[PATCH v3 3/8] libcamera: uvcvideo: Register ExposureTimeMode control

[Paul Elder]

On Thu, Nov 21, 2024 at 05:21:19AM +0200, Laurent Pinchart wrote:
> Hi Paul, Jacopo,
> 
> Thank you for the patch.
> 
> On Wed, Nov 13, 2024 at 10:12:51PM +0900, Paul Elder wrote:
> > From: Jacopo Mondi <jacopo at jmondi.org>
> > 
> > Port the UVC pipeline handler to use the new ExposureTimeMode control
> > when processing Camera controls in place of the AeEnable control.
> > 
> > The V4L2_CID_EXPOSURE_AUTO control allows 4 possible values, which
> > map to ExposureTimeModeAuto and ExposureTimeModeManual.
> 
> Should we fix https://bugs.libcamera.org/show_bug.cgi?id=242 while at it
> ?

I'd rather do it on top than delay this even further.


Paul

> 
> > Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> > Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> > Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>
> > 
> > ---
> > No change in v3
> > ---
> >  src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 54 ++++++++++++++++++--
> >  1 file changed, 49 insertions(+), 5 deletions(-)
> > 
> > diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> > index 8c2c6baf3575..a2f0935181d4 100644
> > --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> > +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> > @@ -298,7 +298,7 @@ int PipelineHandlerUVC::processControl(ControlList *controls, unsigned int id,
> >  		cid = V4L2_CID_CONTRAST;
> >  	else if (id == controls::Saturation)
> >  		cid = V4L2_CID_SATURATION;
> > -	else if (id == controls::AeEnable)
> > +	else if (id == controls::ExposureTimeMode)
> >  		cid = V4L2_CID_EXPOSURE_AUTO;
> >  	else if (id == controls::ExposureTime)
> >  		cid = V4L2_CID_EXPOSURE_ABSOLUTE;
> > @@ -647,7 +647,7 @@ void UVCCameraData::addControl(uint32_t cid, const ControlInfo &v4l2Info,
> >  		id = &controls::Saturation;
> >  		break;
> >  	case V4L2_CID_EXPOSURE_AUTO:
> > -		id = &controls::AeEnable;
> > +		id = &controls::ExposureTimeMode;
> >  		break;
> >  	case V4L2_CID_EXPOSURE_ABSOLUTE:
> >  		id = &controls::ExposureTime;
> > @@ -660,6 +660,7 @@ void UVCCameraData::addControl(uint32_t cid, const ControlInfo &v4l2Info,
> >  	}
> >  
> >  	/* Map the control info. */
> > +	const std::vector<ControlValue> &v4l2Values = v4l2Info.values();
> >  	int32_t min = v4l2Info.min().get<int32_t>();
> >  	int32_t max = v4l2Info.max().get<int32_t>();
> >  	int32_t def = v4l2Info.def().get<int32_t>();
> > @@ -697,10 +698,53 @@ void UVCCameraData::addControl(uint32_t cid, const ControlInfo &v4l2Info,
> >  		};
> >  		break;
> >  
> > -	case V4L2_CID_EXPOSURE_AUTO:
> > -		info = ControlInfo{ false, true, true };
> > +	case V4L2_CID_EXPOSURE_AUTO: {
> > +		/*
> > +		 * From the V4L2_CID_EXPOSURE_AUTO documentation:
> > +		 *
> > +		 * ------------------------------------------------------------
> > +		 * V4L2_EXPOSURE_AUTO:
> > +		 * Automatic exposure time, automatic iris aperture.
> > +		 *
> > +		 * V4L2_EXPOSURE_MANUAL:
> > +		 * Manual exposure time, manual iris.
> > +		 *
> > +		 * V4L2_EXPOSURE_SHUTTER_PRIORITY:
> > +		 * Manual exposure time, auto iris.
> > +		 *
> > +		 * V4L2_EXPOSURE_APERTURE_PRIORITY:
> > +		 * Auto exposure time, manual iris.
> > +		 *-------------------------------------------------------------
> > +		 *
> > +		 * ExposureTimeModeAuto = { V4L2_EXPOSURE_AUTO,
> > +		 * 			    V4L2_EXPOSURE_APERTURE_PRIORITY }
> > +		 *
> > +		 *
> > +		 * ExposureTimeModeManual = { V4L2_EXPOSURE_MANUAL,
> > +		 *			      V4L2_EXPOSURE_SHUTTER_PRIORITY }
> > +		 */
> > +		std::array<int32_t, 2> values{};
> > +
> > +		auto it = std::find_if(v4l2Values.begin(), v4l2Values.end(),
> > +			[&](const ControlValue &val) {
> > +				return (val.get<int32_t>() == V4L2_EXPOSURE_APERTURE_PRIORITY ||
> > +					val.get<int32_t>() == V4L2_EXPOSURE_AUTO) ? true : false;
> > +			});
> > +		if (it != v4l2Values.end())
> > +			values.back() = static_cast<int32_t>(controls::ExposureTimeModeAuto);
> > +
> > +		it = std::find_if(v4l2Values.begin(), v4l2Values.end(),
> > +			[&](const ControlValue &val) {
> > +				return (val.get<int32_t>() == V4L2_EXPOSURE_SHUTTER_PRIORITY ||
> > +					val.get<int32_t>() == V4L2_EXPOSURE_MANUAL) ? true : false;
> > +			});
> > +		if (it != v4l2Values.end())
> > +			values.back() = static_cast<int32_t>(controls::ExposureTimeModeManual);
> > +
> > +		int32_t *data = values.data();
> > +		info = ControlInfo{Span<int32_t>(data, 2), values[0]};
> >  		break;
> > -
> > +	}
> >  	case V4L2_CID_EXPOSURE_ABSOLUTE:
> >  		/*
> >  		 * ExposureTime is in units of 1 µs, and UVC expects
> 
> -- 
> Regards,
> 
> Laurent Pinchart