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/* -*- mode: C++; tab-width: 4 -*- */
/* ===================================================================== *\
Copyright (c) 1999-2001 Palm, Inc. or its subsidiaries.
All rights reserved.
This file is part of the Palm OS Emulator.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
\* ===================================================================== */
#ifndef EmJPEG_h
#define EmJPEG_h
// jmorecfg.h tries to typedef uint32 to be a long. BASETSD.H
// already defines uint32 to be an int. Fortunately, they amount
// to the same thing, so we can turn off the jmorecfg.h attempt
// by defining the following symbol.
#define XMD_H 1
// jmorecfg.h also tries to define FAR. Undefine the one set up
// by windef.h. Yes, that gives us two different definitions of
// FAR, but hopefully that won't lead to conflict.
#undef FAR
extern "C"
{
#include "jinclude.h"
#include "jpeglib.h"
#include "jerror.h"
}
class EmPixMap;
class EmStream;
// Abstract base class that acts as a source for compressed JPEG
// data that needs to be decompressed. Clients subclass from this
// and override the pure-virtual functions.
class EmJPEGDecompressSource : public jpeg_source_mgr
{
public:
EmJPEGDecompressSource (void);
virtual ~EmJPEGDecompressSource (void);
private:
virtual void InitSource (j_decompress_ptr cinfo) = 0;
virtual boolean FillInputBuffer (j_decompress_ptr cinfo) = 0;
virtual void SkipInputData (j_decompress_ptr cinfo, long num_bytes) = 0;
virtual void TermSource (j_decompress_ptr cinfo) = 0;
private:
static void init_source_cb (j_decompress_ptr cinfo);
static boolean fill_input_buffer_cb(j_decompress_ptr cinfo);
static void skip_input_data_cb (j_decompress_ptr cinfo, long num_bytes);
static void term_source_cb (j_decompress_ptr cinfo);
};
// Concrete class that provides compressed JPEG data from a memory buffer.
class EmJPEGDecompressMemSource : public EmJPEGDecompressSource
{
public:
EmJPEGDecompressMemSource (const void* data, long len);
virtual ~EmJPEGDecompressMemSource (void);
private:
virtual void InitSource (j_decompress_ptr cinfo);
virtual boolean FillInputBuffer (j_decompress_ptr cinfo);
virtual void SkipInputData (j_decompress_ptr cinfo, long num_bytes);
virtual void TermSource (j_decompress_ptr cinfo);
private:
const void* fData;
long fDataLen;
};
// Concrete class that provides compressed JPEG data from a stream.
class EmJPEGDecompressStreamSource : public EmJPEGDecompressSource
{
public:
EmJPEGDecompressStreamSource (EmStream&);
virtual ~EmJPEGDecompressStreamSource (void);
private:
virtual void InitSource (j_decompress_ptr cinfo);
virtual boolean FillInputBuffer (j_decompress_ptr cinfo);
virtual void SkipInputData (j_decompress_ptr cinfo, long num_bytes);
virtual void TermSource (j_decompress_ptr cinfo);
private:
EmStream& fStream;
void* fBuffer;
};
// Abstract base class for accepting decompressed JPEG images and
// storing them in some client-specific fashion. Clients subclass
// from this and override the pure-virtual functions.
class EmJPEGDecompressSink
{
public:
EmJPEGDecompressSink (void);
virtual ~EmJPEGDecompressSink (void);
virtual void post_jpeg_read_header (j_decompress_ptr cinfo) = 0;
virtual void start_output (j_decompress_ptr cinfo) = 0;
virtual void put_pixel_rows (j_decompress_ptr cinfo,
JDIMENSION rows_supplied) = 0;
virtual void finish_output (j_decompress_ptr cinfo) = 0;
public:
// These fields are passed jpeg_read_scanlines by ConvertJPEG
JSAMPARRAY fBuffer;
JDIMENSION fBufferHeight;
};
// EmJPEGDecompressSink sub-class that writes the output as an EmPixMap.
class EmJPEGDecompressPixMapSink : public EmJPEGDecompressSink
{
public:
EmJPEGDecompressPixMapSink (EmPixMap&);
virtual ~EmJPEGDecompressPixMapSink (void);
virtual void post_jpeg_read_header (j_decompress_ptr cinfo);
virtual void start_output (j_decompress_ptr cinfo);
virtual void put_pixel_rows (j_decompress_ptr cinfo,
JDIMENSION rows_supplied);
virtual void finish_output (j_decompress_ptr cinfo);
private:
EmPixMap& fPixMap;
JDIMENSION fDataWidth; /* JSAMPLEs per row */
JDIMENSION fRowWidth; /* physical width of one row in the BMP file */
int fPadBytes; /* number of padding bytes needed per row */
JDIMENSION fCurOutputRow; /* next row# to write to virtual array */
};
// Function that drives the decompression process. Clients define
// the compressed JPEG data source and the decompressed JPEG data
// output by providing the appropriate source and sink classes.
void ConvertJPEG (EmJPEGDecompressSource&, EmJPEGDecompressSink&);
// Utility function that converts a JPEG from the stream to the given pixmap.
void JPEGToPixMap (EmStream&, EmPixMap&);
#endif /* EmJPEG_h */
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