1 files changed, 902 insertions, 0 deletions
diff --git a/SrcShared/EmJPEG.cpp b/SrcShared/EmJPEG.cpp
new file mode 100644
index 0000000..2e7193a
--- /dev/null
+++ b/SrcShared/EmJPEG.cpp
@@ -0,0 +1,902 @@
+/* -*- 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.
+\* ===================================================================== */
+
+#include "EmCommon.h"
+#include "EmJPEG.h"
+
+#include "EmPixMap.h"			// SetSize, GetRowBytes, etc.
+#include "EmStream.h"			// GetLength, GetBytes
+#include "Platform.h"			// Platform::DisposeMemory, AllocateMemory
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressSource constructor
+ *
+ * DESCRIPTION:	Create the object.  Initialize all data members.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressSource::EmJPEGDecompressSource (void)
+{
+	this->next_input_byte	= 0;
+	this->bytes_in_buffer	= 0;
+
+	// Fill in fields/function pointers used by JPEG engine
+
+	this->init_source		= &init_source_cb;
+	this->fill_input_buffer	= &fill_input_buffer_cb;
+	this->skip_input_data	= &skip_input_data_cb;
+	this->resync_to_restart	= &jpeg_resync_to_restart;
+	this->term_source		= &term_source_cb;
+
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressSource destructor
+ *
+ * DESCRIPTION:	Destroy the object.  Delete all data members.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressSource::~EmJPEGDecompressSource (void)
+{
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressSource::init_source_cb
+ *
+ * DESCRIPTION:	Callback function that retrieves the pointer to the
+ *				object managing the decompression and then calls the
+ *				appropriate method of that object.
+ *
+ * Initialize source --- called by jpeg_read_header
+ * before any data is actually read.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressSource::init_source_cb (j_decompress_ptr cinfo)
+{
+	((EmJPEGDecompressSource*) cinfo->src)->InitSource (cinfo);
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressSource::fill_input_buffer_cb
+ *
+ * DESCRIPTION:	Callback function that retrieves the pointer to the
+ *				object managing the decompression and then calls the
+ *				appropriate method of that object.
+ *
+ * Fill the input buffer --- called whenever buffer is emptied.
+ *
+ * In typical applications, this should read fresh data into the buffer
+ * (ignoring the current state of next_input_byte & bytes_in_buffer),
+ * reset the pointer & count to the start of the buffer, and return TRUE
+ * indicating that the buffer has been reloaded.  It is not necessary to
+ * fill the buffer entirely, only to obtain at least one more byte.
+ *
+ * There is no such thing as an EOF return.  If the end of the file has been
+ * reached, the routine has a choice of ERREXIT() or inserting fake data into
+ * the buffer.  In most cases, generating a warning message and inserting a
+ * fake EOI marker is the best course of action --- this will allow the
+ * decompressor to output however much of the image is there.  However,
+ * the resulting error message is misleading if the real problem is an empty
+ * input file, so we handle that case specially.
+ *
+ * In applications that need to be able to suspend compression due to input
+ * not being available yet, a FALSE return indicates that no more data can be
+ * obtained right now, but more may be forthcoming later.  In this situation,
+ * the decompressor will return to its caller (with an indication of the
+ * number of scanlines it has read, if any).  The application should resume
+ * decompression after it has loaded more data into the input buffer.  Note
+ * that there are substantial restrictions on the use of suspension --- see
+ * the documentation.
+ *
+ * When suspending, the decompressor will back up to a convenient restart point
+ * (typically the start of the current MCU). next_input_byte & bytes_in_buffer
+ * indicate where the restart point will be if the current call returns FALSE.
+ * Data beyond this point must be rescanned after resumption, so move it to
+ * the front of the buffer rather than discarding it.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+boolean EmJPEGDecompressSource::fill_input_buffer_cb (j_decompress_ptr cinfo)
+{
+	return ((EmJPEGDecompressSource*) cinfo->src)->FillInputBuffer (cinfo);
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressSource::skip_input_data_cb
+ *
+ * DESCRIPTION:	Callback function that retrieves the pointer to the
+ *				object managing the decompression and then calls the
+ *				appropriate method of that object.
+ *
+ * Skip data --- used to skip over a potentially large amount of
+ * uninteresting data (such as an APPn marker).
+ *
+ * Writers of suspendable-input applications must note that skip_input_data
+ * is not granted the right to give a suspension return.  If the skip extends
+ * beyond the data currently in the buffer, the buffer can be marked empty so
+ * that the next read will cause a fill_input_buffer call that can suspend.
+ * Arranging for additional bytes to be discarded before reloading the input
+ * buffer is the application writer's problem.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *				num_bytes - number of bytes to skip.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressSource::skip_input_data_cb (j_decompress_ptr cinfo, long num_bytes)
+{
+	((EmJPEGDecompressSource*) cinfo->src)->SkipInputData (cinfo, num_bytes);
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressSource::term_source_cb
+ *
+ * DESCRIPTION:	Callback function that retrieves the pointer to the
+ *				object managing the decompression and then calls the
+ *				appropriate method of that object.
+ *
+ * Terminate source --- called by jpeg_finish_decompress
+ * after all data has been read.  Often a no-op.
+ *
+ * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
+ * application must deal with any cleanup that should happen even
+ * for error exit.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressSource::term_source_cb (j_decompress_ptr cinfo)
+{
+	((EmJPEGDecompressSource*) cinfo->src)->TermSource (cinfo);
+}
+
+
+#pragma mark -
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressMemSource constructor
+ *
+ * DESCRIPTION:	Create the object.  Initialize all data members.
+ *
+ * PARAMETERS:	data - pointer to the memory buffer holding the
+ *					compressed JPEG data.
+ *				len - number of bytes pointed to by "data".
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressMemSource::EmJPEGDecompressMemSource (const void* data, long len) :
+	fData (data),
+	fDataLen (len)
+{
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressMemSource destructor
+ *
+ * DESCRIPTION:	Destroy the object.  Delete all data members.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressMemSource::~EmJPEGDecompressMemSource (void)
+{
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressMemSource::InitSource
+ *
+ * DESCRIPTION:	Initialize source --- called by jpeg_read_header
+ *				before any data is actually read.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressMemSource::InitSource (j_decompress_ptr /*cinfo*/)
+{
+	// Fill in fields/function pointers used by JPEG engine
+
+	this->next_input_byte		= (const JOCTET*) fData;
+	this->bytes_in_buffer		= (size_t) fDataLen;
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressMemSource::FillInputBuffer
+ *
+ * DESCRIPTION:	See fill_input_buffer_cb. Unused in this class.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+boolean EmJPEGDecompressMemSource::FillInputBuffer (j_decompress_ptr /*cinfo*/)
+{
+	EmAssert (false);
+
+	return TRUE;
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressMemSource::SkipInputData
+ *
+ * DESCRIPTION:	See skip_input_data_cb.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *				num_bytes - number of bytes to skip.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressMemSource::SkipInputData (j_decompress_ptr /*cinfo*/, long num_bytes)
+{
+	this->next_input_byte += (size_t) num_bytes;
+	this->bytes_in_buffer -= (size_t) num_bytes;
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressMemSource::TermSource
+ *
+ * DESCRIPTION:	See term_source_cb
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressMemSource::TermSource (j_decompress_ptr /*cinfo*/)
+{
+}
+
+
+#pragma mark -
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressStreamSource constructor
+ *
+ * DESCRIPTION:	Create the object.  Initialize all data members.
+ *
+ * PARAMETERS:	data - pointer to the memory buffer holding the
+ *					compressed JPEG data.
+ *				len - number of bytes pointed to by "data".
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressStreamSource::EmJPEGDecompressStreamSource (EmStream& s) :
+	fStream (s),
+	fBuffer (NULL)
+{
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressStreamSource destructor
+ *
+ * DESCRIPTION:	Destroy the object.  Delete all data members.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressStreamSource::~EmJPEGDecompressStreamSource (void)
+{
+	Platform::DisposeMemory (fBuffer);
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressStreamSource::InitSource
+ *
+ * DESCRIPTION:	Initialize source --- called by jpeg_read_header
+ *				before any data is actually read.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressStreamSource::InitSource (j_decompress_ptr /*cinfo*/)
+{
+	// Fill in fields/function pointers used by JPEG engine
+
+	this->bytes_in_buffer		= (size_t) fStream.GetLength ();
+	this->fBuffer				= Platform::AllocateMemory (this->bytes_in_buffer);
+	this->next_input_byte		= (const JOCTET*) fBuffer;
+
+	fStream.GetBytes (fBuffer, this->bytes_in_buffer);
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressStreamSource::FillInputBuffer
+ *
+ * DESCRIPTION:	See fill_input_buffer_cb. Unused in this class.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+boolean EmJPEGDecompressStreamSource::FillInputBuffer (j_decompress_ptr /*cinfo*/)
+{
+	EmAssert (false);
+
+	return TRUE;
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressStreamSource::SkipInputData
+ *
+ * DESCRIPTION:	See skip_input_data_cb.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *				num_bytes - number of bytes to skip.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressStreamSource::SkipInputData (j_decompress_ptr /*cinfo*/, long num_bytes)
+{
+	this->next_input_byte += (size_t) num_bytes;
+	this->bytes_in_buffer -= (size_t) num_bytes;
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressStreamSource::TermSource
+ *
+ * DESCRIPTION:	See term_source_cb
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressStreamSource::TermSource (j_decompress_ptr /*cinfo*/)
+{
+}
+
+
+#pragma mark -
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressSink::EmJPEGDecompressSink
+ *
+ * DESCRIPTION:	Create the object.  Initialize all data members.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressSink::EmJPEGDecompressSink	(void) :
+	fBuffer (NULL),
+	fBufferHeight (0)
+{
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressSink::~EmJPEGDecompressSink
+ *
+ * DESCRIPTION:	Destroy the object.  Delete all data members.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressSink::~EmJPEGDecompressSink	(void)
+{
+}
+
+
+#pragma mark -
+
+/***********************************************************************
+ *
+ * FUNCTION:	ErrorExit
+ *
+ * DESCRIPTION:	Error exit handler: must not return to caller.
+ *
+ * Applications may override this if they want to get control back after
+ * an error.  Typically one would longjmp somewhere instead of exiting.
+ * The setjmp buffer can be made a private field within an expanded error
+ * handler object.  Note that the info needed to generate an error message
+ * is stored in the error object, so you can generate the message now or
+ * later, at your convenience.
+ * You should make sure that the JPEG object is cleaned up (with jpeg_abort
+ * or jpeg_destroy) at some point.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+static void ErrorExit (j_common_ptr)
+{
+	// !!! TBD if we want to handle mal-formed JPEG files.
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	OutputMessage
+ *
+ * DESCRIPTION:	Actual output of an error or trace message.
+ *
+ * Applications may override this method to send JPEG messages somewhere
+ * other than stderr.
+ *
+ * On Windows, printing to stderr is generally completely useless,
+ * so we provide optional code to produce an error-dialog popup.
+ * Most Windows applications will still prefer to override this routine,
+ * but if they don't, it'll do something at least marginally useful.
+ *
+ * NOTE: to use the library in an environment that doesn't support the
+ * C stdio library, you may have to delete the call to fprintf() entirely,
+ * not just not use this routine.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+static void OutputMessage (j_common_ptr)
+{
+	// !!! TBD if we want to report messages.
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmitMessage
+ *
+ * DESCRIPTION:	Decide whether to emit a trace or warning message.
+ *
+ * msg_level is one of:
+ *   -1: recoverable corrupt-data warning, may want to abort.
+ *    0: important advisory messages (always display to user).
+ *    1: first level of tracing detail.
+ *    2,3,...: successively more detailed tracing messages.
+ * An application might override this method if it wanted to abort on warnings
+ * or change the policy about which messages to display.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+static void EmitMessage (j_common_ptr, int)
+{
+	// !!! TBD if we want to report messages
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	FormatMessage
+ *
+ * DESCRIPTION:	Format a message string for the most recent JPEG error
+ *				or message.
+ *
+ * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
+ * characters.  Note that no '\n' character is added to the string.
+ * Few applications should need to override this method.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+static void
+FormatMessage (j_common_ptr, char*)
+{
+	// !!! TBD if we want to report messages
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	ResetError
+ *
+ * DESCRIPTION:	Reset error state variables at start of a new image.
+ *
+ * This is called during compression startup to reset trace/error
+ * processing to default state, without losing any application-specific
+ * method pointers.  An application might possibly want to override
+ * this method if it has additional error processing state.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+static void ResetError (j_common_ptr)
+{
+	// !!! TBD if we want to reset after errors
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	InitError
+ *
+ * DESCRIPTION:	Initialize the jpeg_error_mgr object.  We use our own
+ *				routine instead of jpeg_std_error so that we don't pull
+ *				in a bunch of JPEG lib routines we don't want.
+ *
+ * PARAMETERS:	err - pointer to the block used by the JPEG error mgr.
+ *
+ * RETURNED:	Pointer to same.
+ *
+ ***********************************************************************/
+
+static struct jpeg_error_mgr*
+InitError (struct jpeg_error_mgr* err)
+{
+	err->error_exit = ErrorExit;
+	err->emit_message = EmitMessage;
+	err->output_message = OutputMessage;
+	err->format_message = FormatMessage;
+	err->reset_error_mgr = ResetError;
+
+	err->trace_level = 0;		/* default = no tracing */
+	err->num_warnings = 0;		/* no warnings emitted yet */
+	err->msg_code = 0;			/* may be useful as a flag for "no error" */
+
+	/* Initialize message table pointers */
+	err->jpeg_message_table = NULL;
+	err->last_jpeg_message = 0;
+
+	err->addon_message_table = NULL;
+	err->first_addon_message = 0;	/* for safety */
+	err->last_addon_message = 0;
+
+	return err;
+}
+
+
+#pragma mark -
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressPixMapSink c'tor
+ *
+ * DESCRIPTION:	Create the object.  Initialize all data members.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressPixMapSink::EmJPEGDecompressPixMapSink (EmPixMap& pixMap) :
+	EmJPEGDecompressSink (),
+	fPixMap (pixMap),
+	fDataWidth (0),
+	fRowWidth (0),
+	fPadBytes (0),
+	fCurOutputRow (0)
+{
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressPixMapSink d'tor
+ *
+ * DESCRIPTION:	Destroy the object.  Delete all data members.
+ *
+ * PARAMETERS:	None
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+EmJPEGDecompressPixMapSink::~EmJPEGDecompressPixMapSink (void)
+{
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressPixMapSink::post_jpeg_read_header
+ *
+ * DESCRIPTION:	Called by the JPEG decompression engine after the JPEG
+ *				header has been read.  Initializes some of our data
+ *				members according to what was read.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void
+EmJPEGDecompressPixMapSink::post_jpeg_read_header (j_decompress_ptr cinfo)
+{
+	// Calculate output image dimensions so we can allocate space
+
+	jpeg_calc_output_dimensions (cinfo);
+
+	// Prepare the EmPixMap.
+
+	EmAssert (cinfo->out_color_space == JCS_RGB);
+
+	fPixMap.SetSize (EmPoint (cinfo->output_width, cinfo->output_height));
+	fPixMap.SetFormat (kPixMapFormat24RGB);
+
+	// Determine width of rows in the EmPixMap.
+
+	fDataWidth		= cinfo->output_width * cinfo->output_components;
+	fRowWidth		= fPixMap.GetRowBytes ();
+	fPadBytes		= fRowWidth - fDataWidth;
+
+	// Prepare for write pass
+
+	fCurOutputRow	= 0;
+
+	// Create decompressor output buffer.  This buffer is passed to
+	// jpeg_read_scanlines as a scanline output buffer.
+
+	fBuffer = (*cinfo->mem->alloc_sarray)
+		((j_common_ptr) cinfo, JPOOL_IMAGE, fDataWidth, 1);
+	fBufferHeight = 1;
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressPixMapSink::start_output
+ *
+ * DESCRIPTION:	Write any initial part of the output file.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressPixMapSink::start_output (j_decompress_ptr)
+{
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressPixMapSink::put_pixel_rows
+ *
+ * DESCRIPTION:	Write some pixel data.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *				JDIMENSION - number of rows.  This parameter is really
+ *					just a holdover from the JPEG sample code; in our
+ *					implementation, it's always 1.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressPixMapSink::put_pixel_rows (j_decompress_ptr, JDIMENSION)
+{
+	int			line	= fCurOutputRow++;
+	char*		outptr	= (char*) fPixMap.GetBits () + line * fRowWidth;
+	JSAMPROW	inptr	= fBuffer[0];
+
+	// Copy the source pixels.  They're in RGB format, which is what
+	// we've set our destination pixmap to be.
+
+	memcpy (outptr, inptr, fDataWidth);
+
+	// Zero out the pad bytes.
+
+	if (fPadBytes)
+	{
+		memset (outptr + fDataWidth, 0, fPadBytes);
+	}
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	EmJPEGDecompressPixMapSink::finish_output
+ *
+ * DESCRIPTION:	Write any data that needs to be written after all the
+ *				pixel rows have been processed.
+ *
+ * PARAMETERS:	cinfo - data block describing the decompression process.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void EmJPEGDecompressPixMapSink::finish_output (j_decompress_ptr /* cinfo */)
+{
+}
+
+
+#pragma mark -
+
+/***********************************************************************
+ *
+ * FUNCTION:	ConvertJPEG
+ *
+ * DESCRIPTION:	Drive the entire JPEG decompression process.  Compressed
+ *				data is provided by src_mgr; decompressed data is
+ *				handled by dest_mgr.  When this function is completed,
+ *				the decompresed image can be picked up from dest_mgr.
+ *
+ * PARAMETERS:	src_mgr - object that provides compressed JPEG data.
+ *				dest_mgr - object that handles decompressed JPEG data.
+ *
+ * RETURNED:	Nothing
+ *
+ ***********************************************************************/
+
+void ConvertJPEG (EmJPEGDecompressSource& src_mgr, EmJPEGDecompressSink& dest_mgr)
+{
+	// Modelled after main() in djpeg.c.
+
+	struct jpeg_decompress_struct	cinfo;	// Defined by JPEG lib; contains decompression state (including pointer to src manager).
+	struct jpeg_error_mgr			jerr;	// Defined by JPEG lib; contains methods for reporting errors
+
+
+	// Initialize the JPEG decompression object with default error handling.
+
+	cinfo.err = ::InitError (&jerr);
+	jpeg_create_decompress (&cinfo);
+
+	// Specify data source for decompression
+
+	cinfo.src = (jpeg_source_mgr*) &src_mgr;
+
+	// Read file header, set default decompression parameters
+
+	(void) jpeg_read_header (&cinfo, TRUE);
+
+	// Initialize the output module now to let it override any crucial
+	// option settings (for instance, GIF wants to force color quantization).
+
+	dest_mgr.post_jpeg_read_header (&cinfo);
+
+	// Start decompressor
+
+	(void) jpeg_start_decompress (&cinfo);
+
+	// Write output file header
+
+	dest_mgr.start_output (&cinfo);
+
+	// Process data
+
+	while (cinfo.output_scanline < cinfo.output_height)
+	{
+		JDIMENSION		num_scanlines;
+		num_scanlines = jpeg_read_scanlines (&cinfo,
+											dest_mgr.fBuffer,
+											dest_mgr.fBufferHeight);
+		dest_mgr.put_pixel_rows (&cinfo, num_scanlines);
+	}
+
+	// Finish decompression and release memory.
+	// I must do it in this order because output module has allocated memory
+	// of lifespan JPOOL_IMAGE; it needs to finish before releasing memory.
+
+	dest_mgr.finish_output (&cinfo);
+	(void) jpeg_finish_decompress (&cinfo);
+	jpeg_destroy_decompress (&cinfo);
+}
+
+
+/***********************************************************************
+ *
+ * FUNCTION:	JPEGToPixMap
+ *
+ * DESCRIPTION:	Convert a JPEG to an EmPixMap.
+ *
+ * PARAMETERS:	stream - stream providing the input JPEG data
+ *				pixMap - pixMap to receive the uncompressed image.
+ *
+ * RETURNED:	Nothing.
+ *
+ ***********************************************************************/
+
+void JPEGToPixMap (EmStream& stream, EmPixMap& pixMap)
+{
+	EmJPEGDecompressStreamSource	src_data (stream);
+	EmJPEGDecompressPixMapSink		dest_data (pixMap);
+
+	::ConvertJPEG (src_data, dest_data);
+}