3 ms·
There are sync pulses on every line of analog video, as well as to color burst in most analog video standards. You couldn't just sweep theta and r continuously
by gugagore 9y ago
There are sync pulses on every line of analog video, as well as to color burst in most analog video standards. You couldn't just sweep theta and r continuously for a whole frame.
- Shikadi 9y agoWhy not? The sync pulses are because the scan is discontinuous, you could just have one plus color burst every spiral
- gugagore 9y agoI'm guessing that NTSC and PAL have a color burst on every line, vs every frame, because over an entire frame the local oscillator might not be stable enough. At least back in the day. Same with the timing of the sweep circuits, which only need to hold sync for a single line of video.
- Shikadi 9y agoOh cool, didn't realize color burst was used for that, I skimmed over it in the past and misunderstood its purpose. TIL