[PATCH 3/4] libcamera: controls: Add support for querying direction information
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Tue Nov 26 00:19:10 CET 2024
Hi Paul,
Thank you for the patch.
On Tue, Nov 26, 2024 at 12:30:02AM +0900, Paul Elder wrote:
> Add support to ControlId for querying direction information. This allows
> applications to query whether a ControlId is meant for being set in
> controls or to be returned in metadata or both. This also has a side
> effect of properly encoding this information, as previously it was only
> mentioned losely and inconsistently in the control id definition.
>
> Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> ---
> include/libcamera/controls.h | 27 +++++++++++++++++++-
> src/libcamera/control_ids.cpp.in | 4 +--
> src/libcamera/controls.cpp | 42 ++++++++++++++++++++++++++++++--
> 3 files changed, 68 insertions(+), 5 deletions(-)
>
> diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
> index 3cfe2de5973c..cd338ac0d653 100644
> --- a/include/libcamera/controls.h
> +++ b/include/libcamera/controls.h
> @@ -17,6 +17,7 @@
> #include <vector>
>
> #include <libcamera/base/class.h>
> +#include <libcamera/base/flags.h>
> #include <libcamera/base/span.h>
>
> #include <libcamera/geometry.h>
> @@ -235,8 +236,18 @@ private:
> class ControlId
> {
> public:
> + enum class Direction {
> + In = (1 << 0),
> + Out = (1 << 1),
> + };
> +
> + using DirectionFlags = Flags<Direction>;
> +
> ControlId(unsigned int id, const std::string &name, const std::string &vendor,
> ControlType type, std::size_t size = 0,
> + const DirectionFlags &direction =
> + static_cast<DirectionFlags>(Direction::In) |
> + static_cast<DirectionFlags>(Direction::Out),
I think we could make this argument explicit, without a default value,
as all controls have a direction.
> const std::map<std::string, int32_t> &enumStrMap = {});
>
> unsigned int id() const { return id_; }
> @@ -245,6 +256,16 @@ public:
> ControlType type() const { return type_; }
> bool isArray() const { return size_ > 0; }
> std::size_t size() const { return size_; }
> + bool isInput() const
With the changes proposed in the cover letter this now holds on a single
line:
bool isInput() const { return !!(direction_ & Direction::In); }
> + {
> + return static_cast<bool>(
> + direction_ & static_cast<DirectionFlags>(Direction::In));
> + }
> + bool isOutput() const
Same here.
> + {
> + return static_cast<bool>(
> + direction_ & static_cast<DirectionFlags>(Direction::Out));
> + }
> const std::map<int32_t, std::string> &enumerators() const { return reverseMap_; }
>
> private:
> @@ -255,6 +276,7 @@ private:
> std::string vendor_;
> ControlType type_;
> std::size_t size_;
> + DirectionFlags direction_;
> std::map<std::string, int32_t> enumStrMap_;
> std::map<int32_t, std::string> reverseMap_;
> };
> @@ -286,9 +308,12 @@ public:
> using type = T;
>
> Control(unsigned int id, const char *name, const char *vendor,
> + const ControlId::DirectionFlags &direction =
> + static_cast<ControlId::DirectionFlags>(ControlId::Direction::In) |
> + static_cast<ControlId::DirectionFlags>(ControlId::Direction::Out),
Do we want to pass this as an argument to the constructor, or as a
template argument ? The latter would allow handling the direction at
compile time (not sure what the use case would be though).
> const std::map<std::string, int32_t> &enumStrMap = {})
> : ControlId(id, name, vendor, details::control_type<std::remove_cv_t<T>>::value,
> - details::control_type<std::remove_cv_t<T>>::size, enumStrMap)
> + details::control_type<std::remove_cv_t<T>>::size, direction, enumStrMap)
> {
> }
>
> diff --git a/src/libcamera/control_ids.cpp.in b/src/libcamera/control_ids.cpp.in
> index afe9e2c96610..65668d486dbc 100644
> --- a/src/libcamera/control_ids.cpp.in
> +++ b/src/libcamera/control_ids.cpp.in
> @@ -89,9 +89,9 @@ extern const std::map<std::string, {{ctrl.type}}> {{ctrl.name}}NameValueMap = {
> { "{{enum.name}}", {{enum.name}} },
> {%- endfor %}
> };
> -extern const Control<{{ctrl.type}}> {{ctrl.name}}({{ctrl.name|snake_case|upper}}, "{{ctrl.name}}", "{{vendor}}", {{ctrl.name}}NameValueMap);
> +extern const Control<{{ctrl.type}}> {{ctrl.name}}({{ctrl.name|snake_case|upper}}, "{{ctrl.name}}", "{{vendor}}", {{ctrl.direction}}, {{ctrl.name}}NameValueMap);
> {% else -%}
> -extern const Control<{{ctrl.type}}> {{ctrl.name}}({{ctrl.name|snake_case|upper}}, "{{ctrl.name}}", "{{vendor}}");
> +extern const Control<{{ctrl.type}}> {{ctrl.name}}({{ctrl.name|snake_case|upper}}, "{{ctrl.name}}", "{{vendor}}", {{ctrl.direction}});
> {% endif -%}
> {%- endfor %}
>
> diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
> index 2efecf0fc52b..30eb17e7f064 100644
> --- a/src/libcamera/controls.cpp
> +++ b/src/libcamera/controls.cpp
> @@ -397,14 +397,15 @@ void ControlValue::reserve(ControlType type, bool isArray, std::size_t numElemen
> * \param[in] vendor The vendor name
> * \param[in] type The control data type
> * \param[in] size The size of the array control, or 0 if scalar control
> + * \param[in] direction The direction of the control, if it can be used in Controls or Metadata
Line wrap ?
> * \param[in] enumStrMap The map from enum names to values (optional)
> */
> ControlId::ControlId(unsigned int id, const std::string &name,
> const std::string &vendor, ControlType type,
> - std::size_t size,
> + std::size_t size, const DirectionFlags &direction,
> const std::map<std::string, int32_t> &enumStrMap)
> : id_(id), name_(name), vendor_(vendor), type_(type), size_(size),
> - enumStrMap_(enumStrMap)
> + direction_(direction), enumStrMap_(enumStrMap)
> {
> for (const auto &pair : enumStrMap_)
> reverseMap_[pair.second] = pair.first;
> @@ -440,6 +441,26 @@ ControlId::ControlId(unsigned int id, const std::string &name,
> * \return True if the control is an array control, false otherwise
> */
>
> +/**
> + * \fn bool ControlId::isInput() const
> + * \brief Determine if the control is available to be used as an input control
> + *
> + * Controls can be used either as input as a control, or as output in metadata.
> + * This function checks if the control is allowed to be used as the former.
> + *
> + * \return True if the control can be used as an input control, false otherwise
> + */
> +
> +/**
> + * \fn bool ControlId::isOutput() const
> + * \brief Determine if the control is available to be used in output metadata
> + *
> + * Controls can be used either as input as a control, or as output in metadata.
"Controls can be used [...] as a control"
:S I don't have a better suggestion for now that wouldn't involve a
tree-wide rename, so I'm OK with this.
> + * This function checks if the control is allowed to be used as the latter.
> + *
> + * \return True if the control can be returned in output metadata, false otherwise
> + */
> +
> /**
> * \fn std::size_t ControlId::size() const
> * \brief Retrieve the size of the control if it is an array control
> @@ -471,6 +492,22 @@ ControlId::ControlId(unsigned int id, const std::string &name,
> * \return True if \a lhs.id() is equal to \a rhs, false otherwise
> */
>
> +/**
> + * \enum ControlId::Direction
> + * \brief The direction that a control of the ControlId is capable of being passed from/to
> + *
> + * \var ControlId::Direction::In
> + * \brief The control can be passed in controls as input
> + *
> + * \var ControlId::Direction::Out
> + * \brief The control can be returned in output as metadata
The two definitions are not consistent: "in controls as input" vs. "in
output as metadata".
> + */
> +
> +/**
> + * \typedef ControlId::DirectionFlags
> + * \brief A wrapper for ControlId::Direction so that it can be used as flags
> + */
> +
> /**
> * \class Control
> * \brief Describe a control and its intrinsic properties
> @@ -504,6 +541,7 @@ ControlId::ControlId(unsigned int id, const std::string &name,
> * \param[in] id The control numerical ID
> * \param[in] name The control name
> * \param[in] vendor The vendor name
> + * \param[in] direction The direction of the control, if it can be used in Controls or Metadata
> * \param[in] enumStrMap The map from enum names to values (optional)
> *
> * The control data type is automatically deduced from the template type T.
--
Regards,
Laurent Pinchart
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