1 files changed, 103 insertions, 0 deletions
diff --git a/circuitpython/lib/quirc/demo/convert.c b/circuitpython/lib/quirc/demo/convert.c
new file mode 100644
index 0000000..9e6f458
--- /dev/null
+++ b/circuitpython/lib/quirc/demo/convert.c
@@ -0,0 +1,103 @@
+/* quirc -- QR-code recognition library
+ * Copyright (C) 2010-2012 Daniel Beer <dlbeer@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "convert.h"
+
+#define CHANNEL_CLAMP(dst, tmp, lum, chrom) \
+	(tmp) = ((lum) + (chrom)) >> 8; \
+	if ((tmp) < 0) \
+		(tmp) = 0; \
+	if ((tmp) > 255) \
+		(tmp) = 255; \
+	(dst) = (tmp);
+
+void yuyv_to_rgb32(const uint8_t *src, int src_pitch,
+		   int w, int h,
+		   uint8_t *dst, int dst_pitch)
+{
+	int y;
+
+	for (y = 0; y < h; y++) {
+		int x;
+		const uint8_t *srow = src + y * src_pitch;
+		uint8_t *drow = dst + y * dst_pitch;
+
+		for (x = 0; x < w; x += 2) {
+			/* ITU-R colorspace assumed */
+			int y0 = (int)srow[0] * 256;
+			int y1 = (int)srow[2] * 256;
+			int cr = (int)srow[3] - 128;
+			int cb = (int)srow[1] - 128;
+			int r = cr * 359;
+			int g = -cb * 88 - 128 * cr;
+			int b = 454 * cb;
+			int z;
+
+			CHANNEL_CLAMP(drow[0], z, y0, b);
+			CHANNEL_CLAMP(drow[1], z, y0, g);
+			CHANNEL_CLAMP(drow[2], z, y0, r);
+			CHANNEL_CLAMP(drow[4], z, y1, b);
+			CHANNEL_CLAMP(drow[5], z, y1, g);
+			CHANNEL_CLAMP(drow[6], z, y1, r);
+
+			srow += 4;
+			drow += 8;
+		}
+	}
+}
+
+void yuyv_to_luma(const uint8_t *src, int src_pitch,
+		  int w, int h,
+		  uint8_t *dst, int dst_pitch)
+{
+	int y;
+
+	for (y = 0; y < h; y++) {
+		int x;
+		const uint8_t *srow = src + y * src_pitch;
+		uint8_t *drow = dst + y * dst_pitch;
+
+		for (x = 0; x < w; x += 2) {
+			*(drow++) = srow[0];
+			*(drow++) = srow[2];
+			srow += 4;
+		}
+	}
+}
+
+void rgb32_to_luma(const uint8_t *src, int src_pitch,
+		   int w, int h,
+		   uint8_t *dst, int dst_pitch)
+{
+	int y;
+
+	for (y = 0; y < h; y++) {
+		const uint8_t *rgb32 = src + src_pitch * y;
+		uint8_t *gray = dst + y * dst_pitch;
+		int i;
+
+		for (i = 0; i < w; i++) {
+			/* ITU-R colorspace assumed */
+			int r = (int)rgb32[2];
+			int g = (int)rgb32[1];
+			int b = (int)rgb32[0];
+			int sum = r * 59 + g * 150 + b * 29;
+
+			*(gray++) = sum >> 8;
+			rgb32 += 4;
+		}
+	}
+}