Auxiliary lines in the preview image

S.L.P. image questions, stereoscopic video livestream and recording, stereoscopic photo capture etc.
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Posts: 9
Joined: Wed Oct 06, 2021 9:28 am

Auxiliary lines in the preview image

Post by amphi »

Does anyone have any idea how I could add guidelines to the preview image?
This is of great help when you want to compose beautiful photos. The lines help to take photos as straight as possible.
16: 9 guide lines in particular would be of interest to me.

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Re: Auxiliary lines in the preview image

Post by Realizator »

Hi Amphi,
If you are talking about the HDMI and TFT screen preview - uh, this is a painful story :)
You see, in the RPi3 and CM3 epoch it was one version video subsystem, and we were able to draw the advanced OSD data right over the image. WIth the RPi4 and CM4, this subsystem was fully redesigned, and there is (still) no way to use old methods.
For the TFT screen, we are using the special library, which copies the HDMI output buffer to the TFT screen buffer. Theoretically, it is possible to hack this library and add guidelines. If you can tell me the options you need - I'll try to take a closer look at this solution possibility.

As for the browser preview (admin panel) - this is relatively easy, but each browser has adaptive width/height (for mobile phone, tablet, PC, etc.). It will be painful to force this to work correctly on all devices and in all browsers.
Eugene a.k.a. Realizator

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