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

[Pavel Machek]

Hi!

> > > > 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.
> 
> In a way that's good news, it means there's even more room for
> improvement :-)

You are an optimist :-).

> > > > 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.
> 
> It's probably easier, yes, but if the CPU isn't powerful enough, then
> help from the GPU is an option that should be considered.
> 
> GPUs can perform scaling pretty much for free, but they usually can't
> output YUV natively. Tricks can be done with multi-pass rendering
> though.

Thinking about that... There should be plenty of memory bandwidth and
either CPU or GPU should be able to do the job easily. After all,
camera is "only" capable of ~50MB/sec data production, and it is not
1995 any more.

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