X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fardour%2Fardour%2Fdsp_load_calculator.h;h=c7c0c0b83e074384ba4d55f86c719d9b5bbb10e2;hb=3a2ff0a4a740421267254896ff25c17b5280b3cf;hp=1da9786d367d6da007e098ed3cd87e0df785ff68;hpb=08e18a0cb47d862aaa42909fe92e554350dfe302;p=ardour.git

diff --git a/libs/ardour/ardour/dsp_load_calculator.h b/libs/ardour/ardour/dsp_load_calculator.h
index 1da9786d36..c7c0c0b83e 100644
--- a/libs/ardour/ardour/dsp_load_calculator.h
+++ b/libs/ardour/ardour/dsp_load_calculator.h
@@ -36,6 +36,10 @@ public:
 
 	}
 
+	void set_max_time(double samplerate, uint32_t period_size) {
+		m_max_time_us = period_size * 1e6 / samplerate;
+	}
+
 	void set_max_time_us(uint64_t max_time_us) {
 		assert(max_time_us != 0);
 		m_max_time_us = max_time_us;
@@ -60,20 +64,17 @@ public:
 		 */
 		if (m_start_timestamp_us < 0 || m_stop_timestamp_us < 0 ||
 		    m_start_timestamp_us > m_stop_timestamp_us ||
-		    elapsed_time_us() > max_timer_error()) {
+		    elapsed_time_us() > max_timer_error_us()) {
 			return;
 		}
 
-		if (elapsed_time_us() > m_max_time_us) {
-			m_dsp_load = 1.0f;
+		const float load = (float) elapsed_time_us() / (float)m_max_time_us;
+		if (load > m_dsp_load || load > 1.0) {
+			m_dsp_load = load;
 		} else {
-			const float load = elapsed_time_us() / (float)m_max_time_us;
-			if (load > m_dsp_load) {
-				m_dsp_load = load;
-			} else {
-				const float alpha = 0.2f * (m_max_time_us * 1e-6f);
-				m_dsp_load = m_dsp_load + alpha * (load - m_dsp_load) + 1e-12;
-			}
+			const float alpha = 0.2f * (m_max_time_us * 1e-6f);
+			m_dsp_load = std::min (1.f, m_dsp_load);
+			m_dsp_load += alpha * (load - m_dsp_load) + 1e-12;
 		}
 	}
 
@@ -89,17 +90,26 @@ public:
 	 */
 	float get_dsp_load() const
 	{
-		if (m_dsp_load > m_max_time_us) {
-			return 1.0f;
-		}
-		if (m_dsp_load < 0.0f) {
-			return 0.0f;
-		}
+		assert (m_dsp_load >= 0.f); // since stop > start is assured this cannot happen.
+		return std::min (1.f, m_dsp_load);
+	}
+
+	/**
+	 * @return an unbound value representing the percentage of time spent between
+	 * start and stop in proportion to the max expected time in microseconds(us).
+	 * This is useful for cases to estimate overload (e.g. Dummy backend)
+	 */
+	float get_dsp_load_unbound() const
+	{
+		assert (m_dsp_load >= 0.f);
 		return m_dsp_load;
 	}
 
-private: // methods
-	int64_t max_timer_error () { return 4 * m_max_time_us; }
+	/**
+	 * The maximum error in timestamp values that will be tolerated before the
+	 * current dsp load sample will be ignored
+	 */
+	int64_t max_timer_error_us() { return 4 * m_max_time_us; }
 
 private: // data
 	int64_t m_max_time_us;