MarkT:
Well for PAL its 625 lines at 25Hz and estimated horizontal 1000 pixels per line, allow 10% for blanking time,
15 to 20MSPS or so?To write to an SDcard at that speed requires video compression hardware and native mode interface.
Active line length is only 52 us, and there are only 576 active lines.
I can't see where the SD card requirement has crept in.