# HG changeset patch
# User Chris Cannam
# Date 1484156797 0
# Node ID 298d864113f076e270f9f9804a950206ec4acfc0
# Parent  1a8a8980f39a8e735c90837a4c2260248aafe7f1
Fix flickery level meters

diff -r 1a8a8980f39a -r 298d864113f0 audio/AudioCallbackPlaySource.cpp
--- a/audio/AudioCallbackPlaySource.cpp	Thu Jan 05 13:04:30 2017 +0000
+++ b/audio/AudioCallbackPlaySource.cpp	Wed Jan 11 17:46:37 2017 +0000
@@ -72,6 +72,7 @@
     m_ringBufferSize(DEFAULT_RING_BUFFER_SIZE),
     m_outputLeft(0.0),
     m_outputRight(0.0),
+    m_levelsSet(false),
     m_auditioningPlugin(0),
     m_auditioningPluginBypassed(false),
     m_playStartFrame(0),
@@ -967,6 +968,7 @@
 {
     if (left > m_outputLeft) m_outputLeft = left;
     if (right > m_outputRight) m_outputRight = right;
+    m_levelsSet = true;
 }
 
 bool
@@ -974,9 +976,11 @@
 {
     left = m_outputLeft;
     right = m_outputRight;
+    bool valid = m_levelsSet;
     m_outputLeft = 0.f;
     m_outputRight = 0.f;
-    return true;
+    m_levelsSet = false;
+    return valid;
 }
 
 void
diff -r 1a8a8980f39a -r 298d864113f0 audio/AudioCallbackPlaySource.h
--- a/audio/AudioCallbackPlaySource.h	Thu Jan 05 13:04:30 2017 +0000
+++ b/audio/AudioCallbackPlaySource.h	Wed Jan 11 17:46:37 2017 +0000
@@ -188,8 +188,15 @@
     virtual void setOutputLevels(float left, float right) override;
 
     /**
-     * Return the current (or thereabouts) output levels in the range
-     * 0.0 -> 1.0, for metering purposes.
+     * Return the current output levels in the range 0.0 -> 1.0, for
+     * metering purposes. The values returned are the peak values
+     * since the last time this function was called (after which they
+     * are reset to zero until setOutputLevels is called again by the
+     * driver).
+     *
+     * Return true if the values have been set since this function was
+     * last called (i.e. if they are meaningful). Return false if they
+     * have not been set (in which case both will be zero).
      */
     virtual bool getOutputLevels(float &left, float &right) override;
 
@@ -360,6 +367,7 @@
     int                               m_ringBufferSize;
     float                             m_outputLeft;
     float                             m_outputRight;
+    bool                              m_levelsSet;
     RealTimePluginInstance           *m_auditioningPlugin;
     bool                              m_auditioningPluginBypassed;
     Scavenger<RealTimePluginInstance> m_pluginScavenger;
diff -r 1a8a8980f39a -r 298d864113f0 audio/AudioCallbackRecordTarget.cpp
--- a/audio/AudioCallbackRecordTarget.cpp	Thu Jan 05 13:04:30 2017 +0000
+++ b/audio/AudioCallbackRecordTarget.cpp	Wed Jan 11 17:46:37 2017 +0000
@@ -34,7 +34,8 @@
     m_buffers(0),
     m_bufferCount(0),
     m_inputLeft(0.f),
-    m_inputRight(0.f)
+    m_inputRight(0.f),
+    m_levelsSet(false)
 {
     m_viewManager->setAudioRecordTarget(this);
 
@@ -193,6 +194,7 @@
 {
     if (left > m_inputLeft) m_inputLeft = left;
     if (right > m_inputRight) m_inputRight = right;
+    m_levelsSet = true;
 }
 
 bool
@@ -202,7 +204,7 @@
     right = m_inputRight;
     m_inputLeft = 0.f;
     m_inputRight = 0.f;
-    return true;
+    return m_levelsSet;
 }
 
 void
diff -r 1a8a8980f39a -r 298d864113f0 audio/AudioCallbackRecordTarget.h
--- a/audio/AudioCallbackRecordTarget.h	Thu Jan 05 13:04:30 2017 +0000
+++ b/audio/AudioCallbackRecordTarget.h	Wed Jan 11 17:46:37 2017 +0000
@@ -63,7 +63,18 @@
     virtual bool isRecording() const override { return m_recording; }
     virtual sv_frame_t getRecordDuration() const override { return m_frameCount; }
 
-    virtual bool getInputLevels(float &left, float &right) override;
+    /**
+     * Return the current input levels in the range 0.0 -> 1.0, for
+     * metering purposes. The values returned are the peak values
+     * since the last time this function was called (after which they
+     * are reset to zero until setInputLevels is called again by the
+     * driver).
+     *
+     * Return true if the values have been set since this function was
+     * last called (i.e. if they are meaningful). Return false if they
+     * have not been set (in which case both will be zero).
+     */
+     virtual bool getInputLevels(float &left, float &right) override;
 
     WritableWaveFileModel *startRecording(); // caller takes ownership of model
     void stopRecording();
@@ -91,6 +102,7 @@
     int m_bufferCount;
     float m_inputLeft;
     float m_inputRight;
+    bool m_levelsSet;
 
     void recreateBuffers();
 };