commit ac3a690c79467612a12e2c3a216c8ea2c4efbd64
author Eric Laurent <elaurent@google.com> Fri May 11 16:39:10 2018 -0700
committer Eric Laurent <elaurent@google.com> Mon May 14 18:35:05 2018 -0700
tree b192daca5cbceadc29316e9b22413bcb3914a856
parent 2c82a511797920451aa20ad5e089fc71aaff78af

audio policy: reduce mute time when invalidating tracks

Replace fixed 2 seconds mute time in checkOutputForStrategy() by
a variable time based on actual maximum output latency.

Also fix problem where src outputs where queried from mOutputs list
instead of from mPreviousOutputs.

Bug: 70632415
Test: manual connections/disconnection of BT A2DP and USB headset
Change-Id: I3a9ea915a134d95a2dc5abea2fbfe6152f147e80

services/audiopolicy/managerdefault/AudioPolicyManager.cpp

diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index d1d7530..7931176 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -4382,14 +4382,23 @@
     }
 
     if (!vectorsEqual(srcOutputs,dstOutputs)) {
+        // get maximum latency of all source outputs to determine the minimum mute time guaranteeing
+        // audio from invalidated tracks will be rendered when unmuting
+        uint32_t maxLatency = 0;
+        for (audio_io_handle_t srcOut : srcOutputs) {
+            sp<SwAudioOutputDescriptor> desc = mPreviousOutputs.valueFor(srcOut);
+            if (desc != 0 && maxLatency < desc->latency()) {
+                maxLatency = desc->latency();
+            }
+        }
         ALOGV("checkOutputForStrategy() strategy %d, moving from output %d to output %d",
               strategy, srcOutputs[0], dstOutputs[0]);
         // mute strategy while moving tracks from one output to another
         for (audio_io_handle_t srcOut : srcOutputs) {
-            sp<SwAudioOutputDescriptor> desc = mOutputs.valueFor(srcOut);
-            if (isStrategyActive(desc, strategy)) {
+            sp<SwAudioOutputDescriptor> desc = mPreviousOutputs.valueFor(srcOut);
+            if (desc != 0 && isStrategyActive(desc, strategy)) {
                 setStrategyMute(strategy, true, desc);
-                setStrategyMute(strategy, false, desc, MUTE_TIME_MS, newDevice);
+                setStrategyMute(strategy, false, desc, maxLatency * LATENCY_MUTE_FACTOR, newDevice);
             }
             sp<AudioSourceDescriptor> source =
                     getSourceForStrategyOnOutput(srcOut, strategy);