1 files changed, 99 insertions, 0 deletions

diff --git a/firmware/target/arm/gigabeat/meg-fx/lcd-meg-fx.c b/firmware/target/arm/gigabeat/meg-fx/lcd-meg-fx.c
index 5ec62271ad..7c8185d6c8 100644
--- a/firmware/target/arm/gigabeat/meg-fx/lcd-meg-fx.c
+++ b/firmware/target/arm/gigabeat/meg-fx/lcd-meg-fx.c
@@ -29,3 +29,102 @@ void lcd_update(void)
 {
     lcd_update_rect(0, 0, LCD_WIDTH, LCD_HEIGHT);
 }
+
+#define CSUB_X 2
+#define CSUB_Y 2
+
+#define RYFAC (31*257)
+#define GYFAC (63*257)
+#define BYFAC (31*257)
+#define RVFAC 11170     /* 31 * 257 *  1.402    */
+#define GVFAC (-11563)  /* 63 * 257 * -0.714136 */
+#define GUFAC (-5572)   /* 63 * 257 * -0.344136 */
+#define BUFAC 14118     /* 31 * 257 *  1.772    */
+
+#define ROUNDOFFS (127*257)
+
+/* Performance function to blit a YUV bitmap directly to the LCD */
+void lcd_yuv_blit(unsigned char * const src[3],
+                  int src_x, int src_y, int stride,
+                  int x, int y, int width, int height)
+{
+    fb_data *dst, *dst_end;
+
+    width = (width + 1) & ~1;
+
+    dst = (fb_data*)FRAME + LCD_WIDTH * y + x;
+    dst_end = dst + LCD_WIDTH * height;
+
+    do
+    {
+        fb_data *dst_row = dst;
+        fb_data *row_end = dst_row + width;
+        const unsigned char *ysrc = src[0] + stride * src_y + src_x;
+        int y, u, v;
+        int red, green, blue;
+        unsigned rbits, gbits, bbits;
+
+        /* upsampling, YUV->RGB conversion and reduction to RGB565 in one go */
+        const unsigned char *usrc = src[1] + (stride/CSUB_X) * (src_y/CSUB_Y)
+                                           + (src_x/CSUB_X);
+        const unsigned char *vsrc = src[2] + (stride/CSUB_X) * (src_y/CSUB_Y)
+                                           + (src_x/CSUB_X);
+        int xphase = src_x % CSUB_X;
+        int rc, gc, bc;
+
+        u = *usrc++ - 128;
+        v = *vsrc++ - 128;
+        rc = RVFAC * v + ROUNDOFFS;
+        gc = GVFAC * v + GUFAC * u + ROUNDOFFS;
+        bc = BUFAC * u + ROUNDOFFS;
+
+        do
+        {
+            y = *ysrc++;
+            red   = RYFAC * y + rc;
+            green = GYFAC * y + gc;
+            blue  = BYFAC * y + bc;
+
+            if ((unsigned)red > (RYFAC*255+ROUNDOFFS))
+            {
+                if (red < 0)
+                    red = 0;
+                else
+                    red = (RYFAC*255+ROUNDOFFS);
+            }
+            if ((unsigned)green > (GYFAC*255+ROUNDOFFS))
+            {
+                if (green < 0)
+                    green = 0;
+                else
+                    green = (GYFAC*255+ROUNDOFFS);
+            }
+            if ((unsigned)blue > (BYFAC*255+ROUNDOFFS))
+            {
+                if (blue < 0)
+                    blue = 0;
+                else
+                    blue = (BYFAC*255+ROUNDOFFS);
+            }
+            rbits = ((unsigned)red) >> 16 ;
+            gbits = ((unsigned)green) >> 16 ;
+            bbits = ((unsigned)blue) >> 16 ;
+            *dst_row++ = (rbits << 11) | (gbits << 5) | bbits;
+
+            if (++xphase >= CSUB_X)
+            {
+                u = *usrc++ - 128;
+                v = *vsrc++ - 128;
+                rc = RVFAC * v + ROUNDOFFS;
+                gc = GVFAC * v + GUFAC * u + ROUNDOFFS;
+                bc = BUFAC * u + ROUNDOFFS;
+                xphase = 0;
+            }
+        }
+        while (dst_row < row_end);
+
+        src_y++;
+        dst += LCD_WIDTH;
+    }
+    while (dst < dst_end);
+}