[libcamera-devel] Video recording on PinePhone Re: libcamera on pinephone

[Pavel Machek]

Hi!

> > qcam looks like a step in right direction, but .. it needs two streams
> > to be able to take photos, and we don't that capability on pinephone.
> > 
> > For taking photos, I see two possibilities:
> > 
> > a) Do the viewfinder in low resolution, then switch to high
> > resolution, take a photo, and switch back. Unfortunately pipeline
> > reconfiguration is rather slow (> 2 seconds?) on pinephone.
> 
> 2 seconds is a lot, there may be a way to reduce that, it should be
> investigated.

I was optimistic. It is more like 7 seconds.

> > b) Run the chip in high resolution all the time, downscaling for
> > viewfinder. Should result in less shutter lag, but viewfinder will be
> > limited to 15 fps and will need more cpu power.
> 
> Could the GPU be used to scale the full resolution down ?

Probably. But I find CPUs easier to use.

> > Camera seems to be
> > able to do JPEG natively, does it make sense to try to get that to work?
> 
> That's an option, but if you want to have a viewfinder at the same time,
> you would then need to decompress the frames. Furthermore, MJPEG for
> videos isn't great, as the compression ratio will be low.

PinePhone has rather weak CPUs. 4 of them, but not great. I don't
think I can encode something better than MJPEG in 1280x720. So, JPEG
should be good solution for PinePhone.

(But likely dead-end as it will be unavailable on PinePhone Pro /
Librem -- if I understand it correctly).

> Any hope of getting the A64 video encoder to work ?

A64 video encoder? https://forum.pine64.org/showthread.php?tid=9231 ?
Hmm. Looks interesting but a lot of work.

Best regards,

								Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.
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