UHF is just a range of frequencies and can carry anything. The format of the video itself is called composite video or CVBS (color, video, blanking, synchronization), of which PAL, NTSC, etc. They are, so to speak, subforms. The signal received by the TV is some UHF carrier frequency, which is frequency modulated by video and audio signals. The UHF carries many television stations, and the first thing the TV does is tune in a specific channel to isolate the video signal, which it then transfers to its PAL or NTSC decoding scheme, which in turn generates signals that control the CRT.
With that said, I think that you will need to arm yourself with a television block diagram (for example, http://smendes.com/el31l/blockdiagram.jpg .) And write a software emulation for each of the boxes :) (except for CRT material , of course.) “Fortunately”, under it all “simple” mathematicians and most of the parts lend themselves to a good mathematical description, including a lot of differential ones (I think this is how the electronics are designed in the first place, i.e. before creating the prototype and / or mass production. Every branch of electronics (say, an akus teak, filter design, amplifier design and much more) has a kind of mathematical apparatus associated with this.) In the end, your program will analyze PAL, like an analog television, an analog computer, which it)) You can also look at SDR, which means "software defined by radio," which, in my opinion, is one and the same principle.