[libcamera-devel] PinePhone needs S_FRAME_INTERVAL

[Pavel Machek]

Hi!

> > It looks I solved another mystery: Top resolution was not available,
> > and depending on order of commands, sometimes 1280x720 was not
> > available, either.
> > 
> > So I took a look into megapixels, and mystery solved -- libcamera is
> > not setting frame intervals at all.
> > 
> > AFAICT that needs to happen. PinePhone needs lower fps for top
> > resolution, but an use high fps for lower resolutions...
> > 
> > This is obviosly a hack, but we need something like that.
> 
> VIDIOC_SUBDEV_S_FRAME_INTERVAL is deprecated for camera sensors and
> should never have been used. Frame rates are controlled through the
> pixel clock and the horizontal and vertical blanking values. If a sensor
> driver requires VIDIOC_SUBDEV_S_FRAME_INTERVAL, then it should be
> fixed.

Hmm. I can't really change the kernel at the moment.

But... However you call frames per second, it is quite an important
parameter that needs to be controlled by the user, no? Is there plan
to include it in the stream options

  -s, --stream key=value[,key=value,...] ...            Set configuration of a camera stream
            height=integer                                Height in pixels
	    pixelformat=string                            Pixel format name
	    role=string                                   Role for the stream (viewfinder, video, still, raw)
	    width=integer                                 Width in pixels
					  
Confusing thing for me is that without S_FRAME_INTERVAL being set
explicitely, old value was being used, leading to
hard-to-understand/debug problems. I guess that is no longer going to
be a problem with fixed kernel drivers.

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