[PATCH v3] libcamera: pipeline: uvcvideo: Map focus controls
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Sep 26 01:59:29 CEST 2024
Hi Cláudio,
Thank you for the patch.
On Sun, Sep 15, 2024 at 02:31:11PM +0000, Cláudio Paulo wrote:
> Added mapping of controls::LensPosition and controls::AfMode to
> v4l2 controls V4L2_CID_FOCUS_ABSOLUTE and V4L2_CID_FOCUS_AUTO
s/v4l2/V4L2/
> respectively when the device supports them.
>
> If not supported, they are not registered.
>
> Signed-off-by: Cláudio Paulo <claudio.paulo at makewise.pt>
> ---
> Fixed more issues raised in review.
>
> src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 97 ++++++++++++++++++--
> 1 file changed, 91 insertions(+), 6 deletions(-)
>
> diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> index 6b32fa18..401d3052 100644
> --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> @@ -304,13 +304,26 @@ int PipelineHandlerUVC::processControl(ControlList *controls, unsigned int id,
> cid = V4L2_CID_EXPOSURE_ABSOLUTE;
> else if (id == controls::AnalogueGain)
> cid = V4L2_CID_GAIN;
> + else if (id == controls::LensPosition)
> + cid = V4L2_CID_FOCUS_ABSOLUTE;
> + else if (id == controls::AfMode)
> + cid = V4L2_CID_FOCUS_AUTO;
> else
> return -EINVAL;
>
> + /* Check if the device supports this control. */
> + if (controls->idMap()->find(cid) == controls->idMap()->end())
> + return -EINVAL;
> +
> const ControlInfo &v4l2Info = controls->infoMap()->at(cid);
> - int32_t min = v4l2Info.min().get<int32_t>();
> - int32_t def = v4l2Info.def().get<int32_t>();
> - int32_t max = v4l2Info.max().get<int32_t>();
> +
> + int32_t min = -1, def = -1, max = -1;
> + if (v4l2Info.min().type() == ControlTypeInteger32)
> + min = v4l2Info.min().get<int32_t>();
> + if (v4l2Info.min().type() == ControlTypeInteger32)
> + def = v4l2Info.def().get<int32_t>();
> + if (v4l2Info.min().type() == ControlTypeInteger32)
> + max = v4l2Info.max().get<int32_t>();
>
> /*
> * See UVCCameraData::addControl() for explanations of the different
> @@ -358,6 +371,21 @@ int PipelineHandlerUVC::processControl(ControlList *controls, unsigned int id,
> break;
> }
>
> + case V4L2_CID_FOCUS_ABSOLUTE: {
> + float focusedAt50Cm = 0.15f * (max - min);
> + float scale = focusedAt50Cm / 2.0f;
> +
> + float fvalue = value.get<float>() * scale + min;
> + controls->set(cid, static_cast<int32_t>(lroundf(fvalue)));
You should use std::lround() here. Please remember to replace <math.h>
with <cmath> at the top of the file.
> + break;
> + }
> +
> + case V4L2_CID_FOCUS_AUTO: {
> + int32_t ivalue = value.get<int32_t>() != controls::AfModeManual;
> + controls->set(cid, ivalue);
> + break;
> + }
> +
> default: {
> int32_t ivalue = value.get<int32_t>();
> controls->set(cid, ivalue);
> @@ -655,14 +683,32 @@ void UVCCameraData::addControl(uint32_t cid, const ControlInfo &v4l2Info,
> case V4L2_CID_GAIN:
> id = &controls::AnalogueGain;
> break;
> + case V4L2_CID_FOCUS_ABSOLUTE:
> + id = &controls::LensPosition;
> + break;
> + case V4L2_CID_FOCUS_AUTO:
> + id = &controls::AfMode;
> + break;
> default:
> return;
> }
>
> /* Map the control info. */
> - int32_t min = v4l2Info.min().get<int32_t>();
> - int32_t max = v4l2Info.max().get<int32_t>();
> - int32_t def = v4l2Info.def().get<int32_t>();
> + int32_t min = -1, def = -1, max = -1;
> + if (v4l2Info.min().type() == ControlTypeInteger32)
> + min = v4l2Info.min().get<int32_t>();
> + else if (v4l2Info.min().type() == ControlTypeBool)
> + min = v4l2Info.min().get<bool>();
> +
> + if (v4l2Info.def().type() == ControlTypeInteger32)
> + def = v4l2Info.def().get<int32_t>();
> + else if (v4l2Info.def().type() == ControlTypeBool)
> + def = v4l2Info.def().get<bool>();
> +
> + if (v4l2Info.max().type() == ControlTypeInteger32)
> + max = v4l2Info.max().get<int32_t>();
> + else if (v4l2Info.max().type() == ControlTypeBool)
> + max = v4l2Info.max().get<bool>();
As the min, max and def values all have the same type, you can write
if (v4l2Info.min().type() == ControlTypeInteger32) {
min = v4l2Info.min().get<int32_t>();
def = v4l2Info.def().get<int32_t>();
max = v4l2Info.max().get<int32_t>();
} else if (v4l2Info.min().type() == ControlTypeBool) {
min = v4l2Info.min().get<bool>();
def = v4l2Info.def().get<bool>();
max = v4l2Info.max().get<bool>();
}
>
> switch (cid) {
> case V4L2_CID_BRIGHTNESS: {
> @@ -738,6 +784,45 @@ void UVCCameraData::addControl(uint32_t cid, const ControlInfo &v4l2Info,
> };
> break;
> }
Add a blank line here.
> + case V4L2_CID_FOCUS_ABSOLUTE: {
> + /*
> + * LensPosition expects values to be in the range of
> + * [0.0f, maxDioptres], while a value of 0 means focused to
> + * infinity, 0.5 means focused at 2m, 2 means focused at 50cm
> + * and maxDioptres will be the closest possible focus which
> + * will equate to a focus distance of (1 / maxDioptres) metres.
> + *
> + * \todo These values will definitely vary for each different
> + * hardware, so this should be tunable somehow. In this case
> + * 0.15f (~= 150 / (1023 - 1)) was a value read from
> + * V4L2_CID_FOCUS_ABSOLUTE control when using a random camera
> + * and having it autofocus at a distance of about 50cm.
> + * This means the minimum focus distance of this camera should
> + * be 75mm (0.15 / 2) which equals a maxDioptres value of ~=
> + * 13.3333 (2 / 0.15). Also, the values might not scale
> + * linearly, but this implementation assumes they do.
> + */
> + float focusedAt50Cm = 0.15f * (max - min);
> + float scale = 2.0f / focusedAt50Cm;
> +
> + info = ControlInfo{
> + { 0.0f },
> + { (max - min) * scale },
> + { (def - min) * scale }
> + };
> + break;
> + }
And here too.
> + case V4L2_CID_FOCUS_AUTO: {
> + int32_t manual = controls::AfModeManual;
> + int32_t continuous = controls::AfModeContinuous;
> +
> + info = ControlInfo{
> + { manual },
> + { continuous },
> + { def ? continuous : manual },
How about hardcoding the default to continuous, to make it less
device-specific ? Then you could write
info = ControlInfo{
{ controls::AfModeManual },
{ controls::AfModeContinuous },
{ controls::AfModeContinuous },
};
But for enumerated controls, you should use the ControlInfo constructor
that takes a list of supported values:
info = ControlInfo{
std::array<ControlValue, 2>{
static_cast<int32_t>(controls::AfModeManual),
static_cast<int32_t>(controls::AfModeContinuous),
},
{ static_cast<int32_t>(controls::AfModeContinuous) },
};
This is a bit complicated. I've posted a patch ("") that let's you
simplify the construct:
info = ControlInfo{
std::array<ControlValue, 2>{
controls::AfModeManual,
controls::AfModeContinuous,
},
{ controls::AfModeContinuous },
};
This being said, I think you should also check what the minimum and
maximum values are for the V4L2 control. It's conceivable that a UVC
device would implement the V4L2_CID_FOCUS_AUTO control but only supports
manual focus, or auto-focus. I think the following should work.
std::vector<ControlValue> values;
if (!min || !max)
values.push_back(controls::AfModeManual);
if (min ||max)
values.push_back(controls::AfModeContinuous);
info = ControlInfo{ values, values.back() };
break;
With these changes (please test them, as I may have made a mistake), I
think we can merge the next version.
> + };
> + break;
> + }
>
> default:
> info = v4l2Info;
--
Regards,
Laurent Pinchart
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