Add support for decoding to 565 to libjpeg_turbo

djpeg.c

Index: djpeg.c
diff --git a/djpeg.c b/djpeg.c
index 925ca8a8d71aaf90ee726bfec9478b0d3009cc54..237ed515190a4a71cdf34c39c89f478eb239fbe5 100644
--- a/djpeg.c
+++ b/djpeg.c
@@ -110,6 +110,7 @@ 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
@@ -288,6 +289,10 @@ 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 */