Need help tweaking code

I have had a look and these are my thoughts on what might be happening.

1. it takes ages for the script to run .

Since not much has been changed I suspect that the addition of the signal strength may be part of the culprit here. Looking at the code it is refreshing this value several times a second (same rate as the video):

        elif getPath == ('/wifi'):
            # Repeated reading of the WiFi strength, set a delayed refresh
            # We use AJAX to avoid screen refreshes caused by refreshing a frame
            displayDelay = int(1000 / displayRate)

I would slow this down to say once every couple of seconds:

        elif getPath == ('/wifi'):
            # Repeated reading of the WiFi strength, set a delayed refresh
            # We use AJAX to avoid screen refreshes caused by refreshing a frame
            displayDelay = int(2000)

1000 would be one second between updates, larger is slower.

I am not sure how long it takes to run the iwconfig wlan0|grep Link|cut -d"=" -f2|cut -d" " -f1 command, but if it is slow you might want to read the value either in the Watchdog thread or a new thread and save the result to a global value. The new global value can then be read by the elif getPath.startswith('/wifi-once'): section instead of directly calling the WiFiSignalStrength function and having to wait for it to finish each time.

2. when I try "Press CTRL+C " to terminate the web-server I get an error in the terminal ( see attached) and it fails to shutdown even after repeated tries. I have resorted to using my shutdown button but this shuts down the Raspberry pi and I have to disconnect and reboot.

It seems like the WiFiSignalStrength function is not handling the CTRL+C exception as expected. I would insert an exception handler into the function directly with

try:

at the top of the function and

except KeyboardInterrupt:
    global running
    print('User shutdown in WiFiSignalStrength')
    running = False

at the end of the function to catch the CTRL+C and set the script to stop running on its own.

3. my video stream freezes but the buttons still function refreshing the page does nothing.

Does the image go blank / missing, or does it get stuck on a fixed image?

If it gets stuck it could be that the ImageCapture or StreamProcessor thread has failed and has stopped processing images.

4 . video is very slow lagging ( what are the best settings for increased frame rate)

I think part of the problem here is answered in question 1 as the code will slow down with more requests. Changing that may actually fix this problem as well.

Unfortunately the ideal value depends on the WiFi connection quite a lot. If the value is too large the stream gets slower rather than faster, causing the images to get delayed. The best thing to do is to start with a really low number, say 2, which should work correctly but does not update very often. When you have a working value increase it by 1 and see if it keeps working. When the number gets too high the video will get laggy again and you can swap back to the last value that worked correctly.