When using floating-point timestamps, use a double instead of a float.

The vast majority of timestamps are held as a pair of 64-bit integers
(numerator and denominator). For the few cases where floating point
math is used, use a double for the numerator instead of a float (the
denominator is always an int64_t.) This will provide more precision.

mythtv/libs/libmythbase/housekeeper.cpp

@@ -386,23 +386,23 @@ bool PeriodicHouseKeeperTask::DoCheckRun(const QDateTime& now)
 
     // calculate probability that task should not have yet run
     // it's backwards, but it makes the math simplier
-    float prob = 1.0F - (duration_cast<floatsecs>(elapsed - m_windowElapsed.first) /
+    double prob = 1.0 - (duration_cast<floatsecs>(elapsed - m_windowElapsed.first) /
                          duration_cast<floatsecs>(m_windowElapsed.second - m_windowElapsed.first));
     if (m_currentProb < prob)
         // more bad stuff
         return false;
 
     // calculate current probability to achieve overall probability
     // this should be nearly one
-    float prob2 = prob/m_currentProb;
+    double prob2 = prob/m_currentProb;
     // so rand() should have to return nearly RAND_MAX to get a positive
     // remember, this is computing the probability that up to this point, one
     //      of these tests has returned positive, so each individual test has
     //      a necessarily low probability
     //
     // Pseudo-random is good enough. Don't need a true random.
     // NOLINTNEXTLINE(cert-msc30-c,cert-msc50-cpp)
-    bool res = (rand() > (int)(prob2 * static_cast<float>(RAND_MAX)));
+    bool res = (rand() > (int)(prob2 * static_cast<double>(RAND_MAX)));
     m_currentProb = prob;
 //  if (res)
 //      LOG(VB_GENERAL, LOG_DEBUG, QString("%1 will run: this=%2; total=%3")

mythtv/libs/libmythbase/housekeeper.h

@@ -102,7 +102,7 @@ class MBASE_PUBLIC PeriodicHouseKeeperTask : public HouseKeeperTask
     std::chrono::seconds        m_retry;
     QPair<float,float>          m_windowPercent;
     QPair<std::chrono::seconds,std::chrono::seconds> m_windowElapsed;
-    float                       m_currentProb;
+    double                      m_currentProb;
 };
 
 class MBASE_PUBLIC DailyHouseKeeperTask : public PeriodicHouseKeeperTask

mythtv/libs/libmythbase/mythchrono.h

@@ -36,9 +36,9 @@ namespace std::chrono // NOLINT(cert-dcl58-cpp)
 
 // There are a number of places that hold/manipulate time in the form
 // of a floating point number. Create unique types for these.
-using floatsecs = std::chrono::duration<float>;
-using floatmsecs = std::chrono::duration<float, std::milli>;
-using floatusecs = std::chrono::duration<float, std::micro>;
+using floatsecs = std::chrono::duration<double>;
+using floatmsecs = std::chrono::duration<double, std::milli>;
+using floatusecs = std::chrono::duration<double, std::micro>;
 
 // There are a handful of places that hold a time value in units of
 // AV_TIME_BASE. Create a unique type for this.
@@ -196,13 +196,13 @@ T nowAsDuration (bool adjustForTZ = false)
 
 /// \brief Multiply a duration by a float, returning a duration.
 template <typename T>
-static constexpr T chronomult(T duration, float f)
+static constexpr T chronomult(T duration, double f)
 {
     return T(std::llround(duration.count() * f));
 }
 /// \brief Divide a duration by a float, returning a duration.
 template <typename T>
-static constexpr T chronodivide(T duration, float f)
+static constexpr T chronodivide(T duration, double f)
 {
     return T(std::llround(duration.count() / f));
 }