Rolling Shutter Info?

[Mark B.]

Does rolling shutter information get saved with the video data? In particular, I'm hoping for the y coordinate on the cmos chip that represents the beginning and end of each captured frame.

[I Bloom]

Does rolling shutter information get saved with the video data? In particular, I'm hoping for the y coordinate on the cmos chip that represents the beginning and end of each captured frame.

It's always zero. The frame always starts exposing at the top of the format window (4K, 2K, or 4.5K) and the bottom is always the bottom of the window.
http://www.redhax.net/wiki/Understanding_Rolling_Shutter_Artifacts

IBloom

[Rob Lohman]

ibloom: that's incorrect, only true when recording 4K and you're seeing 4.5K (look around), for 2K you're windowing and the top and bottom or not on the edges of the chip.

you really don't need to store such information since it's easy to calculate. We record the center of the sensor, so if you're recording 4K the height is 2304 while the maximum height of the sensor is 2580 (2540 active), so 2580 - 2304 = 276. Divide by 2 to get the start and that's the 138th row.

[I Bloom]

ibloom: that's incorrect, only true when recording 4K and you're seeing 4.5K (look around), for 2K you're windowing and the top and bottom or not on the edges of the chip.

you really don't need to store such information since it's easy to calculate. We record the center of the sensor, so if you're recording 4K the height is 2304 while the maximum height of the sensor is 2580 (2540 active), so 2580 - 2304 = 276. Divide by 2 to get the start and that's the 138th row.

Isn't he asking for rolling shutter information, though. As in the position of the shutter?

[Rob Lohman]

Yes... I see your point. I must meditate on this....

[I Bloom]

So within the window. That's always zero. (depending on how you set up your coordinates).

Both numbers seem to be of limited use.

Anyway, Rob what are your thoughts on the above linked article? All correct?

Ian