up0, + const int column); + static int get_cross_context( unsigned char const * const up1, + unsigned char const * const up0, unsigned char const * const xup1, + unsigned char const * const xup0, unsigned char const * const xdn1, + const int column ); + static int shift_cross_context( const int context, + const int n, unsigned char const * const up1, + unsigned char const * const up0, unsigned char const * const xup1, + unsigned char const * const xup0, unsigned char const * const xdn1, + const int column ); + + virtual bool CodeBit(const bool bit, BitContext &ctx) = 0; + virtual void code_comment(GUTF8String &comment) = 0; + virtual void code_record_type(int &rectype) = 0; + virtual int code_match_index(int &index, JB2Dict &jim)=0; + virtual void code_inherited_shape_count(JB2Dict &jim)=0; + virtual void code_image_size(JB2Dict &jim); + virtual void code_image_size(JB2Image &jim); + virtual void code_absolute_location(JB2Blit *jblt, int rows, int columns)=0; + virtual void code_absolute_mark_size(GBitmap &bm, int border=0) = 0; + virtual void code_relative_mark_size(GBitmap &bm, int cw, int ch, int border=0) = 0; + virtual void code_bitmap_directly(GBitmap &bm,const int dw, int dy, + unsigned char *up2, unsigned char *up1, unsigned char *up0 )=0; + virtual void code_bitmap_by_cross_coding (GBitmap &bm, GBitmap &cbm, + const int xd2c, const int dw, int dy, int cy, + unsigned char *up1, unsigned char *up0, unsigned char *xup1, + unsigned char *xup0, unsigned char *xdn1 )=0; + // Code records + virtual int get_diff(const int x_diff,NumContext &rel_loc) = 0; + +private: + bool encoding; + +protected: + // NumCoder + int cur_ncell; + BitContext *bitcells; + GPBuffer<BitContext> gbitcells; + NumContext *leftcell; + GPBuffer<NumContext> gleftcell; + NumContext *rightcell; + GPBuffer<NumContext> grightcell; + // Info + bool refinementp; + char gotstartrecordp; + // Code comment + NumContext dist_comment_byte; + NumContext dist_comment_length; + // Code values + NumContext dist_record_type; + NumContext dist_match_index; + BitContext dist_refinement_flag; + // Library + GTArray<int> shape2lib; + GTArray<int> lib2shape; + GTArray<LibRect> libinfo; + // Code pairs + NumContext abs_loc_x; + NumContext abs_loc_y; + NumContext abs_size_x; + NumContext abs_size_y; + NumContext image_size_dist; + NumContext inherited_shape_count_dist; + BitContext offset_type_dist; + NumContext rel_loc_x_current; + NumContext rel_loc_x_last; + NumContext rel_loc_y_current; + NumContext rel_loc_y_last; + NumContext rel_size_x; + NumContext rel_size_y; + int last_bottom; + int last_left; + int last_right; + int last_row_bottom; + int last_row_left; + int image_columns; + int image_rows; + int short_list[3]; + int short_list_pos; + inline void fill_short_list(const int v); + int update_short_list(const int v); + // Code bitmaps + BitContext bitdist[1024]; + BitContext cbitdist[2048]; +}; + +inline void +JB2Dict::JB2Codec::code_eventual_lossless_refinement(void) +{ + refinementp=CodeBit(refinementp, dist_refinement_flag); +} + +inline void +JB2Dict::JB2Codec::fill_short_list(const int v) +{ + short_list[0] = short_list[1] = short_list[2] = v; + short_list_pos = 0; +} + +inline int +JB2Dict::JB2Codec::get_direct_context( unsigned char const * const up2, + unsigned char const * const up1, + unsigned char const * const up0, + const int column) +{ + return ( (up2[column - 1] << 9) | + (up2[column ] << 8) | + (up2[column + 1] << 7) | + (up1[column - 2] << 6) | + (up1[column - 1] << 5) | + (up1[column ] << 4) | + (up1[column + 1] << 3) | + (up1[column + 2] << 2) | + (up0[column - 2] << 1) | + (up0[column - 1] << 0) ); +} + +inline int +JB2Dict::JB2Codec::shift_direct_context(const int context, const int next, + unsigned char const * const up2, + unsigned char const * const up1, + unsigned char const * const up0, + const int column) +{ + return ( ((context << 1) & 0x37a) | + (up1[column + 2] << 2) | + (up2[column + 1] << 7) | + (next << 0) ); +} + +inline int +JB2Dict::JB2Codec::get_cross_context( unsigned char const * const up1, + unsigned char const * const up0, + unsigned char const * const xup1, + unsigned char const * const xup0, + unsigned char const * const xdn1, + const int column ) +{ + return ( ( up1[column - 1] << 10) | + ( up1[column ] << 9) | + ( up1[column + 1] << 8) | + ( up0[column - 1] << 7) | + (xup1[column ] << 6) | + (xup0[column - 1] << 5) | + (xup0[column ] << 4) | + (xup0[column + 1] << 3) | + (xdn1[column - 1] << 2) | + (xdn1[column ] << 1) | + (xdn1[column + 1] << 0) ); +} + +inline int +JB2Dict::JB2Codec::shift_cross_context( const int context, const int n, + unsigned char const * const up1, + unsigned char const * const up0, + unsigned char const * const xup1, + unsigned char const * const xup0, + unsigned char const * const xdn1, + const int column ) +{ + return ( ((context<<1) & 0x636) | + ( up1[column + 1] << 8) | + (xup1[column ] << 6) | + (xup0[column + 1] << 3) | + (xdn1[column + 1] << 0) | + (n << 7) ); +} + +// ---------- THE END + +#ifdef HAVE_NAMESPACES +} +# ifndef NOT_USING_DJVU_NAMESPACE +using namespace DJVU; +# endif +#endif +#endif + |