From a69b4089f5e88444e03c7dda282f5edda38705fd Mon Sep 17 00:00:00 2001
From: Ahmet Inan <xdsopl@googlemail.com>
Date: Thu, 1 Jan 2015 17:06:48 +0100
Subject: [PATCH] WIP: replaced linear with much more flexible circular buffer

---
 app/src/main/rs/blur.rsh           |    1 +
 app/src/main/rs/blur_generated.rsh | 1111 ++++++++++++++--------------
 app/src/main/rs/constants.rsh      |    2 +
 app/src/main/rs/decoder.rs         |   96 +--
 app/src/main/rs/initialization.rsh |    6 +-
 app/src/main/rs/modes.rsh          |   45 +-
 app/src/main/rs/state.rsh          |    6 +-
 utils/blur.c                       |   15 +-
 8 files changed, 630 insertions(+), 652 deletions(-)

diff --git a/app/src/main/rs/blur.rsh b/app/src/main/rs/blur.rsh
index 8e6f6da..c0a81d3 100644
--- a/app/src/main/rs/blur.rsh
+++ b/app/src/main/rs/blur.rsh
@@ -18,6 +18,7 @@ limitations under the License.
 #define BLUR_RSH
 
 #include "exports.rsh"
+#include "state.rsh"
 #include "blur_generated.rsh"
 
 void incr_blur()
diff --git a/app/src/main/rs/blur_generated.rsh b/app/src/main/rs/blur_generated.rsh
index 178e53b..a7afb4d 100644
--- a/app/src/main/rs/blur_generated.rsh
+++ b/app/src/main/rs/blur_generated.rsh
@@ -1,23 +1,24 @@
 /* code generated by 'utils/blur.c' */
 static uchar value_blur(int pixel, int begin, int end)
 {
-	int i = (pixel * (end - begin) + (end - begin) / 2) / bitmap_width + begin;
+	int p = (pixel * (end - begin) + (end - begin) / 2) / bitmap_width + begin;
+	int i = p & buffer_mask;
 	int weight_sum = 0;
 	int value_sum = 0;
 	switch (blur_power) {
 	case 0:
-		if ((i-1) < begin || end <= (i+1)) {
-			if (begin <= (i-1)) {
+		if ((p-1) < begin || end <= (p+1) || (i-1) < 0 || buffer_length <= (i+1)) {
+			if (begin <= (p-1)) {
 				weight_sum += 217;
-				value_sum += 217 * value_buffer[i-1];
+				value_sum += 217 * value_buffer[(i-1)&buffer_mask];
 			}
-			if ((i+0) < end) {
+			if ((p+0) < end) {
 				weight_sum += 19608;
-				value_sum += 19608 * value_buffer[i+0];
+				value_sum += 19608 * value_buffer[(i+0)&buffer_mask];
 			}
-			if ((i+1) < end) {
+			if ((p+1) < end) {
 				weight_sum += 217;
-				value_sum += 217 * value_buffer[i+1];
+				value_sum += 217 * value_buffer[(i+1)&buffer_mask];
 			}
 			return value_sum / weight_sum;
 		}
@@ -25,34 +26,34 @@ static uchar value_blur(int pixel, int begin, int end)
 			16027 * value_buffer[i+0] +
 			178 * value_buffer[i+1]) >> 14;
 	case 1:
-		if ((i-3) < begin || end <= (i+3)) {
-			if (begin <= (i-3)) {
+		if ((p-3) < begin || end <= (p+3) || (i-3) < 0 || buffer_length <= (i+3)) {
+			if (begin <= (p-3)) {
 				weight_sum += 72;
-				value_sum += 72 * value_buffer[i-3];
+				value_sum += 72 * value_buffer[(i-3)&buffer_mask];
 			}
-			if (begin <= (i-2)) {
+			if (begin <= (p-2)) {
 				weight_sum += 884;
-				value_sum += 884 * value_buffer[i-2];
+				value_sum += 884 * value_buffer[(i-2)&buffer_mask];
 			}
-			if (begin <= (i-1)) {
+			if (begin <= (p-1)) {
 				weight_sum += 3964;
-				value_sum += 3964 * value_buffer[i-1];
+				value_sum += 3964 * value_buffer[(i-1)&buffer_mask];
 			}
-			if ((i+0) < end) {
+			if ((p+0) < end) {
 				weight_sum += 6536;
-				value_sum += 6536 * value_buffer[i+0];
+				value_sum += 6536 * value_buffer[(i+0)&buffer_mask];
 			}
-			if ((i+1) < end) {
+			if ((p+1) < end) {
 				weight_sum += 3964;
-				value_sum += 3964 * value_buffer[i+1];
+				value_sum += 3964 * value_buffer[(i+1)&buffer_mask];
 			}
-			if ((i+2) < end) {
+			if ((p+2) < end) {
 				weight_sum += 884;
-				value_sum += 884 * value_buffer[i+2];
+				value_sum += 884 * value_buffer[(i+2)&buffer_mask];
 			}
-			if ((i+3) < end) {
+			if ((p+3) < end) {
 				weight_sum += 72;
-				value_sum += 72 * value_buffer[i+3];
+				value_sum += 72 * value_buffer[(i+3)&buffer_mask];
 			}
 			return value_sum / weight_sum;
 		}
@@ -64,50 +65,50 @@ static uchar value_blur(int pixel, int begin, int end)
 			884 * value_buffer[i+2] +
 			72 * value_buffer[i+3]) >> 14;
 	case 2:
-		if ((i-5) < begin || end <= (i+5)) {
-			if (begin <= (i-5)) {
+		if ((p-5) < begin || end <= (p+5) || (i-5) < 0 || buffer_length <= (i+5)) {
+			if (begin <= (p-5)) {
 				weight_sum += 43;
-				value_sum += 43 * value_buffer[i-5];
+				value_sum += 43 * value_buffer[(i-5)&buffer_mask];
 			}
-			if (begin <= (i-4)) {
+			if (begin <= (p-4)) {
 				weight_sum += 220;
-				value_sum += 220 * value_buffer[i-4];
+				value_sum += 220 * value_buffer[(i-4)&buffer_mask];
 			}
-			if (begin <= (i-3)) {
+			if (begin <= (p-3)) {
 				weight_sum += 776;
-				value_sum += 776 * value_buffer[i-3];
+				value_sum += 776 * value_buffer[(i-3)&buffer_mask];
 			}
-			if (begin <= (i-2)) {
+			if (begin <= (p-2)) {
 				weight_sum += 1908;
-				value_sum += 1908 * value_buffer[i-2];
+				value_sum += 1908 * value_buffer[(i-2)&buffer_mask];
 			}
-			if (begin <= (i-1)) {
+			if (begin <= (p-1)) {
 				weight_sum += 3275;
-				value_sum += 3275 * value_buffer[i-1];
+				value_sum += 3275 * value_buffer[(i-1)&buffer_mask];
 			}
-			if ((i+0) < end) {
+			if ((p+0) < end) {
 				weight_sum += 3921;
-				value_sum += 3921 * value_buffer[i+0];
+				value_sum += 3921 * value_buffer[(i+0)&buffer_mask];
 			}
-			if ((i+1) < end) {
+			if ((p+1) < end) {
 				weight_sum += 3275;
-				value_sum += 3275 * value_buffer[i+1];
+				value_sum += 3275 * value_buffer[(i+1)&buffer_mask];
 			}
-			if ((i+2) < end) {
+			if ((p+2) < end) {
 				weight_sum += 1908;
-				value_sum += 1908 * value_buffer[i+2];
+				value_sum += 1908 * value_buffer[(i+2)&buffer_mask];
 			}
-			if ((i+3) < end) {
+			if ((p+3) < end) {
 				weight_sum += 776;
-				value_sum += 776 * value_buffer[i+3];
+				value_sum += 776 * value_buffer[(i+3)&buffer_mask];
 			}
-			if ((i+4) < end) {
+			if ((p+4) < end) {
 				weight_sum += 220;
-				value_sum += 220 * value_buffer[i+4];
+				value_sum += 220 * value_buffer[(i+4)&buffer_mask];
 			}
-			if ((i+5) < end) {
+			if ((p+5) < end) {
 				weight_sum += 43;
-				value_sum += 43 * value_buffer[i+5];
+				value_sum += 43 * value_buffer[(i+5)&buffer_mask];
 			}
 			return value_sum / weight_sum;
 		}
@@ -123,82 +124,82 @@ static uchar value_blur(int pixel, int begin, int end)
 			220 * value_buffer[i+4] +
 			43 * value_buffer[i+5]) >> 14;
 	case 3:
-		if ((i-9) < begin || end <= (i+9)) {
-			if (begin <= (i-9)) {
+		if ((p-9) < begin || end <= (p+9) || (i-9) < 0 || buffer_length <= (i+9)) {
+			if (begin <= (p-9)) {
 				weight_sum += 24;
-				value_sum += 24 * value_buffer[i-9];
+				value_sum += 24 * value_buffer[(i-9)&buffer_mask];
 			}
-			if (begin <= (i-8)) {
+			if (begin <= (p-8)) {
 				weight_sum += 62;
-				value_sum += 62 * value_buffer[i-8];
+				value_sum += 62 * value_buffer[(i-8)&buffer_mask];
 			}
-			if (begin <= (i-7)) {
+			if (begin <= (p-7)) {
 				weight_sum += 143;
-				value_sum += 143 * value_buffer[i-7];
+				value_sum += 143 * value_buffer[(i-7)&buffer_mask];
 			}
-			if (begin <= (i-6)) {
+			if (begin <= (p-6)) {
 				weight_sum += 294;
-				value_sum += 294 * value_buffer[i-6];
+				value_sum += 294 * value_buffer[(i-6)&buffer_mask];
 			}
-			if (begin <= (i-5)) {
+			if (begin <= (p-5)) {
 				weight_sum += 543;
-				value_sum += 543 * value_buffer[i-5];
+				value_sum += 543 * value_buffer[(i-5)&buffer_mask];
 			}
-			if (begin <= (i-4)) {
+			if (begin <= (p-4)) {
 				weight_sum += 895;
-				value_sum += 895 * value_buffer[i-4];
+				value_sum += 895 * value_buffer[(i-4)&buffer_mask];
 			}
-			if (begin <= (i-3)) {
+			if (begin <= (p-3)) {
 				weight_sum += 1321;
-				value_sum += 1321 * value_buffer[i-3];
+				value_sum += 1321 * value_buffer[(i-3)&buffer_mask];
 			}
-			if (begin <= (i-2)) {
+			if (begin <= (p-2)) {
 				weight_sum += 1744;
-				value_sum += 1744 * value_buffer[i-2];
+				value_sum += 1744 * value_buffer[(i-2)&buffer_mask];
 			}
-			if (begin <= (i-1)) {
+			if (begin <= (p-1)) {
 				weight_sum += 2061;
-				value_sum += 2061 * value_buffer[i-1];
+				value_sum += 2061 * value_buffer[(i-1)&buffer_mask];
 			}
-			if ((i+0) < end) {
+			if ((p+0) < end) {
 				weight_sum += 2178;
-				value_sum += 2178 * value_buffer[i+0];
+				value_sum += 2178 * value_buffer[(i+0)&buffer_mask];
 			}
-			if ((i+1) < end) {
+			if ((p+1) < end) {
 				weight_sum += 2061;
-				value_sum += 2061 * value_buffer[i+1];
+				value_sum += 2061 * value_buffer[(i+1)&buffer_mask];
 			}
-			if ((i+2) < end) {
+			if ((p+2) < end) {
 				weight_sum += 1744;
-				value_sum += 1744 * value_buffer[i+2];
+				value_sum += 1744 * value_buffer[(i+2)&buffer_mask];
 			}
-			if ((i+3) < end) {
+			if ((p+3) < end) {
 				weight_sum += 1321;
-				value_sum += 1321 * value_buffer[i+3];
+				value_sum += 1321 * value_buffer[(i+3)&buffer_mask];
 			}
-			if ((i+4) < end) {
+			if ((p+4) < end) {
 				weight_sum += 895;
-				value_sum += 895 * value_buffer[i+4];
+				value_sum += 895 * value_buffer[(i+4)&buffer_mask];
 			}
-			if ((i+5) < end) {
+			if ((p+5) < end) {
 				weight_sum += 543;
-				value_sum += 543 * value_buffer[i+5];
+				value_sum += 543 * value_buffer[(i+5)&buffer_mask];
 			}
-			if ((i+6) < end) {
+			if ((p+6) < end) {
 				weight_sum += 294;
-				value_sum += 294 * value_buffer[i+6];
+				value_sum += 294 * value_buffer[(i+6)&buffer_mask];
 			}
-			if ((i+7) < end) {
+			if ((p+7) < end) {
 				weight_sum += 143;
-				value_sum += 143 * value_buffer[i+7];
+				value_sum += 143 * value_buffer[(i+7)&buffer_mask];
 			}
-			if ((i+8) < end) {
+			if ((p+8) < end) {
 				weight_sum += 62;
-				value_sum += 62 * value_buffer[i+8];
+				value_sum += 62 * value_buffer[(i+8)&buffer_mask];
 			}
-			if ((i+9) < end) {
+			if ((p+9) < end) {
 				weight_sum += 24;
-				value_sum += 24 * value_buffer[i+9];
+				value_sum += 24 * value_buffer[(i+9)&buffer_mask];
 			}
 			return value_sum / weight_sum;
 		}
@@ -222,146 +223,146 @@ static uchar value_blur(int pixel, int begin, int end)
 			62 * value_buffer[i+8] +
 			24 * value_buffer[i+9]) >> 14;
 	case 4:
-		if ((i-17) < begin || end <= (i+17)) {
-			if (begin <= (i-17)) {
+		if ((p-17) < begin || end <= (p+17) || (i-17) < 0 || buffer_length <= (i+17)) {
+			if (begin <= (p-17)) {
 				weight_sum += 12;
-				value_sum += 12 * value_buffer[i-17];
+				value_sum += 12 * value_buffer[(i-17)&buffer_mask];
 			}
-			if (begin <= (i-16)) {
+			if (begin <= (p-16)) {
 				weight_sum += 21;
-				value_sum += 21 * value_buffer[i-16];
+				value_sum += 21 * value_buffer[(i-16)&buffer_mask];
 			}
-			if (begin <= (i-15)) {
+			if (begin <= (p-15)) {
 				weight_sum += 34;
-				value_sum += 34 * value_buffer[i-15];
+				value_sum += 34 * value_buffer[(i-15)&buffer_mask];
 			}
-			if (begin <= (i-14)) {
+			if (begin <= (p-14)) {
 				weight_sum += 54;
-				value_sum += 54 * value_buffer[i-14];
+				value_sum += 54 * value_buffer[(i-14)&buffer_mask];
 			}
-			if (begin <= (i-13)) {
+			if (begin <= (p-13)) {
 				weight_sum += 83;
-				value_sum += 83 * value_buffer[i-13];
+				value_sum += 83 * value_buffer[(i-13)&buffer_mask];
 			}
-			if (begin <= (i-12)) {
+			if (begin <= (p-12)) {
 				weight_sum += 122;
-				value_sum += 122 * value_buffer[i-12];
+				value_sum += 122 * value_buffer[(i-12)&buffer_mask];
 			}
-			if (begin <= (i-11)) {
+			if (begin <= (p-11)) {
 				weight_sum += 175;
-				value_sum += 175 * value_buffer[i-11];
+				value_sum += 175 * value_buffer[(i-11)&buffer_mask];
 			}
-			if (begin <= (i-10)) {
+			if (begin <= (p-10)) {
 				weight_sum += 243;
-				value_sum += 243 * value_buffer[i-10];
+				value_sum += 243 * value_buffer[(i-10)&buffer_mask];
 			}
-			if (begin <= (i-9)) {
+			if (begin <= (p-9)) {
 				weight_sum += 326;
-				value_sum += 326 * value_buffer[i-9];
+				value_sum += 326 * value_buffer[(i-9)&buffer_mask];
 			}
-			if (begin <= (i-8)) {
+			if (begin <= (p-8)) {
 				weight_sum += 425;
-				value_sum += 425 * value_buffer[i-8];
+				value_sum += 425 * value_buffer[(i-8)&buffer_mask];
 			}
-			if (begin <= (i-7)) {
+			if (begin <= (p-7)) {
 				weight_sum += 537;
-				value_sum += 537 * value_buffer[i-7];
+				value_sum += 537 * value_buffer[(i-7)&buffer_mask];
 			}
-			if (begin <= (i-6)) {
+			if (begin <= (p-6)) {
 				weight_sum += 658;
-				value_sum += 658 * value_buffer[i-6];
+				value_sum += 658 * value_buffer[(i-6)&buffer_mask];
 			}
-			if (begin <= (i-5)) {
+			if (begin <= (p-5)) {
 				weight_sum += 781;
-				value_sum += 781 * value_buffer[i-5];
+				value_sum += 781 * value_buffer[(i-5)&buffer_mask];
 			}
-			if (begin <= (i-4)) {
+			if (begin <= (p-4)) {
 				weight_sum += 899;
-				value_sum += 899 * value_buffer[i-4];
+				value_sum += 899 * value_buffer[(i-4)&buffer_mask];
 			}
-			if (begin <= (i-3)) {
+			if (begin <= (p-3)) {
 				weight_sum += 1002;
-				value_sum += 1002 * value_buffer[i-3];
+				value_sum += 1002 * value_buffer[(i-3)&buffer_mask];
 			}
-			if (begin <= (i-2)) {
+			if (begin <= (p-2)) {
 				weight_sum += 1083;
-				value_sum += 1083 * value_buffer[i-2];
+				value_sum += 1083 * value_buffer[(i-2)&buffer_mask];
 			}
-			if (begin <= (i-1)) {
+			if (begin <= (p-1)) {
 				weight_sum += 1135;
-				value_sum += 1135 * value_buffer[i-1];
+				value_sum += 1135 * value_buffer[(i-1)&buffer_mask];
 			}
-			if ((i+0) < end) {
+			if ((p+0) < end) {
 				weight_sum += 1153;
-				value_sum += 1153 * value_buffer[i+0];
+				value_sum += 1153 * value_buffer[(i+0)&buffer_mask];
 			}
-			if ((i+1) < end) {
+			if ((p+1) < end) {
 				weight_sum += 1135;
-				value_sum += 1135 * value_buffer[i+1];
+				value_sum += 1135 * value_buffer[(i+1)&buffer_mask];
 			}
-			if ((i+2) < end) {
+			if ((p+2) < end) {
 				weight_sum += 1083;
-				value_sum += 1083 * value_buffer[i+2];
+				value_sum += 1083 * value_buffer[(i+2)&buffer_mask];
 			}
-			if ((i+3) < end) {
+			if ((p+3) < end) {
 				weight_sum += 1002;
-				value_sum += 1002 * value_buffer[i+3];
+				value_sum += 1002 * value_buffer[(i+3)&buffer_mask];
 			}
-			if ((i+4) < end) {
+			if ((p+4) < end) {
 				weight_sum += 899;
-				value_sum += 899 * value_buffer[i+4];
+				value_sum += 899 * value_buffer[(i+4)&buffer_mask];
 			}
-			if ((i+5) < end) {
+			if ((p+5) < end) {
 				weight_sum += 781;
-				value_sum += 781 * value_buffer[i+5];
+				value_sum += 781 * value_buffer[(i+5)&buffer_mask];
 			}
-			if ((i+6) < end) {
+			if ((p+6) < end) {
 				weight_sum += 658;
-				value_sum += 658 * value_buffer[i+6];
+				value_sum += 658 * value_buffer[(i+6)&buffer_mask];
 			}
-			if ((i+7) < end) {
+			if ((p+7) < end) {
 				weight_sum += 537;
-				value_sum += 537 * value_buffer[i+7];
+				value_sum += 537 * value_buffer[(i+7)&buffer_mask];
 			}
-			if ((i+8) < end) {
+			if ((p+8) < end) {
 				weight_sum += 425;
-				value_sum += 425 * value_buffer[i+8];
+				value_sum += 425 * value_buffer[(i+8)&buffer_mask];
 			}
-			if ((i+9) < end) {
+			if ((p+9) < end) {
 				weight_sum += 326;
-				value_sum += 326 * value_buffer[i+9];
+				value_sum += 326 * value_buffer[(i+9)&buffer_mask];
 			}
-			if ((i+10) < end) {
+			if ((p+10) < end) {
 				weight_sum += 243;
-				value_sum += 243 * value_buffer[i+10];
+				value_sum += 243 * value_buffer[(i+10)&buffer_mask];
 			}
-			if ((i+11) < end) {
+			if ((p+11) < end) {
 				weight_sum += 175;
-				value_sum += 175 * value_buffer[i+11];
+				value_sum += 175 * value_buffer[(i+11)&buffer_mask];
 			}
-			if ((i+12) < end) {
+			if ((p+12) < end) {
 				weight_sum += 122;
-				value_sum += 122 * value_buffer[i+12];
+				value_sum += 122 * value_buffer[(i+12)&buffer_mask];
 			}
-			if ((i+13) < end) {
+			if ((p+13) < end) {
 				weight_sum += 83;
-				value_sum += 83 * value_buffer[i+13];
+				value_sum += 83 * value_buffer[(i+13)&buffer_mask];
 			}
-			if ((i+14) < end) {
+			if ((p+14) < end) {
 				weight_sum += 54;
-				value_sum += 54 * value_buffer[i+14];
+				value_sum += 54 * value_buffer[(i+14)&buffer_mask];
 			}
-			if ((i+15) < end) {
+			if ((p+15) < end) {
 				weight_sum += 34;
-				value_sum += 34 * value_buffer[i+15];
+				value_sum += 34 * value_buffer[(i+15)&buffer_mask];
 			}
-			if ((i+16) < end) {
+			if ((p+16) < end) {
 				weight_sum += 21;
-				value_sum += 21 * value_buffer[i+16];
+				value_sum += 21 * value_buffer[(i+16)&buffer_mask];
 			}
-			if ((i+17) < end) {
+			if ((p+17) < end) {
 				weight_sum += 12;
-				value_sum += 12 * value_buffer[i+17];
+				value_sum += 12 * value_buffer[(i+17)&buffer_mask];
 			}
 			return value_sum / weight_sum;
 		}
@@ -401,274 +402,274 @@ static uchar value_blur(int pixel, int begin, int end)
 			21 * value_buffer[i+16] +
 			12 * value_buffer[i+17]) >> 14;
 	case 5:
-		if ((i-33) < begin || end <= (i+33)) {
-			if (begin <= (i-33)) {
+		if ((p-33) < begin || end <= (p+33) || (i-33) < 0 || buffer_length <= (i+33)) {
+			if (begin <= (p-33)) {
 				weight_sum += 6;
-				value_sum += 6 * value_buffer[i-33];
+				value_sum += 6 * value_buffer[(i-33)&buffer_mask];
 			}
-			if (begin <= (i-32)) {
+			if (begin <= (p-32)) {
 				weight_sum += 8;
-				value_sum += 8 * value_buffer[i-32];
+				value_sum += 8 * value_buffer[(i-32)&buffer_mask];
 			}
-			if (begin <= (i-31)) {
+			if (begin <= (p-31)) {
 				weight_sum += 11;
-				value_sum += 11 * value_buffer[i-31];
+				value_sum += 11 * value_buffer[(i-31)&buffer_mask];
 			}
-			if (begin <= (i-30)) {
+			if (begin <= (p-30)) {
 				weight_sum += 14;
-				value_sum += 14 * value_buffer[i-30];
+				value_sum += 14 * value_buffer[(i-30)&buffer_mask];
 			}
-			if (begin <= (i-29)) {
+			if (begin <= (p-29)) {
 				weight_sum += 18;
-				value_sum += 18 * value_buffer[i-29];
+				value_sum += 18 * value_buffer[(i-29)&buffer_mask];
 			}
-			if (begin <= (i-28)) {
+			if (begin <= (p-28)) {
 				weight_sum += 23;
-				value_sum += 23 * value_buffer[i-28];
+				value_sum += 23 * value_buffer[(i-28)&buffer_mask];
 			}
-			if (begin <= (i-27)) {
+			if (begin <= (p-27)) {
 				weight_sum += 29;
-				value_sum += 29 * value_buffer[i-27];
+				value_sum += 29 * value_buffer[(i-27)&buffer_mask];
 			}
-			if (begin <= (i-26)) {
+			if (begin <= (p-26)) {
 				weight_sum += 36;
-				value_sum += 36 * value_buffer[i-26];
+				value_sum += 36 * value_buffer[(i-26)&buffer_mask];
 			}
-			if (begin <= (i-25)) {
+			if (begin <= (p-25)) {
 				weight_sum += 44;
-				value_sum += 44 * value_buffer[i-25];
+				value_sum += 44 * value_buffer[(i-25)&buffer_mask];
 			}
-			if (begin <= (i-24)) {
+			if (begin <= (p-24)) {
 				weight_sum += 54;
-				value_sum += 54 * value_buffer[i-24];
+				value_sum += 54 * value_buffer[(i-24)&buffer_mask];
 			}
-			if (begin <= (i-23)) {
+			if (begin <= (p-23)) {
 				weight_sum += 66;
-				value_sum += 66 * value_buffer[i-23];
+				value_sum += 66 * value_buffer[(i-23)&buffer_mask];
 			}
-			if (begin <= (i-22)) {
+			if (begin <= (p-22)) {
 				weight_sum += 80;
-				value_sum += 80 * value_buffer[i-22];
+				value_sum += 80 * value_buffer[(i-22)&buffer_mask];
 			}
-			if (begin <= (i-21)) {
+			if (begin <= (p-21)) {
 				weight_sum += 96;
-				value_sum += 96 * value_buffer[i-21];
+				value_sum += 96 * value_buffer[(i-21)&buffer_mask];
 			}
-			if (begin <= (i-20)) {
+			if (begin <= (p-20)) {
 				weight_sum += 113;
-				value_sum += 113 * value_buffer[i-20];
+				value_sum += 113 * value_buffer[(i-20)&buffer_mask];
 			}
-			if (begin <= (i-19)) {
+			if (begin <= (p-19)) {
 				weight_sum += 133;
-				value_sum += 133 * value_buffer[i-19];
+				value_sum += 133 * value_buffer[(i-19)&buffer_mask];
 			}
-			if (begin <= (i-18)) {
+			if (begin <= (p-18)) {
 				weight_sum += 155;
-				value_sum += 155 * value_buffer[i-18];
+				value_sum += 155 * value_buffer[(i-18)&buffer_mask];
 			}
-			if (begin <= (i-17)) {
+			if (begin <= (p-17)) {
 				weight_sum += 180;
-				value_sum += 180 * value_buffer[i-17];
+				value_sum += 180 * value_buffer[(i-17)&buffer_mask];
 			}
-			if (begin <= (i-16)) {
+			if (begin <= (p-16)) {
 				weight_sum += 206;
-				value_sum += 206 * value_buffer[i-16];
+				value_sum += 206 * value_buffer[(i-16)&buffer_mask];
 			}
-			if (begin <= (i-15)) {
+			if (begin <= (p-15)) {
 				weight_sum += 234;
-				value_sum += 234 * value_buffer[i-15];
+				value_sum += 234 * value_buffer[(i-15)&buffer_mask];
 			}
-			if (begin <= (i-14)) {
+			if (begin <= (p-14)) {
 				weight_sum += 264;
-				value_sum += 264 * value_buffer[i-14];
+				value_sum += 264 * value_buffer[(i-14)&buffer_mask];
 			}
-			if (begin <= (i-13)) {
+			if (begin <= (p-13)) {
 				weight_sum += 295;
-				value_sum += 295 * value_buffer[i-13];
+				value_sum += 295 * value_buffer[(i-13)&buffer_mask];
 			}
-			if (begin <= (i-12)) {
+			if (begin <= (p-12)) {
 				weight_sum += 327;
-				value_sum += 327 * value_buffer[i-12];
+				value_sum += 327 * value_buffer[(i-12)&buffer_mask];
 			}
-			if (begin <= (i-11)) {
+			if (begin <= (p-11)) {
 				weight_sum += 360;
-				value_sum += 360 * value_buffer[i-11];
+				value_sum += 360 * value_buffer[(i-11)&buffer_mask];
 			}
-			if (begin <= (i-10)) {
+			if (begin <= (p-10)) {
 				weight_sum += 393;
-				value_sum += 393 * value_buffer[i-10];
+				value_sum += 393 * value_buffer[(i-10)&buffer_mask];
 			}
-			if (begin <= (i-9)) {
+			if (begin <= (p-9)) {
 				weight_sum += 425;
-				value_sum += 425 * value_buffer[i-9];
+				value_sum += 425 * value_buffer[(i-9)&buffer_mask];
 			}
-			if (begin <= (i-8)) {
+			if (begin <= (p-8)) {
 				weight_sum += 456;
-				value_sum += 456 * value_buffer[i-8];
+				value_sum += 456 * value_buffer[(i-8)&buffer_mask];
 			}
-			if (begin <= (i-7)) {
+			if (begin <= (p-7)) {
 				weight_sum += 485;
-				value_sum += 485 * value_buffer[i-7];
+				value_sum += 485 * value_buffer[(i-7)&buffer_mask];
 			}
-			if (begin <= (i-6)) {
+			if (begin <= (p-6)) {
 				weight_sum += 512;
-				value_sum += 512 * value_buffer[i-6];
+				value_sum += 512 * value_buffer[(i-6)&buffer_mask];
 			}
-			if (begin <= (i-5)) {
+			if (begin <= (p-5)) {
 				weight_sum += 535;
-				value_sum += 535 * value_buffer[i-5];
+				value_sum += 535 * value_buffer[(i-5)&buffer_mask];
 			}
-			if (begin <= (i-4)) {
+			if (begin <= (p-4)) {
 				weight_sum += 556;
-				value_sum += 556 * value_buffer[i-4];
+				value_sum += 556 * value_buffer[(i-4)&buffer_mask];
 			}
-			if (begin <= (i-3)) {
+			if (begin <= (p-3)) {
 				weight_sum += 572;
-				value_sum += 572 * value_buffer[i-3];
+				value_sum += 572 * value_buffer[(i-3)&buffer_mask];
 			}
-			if (begin <= (i-2)) {
+			if (begin <= (p-2)) {
 				weight_sum += 584;
-				value_sum += 584 * value_buffer[i-2];
+				value_sum += 584 * value_buffer[(i-2)&buffer_mask];
 			}
-			if (begin <= (i-1)) {
+			if (begin <= (p-1)) {
 				weight_sum += 591;
-				value_sum += 591 * value_buffer[i-1];
+				value_sum += 591 * value_buffer[(i-1)&buffer_mask];
 			}
-			if ((i+0) < end) {
+			if ((p+0) < end) {
 				weight_sum += 594;
-				value_sum += 594 * value_buffer[i+0];
+				value_sum += 594 * value_buffer[(i+0)&buffer_mask];
 			}
-			if ((i+1) < end) {
+			if ((p+1) < end) {
 				weight_sum += 591;
-				value_sum += 591 * value_buffer[i+1];
+				value_sum += 591 * value_buffer[(i+1)&buffer_mask];
 			}
-			if ((i+2) < end) {
+			if ((p+2) < end) {
 				weight_sum += 584;
-				value_sum += 584 * value_buffer[i+2];
+				value_sum += 584 * value_buffer[(i+2)&buffer_mask];
 			}
-			if ((i+3) < end) {
+			if ((p+3) < end) {
 				weight_sum += 572;
-				value_sum += 572 * value_buffer[i+3];
+				value_sum += 572 * value_buffer[(i+3)&buffer_mask];
 			}
-			if ((i+4) < end) {
+			if ((p+4) < end) {
 				weight_sum += 556;
-				value_sum += 556 * value_buffer[i+4];
+				value_sum += 556 * value_buffer[(i+4)&buffer_mask];
 			}
-			if ((i+5) < end) {
+			if ((p+5) < end) {
 				weight_sum += 535;
-				value_sum += 535 * value_buffer[i+5];
+				value_sum += 535 * value_buffer[(i+5)&buffer_mask];
 			}
-			if ((i+6) < end) {
+			if ((p+6) < end) {
 				weight_sum += 512;
-				value_sum += 512 * value_buffer[i+6];
+				value_sum += 512 * value_buffer[(i+6)&buffer_mask];
 			}
-			if ((i+7) < end) {
+			if ((p+7) < end) {
 				weight_sum += 485;
-				value_sum += 485 * value_buffer[i+7];
+				value_sum += 485 * value_buffer[(i+7)&buffer_mask];
 			}
-			if ((i+8) < end) {
+			if ((p+8) < end) {
 				weight_sum += 456;
-				value_sum += 456 * value_buffer[i+8];
+				value_sum += 456 * value_buffer[(i+8)&buffer_mask];
 			}
-			if ((i+9) < end) {
+			if ((p+9) < end) {
 				weight_sum += 425;
-				value_sum += 425 * value_buffer[i+9];
+				value_sum += 425 * value_buffer[(i+9)&buffer_mask];
 			}
-			if ((i+10) < end) {
+			if ((p+10) < end) {
 				weight_sum += 393;
-				value_sum += 393 * value_buffer[i+10];
+				value_sum += 393 * value_buffer[(i+10)&buffer_mask];
 			}
-			if ((i+11) < end) {
+			if ((p+11) < end) {
 				weight_sum += 360;
-				value_sum += 360 * value_buffer[i+11];
+				value_sum += 360 * value_buffer[(i+11)&buffer_mask];
 			}
-			if ((i+12) < end) {
+			if ((p+12) < end) {
 				weight_sum += 327;
-				value_sum += 327 * value_buffer[i+12];
+				value_sum += 327 * value_buffer[(i+12)&buffer_mask];
 			}
-			if ((i+13) < end) {
+			if ((p+13) < end) {
 				weight_sum += 295;
-				value_sum += 295 * value_buffer[i+13];
+				value_sum += 295 * value_buffer[(i+13)&buffer_mask];
 			}
-			if ((i+14) < end) {
+			if ((p+14) < end) {
 				weight_sum += 264;
-				value_sum += 264 * value_buffer[i+14];
+				value_sum += 264 * value_buffer[(i+14)&buffer_mask];
 			}
-			if ((i+15) < end) {
+			if ((p+15) < end) {
 				weight_sum += 234;
-				value_sum += 234 * value_buffer[i+15];
+				value_sum += 234 * value_buffer[(i+15)&buffer_mask];
 			}
-			if ((i+16) < end) {
+			if ((p+16) < end) {
 				weight_sum += 206;
-				value_sum += 206 * value_buffer[i+16];
+				value_sum += 206 * value_buffer[(i+16)&buffer_mask];
 			}
-			if ((i+17) < end) {
+			if ((p+17) < end) {
 				weight_sum += 180;
-				value_sum += 180 * value_buffer[i+17];
+				value_sum += 180 * value_buffer[(i+17)&buffer_mask];
 			}
-			if ((i+18) < end) {
+			if ((p+18) < end) {
 				weight_sum += 155;
-				value_sum += 155 * value_buffer[i+18];
+				value_sum += 155 * value_buffer[(i+18)&buffer_mask];
 			}
-			if ((i+19) < end) {
+			if ((p+19) < end) {
 				weight_sum += 133;
-				value_sum += 133 * value_buffer[i+19];
+				value_sum += 133 * value_buffer[(i+19)&buffer_mask];
 			}
-			if ((i+20) < end) {
+			if ((p+20) < end) {
 				weight_sum += 113;
-				value_sum += 113 * value_buffer[i+20];
+				value_sum += 113 * value_buffer[(i+20)&buffer_mask];
 			}
-			if ((i+21) < end) {
+			if ((p+21) < end) {
 				weight_sum += 96;
-				value_sum += 96 * value_buffer[i+21];
+				value_sum += 96 * value_buffer[(i+21)&buffer_mask];
 			}
-			if ((i+22) < end) {
+			if ((p+22) < end) {
 				weight_sum += 80;
-				value_sum += 80 * value_buffer[i+22];
+				value_sum += 80 * value_buffer[(i+22)&buffer_mask];
 			}
-			if ((i+23) < end) {
+			if ((p+23) < end) {
 				weight_sum += 66;
-				value_sum += 66 * value_buffer[i+23];
+				value_sum += 66 * value_buffer[(i+23)&buffer_mask];
 			}
-			if ((i+24) < end) {
+			if ((p+24) < end) {
 				weight_sum += 54;
-				value_sum += 54 * value_buffer[i+24];
+				value_sum += 54 * value_buffer[(i+24)&buffer_mask];
 			}
-			if ((i+25) < end) {
+			if ((p+25) < end) {
 				weight_sum += 44;
-				value_sum += 44 * value_buffer[i+25];
+				value_sum += 44 * value_buffer[(i+25)&buffer_mask];
 			}
-			if ((i+26) < end) {
+			if ((p+26) < end) {
 				weight_sum += 36;
-				value_sum += 36 * value_buffer[i+26];
+				value_sum += 36 * value_buffer[(i+26)&buffer_mask];
 			}
-			if ((i+27) < end) {
+			if ((p+27) < end) {
 				weight_sum += 29;
-				value_sum += 29 * value_buffer[i+27];
+				value_sum += 29 * value_buffer[(i+27)&buffer_mask];
 			}
-			if ((i+28) < end) {
+			if ((p+28) < end) {
 				weight_sum += 23;
-				value_sum += 23 * value_buffer[i+28];
+				value_sum += 23 * value_buffer[(i+28)&buffer_mask];
 			}
-			if ((i+29) < end) {
+			if ((p+29) < end) {
 				weight_sum += 18;
-				value_sum += 18 * value_buffer[i+29];
+				value_sum += 18 * value_buffer[(i+29)&buffer_mask];
 			}
-			if ((i+30) < end) {
+			if ((p+30) < end) {
 				weight_sum += 14;
-				value_sum += 14 * value_buffer[i+30];
+				value_sum += 14 * value_buffer[(i+30)&buffer_mask];
 			}
-			if ((i+31) < end) {
+			if ((p+31) < end) {
 				weight_sum += 11;
-				value_sum += 11 * value_buffer[i+31];
+				value_sum += 11 * value_buffer[(i+31)&buffer_mask];
 			}
-			if ((i+32) < end) {
+			if ((p+32) < end) {
 				weight_sum += 8;
-				value_sum += 8 * value_buffer[i+32];
+				value_sum += 8 * value_buffer[(i+32)&buffer_mask];
 			}
-			if ((i+33) < end) {
+			if ((p+33) < end) {
 				weight_sum += 6;
-				value_sum += 6 * value_buffer[i+33];
+				value_sum += 6 * value_buffer[(i+33)&buffer_mask];
 			}
 			return value_sum / weight_sum;
 		}
@@ -740,530 +741,530 @@ static uchar value_blur(int pixel, int begin, int end)
 			8 * value_buffer[i+32] +
 			6 * value_buffer[i+33]) >> 14;
 	case 6:
-		if ((i-65) < begin || end <= (i+65)) {
-			if (begin <= (i-65)) {
+		if ((p-65) < begin || end <= (p+65) || (i-65) < 0 || buffer_length <= (i+65)) {
+			if (begin <= (p-65)) {
 				weight_sum += 3;
-				value_sum += 3 * value_buffer[i-65];
+				value_sum += 3 * value_buffer[(i-65)&buffer_mask];
 			}
-			if (begin <= (i-64)) {
+			if (begin <= (p-64)) {
 				weight_sum += 3;
-				value_sum += 3 * value_buffer[i-64];
+				value_sum += 3 * value_buffer[(i-64)&buffer_mask];
 			}
-			if (begin <= (i-63)) {
+			if (begin <= (p-63)) {
 				weight_sum += 4;
-				value_sum += 4 * value_buffer[i-63];
+				value_sum += 4 * value_buffer[(i-63)&buffer_mask];
 			}
-			if (begin <= (i-62)) {
+			if (begin <= (p-62)) {
 				weight_sum += 5;
-				value_sum += 5 * value_buffer[i-62];
+				value_sum += 5 * value_buffer[(i-62)&buffer_mask];
 			}
-			if (begin <= (i-61)) {
+			if (begin <= (p-61)) {
 				weight_sum += 5;
-				value_sum += 5 * value_buffer[i-61];
+				value_sum += 5 * value_buffer[(i-61)&buffer_mask];
 			}
-			if (begin <= (i-60)) {
+			if (begin <= (p-60)) {
 				weight_sum += 6;
-				value_sum += 6 * value_buffer[i-60];
+				value_sum += 6 * value_buffer[(i-60)&buffer_mask];
 			}
-			if (begin <= (i-59)) {
+			if (begin <= (p-59)) {
 				weight_sum += 7;
-				value_sum += 7 * value_buffer[i-59];
+				value_sum += 7 * value_buffer[(i-59)&buffer_mask];
 			}
-			if (begin <= (i-58)) {
+			if (begin <= (p-58)) {
 				weight_sum += 8;
-				value_sum += 8 * value_buffer[i-58];
+				value_sum += 8 * value_buffer[(i-58)&buffer_mask];
 			}
-			if (begin <= (i-57)) {
+			if (begin <= (p-57)) {
 				weight_sum += 9;
-				value_sum += 9 * value_buffer[i-57];
+				value_sum += 9 * value_buffer[(i-57)&buffer_mask];
 			}
-			if (begin <= (i-56)) {
+			if (begin <= (p-56)) {
 				weight_sum += 10;
-				value_sum += 10 * value_buffer[i-56];
+				value_sum += 10 * value_buffer[(i-56)&buffer_mask];
 			}
-			if (begin <= (i-55)) {
+			if (begin <= (p-55)) {
 				weight_sum += 12;
-				value_sum += 12 * value_buffer[i-55];
+				value_sum += 12 * value_buffer[(i-55)&buffer_mask];
 			}
-			if (begin <= (i-54)) {
+			if (begin <= (p-54)) {
 				weight_sum += 13;
-				value_sum += 13 * value_buffer[i-54];
+				value_sum += 13 * value_buffer[(i-54)&buffer_mask];
 			}
-			if (begin <= (i-53)) {
+			if (begin <= (p-53)) {
 				weight_sum += 15;
-				value_sum += 15 * value_buffer[i-53];
+				value_sum += 15 * value_buffer[(i-53)&buffer_mask];
 			}
-			if (begin <= (i-52)) {
+			if (begin <= (p-52)) {
 				weight_sum += 16;
-				value_sum += 16 * value_buffer[i-52];
+				value_sum += 16 * value_buffer[(i-52)&buffer_mask];
 			}
-			if (begin <= (i-51)) {
+			if (begin <= (p-51)) {
 				weight_sum += 18;
-				value_sum += 18 * value_buffer[i-51];
+				value_sum += 18 * value_buffer[(i-51)&buffer_mask];
 			}
-			if (begin <= (i-50)) {
+			if (begin <= (p-50)) {
 				weight_sum += 21;
-				value_sum += 21 * value_buffer[i-50];
+				value_sum += 21 * value_buffer[(i-50)&buffer_mask];
 			}
-			if (begin <= (i-49)) {
+			if (begin <= (p-49)) {
 				weight_sum += 23;
-				value_sum += 23 * value_buffer[i-49];
+				value_sum += 23 * value_buffer[(i-49)&buffer_mask];
 			}
-			if (begin <= (i-48)) {
+			if (begin <= (p-48)) {
 				weight_sum += 25;
-				value_sum += 25 * value_buffer[i-48];
+				value_sum += 25 * value_buffer[(i-48)&buffer_mask];
 			}
-			if (begin <= (i-47)) {
+			if (begin <= (p-47)) {
 				weight_sum += 28;
-				value_sum += 28 * value_buffer[i-47];
+				value_sum += 28 * value_buffer[(i-47)&buffer_mask];
 			}
-			if (begin <= (i-46)) {
+			if (begin <= (p-46)) {
 				weight_sum += 31;
-				value_sum += 31 * value_buffer[i-46];
+				value_sum += 31 * value_buffer[(i-46)&buffer_mask];
 			}
-			if (begin <= (i-45)) {
+			if (begin <= (p-45)) {
 				weight_sum += 34;
-				value_sum += 34 * value_buffer[i-45];
+				value_sum += 34 * value_buffer[(i-45)&buffer_mask];
 			}
-			if (begin <= (i-44)) {
+			if (begin <= (p-44)) {
 				weight_sum += 38;
-				value_sum += 38 * value_buffer[i-44];
+				value_sum += 38 * value_buffer[(i-44)&buffer_mask];
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+			if ((p+48) < end) {
 				weight_sum += 25;
-				value_sum += 25 * value_buffer[i+48];
+				value_sum += 25 * value_buffer[(i+48)&buffer_mask];
 			}
-			if ((i+49) < end) {
+			if ((p+49) < end) {
 				weight_sum += 23;
-				value_sum += 23 * value_buffer[i+49];
+				value_sum += 23 * value_buffer[(i+49)&buffer_mask];
 			}
-			if ((i+50) < end) {
+			if ((p+50) < end) {
 				weight_sum += 21;
-				value_sum += 21 * value_buffer[i+50];
+				value_sum += 21 * value_buffer[(i+50)&buffer_mask];
 			}
-			if ((i+51) < end) {
+			if ((p+51) < end) {
 				weight_sum += 18;
-				value_sum += 18 * value_buffer[i+51];
+				value_sum += 18 * value_buffer[(i+51)&buffer_mask];
 			}
-			if ((i+52) < end) {
+			if ((p+52) < end) {
 				weight_sum += 16;
-				value_sum += 16 * value_buffer[i+52];
+				value_sum += 16 * value_buffer[(i+52)&buffer_mask];
 			}
-			if ((i+53) < end) {
+			if ((p+53) < end) {
 				weight_sum += 15;
-				value_sum += 15 * value_buffer[i+53];
+				value_sum += 15 * value_buffer[(i+53)&buffer_mask];
 			}
-			if ((i+54) < end) {
+			if ((p+54) < end) {
 				weight_sum += 13;
-				value_sum += 13 * value_buffer[i+54];
+				value_sum += 13 * value_buffer[(i+54)&buffer_mask];
 			}
-			if ((i+55) < end) {
+			if ((p+55) < end) {
 				weight_sum += 12;
-				value_sum += 12 * value_buffer[i+55];
+				value_sum += 12 * value_buffer[(i+55)&buffer_mask];
 			}
-			if ((i+56) < end) {
+			if ((p+56) < end) {
 				weight_sum += 10;
-				value_sum += 10 * value_buffer[i+56];
+				value_sum += 10 * value_buffer[(i+56)&buffer_mask];
 			}
-			if ((i+57) < end) {
+			if ((p+57) < end) {
 				weight_sum += 9;
-				value_sum += 9 * value_buffer[i+57];
+				value_sum += 9 * value_buffer[(i+57)&buffer_mask];
 			}
-			if ((i+58) < end) {
+			if ((p+58) < end) {
 				weight_sum += 8;
-				value_sum += 8 * value_buffer[i+58];
+				value_sum += 8 * value_buffer[(i+58)&buffer_mask];
 			}
-			if ((i+59) < end) {
+			if ((p+59) < end) {
 				weight_sum += 7;
-				value_sum += 7 * value_buffer[i+59];
+				value_sum += 7 * value_buffer[(i+59)&buffer_mask];
 			}
-			if ((i+60) < end) {
+			if ((p+60) < end) {
 				weight_sum += 6;
-				value_sum += 6 * value_buffer[i+60];
+				value_sum += 6 * value_buffer[(i+60)&buffer_mask];
 			}
-			if ((i+61) < end) {
+			if ((p+61) < end) {
 				weight_sum += 5;
-				value_sum += 5 * value_buffer[i+61];
+				value_sum += 5 * value_buffer[(i+61)&buffer_mask];
 			}
-			if ((i+62) < end) {
+			if ((p+62) < end) {
 				weight_sum += 5;
-				value_sum += 5 * value_buffer[i+62];
+				value_sum += 5 * value_buffer[(i+62)&buffer_mask];
 			}
-			if ((i+63) < end) {
+			if ((p+63) < end) {
 				weight_sum += 4;
-				value_sum += 4 * value_buffer[i+63];
+				value_sum += 4 * value_buffer[(i+63)&buffer_mask];
 			}
-			if ((i+64) < end) {
+			if ((p+64) < end) {
 				weight_sum += 3;
-				value_sum += 3 * value_buffer[i+64];
+				value_sum += 3 * value_buffer[(i+64)&buffer_mask];
 			}
-			if ((i+65) < end) {
+			if ((p+65) < end) {
 				weight_sum += 3;
-				value_sum += 3 * value_buffer[i+65];
+				value_sum += 3 * value_buffer[(i+65)&buffer_mask];
 			}
 			return value_sum / weight_sum;
 		}
@@ -1399,8 +1400,6 @@ static uchar value_blur(int pixel, int begin, int end)
 			3 * value_buffer[i+64] +
 			3 * value_buffer[i+65]) >> 14;
 	default:
-		if (i < begin || end <= i)
-			return 0;
 		return value_buffer[i];
 	}
 	return 0;
diff --git a/app/src/main/rs/constants.rsh b/app/src/main/rs/constants.rsh
index d139a54..2c8b45c 100644
--- a/app/src/main/rs/constants.rsh
+++ b/app/src/main/rs/constants.rsh
@@ -33,6 +33,8 @@ static const int mode_scottie2 = 6;
 static const int mode_scottieDX = 7;
 static const int mode_wrasseSC2_180 = 8;
 
+
+static const float sync_buildup_seconds = 0.0011f;
 static const float robot36_scanline_seconds = 0.15f;
 static const float robot72_scanline_seconds = 0.3f;
 static const float martin1_scanline_seconds = 0.446446f;
diff --git a/app/src/main/rs/decoder.rs b/app/src/main/rs/decoder.rs
index 7bb1770..3e60a3b 100644
--- a/app/src/main/rs/decoder.rs
+++ b/app/src/main/rs/decoder.rs
@@ -41,7 +41,8 @@ static void reset_buffer()
 {
     vpos = 0;
     hpos = 0;
-    prev_hpos = 0;
+    prev_sync_pos = sync_pos = 0;
+    buffer_pos = 0;
     seperator_counter = 0;
     sync_counter = sync_length;
     buffer_cleared = 1;
@@ -69,103 +70,66 @@ static void robot36_decoder()
     if ((free_running && mismatch_counter > 1) || mismatch_counter > 5)
         vpos ^= 1;
     prev_timeout = hpos >= maximum_length;
+    static int even_sync_pos, odd_sync_pos;
     if (vpos & 1) {
+        odd_sync_pos = prev_sync_pos;
         for (int i = 0; i < bitmap_width; ++i) {
-            uchar even_y = value_blur(i, y_begin, y_end);
-            uchar v = value_blur(i, v_begin, v_end);
-            uchar odd_y = value_blur(i, prev_hpos + y_begin, prev_hpos + y_end);
-            uchar u = value_blur(i, prev_hpos + u_begin, prev_hpos + u_end);
+            uchar even_y = value_blur(i, even_sync_pos + y_begin, even_sync_pos + y_end);
+            uchar v = value_blur(i, even_sync_pos + v_begin, even_sync_pos + v_end);
+            uchar odd_y = value_blur(i, odd_sync_pos + y_begin, odd_sync_pos + y_end);
+            uchar u = value_blur(i, odd_sync_pos + u_begin, odd_sync_pos + u_end);
             pixel_buffer[bitmap_width * (vpos-1) + i] = yuv(even_y, u, v);
             pixel_buffer[bitmap_width * vpos + i] = yuv(odd_y, u, v);
         }
-        if (prev_timeout)
-            hpos -= scanline_length;
-        else
-            hpos = 0;
-        prev_hpos = 0;
     } else {
-        if (prev_timeout) {
-            prev_hpos = scanline_length;
-            hpos -= scanline_length;
-        } else {
-            prev_hpos = hpos;
-            hpos = 0;
-        }
+        even_sync_pos = prev_sync_pos;
     }
-    ++vpos;
 }
 
 static void yuv_decoder()
 {
     for (int i = 0; i < bitmap_width; ++i) {
-        uchar y = value_blur(i, y_begin, y_end);
-        uchar u = value_blur(i, u_begin, u_end);
-        uchar v = value_blur(i, v_begin, v_end);
+        uchar y = value_blur(i, y_begin + prev_sync_pos, y_end + prev_sync_pos);
+        uchar u = value_blur(i, u_begin + prev_sync_pos, u_end + prev_sync_pos);
+        uchar v = value_blur(i, v_begin + prev_sync_pos, v_end + prev_sync_pos);
         pixel_buffer[bitmap_width * vpos + i] = yuv(y, u, v);
     }
-    if (hpos >= maximum_length)
-        hpos -= scanline_length;
-    else
-        hpos = 0;
-    prev_hpos = 0;
-    ++vpos;
 }
 
 static void rgb_decoder()
 {
     for (int i = 0; i < bitmap_width; ++i) {
-        uchar r = value_blur(i, r_begin, r_end);
-        uchar g = value_blur(i, g_begin, g_end);
-        uchar b = value_blur(i, b_begin, b_end);
+        uchar r = value_blur(i, r_begin + prev_sync_pos, r_end + prev_sync_pos);
+        uchar g = value_blur(i, g_begin + prev_sync_pos, g_end + prev_sync_pos);
+        uchar b = value_blur(i, b_begin + prev_sync_pos, b_end + prev_sync_pos);
         pixel_buffer[bitmap_width * vpos + i] = rgb(r, g, b);
     }
-    if (hpos >= maximum_length)
-        hpos -= scanline_length;
-    else
-        hpos = 0;
-    prev_hpos = 0;
-    ++vpos;
 }
 
 static void raw_decoder()
 {
     for (int i = 0; i < bitmap_width; ++i) {
-        uchar value = value_blur(i, 0, hpos);
+        uchar value = value_blur(i, prev_sync_pos, sync_pos);
         pixel_buffer[bitmap_width * vpos + i] = rgb(value, value, value);
     }
-    prev_hpos = hpos = 0;
-    ++vpos;
 }
 
 // don't you guys have anything better to do?
 static void scottie_decoder()
 {
-    if (!prev_hpos) {
-        for (int i = g_begin; i < g_end; ++i)
-            value_buffer[i + b_begin - g_begin] = value_buffer[i];
-        for (int i = r_begin; i < r_end; ++i)
-            value_buffer[i + g_begin - r_begin] = value_buffer[i];
-        prev_hpos = scanline_length;
-        hpos = 0;
+    static int first_sync = 1;
+    if (!free_running && !vpos && first_sync) {
+        first_sync = 0;
         return;
     }
-    for (int i = 0; i < bitmap_width; ++i) {
-        uchar r = value_blur(i, prev_hpos + r_begin, prev_hpos + r_end);
-        uchar g = value_blur(i, g_begin, g_end);
-        uchar b = value_blur(i, b_begin, b_end);
-        pixel_buffer[bitmap_width * vpos + i] = rgb(r, g, b);
-    }
-    for (int i = 0; i < scanline_length; ++i)
-        value_buffer[i] = value_buffer[i + prev_hpos];
-    prev_hpos = scanline_length;
-    hpos = 0;
-    ++vpos;
+    first_sync = 1;
+    rgb_decoder();
 }
 
 void decode(int samples) {
     *saved_width = 0;
     *saved_height = 0;
-    for (int sample = 0; sample < samples; ++sample) {
+    for (int sample = 0; sample < samples; ++sample, ++buffer_pos) {
         float amp = audio_buffer[sample] / 32768.0f;
         float power = amp * amp;
         if (filter(&avg_power, power) < 0.0000001f)
@@ -184,7 +148,7 @@ void decode(int samples) {
         int dat_active = cnt_amp < 2.0f * dat_amp;
         uchar cnt_level = save_cnt && cnt_active ? 127.5f - 127.5f * cnt_value : 0.0f;
         uchar dat_level = save_dat && dat_active ? 127.5f + 127.5f * dat_value : 0.0f;
-        value_buffer[hpos + prev_hpos] = cnt_level | dat_level;
+        value_buffer[buffer_pos & buffer_mask] = cnt_level | dat_level;
 
         int cnt_quantized = round(cnt_value);
         int dat_quantized = round(dat_value);
@@ -192,6 +156,10 @@ void decode(int samples) {
         int sync_level = cnt_active && cnt_quantized == 0;
         int sync_pulse = !sync_level && sync_counter >= sync_length;
         sync_counter = sync_level ? sync_counter + 1 : 0;
+        if (sync_pulse) {
+            prev_sync_pos = sync_pos;
+            sync_pos = buffer_pos - sync_buildup_length;
+        }
 
         if (*current_mode != mode_debug) {
             int detected_mode = calibration_detector(dat_value, dat_amp, cnt_amp, cnt_quantized);
@@ -214,8 +182,7 @@ void decode(int samples) {
 
         if (++hpos >= maximum_length || sync_pulse) {
             if (hpos < minimum_length) {
-                hpos = 0;
-                prev_hpos = 0;
+                hpos = buffer_pos - sync_pos;
                 seperator_counter = 0;
                 continue;
             }
@@ -235,6 +202,13 @@ void decode(int samples) {
                 default:
                     raw_decoder();
             }
+            if (hpos >= maximum_length) {
+                hpos -= scanline_length;
+                sync_pos = prev_sync_pos + scanline_length;
+            } else {
+                hpos = buffer_pos - sync_pos;
+            }
+            ++vpos;
             if (vpos == bitmap_height)
                 save_buffer();
             if (vpos >= maximum_height)
diff --git a/app/src/main/rs/initialization.rsh b/app/src/main/rs/initialization.rsh
index 21f2a2d..3a3317a 100644
--- a/app/src/main/rs/initialization.rsh
+++ b/app/src/main/rs/initialization.rsh
@@ -25,6 +25,7 @@ void initialize(float rate, int length, int width, int height)
 {
     sample_rate = rate;
     buffer_length = length;
+    buffer_mask = length - 1;
     maximum_width = width;
     maximum_height = height;
 
@@ -32,13 +33,16 @@ void initialize(float rate, int length, int width, int height)
         pixel_buffer[i] = 0;
 
     vpos = 0;
-    prev_hpos = hpos = 0;
+    hpos = 0;
+    prev_sync_pos = sync_pos = 0;
+    buffer_pos = 0;
     sync_counter = 0;
     seperator_counter = 0;
     buffer_cleared = 0;
     free_running = 1;
     minimum_length = 0.05f * sample_rate;
     minimum_sync_length = 0.002f * sample_rate;
+    sync_buildup_length = sync_buildup_seconds * sample_rate;
 
     robot36_scanline_length = robot36_scanline_seconds * sample_rate;
     robot72_scanline_length = robot72_scanline_seconds * sample_rate;
diff --git a/app/src/main/rs/modes.rsh b/app/src/main/rs/modes.rsh
index 60d0a97..be17003 100644
--- a/app/src/main/rs/modes.rsh
+++ b/app/src/main/rs/modes.rsh
@@ -70,7 +70,6 @@ void robot36_mode()
     bitmap_width = 320;
     bitmap_height = 240;
     const float tolerance = 0.8f;
-    const float settling_time = 0.0011f;
     const float sync_seconds = 0.009f;
     const float sync_porch_seconds = 0.003f;
     const float sep_porch_seconds = 0.0015f;
@@ -79,7 +78,7 @@ void robot36_mode()
     const float seperator_seconds = 0.0045f;
     seperator_length = seperator_seconds * sample_rate;
     sync_length = tolerance * sync_seconds * sample_rate;
-    y_begin = (sync_porch_seconds - settling_time) * sample_rate;
+    y_begin = sync_porch_seconds * sample_rate;
     y_end = y_begin + y_scan_seconds * sample_rate;
     u_sep_begin = v_sep_begin = y_end;
     u_sep_end = v_sep_end = u_sep_begin + seperator_seconds * sample_rate;
@@ -98,7 +97,6 @@ void robot72_mode()
     bitmap_width = 320;
     bitmap_height = 240;
     const float tolerance = 0.8f;
-    const float settling_time = 0.0011f;
     const float sync_seconds = 0.009f;
     const float sync_porch_seconds = 0.003f;
     const float sep_porch_seconds = 0.0015f;
@@ -107,7 +105,7 @@ void robot72_mode()
     const float seperator_seconds = 0.0045f;
     seperator_length = seperator_seconds * sample_rate;
     sync_length = tolerance * sync_seconds * sample_rate;
-    y_begin = (sync_porch_seconds - settling_time) * sample_rate;
+    y_begin = sync_porch_seconds * sample_rate;
     y_end = y_begin + y_scan_seconds * sample_rate;
     v_sep_begin = y_end;
     v_sep_end = v_sep_begin + seperator_seconds * sample_rate;
@@ -138,7 +136,7 @@ void martin1_mode()
     const float seperator_seconds = 0.000572f;
     seperator_length = seperator_seconds * sample_rate;
     sync_length = tolerance * sync_seconds * sample_rate;
-    g_begin = 0;
+    g_begin = sync_porch_seconds * sample_rate;
     g_end = g_begin + g_scan_seconds * sample_rate;
     b_begin = g_end + seperator_seconds * sample_rate;
     b_end = b_begin + b_scan_seconds * sample_rate;
@@ -165,7 +163,7 @@ void martin2_mode()
     const float seperator_seconds = 0.000572f;
     seperator_length = seperator_seconds * sample_rate;
     sync_length = tolerance * sync_seconds * sample_rate;
-    g_begin = 0;
+    g_begin = sync_porch_seconds * sample_rate;
     g_end = g_begin + g_scan_seconds * sample_rate;
     b_begin = g_end + seperator_seconds * sample_rate;
     b_end = b_begin + b_scan_seconds * sample_rate;
@@ -184,19 +182,18 @@ void scottie1_mode()
     bitmap_width = 320;
     bitmap_height = 256;
     const float tolerance = 0.8f;
-    const float settling_time = 0.0011f;
     const float sync_seconds = 0.009f;
     const float sync_porch_seconds = 0.0015f;
     const float rgb_scan_seconds = 0.138240f;
     const float seperator_seconds = 0.0015f;
     seperator_length = seperator_seconds * sample_rate;
     sync_length = tolerance * sync_seconds * sample_rate;
-    r_begin = (sync_porch_seconds - settling_time) * sample_rate;
+    r_begin = sync_porch_seconds * sample_rate;
     r_end = r_begin + rgb_scan_seconds * sample_rate;
-    g_begin = r_end + seperator_seconds * sample_rate;
-    g_end = g_begin + rgb_scan_seconds * sample_rate;
-    b_begin = g_end + seperator_seconds * sample_rate;
-    b_end = b_begin + rgb_scan_seconds * sample_rate;
+    b_end = - sync_seconds * sample_rate;
+    b_begin = b_end - rgb_scan_seconds * sample_rate;
+    g_end = b_begin - seperator_seconds * sample_rate;
+    g_begin = g_end - rgb_scan_seconds * sample_rate;
     scanline_length = scottie1_scanline_length;
     maximum_length = scanline_length + sync_porch_seconds * sample_rate;
 }
@@ -210,19 +207,18 @@ void scottie2_mode()
     bitmap_width = 320;
     bitmap_height = 256;
     const float tolerance = 0.8f;
-    const float settling_time = 0.0011f;
     const float sync_seconds = 0.009f;
     const float sync_porch_seconds = 0.0015f;
     const float rgb_scan_seconds = 0.088064f;
     const float seperator_seconds = 0.0015f;
     seperator_length = seperator_seconds * sample_rate;
     sync_length = tolerance * sync_seconds * sample_rate;
-    r_begin = (sync_porch_seconds - settling_time) * sample_rate;
+    r_begin = sync_porch_seconds * sample_rate;
     r_end = r_begin + rgb_scan_seconds * sample_rate;
-    g_begin = r_end + seperator_seconds * sample_rate;
-    g_end = g_begin + rgb_scan_seconds * sample_rate;
-    b_begin = g_end + seperator_seconds * sample_rate;
-    b_end = b_begin + rgb_scan_seconds * sample_rate;
+    b_end = - sync_seconds * sample_rate;
+    b_begin = b_end - rgb_scan_seconds * sample_rate;
+    g_end = b_begin - seperator_seconds * sample_rate;
+    g_begin = g_end - rgb_scan_seconds * sample_rate;
     scanline_length = scottie2_scanline_length;
     maximum_length = scanline_length + sync_porch_seconds * sample_rate;
 }
@@ -236,19 +232,18 @@ void scottieDX_mode()
     bitmap_width = 320;
     bitmap_height = 256;
     const float tolerance = 0.8f;
-    const float settling_time = 0.0011f;
     const float sync_seconds = 0.009f;
     const float sync_porch_seconds = 0.0015f;
     const float rgb_scan_seconds = 0.3456f;
     const float seperator_seconds = 0.0015f;
     seperator_length = seperator_seconds * sample_rate;
     sync_length = tolerance * sync_seconds * sample_rate;
-    r_begin = (sync_porch_seconds - settling_time) * sample_rate;
+    r_begin = sync_porch_seconds * sample_rate;
     r_end = r_begin + rgb_scan_seconds * sample_rate;
-    g_begin = r_end + seperator_seconds * sample_rate;
-    g_end = g_begin + rgb_scan_seconds * sample_rate;
-    b_begin = g_end + seperator_seconds * sample_rate;
-    b_end = b_begin + rgb_scan_seconds * sample_rate;
+    b_end = - sync_seconds * sample_rate;
+    b_begin = b_end - rgb_scan_seconds * sample_rate;
+    g_end = b_begin - seperator_seconds * sample_rate;
+    g_begin = g_end - rgb_scan_seconds * sample_rate;
     scanline_length = scottieDX_scanline_length;
     maximum_length = scanline_length + sync_porch_seconds * sample_rate;
 }
@@ -266,7 +261,7 @@ void wrasseSC2_180_mode()
     const float sync_porch_seconds = 0.0005f;
     const float rgb_scan_seconds = 0.235f;
     sync_length = tolerance * sync_seconds * sample_rate;
-    r_begin = 0;
+    r_begin = sync_porch_seconds * sample_rate;
     r_end = r_begin + rgb_scan_seconds * sample_rate;
     g_begin = r_end;
     g_end = g_begin + rgb_scan_seconds * sample_rate;
diff --git a/app/src/main/rs/state.rsh b/app/src/main/rs/state.rsh
index 11201d1..b7fb925 100644
--- a/app/src/main/rs/state.rsh
+++ b/app/src/main/rs/state.rsh
@@ -22,14 +22,15 @@ static ddc_t cnt_ddc, dat_ddc;
 static fmd_t cnt_fmd, dat_fmd;
 static int current_decoder;
 static int blur_power, free_running;
-static int sample_rate, prev_hpos;
+static int sample_rate, sync_pos, prev_sync_pos;
 static int maximum_variance, minimum_sync_length;
 static int scanline_length, minimum_length, maximum_length;
 static int vis_timeout, vis_length, bit_length;
 static int break_timeout, break_length;
 static int leader_timeout, leader_length;
 static int first_leader_length, second_leader_length;
-static int buffer_length, buffer_cleared;
+static int buffer_length, buffer_mask, buffer_pos;
+static int buffer_cleared;
 static int bitmap_width, bitmap_height;
 static int maximum_width, maximum_height;
 static int sync_length, sync_counter, vpos, hpos;
@@ -37,6 +38,7 @@ static int save_cnt, save_dat, seperator_counter, seperator_length;
 static int u_sep_begin, u_sep_end, v_sep_begin, v_sep_end;
 static int y_begin, y_end, u_begin, u_end, v_begin, v_end;
 static int r_begin, r_end, b_begin, b_end, g_begin, g_end;
+static int sync_buildup_length;
 static int robot36_scanline_length;
 static int robot72_scanline_length;
 static int martin1_scanline_length;
diff --git a/utils/blur.c b/utils/blur.c
index 24183c2..43ca1c6 100644
--- a/utils/blur.c
+++ b/utils/blur.c
@@ -24,20 +24,20 @@ double gauss(double x, double radius)
 }
 void emit(int radius)
 {
-	printf("\t\tif ((i-%d) < begin || end <= (i+%d)) {\n", radius, radius);
+	printf("\t\tif ((p-%d) < begin || end <= (p+%d) || (i-%d) < 0 || buffer_length <= (i+%d)) {\n", radius, radius, radius, radius);
 	for (int i = -radius; i < 0; ++i) {
-		printf("\t\t\tif (begin <= (i%d)) {\n", i);
+		printf("\t\t\tif (begin <= (p%d)) {\n", i);
 		printf("\t\t\t\tweight_sum += %d;\n",
 			(int)(16384 * gauss(i, radius)));
-		printf("\t\t\t\tvalue_sum += %d * value_buffer[i%d];\n",
+		printf("\t\t\t\tvalue_sum += %d * value_buffer[(i%d)&buffer_mask];\n",
 			(int)(16384 * gauss(i, radius)), i);
 		printf("\t\t\t}\n");
 	}
 	for (int i = 0; i <= radius; ++i) {
-		printf("\t\t\tif ((i+%d) < end) {\n", i);
+		printf("\t\t\tif ((p+%d) < end) {\n", i);
 		printf("\t\t\t\tweight_sum += %d;\n",
 			(int)(16384 * gauss(i, radius)));
-		printf("\t\t\t\tvalue_sum += %d * value_buffer[i+%d];\n",
+		printf("\t\t\t\tvalue_sum += %d * value_buffer[(i+%d)&buffer_mask];\n",
 			(int)(16384 * gauss(i, radius)), i);
 		printf("\t\t\t}\n");
 	}
@@ -59,7 +59,8 @@ int main()
 {
 	printf("/* code generated by 'utils/blur.c' */\n");
 	printf("static uchar value_blur(int pixel, int begin, int end)\n{\n");
-	printf("\tint i = (pixel * (end - begin) + (end - begin) / 2) / bitmap_width + begin;\n");
+	printf("\tint p = (pixel * (end - begin) + (end - begin) / 2) / bitmap_width + begin;\n");
+	printf("\tint i = p & buffer_mask;\n");
 	printf("\tint weight_sum = 0;\n");
 	printf("\tint value_sum = 0;\n");
 	printf("\tswitch (blur_power) {\n");
@@ -67,6 +68,6 @@ int main()
 		printf("\tcase %d:\n", i);
 		emit((1 << i) | 1);
 	}
-	printf("\tdefault:\n\t\tif (i < begin || end <= i)\n\t\t\treturn 0;\n\t\treturn value_buffer[i];\n\t}\n\treturn 0;\n}\n");
+	printf("\tdefault:\n\t\treturn value_buffer[i];\n\t}\n\treturn 0;\n}\n");
 	return 0;
 }