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Diffstat (limited to 'SrcShared/EmJPEG.h')
| -rw-r--r-- | SrcShared/EmJPEG.h | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/SrcShared/EmJPEG.h b/SrcShared/EmJPEG.h new file mode 100644 index 0000000..4cdead5 --- /dev/null +++ b/SrcShared/EmJPEG.h @@ -0,0 +1,167 @@ +/* -*- 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 */ |