Add support for decompressing to RGB565 (16-bit) pixels

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1295 632fc199-4ca6-4c93-a231-07263d6284db

djpeg.c

@@ -4,7 +4,7 @@
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1991-1997, Thomas G. Lane.
  * libjpeg-turbo Modifications:
- * Copyright (C) 2010-2011, 2013, D. R. Commander.
+ * Copyright (C) 2010-2011, 2013-2014, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This file contains a command-line user interface for the JPEG decompressor.
@@ -107,6 +107,7 @@ usage (void)
   fprintf(stderr, "  -fast          Fast, low-quality processing\n");
   fprintf(stderr, "  -grayscale     Force grayscale output\n");
   fprintf(stderr, "  -rgb           Force RGB output\n");
+  fprintf(stderr, "  -rgb565        Force RGB565 output\n");
 #ifdef IDCT_SCALING_SUPPORTED
   fprintf(stderr, "  -scale M/N     Scale output image by fraction M/N, eg, 1/8\n");
 #endif
@@ -281,6 +282,10 @@ parse_switches (j_decompress_ptr cinfo, int argc, char **argv,
       /* Force RGB output. */
       cinfo->out_color_space = JCS_RGB;
 
+    } else if (keymatch(arg, "rgb565", 2)) {
+      /* Force RGB565 output. */
+      cinfo->out_color_space = JCS_RGB565;
+
     } else if (keymatch(arg, "map", 3)) {
       /* Quantize to a color map taken from an input file. */
       if (++argn >= argc)       /* advance to next argument */