Delay slaving to audio clock until it progresses

2 files changed, 31 insertions, 11 deletions

diff --git a/src/MyClock.cpp b/src/MyClock.cpp
index e5ed900..b147c8e 100644
--- a/src/MyClock.cpp
+++ b/src/MyClock.cpp
@@ -24,9 +24,15 @@ namespace SaneAudioRenderer
     {

         CAutoLock lock(this);

 

+    #ifndef NDEBUG

+        const int64_t oldCounterOffset = m_counterOffset;

+    #endif

+

         if (m_guidedReclockSlaving && !CanDoGuidedReclock())

             UnslaveClock();

 

+        REFERENCE_TIME audioClockTime, counterTime, clockTime;

+

         if (m_guidedReclockSlaving)

         {

             auto getGuidedReclockTime = [this](int64_t counterTime)

@@ -35,7 +41,6 @@ namespace SaneAudioRenderer
                 return m_guidedReclockStartClock + progress;

             };

 

-            REFERENCE_TIME audioClockTime, counterTime, clockTime;

             if (SUCCEEDED(GetAudioClockTime(&audioClockTime, &counterTime)))

             {

                 clockTime = getGuidedReclockTime(counterTime);

@@ -50,34 +55,47 @@ namespace SaneAudioRenderer
             }

 

             m_counterOffset = clockTime - counterTime;

-

-            return clockTime;

         }

-

-        REFERENCE_TIME audioClockTime, counterTime;

-        if (SUCCEEDED(GetAudioClockTime(&audioClockTime, &counterTime)))

+        else if (SUCCEEDED(GetAudioClockTime(&audioClockTime, &counterTime)))

         {

+            clockTime = audioClockTime;

             m_counterOffset = audioClockTime - counterTime;

-            return audioClockTime;

         }

+        else

+        {

+            clockTime = m_counterOffset + GetCounterTime();

+        }

+

+    #ifndef NDEBUG

+        int64_t counterOffsetDiff = m_counterOffset - oldCounterOffset;

+        if (std::abs(counterOffsetDiff) > OneMillisecond)

+            DebugOut(ClassName(this), "observed clock warp of", counterOffsetDiff / 10000., "ms");

+    #endif

 

-        return m_counterOffset + GetCounterTime();

+        return clockTime;

     }

 

     void MyClock::SlaveClockToAudio(IAudioClock* pAudioClock, int64_t audioStart)

     {

+        assert(pAudioClock);

+

         CAutoLock lock(this);

 

+        DebugOut(ClassName(this), "slave clock to audio device (delayed until it progresses)");

+

         m_audioClock = pAudioClock;

         m_audioStart = audioStart;

+        m_audioInitialPosition = 0;

+        m_audioClock->GetPosition(&m_audioInitialPosition, nullptr);

         m_audioOffset = 0;

-        m_counterOffset = audioStart - GetCounterTime();

     }

 

     void MyClock::UnslaveClockFromAudio()

     {

         CAutoLock lock(this);

 

+        DebugOut(ClassName(this), "unslave clock from audio device");

+

         m_audioClock = nullptr;

     }

 

@@ -98,11 +116,12 @@ namespace SaneAudioRenderer
         {

             uint64_t audioFrequency, audioPosition, audioTime;

             if (SUCCEEDED(m_audioClock->GetFrequency(&audioFrequency)) &&

-                SUCCEEDED(m_audioClock->GetPosition(&audioPosition, &audioTime)))

+                SUCCEEDED(m_audioClock->GetPosition(&audioPosition, &audioTime)) &&

+                audioPosition > m_audioInitialPosition)

             {

                 int64_t counterTime = GetCounterTime();

                 int64_t clockTime = llMulDiv(audioPosition, OneSecond, audioFrequency, 0) +

-                                    m_audioStart + m_audioOffset + (audioPosition > 0 ? counterTime - audioTime : 0);

+                                    m_audioStart + m_audioOffset + counterTime - audioTime;

 

                 *pAudioTime = clockTime;

 

diff --git a/src/MyClock.h b/src/MyClock.h
index 31ad742..575a435 100644
--- a/src/MyClock.h
+++ b/src/MyClock.h
@@ -45,6 +45,7 @@ namespace SaneAudioRenderer
 

         IAudioClockPtr m_audioClock;

         int64_t m_audioStart = 0;

+        uint64_t m_audioInitialPosition = 0;

         int64_t m_audioOffset = 0;

         int64_t m_counterOffset = 0;