audioflinger: fix noise when skipping to next song
When audio effects are enabled, a noise can be heard at the
beginning of the new song when skipping to next song in music app.
This is because some effects (especially virtualizer) have a tail.
This tail was not played when previous song was stopped because effects were
not processed when no tracks were present on a given session. This is to
reduce CPU load when effects are enabled but no audio is playing.
The tail was then rendered when the new song was started.
Added a delay before stopping effect process after all tracks have been removed from a session.
Issue 5584880.
Change-Id: I815e0f7441f9302e8dfe413dc269a94e4cc6fd95
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index ff262f1..780c0d2 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -7028,11 +7028,17 @@
AudioFlinger::EffectChain::EffectChain(const wp<ThreadBase>& wThread,
int sessionId)
- : mThread(wThread), mSessionId(sessionId), mActiveTrackCnt(0), mTrackCnt(0),
+ : mThread(wThread), mSessionId(sessionId), mActiveTrackCnt(0), mTrackCnt(0), mTailBufferCount(0),
mOwnInBuffer(false), mVolumeCtrlIdx(-1), mLeftVolume(UINT_MAX), mRightVolume(UINT_MAX),
mNewLeftVolume(UINT_MAX), mNewRightVolume(UINT_MAX)
{
mStrategy = AudioSystem::getStrategyForStream(AUDIO_STREAM_MUSIC);
+ sp<ThreadBase> thread = mThread.promote();
+ if (thread == 0) {
+ return;
+ }
+ mMaxTailBuffers = ((kProcessTailDurationMs * thread->sampleRate()) / 1000) /
+ thread->frameCount();
}
AudioFlinger::EffectChain::~EffectChain()
@@ -7100,22 +7106,31 @@
}
bool isGlobalSession = (mSessionId == AUDIO_SESSION_OUTPUT_MIX) ||
(mSessionId == AUDIO_SESSION_OUTPUT_STAGE);
- bool tracksOnSession = false;
+ // always process effects unless no more tracks are on the session and the effect tail
+ // has been rendered
+ bool doProcess = true;
if (!isGlobalSession) {
- tracksOnSession = (trackCnt() != 0);
- }
+ bool tracksOnSession = (trackCnt() != 0);
- // if no track is active, input buffer must be cleared here as the mixer process
- // will not do it
- if (tracksOnSession &&
- activeTrackCnt() == 0) {
- size_t numSamples = thread->frameCount() * thread->channelCount();
- memset(mInBuffer, 0, numSamples * sizeof(int16_t));
+ if (!tracksOnSession && mTailBufferCount == 0) {
+ doProcess = false;
+ }
+
+ if (activeTrackCnt() == 0) {
+ // if no track is active and the effect tail has not been rendered,
+ // the input buffer must be cleared here as the mixer process will not do it
+ if (tracksOnSession || mTailBufferCount > 0) {
+ size_t numSamples = thread->frameCount() * thread->channelCount();
+ memset(mInBuffer, 0, numSamples * sizeof(int16_t));
+ if (mTailBufferCount > 0) {
+ mTailBufferCount--;
+ }
+ }
+ }
}
size_t size = mEffects.size();
- // do not process effect if no track is present in same audio session
- if (isGlobalSession || tracksOnSession) {
+ if (doProcess) {
for (size_t i = 0; i < size; i++) {
mEffects[i]->process();
}