-/******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/
-
-/* This half of the example shows how to read data from the JPEG decompressor.
- * It's a bit more refined than the above, in that we show:
- * (a) how to modify the JPEG library's standard error-reporting behavior;
- * (b) how to allocate workspace using the library's memory manager.
- *
- * Just to make this example a little different from the first one, we'll
- * assume that we do not intend to put the whole image into an in-memory
- * buffer, but to send it line-by-line someplace else. We need a one-
- * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG
- * memory manager allocate it for us. This approach is actually quite useful
- * because we don't need to remember to deallocate the buffer separately: it
- * will go away automatically when the JPEG object is cleaned up.
- */
+ /* 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.
+ */
+ // if ((outfile = fopen(filename, "wb")) == NULL) {
+ // fprintf(stderr, "can't open %s\n", filename);
+ // exit(1);
+ //
+ // }
+ jpeg_stdio_dest(&cinfo, fp);
+
+ /* 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;
+ 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, 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.
+ */
+ row_stride = image_width * 3;/* JSAMPLEs per row in 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];
+
+ (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
+ }
+
+ /* Step 6: Finish compression */
+
+ jpeg_finish_compress(&cinfo);
+
+ /* After finish_compress, we can close the output file. */
+
+ // fclose(fp); --> the caller will close (multiframe treatement)
+
+ /* 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; //???
+}