Fix issue 2305382: Pick up original call makes a noisy beep when wired headset connected.

The noise is the residual ring tone that is still playing while the call is answered and the
audio route changed to headset or earpiece.

The fix consists in muting the ringing tone when changing mode from ringtone to in call
and delaying the route change until the audio buffers are emptied.

1 files changed, 21 insertions, 3 deletions

diff --git a/libs/audioflinger/AudioPolicyManagerBase.cpp b/libs/audioflinger/AudioPolicyManagerBase.cpp
index 096aa73..42b6508 100644
--- a/libs/audioflinger/AudioPolicyManagerBase.cpp
+++ b/libs/audioflinger/AudioPolicyManagerBase.cpp
@@ -295,13 +295,31 @@ void AudioPolicyManagerBase::setPhoneState(int state)
     if (oldState == AudioSystem::MODE_IN_CALL && newDevice == 0) {
         newDevice = hwOutputDesc->device();
     }
+
+    // when changing from ring tone to in call mode, mute the ringing tone
+    // immediately and delay the route change to avoid sending the ring tone
+    // tail into the earpiece or headset.
+    int delayMs = 0;
+    if (state == AudioSystem::MODE_IN_CALL && oldState == AudioSystem::MODE_RINGTONE) {
+        // delay the device change command by twice the output latency to have some margin
+        // and be sure that audio buffers not yet affected by the mute are out when
+        // we actually apply the route change
+        delayMs = hwOutputDesc->mLatency*2;
+        setStreamMute(AudioSystem::RING, true, mHardwareOutput);
+    }
+
     // change routing is necessary
-    setOutputDevice(mHardwareOutput, newDevice, force);
+    setOutputDevice(mHardwareOutput, newDevice, force, delayMs);
 
     // if entering in call state, handle special case of active streams
     // pertaining to sonification strategy see handleIncallSonification()
     if (state == AudioSystem::MODE_IN_CALL) {
         LOGV("setPhoneState() in call state management: new state is %d", state);
+        // unmute the ringing tone after a sufficient delay if it was muted before
+        // setting output device above
+        if (oldState == AudioSystem::MODE_RINGTONE) {
+            setStreamMute(AudioSystem::RING, false, mHardwareOutput, MUTE_TIME_MS);
+        }
         for (int stream = 0; stream < AudioSystem::NUM_STREAM_TYPES; stream++) {
             handleIncallSonification(stream, true, true);
         }
@@ -1207,10 +1225,10 @@ status_t AudioPolicyManagerBase::handleA2dpDisconnection(AudioSystem::audio_devi
         return INVALID_OPERATION;
     }
 
-    // mute media during 2 seconds to avoid outputing sound on hardware output while music stream
+    // mute media strategy to avoid outputting sound on hardware output while music stream
     // is switched from A2DP output and before music is paused by music application
     setStrategyMute(STRATEGY_MEDIA, true, mHardwareOutput);
-    setStrategyMute(STRATEGY_MEDIA, false, mHardwareOutput, 2000);
+    setStrategyMute(STRATEGY_MEDIA, false, mHardwareOutput, MUTE_TIME_MS);
 
     if (!a2dpUsedForSonification()) {
         // unmute music on A2DP output if a notification or ringtone is playing