There is an EPT signal in the room. What is it trying to tell you?
flag = flag.replace("(", "{").replace(")", "}").replace("-", "_").upper()
This onsite challenge consisted of the EPT-logo blinking in morse-code.
To solve this we filmed the entire sequence of morse-code which lasted roughly 2 minutes and 40 seconds. To be able to better differentatiate between on and off, we converted the video from color to grayscale. This was done using ffmpeg:
ffmpeg -i input_video.mov -vf format=gray output_video.mov
By googling we found a GitHub repository which contained a script that could extract morse-code from videos. video-morse-decoder
After running the script we got this string
THISCHALLENGEISONFIRE?THEFLAGISCOMINGREALLYSOONNOW?AREYOUREADY?EPT?WELL?DONE?MORSE?IS?C00L??THATISIT?ENJOYTHERESTOFTHE
We saw that the flag part of the string was this:
EPT?WELL?DONE?MORSE?IS?C00L?
In the task description we were given a Python-command which would format the flag correctly. The script we used could not understand every sign, but the Python-command would switch dashes to underlines. This gave us the flag:
EPT{WELL_DONE_MORSE_IS_C00L}