usb_example/main.cpp code syntax error

[mannly01]

While trying to run the usb_example code on 3 different Linux systems I encountered multiple and completely random errors. I have troubleshot my specific problems to the syntax error described below:

Line 230 shows this if (key > 0) and then immediately moves into another if statement on Line 231 if(key=='j' || key=='k' || key=='m' || key=='n'){.

If you notice, Line 230 does not have a { at the end of the line. When this code is executed and no key is pressed, the if statement on Line 231 is ignored, but the else statement on Line 252 is then executed. When running this code on a NVIDIA Jetson TK1, Line 254 destroyAllWindows(); was continuously running through every loop and blocking the system. The same thing was happening with the Raspberry Pi 2.

The quick fix is to put a { at the end of Line 230 and add a line after Line 276 with a }.

While I was optimizing the code, I also changed Line 252 else {// switch image direction to else if(key=='q' || key=='w' || key=='d' || key=='x' || key=='a' || key=='s') {//switch image direction so that code would only execute when the user pressed one of the 'option' keys.

The program seemed to gain quite a bit of speed and allowed all of the 'options' to be used.

[tangketan]

Thanks a lot! The code is modified according to your suggestion.