1 files changed, 105 insertions, 0 deletions
diff --git a/overlay/x11/rgb2yuv.c b/overlay/x11/rgb2yuv.c
new file mode 100644
index 00000000..8e0c080e
--- /dev/null
+++ b/overlay/x11/rgb2yuv.c
@@ -0,0 +1,105 @@
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "rgb2yuv.h"
+
+static int RGB2YUV_YR[256], RGB2YUV_YG[256], RGB2YUV_YB[256];
+static int RGB2YUV_UR[256], RGB2YUV_UG[256], RGB2YUV_UBVR[256];
+static int RGB2YUV_VG[256], RGB2YUV_VB[256];
+
+void rgb2yuv_init(void)
+{
+	int i;
+
+	for (i = 0; i < 256; i++)
+		RGB2YUV_YR[i] = 65.481 * (i << 8);
+
+	for (i = 0; i < 256; i++)
+		RGB2YUV_YG[i] = 128.553 * (i << 8);
+
+	for (i = 0; i < 256; i++)
+		RGB2YUV_YB[i] = 24.966 * (i << 8);
+
+	for (i = 0; i < 256; i++)
+		RGB2YUV_UR[i] = 37.797 * (i << 8);
+
+	for (i = 0; i < 256; i++)
+		RGB2YUV_UG[i] = 74.203 * (i << 8);
+
+	for (i = 0; i < 256; i++)
+		RGB2YUV_VG[i] = 93.786 * (i << 8);
+
+	for (i = 0; i < 256; i++)
+		RGB2YUV_VB[i] = 18.214 * (i << 8);
+
+	for (i = 0; i < 256; i++)
+		RGB2YUV_UBVR[i] = 112 * (i << 8);
+}
+
+int rgb2yuv(cairo_surface_t *surface, XvImage *image, uint8_t *yuv)
+{
+	uint8_t *data = cairo_image_surface_get_data(surface);
+	int rgb_stride = cairo_image_surface_get_stride(surface);
+	int width = cairo_image_surface_get_width(surface);
+	int height = cairo_image_surface_get_height(surface);
+	int y_stride = image->pitches[0];
+	int uv_stride = image->pitches[1];
+	uint8_t *tmp, *tl, *tr, *bl, *br;
+	int i, j;
+
+	tmp = malloc(2*width*height);
+	if (tmp == NULL)
+		return 0;
+
+	tl = tmp;
+	bl = tmp + width*height;
+
+	for (i = 0; i < height; i++) {
+		uint16_t *rgb = (uint16_t *)(data + i * rgb_stride);
+		for (j = 0; j < width; j++) {
+			uint8_t r = (rgb[j] >> 11) & 0x1f;
+			uint8_t g = (rgb[j] >>  5) & 0x3f;
+			uint8_t b = (rgb[j] >>  0) & 0x1f;
+
+			r = r<<3 | r>>2;
+			g = g<<2 | g>>4;
+			b = b<<3 | b>>2;
+
+			yuv[j] = (RGB2YUV_YR[r] + RGB2YUV_YG[g] + RGB2YUV_YB[b] + 1048576) >> 16;
+			*tl++ = (-RGB2YUV_UR[r] - RGB2YUV_UG[g] + RGB2YUV_UBVR[b] + 8388608) >> 16;
+			*bl++ = (RGB2YUV_UBVR[r] - RGB2YUV_VG[g] - RGB2YUV_VB[b] + 8388608) >> 16;
+		}
+		yuv += y_stride;
+	}
+
+	tl = tmp; tr = tl + 1;
+	bl = tl + width; br = bl + 1;
+	for (i = 0; i < height/2; i ++) {
+		for (j = 0; j < width/2; j ++) {
+			yuv[j] = ((int)*tl + *tr + *bl + *br) >> 2;
+			tl += 2; tr += 2;
+			bl += 2; br += 2;
+		}
+		yuv += uv_stride;
+
+		tl += width; tr += width;
+		bl += width; br += width;
+	}
+
+	tl = tmp + width*height; tr = tl + 1;
+	bl = tl + width; br = bl + 1;
+	for (i = 0; i < height/2; i++) {
+		for (j = 0; j < width/2; j++) {
+			yuv[j] = ((int)*tl + *tr + *bl + *br) >> 2;
+			tl += 2; tr += 2;
+			bl += 2; br += 2;
+		}
+		yuv += uv_stride;
+
+		tl += width; tr += width;
+		bl += width; br += width;
+	}
+
+	free(tmp);
+	return 1;
+}