Reply To: OSSC Profiles for PAL users

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Hello, I wanted to connect an old PAL 4: 3 576i video camera, but using the above “Generic 4:3” profile resulted in the image being displayed in the 16: 9 aspect ratio – the image was stretched. I have read a bit about the PAL signal itself in the book “Video Demystified A Handbook for the Digital Engineer 4th ed – Keith Jack” and you can find a solution there based on the graph analysis on page 48.

We know, from 576i graph mentionet above, that 576i has 720 active horizontal samples (h_active), for 4:3 ratio total samples (h_total) will be:

h_total = h_active / 0,75

h_synclen = h_active * 0,0904716073147257
h_backporch = h_active * 0,0890625

v_active = 270
v_backporch = 312 – v_active – 14

So:
h_total : 960
h_active : 720
h_synclen : 65
h_backporch : 86

v_active : 270
v_backporch : 28

It works perfect 🙂