text: /* +------------------------------------------------------------------------+
     |                     Mobile Robot Programming Toolkit (MRPT)            |
     |                          http://www.mrpt.org/                          |
     |                                                                        |
     | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
     | See: http://www.mrpt.org/Authors - All rights reserved.                |
     | Released under BSD License. See details in http://www.mrpt.org/License |
     +------------------------------------------------------------------------+ */
  
  #include "img-precomp.h"  // Precompiled headers
  
  #include <mrpt/img/CImage.h>
  #include <mrpt/io/CStream.h>
  
  // Universal include for all versions of OpenCV
  #include <mrpt/otherlibs/do_opencv_includes.h>
  
  using namespace mrpt;
  using namespace mrpt::img;
  
  // ---------------------------------------------------------------------------------------
  //							START OF JPEG FUNCTIONS PART
  // ---------------------------------------------------------------------------------------
  /* Expanded data destination object for stdio output */
  
  //#undef INT32
  #undef FAR
  #define XMD_H
  
  #include <stdio.h>
  
  // In Windows, we HAVE TO (YES dear...) include our custom jpeglib
  //  The problem is that, without .so/.dlls, all the libs have their
  //  own jpeglib and runtime checks of expected type-sizes fail
  //  causing asserts.... (fix: JLBC 20/OCT/2008)
  #if MRPT_HAS_JPEG_SYSTEM
  // Normal: System libraries (typ. unix)
  #include <jpeglib.h>
  
  // Convert mrpt-names to normal ones:
  #define mrpt_jpeg_source_mgr jpeg_source_mgr
  
  #elif MRPT_HAS_JPEG  // Built-in version
  #include "jpeglib/mrpt_jpeglib.h"
  #define mrpt_jpeg_source_mgr jpeg_source_mgr
  #endif
  
  using mrpt::io::CStream;
  
  typedef struct
  {
  	struct jpeg_destination_mgr pub; /* public fields */
  
  	CStream* out; /* target stream */
  	JOCTET* buffer; /* start of buffer */
  } mrpt_destination_mgr;
  
  using mrpt_dest_ptr = mrpt_destination_mgr*;
  
  #define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
  
  /*
   * Initialize destination --- called by jpeg_start_compress
   * before any data is actually written.
   */
  
  METHODDEF(void)
  init_destination(j_compress_ptr cinfo)
  {
  	mrpt_dest_ptr dest = (mrpt_dest_ptr)cinfo->dest;
  
  	/* Allocate the output buffer --- it will be released when done with image
  	 */
  	dest->buffer = (JOCTET*)(*cinfo->mem->alloc_small)(
  		(j_common_ptr)cinfo, JPOOL_IMAGE, OUTPUT_BUF_SIZE * sizeof(JOCTET));
  
  	dest->pub.next_output_byte = dest->buffer;
  	dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
  }
  
  /*
   * Empty the output buffer --- called whenever buffer fills up.
   *
   * In typical applications, this should write the entire output buffer
   * (ignoring the current state of next_output_byte & free_in_buffer),
   * reset the pointer & count to the start of the buffer, and return TRUE
   * indicating that the buffer has been dumped.
   *
   * In applications that need to be able to suspend compression due to output
   * overrun, a FALSE return indicates that the buffer cannot be emptied now.
   * In this situation, the compressor will return to its caller (possibly with
   * an indication that it has not accepted all the supplied scanlines).  The
   * application should resume compression after it has made more room in the
   * output buffer.  Note that there are substantial restrictions on the use of
   * suspension --- see the documentation.
   *
   * When suspending, the compressor will back up to a convenient restart point
   * (typically the start of the current MCU). next_output_byte & free_in_buffer
   * indicate where the restart point will be if the current call returns FALSE.
   * Data beyond this point will be regenerated after resumption, so do not
   * write it out when emptying the buffer externally.
   */
  
  METHODDEF(boolean)
  empty_output_buffer(j_compress_ptr cinfo)
  {
  	mrpt_dest_ptr dest = (mrpt_dest_ptr)cinfo->dest;
  
  	dest->out->Write(dest->buffer, OUTPUT_BUF_SIZE);
  
  	dest->pub.next_output_byte = dest->buffer;
  	dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
  
  	return TRUE;
  }
  
  /*
   * Terminate destination --- called by jpeg_finish_compress
   * after all data has been written.  Usually needs to flush buffer.
   *
   * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
   * application must deal with any cleanup that should happen even
   * for error exit.
   */
  
  METHODDEF(void)
  term_destination(j_compress_ptr cinfo)
  {
  	mrpt_dest_ptr dest = (mrpt_dest_ptr)cinfo->dest;
  	size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
  
  	/* Write any data remaining in the buffer */
  	if (datacount > 0) dest->out->Write(dest->buffer, (int)datacount);
  }
  
  GLOBAL(void)
  jpeg_stdio_dest(j_compress_ptr cinfo, CStream* out)
  {
  	mrpt_dest_ptr dest;
  
  	/* The destination object is made permanent so that multiple JPEG images
  	 * can be written to the same file without re-executing jpeg_stdio_dest.
  	 * This makes it dangerous to use this manager and a different destination
  	 * manager serially with the same JPEG object, because their private object
  	 * sizes may be different.  Caveat programmer.
  	 */
  	if (cinfo->dest == nullptr)
  	{ /* first time for this JPEG object? */
  		cinfo->dest = (jpeg_destination_mgr*)(*cinfo->mem->alloc_small)(
  			(j_common_ptr)cinfo, JPOOL_PERMANENT, sizeof(mrpt_destination_mgr));
  	}
  
  	dest = (mrpt_dest_ptr)cinfo->dest;
  	dest->pub.init_destination = init_destination;
  	dest->pub.empty_output_buffer = empty_output_buffer;
  	dest->pub.term_destination = term_destination;
  	dest->out = out;
  }
  
  // -------------------------------------------------------------
  
  /* Expanded data source object for stdio input */
  
  typedef struct
  {
  	mrpt_jpeg_source_mgr pub; /* public fields */
  	CStream* in; /* source stream */
  	JOCTET* buffer; /* start of buffer */
  	boolean start_of_file; /* have we gotten any data yet? */
  } my_source_mgr;
  
  using my_src_ptr = my_source_mgr*;
  
  #define INPUT_BUF_SIZE 4096 /* choose an efficiently fread'able size */
  
  /*
   * Initialize source --- called by jpeg_read_header
   * before any data is actually read.
   */
  
  METHODDEF(void)
  init_source(j_decompress_ptr cinfo)
  {
  	my_src_ptr src = (my_src_ptr)cinfo->src;
  
  	/* We reset the empty-input-file flag for each image,
  	 * but we don't clear the input buffer.
  	 * This is correct behavior for reading a series of images from one source.
  	 */
  	src->start_of_file = TRUE;
  }
  
  /*
   * 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.
   */
  
  METHODDEF(boolean)
  fill_input_buffer(j_decompress_ptr cinfo)
  {
  	my_src_ptr src = (my_src_ptr)cinfo->src;
  	size_t nbytes;
  
  	nbytes = src->in->Read(src->buffer, INPUT_BUF_SIZE);
  
  	if (nbytes <= 0)
  	{
  		if (src->start_of_file) /* Treat empty input file as fatal error */
  		{
  			THROW_EXCEPTION("Error looking for JPEG start data!");
  		}
  
  		/* Insert a fake EOI marker */
  		src->buffer[0] = (JOCTET)0xFF;
  		src->buffer[1] = (JOCTET)JPEG_EOI;
  		nbytes = 2;
  	}
  
  	src->pub.next_input_byte = src->buffer;
  	src->pub.bytes_in_buffer = nbytes;
  	src->start_of_file = FALSE;
  
  	return TRUE;
  }
  
  /*
   * 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.
   */
  
  METHODDEF(void)
  skip_input_data(j_decompress_ptr cinfo, long num_bytes)
  {
  	my_src_ptr src = (my_src_ptr)cinfo->src;
  
  	/* Just a dumb implementation for now.  Could use fseek() except
  	 * it doesn't work on pipes.  Not clear that being smart is worth
  	 * any trouble anyway --- large skips are infrequent.
  	 */
  	if (num_bytes > 0)
  	{
  		while (num_bytes > (long)src->pub.bytes_in_buffer)
  		{
  			num_bytes -= (long)src->pub.bytes_in_buffer;
  			(void)fill_input_buffer(cinfo);
  			/* note we assume that fill_input_buffer will never return FALSE,
  			 * so suspension need not be handled.
  			 */
  		}
  		src->pub.next_input_byte += (size_t)num_bytes;
  		src->pub.bytes_in_buffer -= (size_t)num_bytes;
  	}
  }
  
  /*
   * An additional method that can be provided by data source modules is the
   * resync_to_restart method for error recovery in the presence of RST markers.
   * For the moment, this source module just uses the default resync method
   * provided by the JPEG library.  That method assumes that no backtracking
   * is possible.
   */
  
  /*
   * 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.
   */
  
  METHODDEF(void)
  term_source(j_decompress_ptr cinfo)
  {
  	MRPT_UNUSED_PARAM(cinfo);
  	/* no work necessary here */
  }
  
  /*
   * Prepare for input from a stdio stream.
   * The caller must have already opened the stream, and is responsible
   * for closing it after finishing decompression.
   */
  
  GLOBAL(void)
  jpeg_stdio_src(j_decompress_ptr cinfo, CStream* in)
  {
  	my_src_ptr src;
  
  	/* The source object and input buffer are made permanent so that a series
  	 * of JPEG images can be read from the same file by calling jpeg_stdio_src
  	 * only before the first one.  (If we discarded the buffer at the end of
  	 * one image, we'd likely lose the start of the next one.)
  	 * This makes it unsafe to use this manager and a different source
  	 * manager serially with the same JPEG object.  Caveat programmer.
  	 */
  	if (cinfo->src == nullptr)
  	{ /* first time for this JPEG object? */
  		cinfo->src = (mrpt_jpeg_source_mgr*)(*cinfo->mem->alloc_small)(
  			(j_common_ptr)cinfo, JPOOL_PERMANENT, sizeof(my_source_mgr));
  		src = (my_src_ptr)cinfo->src;
  		src->buffer = (JOCTET*)(*cinfo->mem->alloc_small)(
  			(j_common_ptr)cinfo, JPOOL_PERMANENT,
  			INPUT_BUF_SIZE * sizeof(JOCTET));
  	}
  
  	src = (my_src_ptr)cinfo->src;
  	src->pub.init_source = init_source;
  	src->pub.fill_input_buffer = fill_input_buffer;
  	src->pub.skip_input_data = skip_input_data;
  	src->pub.resync_to_restart =
  		jpeg_resync_to_restart; /* use default method */
  	src->pub.term_source = term_source;
  	src->in = in;
  	src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
  	src->pub.next_input_byte = nullptr; /* until buffer loaded */
  }
  
  // ---------------------------------------------------------------------------------------
  //							END OF JPEG FUNCTIONS PART
  // ---------------------------------------------------------------------------------------
  
  /*---------------------------------------------------------------
  					saveToStreamAsJPEG
   ---------------------------------------------------------------*/
  void CImage::saveToStreamAsJPEG(CStream& out, const int jpeg_quality) const
  {
  #if MRPT_HAS_OPENCV
  	MRPT_START
  
  	makeSureImageIsLoaded();  // For delayed loaded images stored externally
  
  	struct jpeg_compress_struct cinfo;
  	struct jpeg_error_mgr jerr;
  
  	const IplImage* ipl = static_cast<const IplImage*>(img);
  
  	const unsigned int nCols = ipl->width;
  	const unsigned int nRows = ipl->height;
  	const bool is_color = (ipl->nChannels == 3);
  
  	// Some previous verification:
  	ASSERT_(nCols >= 1 && nRows >= 1);
  	ASSERT_(ipl);
  	ASSERT_(ipl->nChannels == 1 || ipl->nChannels == 3);
  
  	// 1) Initialization of the JPEG compresion object:
  	// --------------------------------------------------
  	cinfo.err = jpeg_std_error(&jerr);
  	jpeg_create_compress(&cinfo);
  
  	// 2) Set the destination of jpeg data:
  	// --------------------------------------------------
  	jpeg_stdio_dest(&cinfo, &out);
  
  	// 3) Set parameters for compression:
  	// --------------------------------------------------
  	cinfo.image_width = nCols;
  	cinfo.image_height = nRows;
  	cinfo.input_components = is_color ? 3 : 1;
  	cinfo.in_color_space = is_color ? JCS_RGB : JCS_GRAYSCALE;
  
  	jpeg_set_defaults(&cinfo);
  	/* Make optional parameter settings here */
  	/* Now you can set any non-default parameters you wish to.
  	 * Here we just illustrate the use of quality (quantization table) scaling:
  	 */
  	jpeg_set_quality(
  		&cinfo, jpeg_quality /* quality per cent */,
  		TRUE /* limit to baseline-JPEG values */);
  
  	// 4) Start:
  	// --------------------------------------------------
  	jpeg_start_compress(&cinfo, TRUE);
  
  	// 5) Write scan lines:
  	// --------------------------------------------------
  	if (is_color)
  	{
  		JSAMPROW row_pointer[1]; /* pointer to a single row */
  		row_pointer[0] = (JSAMPROW) new char[ipl->widthStep];
  
  		for (unsigned int row = 0; row < nRows; row++)
  		{
  			// Flip RGB bytes order!
  			char* src;
  			if (ipl->origin == 0)
  				src = &ipl->imageData[row * ipl->widthStep];
  			else
  				src = &ipl->imageData[(nRows - 1 - row) * ipl->widthStep];
  			char* target = (char*)row_pointer[0];
  			for (unsigned int col = 0; col < nCols; col++)
  			{
  				target[0] = src[2];
  				target[1] = src[1];
  				target[2] = src[0];
  
  				target += 3;
  				src += 3;
  			}
  
  			if (1 != jpeg_write_scanlines(&cinfo, row_pointer, 1))
  			{
  				THROW_EXCEPTION("jpeg_write_scanlines: didn't work!!");
  			}
  		}
  
  		delete[] row_pointer[0];
  	}  // end "color"
  	else
  	{  // Is grayscale:
  		JSAMPROW row_pointer[1]; /* pointer to a single row */
  
  		for (unsigned int row = 0; row < nRows; row++)
  		{
  			if (ipl->origin == 0)
  				row_pointer[0] =
  					(JSAMPROW)&ipl->imageData[row * ipl->widthStep];
  			else
  				row_pointer[0] =
  					(JSAMPROW)&ipl
  						->imageData[(nRows - 1 - row) * ipl->widthStep];
  
  			// Gray scale:
  			if (1 != jpeg_write_scanlines(&cinfo, row_pointer, 1))
  			{
  				THROW_EXCEPTION("jpeg_write_scanlines: didn't work!!");
  			}
  		}
  	}
  
  	// 6) Compress and finish:
  	// --------------------------------------------------
  	jpeg_finish_compress(&cinfo);
  	jpeg_destroy_compress(&cinfo);
  
  	// DONE!
  	MRPT_END
  #endif
  }
  
  /*---------------------------------------------------------------
  					saveToStreamAsJPEG
   ---------------------------------------------------------------*/
  void CImage::loadFromStreamAsJPEG(CStream& in)
  {
  #if MRPT_HAS_OPENCV
  	MRPT_START
  
  	struct jpeg_decompress_struct cinfo;
  	struct jpeg_error_mgr jerr;
  
  	/* Step 1: allocate and initialize JPEG decompression object */
  
  	/* We set up the normal JPEG error routines, then override error_exit. */
  	cinfo.err = jpeg_std_error(&jerr);
  
  	/* Now we can initialize the JPEG decompression object. */
  	jpeg_create_decompress(&cinfo);
  
  	/* Step 2: specify data source (eg, a file) */
  	jpeg_stdio_src(&cinfo, &in);
  
  	/* Step 3: read file parameters with jpeg_read_header() */
  	jpeg_read_header(&cinfo, TRUE);
  
  	/* Step 4: set parameters for decompression */
  
  	/* Step 5: Start decompressor */
  	jpeg_start_decompress(&cinfo);
  
  	/* We may need to do some setup of our own at this point before reading
  	 * the data.  After jpeg_start_decompress() we have the correct scaled
  	 * output image dimensions available, as well as the output colormap
  	 * if we asked for color quantization.
  	 * In this example, we need to make an output work buffer of the right size.
  	 */
  	/* JSAMPLEs per row in output buffer */
  	/* physical row width in output buffer */
  	const int row_stride = cinfo.output_width * cinfo.output_components;
  	/* Make a one-row-high sample array that will go away when done with image
  	 */
  	/* Output row buffer */
  	JSAMPARRAY buffer = (*cinfo.mem->alloc_sarray)(
  		(j_common_ptr)&cinfo, JPOOL_IMAGE, row_stride, 1);
  
  	// Resize the CImage now:
  	this->changeSize(
  		cinfo.output_width, cinfo.output_height, cinfo.out_color_components,
  		true);
  	IplImage* ipl = static_cast<IplImage*>(img);
  
  	/* Step 6: while (scan lines remain to be read) */
  	/*           jpeg_read_scanlines(...); */
  
  	/* Here we use the library's state variable cinfo.output_scanline as the
  	 * loop counter, so that we don't have to keep track ourselves.
  	 */
  	const unsigned int nCols = cinfo.output_width;
  	const unsigned int nRows = cinfo.output_height;
  
  	for (unsigned int row = 0; row < nRows; row++)
  	{
  		/* jpeg_read_scanlines expects an array of pointers to scanlines.
  		 * Here the array is only one element long, but you could ask for
  		 * more than one scanline at a time if that's more convenient.
  		 */
  		jpeg_read_scanlines(&cinfo, buffer, 1);
  
  		/* Copy into the CImage object */
  		if (isColor())
  		{
  			// Flip RGB bytes order!
  			char* target = &ipl->imageData[row * ipl->widthStep];
  			const char* src = (char*)buffer[0];
  			for (unsigned int col = 0; col < nCols; col++)
  			{
  				target[0] = src[2];
  				target[1] = src[1];
  				target[2] = src[0];
  
  				target += 3;
  				src += 3;
  			}
  		}
  		else
  		{
  			// Gray scale:
  			memcpy(
  				&ipl->imageData[row * ipl->widthStep], buffer[0], row_stride);
  		}
  	}
  
  	/* Step 7: Finish decompression */
  
  	jpeg_finish_decompress(&cinfo);
  	/* We can ignore the return value since suspension is not possible
  	 * with the stdio data source.
  	 */
  
  	/* Step 8: Release JPEG decompression object */
  
  	/* This is an important step since it will release a good deal of memory. */
  	jpeg_destroy_decompress(&cinfo);
  
  	// DONE!
  	MRPT_END
  #endif
  }
  