@@ -316,6 +316,48 @@ auto enumerate(T (&iterable)[N]) -> details::enumerate_adapter<T *>
}
#endif
+using BaseDuration = std::chrono::duration<double, std::nano>;
+
+class Duration : public BaseDuration
+{
+public:
+ Duration() = default;
+
+ template<typename Rep, typename Period>
+ constexpr Duration(const std::chrono::duration<Rep, Period> &d)
+ : BaseDuration(d)
+ {
+ }
+
+ template<typename Period>
+ double get() const
+ {
+ auto const c = std::chrono::duration_cast<std::chrono::duration<double, Period>>(*this);
+ return c.count();
+ }
+
+ explicit constexpr operator bool() const
+ {
+ return *this != BaseDuration::zero();
+ }
+};
+
+#ifndef __DOXYGEN__
+template<class CharT, class Traits>
+static inline std::basic_ostream<CharT, Traits> &operator<<(std::basic_ostream<CharT, Traits> &os,
+ const Duration &d)
+{
+ std::basic_ostringstream<CharT, Traits> s;
+
+ s.flags(os.flags());
+ s.imbue(os.getloc());
+ s.setf(std::ios_base::fixed, std::ios_base::floatfield);
+ s.precision(2);
+ s << d.get<std::micro>() << "us";
+ return os << s.str();
+}
+#endif
+
} /* namespace utils */
} /* namespace libcamera */
@@ -506,6 +506,42 @@ std::string libcameraSourcePath()
* loop, iterates over an indexed view of the \a iterable
*/
+/**
+ * \class Duration
+ * \brief Helper for std::chrono::duration types. Derived from \a BaseDuration
+ */
+
+/**
+ * \fn Duration::Duration(const std::chrono::duration<Rep, Period> &d)
+ * \brief Copy constructor from a \a std::chrono::duration type.
+ * \param[in] d The std::chrono::duration object to convert from.
+ *
+ * Constructs a \a Duration object from a \a std::chrono::duration object,
+ * converting the representation to \a BaseDuration type.
+ */
+
+/**
+ * \fn Duration::get<Period>()
+ * \brief Retrieve the tick count, coverted to the timebase provided by the
+ * template argument Period of type \a std::ratio.
+ *
+ * A typical usage example is given below:
+ *
+ * \code{.cpp}
+ * utils::Duration d = 5s;
+ * double d_in_ms = d.get<std::milli>();
+ * \endcode
+ *
+ * \return Tick count
+ */
+
+/**
+ * \fn Duration::operator bool()
+ * \brief Boolean operator to test if a \a Duration holds a non-zero time value.
+ *
+ * \return True if \a Duration is a non-zero time value, False otherwise.
+ */
+
} /* namespace utils */
} /* namespace libcamera */
A new utils::Duration class is defined to represent a std::chrono::duration type with double precision nanosecond timebase. Using a double minimises the loss of precision when converting timebases. This helper class may be used by IPAs to represent variables such as frame durations and exposure times. An operator << overload is define to help with displaying utils::Duration value in stream objects. Currently, this will display the duration value in microseconds. Signed-off-by: Naushir Patuck <naush@raspberrypi.com> --- include/libcamera/internal/utils.h | 42 ++++++++++++++++++++++++++++++ src/libcamera/utils.cpp | 36 +++++++++++++++++++++++++ 2 files changed, 78 insertions(+)