Messages in this thread | | | Date | Thu, 24 Aug 2023 12:26:42 +0000 | From | Sakari Ailus <> | Subject | Re: [PATCH v1 3/5] media: stm32-dcmipp: STM32 DCMIPP camera interface driver |
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Hi Alanin,
On Thu, Aug 24, 2023 at 01:09:34PM +0200, Alain Volmat wrote: > Hi Sakari, > > thanks a lot for the review. I've already taken care of the comments I got > from Dan and will also add fixes for your comments as well before > pushing the v2. Before going into that I thought I'd better clarify the > framerate part which seems the most tricky part. > > On Mon, Aug 07, 2023 at 09:29:55AM +0000, Sakari Ailus wrote:
...
> > > +static int dcmipp_byteproc_g_frame_interval(struct v4l2_subdev *sd, > > > + struct v4l2_subdev_frame_interval *fi) > > > +{ > > > + struct dcmipp_byteproc_device *byteproc = v4l2_get_subdevdata(sd); > > > + > > > + if (IS_SINK(fi->pad)) > > > + fi->interval = byteproc->sink_interval; > > > + else > > > + fi->interval = byteproc->src_interval; > > > + > > > + return 0; > > > +} > > > + > > > +static int dcmipp_byteproc_s_frame_interval(struct v4l2_subdev *sd, > > > + struct v4l2_subdev_frame_interval *fi) > > > +{ > > > + struct dcmipp_byteproc_device *byteproc = v4l2_get_subdevdata(sd); > > > + > > > + mutex_lock(&byteproc->lock); > > > + > > > + if (byteproc->streaming) { > > > + mutex_unlock(&byteproc->lock); > > > + return -EBUSY; > > > + } > > > + > > > + if (fi->interval.numerator == 0 || fi->interval.denominator == 0) > > > + fi->interval = byteproc->sink_interval; > > > + > > > + if (IS_SINK(fi->pad)) { > > > + /* > > > + * Setting sink frame interval resets frame skipping. > > > + * Sink frame interval is propagated to src. > > > + */ > > > + byteproc->frate = 0; > > > + byteproc->sink_interval = fi->interval; > > > + byteproc->src_interval = byteproc->sink_interval; > > > > Is this used for anything else than configure skipping? > > > > I think I'd just have a control for it in that case. > > > > I don't think exposing frame interval configuration is necessarily even > > meaningful for a device that just processes data but does not produce it. > > The DCMIPP is able to perform frame drop, 1/2, 1/4, 1/8 basically. > As Dan pointed me out, indeed setting frame interval as we did on both > sink and source pad isn't a defined behavior. I first thought that > using the frame interval was the proper way to do that but that is > indeed only used on producers such as sensors .... > Which ctrl would you propose in such case ?
We don't have one, AFAIK, and I think it may be unlikely this will be needed elsewhere. So I'd use a private control.
I wonder what others think. Cc Laurent as well.
-- Regards,
Sakari Ailus
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