-/*
- * ERROR HANDLING:
- *
- * The JPEG library's standard error handler (jerror.c) is divided into
- * several "methods" which you can override individually. This lets you
- * adjust the behavior without duplicating a lot of code, which you might
- * have to update with each future release.
- *
- * Our example here shows how to override the "error_exit" method so that
- * control is returned to the library's caller when a fatal error occurs,
- * rather than calling exit() as the standard error_exit method does.
- *
- * We use C's setjmp/longjmp facility to return control. This means that the
- * routine which calls the JPEG library must first execute a setjmp() call to
- * establish the return point. We want the replacement error_exit to do a
- * longjmp(). But we need to make the setjmp buffer accessible to the
- * error_exit routine. To do this, we make a private extension of the
- * standard JPEG error handler object. (If we were using C++, we'd say we
- * were making a subclass of the regular error handler.)
- *
- * Here's the extended error handler struct:
- */
+ int fragment_size = inputlength;
+ jpeg_stdio_dest(&cinfo, fp, fragment_size, 1);
+
+ /* 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 = image_width;/* image width and height, in pixels */
+ cinfo.image_height = image_height;
+ if ( sample_pixel == 3 )
+ {
+ cinfo.input_components = 3; /* # of color components per pixel */
+ cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
+ }
+ else
+ {
+ cinfo.input_components = 1; /* # of color components per pixel */
+ cinfo.in_color_space = JCS_GRAYSCALE; /* 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);
+ /*
+ * http://www.koders.com/c/fid80DBBF1D49D004EF71CE7C493C34610C4F17D3D3.aspx
+ * http://studio.imagemagick.org/pipermail/magick-users/2002-September/004685.html
+ * You need to set -quality 101 or greater. If quality is 100 or less you
+ * get regular JPEG output. This is not explained in the documentation, only
+ * in the comments in coder/jpeg.c. When you have configured libjpeg with
+ * lossless support, then
+ *
+ * quality=predictor*100 + point_transform
+ *
+ * If you don't know what these values should be, just use 101.
+ * They only affect the compression ratio, not the image appearance,
+ * which is lossless.
+ */
+ jpeg_simple_lossless (&cinfo, 1, 1);
+ /* 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, quality, TRUE /* limit to baseline-JPEG values */);
+
+ /* 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.
+ */
+ if (sample_pixel == 3)
+ {
+ row_stride = image_width * 3;/* JSAMPLEs per row in image_buffer */
+ }
+ else
+ {
+ assert( sample_pixel == 1 );
+ row_stride = image_width * 1;/* JSAMPLEs per row in image_buffer */
+ }
+
+ (void)numZ;
+
+ uint8_t* input_buffer = (uint8_t*)inputdata;
+ //uint8_t *pbuffer = input_buffer;
+ //int i;
+ //for(i=0; i<numZ; ++i)
+// {
+ JSAMPLE *image_buffer = (JSAMPLE*) input_buffer;
+ JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
+ row_pointer[0] = image_buffer;
+
+ while (cinfo.next_scanline < cinfo.image_height) {
+ /* jpeg_write_scanlines expects an array of pointers to scanlines.
+ * Here the array is only one element long, but you could pass
+ * more than one scanline at a time if that's more convenient.
+ */
+ //row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride];
+
+ if( jpeg_write_scanlines(&cinfo, row_pointer, 1) != 1)
+ {
+ //entering suspension mode, basically we wrote the whole jpeg fragment
+ // technically we could enforce that by checkig the value of row_pointer to
+ // actually be at the end of the image...TODO
+ return false;
+ }
+ row_pointer[0] += row_stride;
+ }
+// pbuffer+=fragment_size; //shift to next image
+
+ //Upodate frag size
+// size_t end = fp->tellp();
+// std::cerr << "DIFF: " << end-beg << std::endl;
+
+// JpegPair &jp = v[i];
+// jp.second = end-beg;
+ //beg = end; //
+ // }
+
+ /* 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;
+}