set_simple_lossless (j_compress_ptr cinfo, char *arg)
{
int pred, pt = 0;
char ch;
ch = ','; /* if not set by sscanf, will be ',' */
if (sscanf(arg, "%d%c", &pred, &ch) < 1)
return FALSE;
if (ch != ',') /* syntax check */
return FALSE;
while (*arg && *arg++ != ',') /* advance to next segment of arg string */
;
if (*arg) {
if (sscanf(arg, "%d", &pt) != 1)
pt = 0;
}
jpeg_simple_lossless(cinfo, pred, pt);
return TRUE;
}
bool CxImageJPG::Encode(CxFile * hFile)
{
if (EncodeSafeCheck(hFile)) return false;
if (head.biClrUsed!=0 && !IsGrayScale()){
strcpy(info.szLastError,"JPEG can save only RGB or GreyScale images");
return false;
}
/* This struct contains the JPEG compression parameters and pointers to
* working space (which is allocated as needed by the JPEG library).
* It is possible to have several such structures, representing multiple
* compression/decompression processes, in existence at once. We refer
* to any one struct (and its associated working data) as a "JPEG object".
*/
struct jpeg_compress_struct cinfo;
/* This struct represents a JPEG error handler. It is declared separately
* because applications often want to supply a specialized error handler
* (see the second half of this file for an example). But here we just
* take the easy way out and use the standard error handler, which will
* print a message on stderr and call exit() if compression fails.
* Note that this struct must live as long as the main JPEG parameter
* struct, to avoid dangling-pointer problems.
*/
//struct jpeg_error_mgr jerr;
/* We use our private extension JPEG error handler. <CSC> */
struct ima_error_mgr jerr;
jerr.buffer=info.szLastError;
/* More stuff */
int row_stride; /* physical row width in image buffer */
JSAMPARRAY buffer; /* Output row buffer */
/* Step 1: allocate and initialize JPEG compression object */
/* We have to set up the error handler first, in case the initialization
* step fails. (Unlikely, but it could happen if you are out of memory.)
* This routine fills in the contents of struct jerr, and returns jerr's
* address which we place into the link field in cinfo.
*/
//cinfo.err = jpeg_std_error(&jerr); <CSC>
/* We set up the normal JPEG error routines, then override error_exit. */
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = ima_jpeg_error_exit;
/* Establish the setjmp return context for my_error_exit to use. */
if (setjmp(jerr.setjmp_buffer)) {
/* If we get here, the JPEG code has signaled an error.
* We need to clean up the JPEG object, close the input file, and return.
*/
strcpy(info.szLastError, jerr.buffer); //<CSC>
jpeg_destroy_compress(&cinfo);
return 0;
}
/* Now we can initialize the JPEG compression object. */
jpeg_create_compress(&cinfo);
/* Step 2: specify data destination (eg, a file) */
/* Note: steps 2 and 3 can be done in either order. */
/* Here we use the library-supplied code to send compressed data to a
* stdio stream. You can also write your own code to do something else.
* VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
* requires it in order to write binary files.
*/
//jpeg_stdio_dest(&cinfo, outfile);
CxFileJpg dest(hFile);
cinfo.dest = &dest;
/* Step 3: set parameters for compression */
/* First we supply a description of the input image.
* Four fields of the cinfo struct must be filled in:
*/
cinfo.image_width = GetWidth(); // image width and height, in pixels
cinfo.image_height = GetHeight();
if (IsGrayScale()){
cinfo.input_components = 1; // # of color components per pixel
cinfo.in_color_space = JCS_GRAYSCALE; /* colorspace of input image */
} else {
cinfo.input_components = 3; // # of color components per pixel
cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
}
/* Now use the library's routine to set default compression parameters.
* (You must set at least cinfo.in_color_space before calling this,
* since the defaults depend on the source color space.)
*/
jpeg_set_defaults(&cinfo);
/* 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, info.nQuality, TRUE /* limit to baseline-JPEG values */);
#ifdef C_ARITH_CODING_SUPPORTED
if ((GetCodecOption() & ENCODE_ARITHMETIC) != 0)
cinfo.arith_code = TRUE;
#endif
#ifdef ENTRPY_OPT_SUPPORTED
if ((GetCodecOption() & ENCODE_OPTIMIZE) != 0)
cinfo.optimize_coding = TRUE;
#endif
if ((GetCodecOption() & ENCODE_GRAYSCALE) != 0)
jpeg_set_colorspace(&cinfo, JCS_GRAYSCALE);
if ((GetCodecOption() & ENCODE_SMOOTHING) != 0)
cinfo.smoothing_factor = m_nSmoothing;
jpeg_set_quality(&cinfo, GetJpegQuality(), (GetCodecOption() & ENCODE_BASELINE) != 0);
#ifdef C_PROGRESSIVE_SUPPORTED
if ((GetCodecOption() & ENCODE_PROGRESSIVE) != 0)
jpeg_simple_progression(&cinfo);
#endif
#ifdef C_LOSSLES_SUPPORTED
if ((GetCodecOption() & ENCODE_LOSSLESS) != 0)
jpeg_simple_lossless(&cinfo, m_nPredictor, m_nPointTransform);
#endif
cinfo.density_unit=1;
cinfo.X_density=(unsigned short)GetXDPI();
cinfo.Y_density=(unsigned short)GetYDPI();
/* Step 4: Start compressor */
/* TRUE ensures that we will write a complete interchange-JPEG file.
* Pass TRUE unless you are very sure of what you're doing.
*/
jpeg_start_compress(&cinfo, TRUE);
/* Step 5: while (scan lines remain to be written) */
/* jpeg_write_scanlines(...); */
/* Here we use the library's state variable cinfo.next_scanline as the
* loop counter, so that we don't have to keep track ourselves.
* To keep things simple, we pass one scanline per call; you can pass
* more if you wish, though.
*/
row_stride = info.dwEffWidth; /* JSAMPLEs per row in image_buffer */
//<DP> "8+row_stride" fix heap deallocation problem during debug???
buffer = (*cinfo.mem->alloc_sarray)
((j_common_ptr) &cinfo, JPOOL_IMAGE, 8+row_stride, 1);
CImageIterator iter(this);
iter.Upset();
while (cinfo.next_scanline < cinfo.image_height) {
// info.nProgress = (long)(100*cinfo.next_scanline/cinfo.image_height);
iter.GetRow(buffer[0], row_stride);
// not necessary if swapped red and blue definition in jmorecfg.h;ln322 <W. Morrison>
if (head.biClrUsed==0){ // swap R & B for RGB images
RGBtoBGR(buffer[0], row_stride); // Lance : 1998/09/01 : Bug ID: EXP-2.1.1-9
}
iter.PrevRow();
(void) jpeg_write_scanlines(&cinfo, buffer, 1);
}
/* Step 6: Finish compression */
jpeg_finish_compress(&cinfo);
/* Step 7: release JPEG compression object */
/* This is an important step since it will release a good deal of memory. */
jpeg_destroy_compress(&cinfo);
/* And we're done! */
return true;
}
