[libcamera-devel] [RFC PATCH 2/6] libcamera: stream: Add frame interval attribute

[Laurent Pinchart]

Hi Jacopo,

On Tue, Mar 16, 2021 at 10:15:00PM +0100, Jacopo Mondi wrote:
> On Tue, Mar 16, 2021 at 09:28:47PM +0200, Laurent Pinchart wrote:
> > On Tue, Mar 16, 2021 at 04:52:07PM +0100, Marian Cichy wrote:
> > > The frame interval can be get and set from and on v4l2-subdevices and is
> > > part of the stream configuration.
> > >
> > > Signed-off-by: Marian Cichy <m.cichy at pengutronix.de>
> > > ---
> > >  include/libcamera/stream.h | 2 ++
> > >  1 file changed, 2 insertions(+)
> > >
> > > diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
> > > index bb47c390..14bfbf44 100644
> > > --- a/include/libcamera/stream.h
> > > +++ b/include/libcamera/stream.h
> > > @@ -13,6 +13,7 @@
> > >  #include <vector>
> > >
> > >  #include <libcamera/buffer.h>
> > > +#include <libcamera/fraction.h>
> > >  #include <libcamera/geometry.h>
> > >  #include <libcamera/pixel_format.h>
> > >
> > > @@ -44,6 +45,7 @@ struct StreamConfiguration {
> > >  	Size size;
> > >  	unsigned int stride;
> > >  	unsigned int frameSize;
> > > +	Fraction frameInterval;
> >
> > This should use the FrameDurations control instead.
> 
> This might turn out to be rather nasty as we don't support per-stream
> controls (yet?) :/

This patch series targets a single stream as it configures the frame
duration on the sensor, so I think that's fine (at least for now).

> What are you trying to achieve here ? Setting the frame duration
> during a capture session ? In that case the setting should go through
> the Request::controls control list (and should be reported per-request
> through Request::metadata).
> 
> Or should the frame duration be made a property of the
> CameraConfiguration and set at configure() time ? What is the use case
> for this last option ?
> 
> > >  	unsigned int bufferCount;

-- 
Regards,

Laurent Pinchart