Rounding error causing crash and skewed image xLightsSequencer#5208

derwin12 · Feb 18, 2025 · a88af55 · a88af55
1 parent 5a54b39
commit a88af55
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Showing 3 changed files with 12 additions and 8 deletions.
diff --git a/xLights/effects/VideoEffect.cpp b/xLights/effects/VideoEffect.cpp
@@ -486,6 +486,8 @@ void VideoEffect::Render(RenderBuffer &buffer, std::string filename,
                     ispc::VideoData rdata;
                     rdata.width = _videoreader->GetWidth() - xoffset - xtail;
                     rdata.height = _videoreader->GetHeight() - yoffset - ytail;
+                    rdata.buffer_width = buffer.BufferWi;
+                    rdata.buffer_height = buffer.BufferHt;
                     rdata.ytail = ytail;
                     rdata.xtail = xtail;
                     rdata.yoffset = yoffset;

diff --git a/xLights/effects/ispc/VideoFunctions.ispc b/xLights/effects/ispc/VideoFunctions.ispc
@@ -1,6 +1,8 @@
 export struct VideoData {
     uint16 width;
     uint16 height;
+    uint16 buffer_width;
+    uint16 buffer_height;
     int16 yoffset;
     int16 xoffset;
     int16 ytail;
@@ -19,20 +21,17 @@ export struct VideoData {
 };
 
 export void VideoEffectProcess(const uniform VideoData &data,
-                                  uniform int startIdx, uniform int endIdx,
-                                  uniform uint8<4> result[])
+                               uniform int startIdx, uniform int endIdx,
+                               uniform uint8<4> result[])
 {
-    uniform float width = data.width;
-    uniform float rszw = 1.0 / width;
-    uniform float height = data.height;
     uniform int ch = data.ch;
 
 
     foreach (index = startIdx...endIdx) {
         float fidx = index;
-        float y = (floor)(fidx * rszw + 0.00001);
-        float x = fidx - (y * width);
-        int newIndex = x + data.startx + ((y + data.starty) * width);
+        float y = (floor)(fidx / data.buffer_width);
+        float x = fidx - (y * data.buffer_width);
+        int newIndex = x + data.startx + ((y + data.starty) * data.buffer_width);
 
         uint8* ptr = data.image + (data.image_height - 1 - y - data.yoffset) * (data.image_width * ch) + (data.xoffset * ch) + (x * ch);
         uint8<4> c;

diff --git a/xLights/effects/ispc/VideoFunctions.ispc.h b/xLights/effects/ispc/VideoFunctions.ispc.h
@@ -1,4 +1,5 @@
 //
+// effects\\ispc\\VideoFunctions.ispc.h
 // (Header automatically generated by the ispc compiler.)
 // DO NOT EDIT THIS FILE.
 //
@@ -51,6 +52,8 @@ struct uint8_t4 { uint8_t v[4]; } __attribute__ ((aligned(4)));
 struct VideoData {
     uint16_t width;
     uint16_t height;
+    uint16_t buffer_width;
+    uint16_t buffer_height;
     int16_t yoffset;
     int16_t xoffset;
     int16_t ytail;