minor improvements to comments and order of exec

src/nanovg/nanovg-demo.cpp

@@ -248,7 +248,7 @@ int main(int argc, char **argv) {
 
         //Activate the OpenCL context for VAAPI
         va::bind();
-        //The frameBuffer is upside-down. Flip videoFrame. (OpenCL)
+        //The videoFrame is upside-down. Flip. (OpenCL)
         cv::flip(videoFrame, videoFrame, 0);
         //Encode the frame using VAAPI on the GPU.
         writer.write(videoFrame);

src/tetra/tetra-demo.cpp

@@ -125,8 +125,6 @@ int main(int argc, char **argv) {
         glow_effect(frameBuffer);
         //Color-conversion from BGRA to RGB. OpenCV/OpenCL.
         cv::cvtColor(frameBuffer, videoFrame, cv::COLOR_BGRA2RGB);
-        //Video frame is upside down -> flip it (OpenCL)
-        cv::flip(videoFrame, videoFrame, 0);
         //Release the frame buffer for use by OpenGL
         gl::release_to_gl(frameBuffer);
 
@@ -144,6 +142,8 @@ int main(int argc, char **argv) {
 
         //Activate the OpenCL context for VAAPI
         va::bind();
+        //Video frame is upside down because the frameBuffer is. -> flip it (OpenCL)
+        cv::flip(videoFrame, videoFrame, 0);
         //Encode the frame using VAAPI on the GPU.
         encoder.write(videoFrame);
 

src/video/video-demo.cpp

@@ -168,8 +168,6 @@ int main(int argc, char **argv) {
         glow_effect(frameBuffer);
         //Color-conversion from BGRA to RGB. (OpenCL)
         cv::cvtColor(frameBuffer, videoFrame, cv::COLOR_BGRA2RGB);
-        //Video frame is upside down -> flip it (OpenCL)
-        cv::flip(videoFrame, videoFrame, 0);
         //Release the frame buffer for use by OpenGL
         gl::release_to_gl(frameBuffer);
 
@@ -187,6 +185,8 @@ int main(int argc, char **argv) {
 
         //Activate the OpenCL context for VAAPI
         va::bind();
+        //Video frame is upside down -> flip it (OpenCL)
+        cv::flip(videoFrame, videoFrame, 0);
         //Encode the frame using VAAPI on the GPU.
         writer.write(videoFrame);