audioflinger: fix effect problem during underrun
When an audio track underruns, the input buffer of the
corresponding effect chain (if any) must be cleared, otherwise
audio from previous mixer run will be fed again to the effect process
function.
Bug 6551652.
Change-Id: I5cd02196745f756c85af82d6937e9dc54369b37f
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 57d7089..eea3cd2 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -3147,6 +3147,13 @@
mixerStatus = MIXER_TRACKS_READY;
}
} else {
+ // clear effect chain input buffer if an active track underruns to avoid sending
+ // previous audio buffer again to effects
+ chain = getEffectChain_l(track->sessionId());
+ if (chain != 0) {
+ chain->clearInputBuffer();
+ }
+
//ALOGV("track %d u=%08x, s=%08x [NOT READY] on thread %p", name, cblk->user, cblk->server, this);
if ((track->sharedBuffer() != 0) || track->isTerminated() ||
track->isStopped() || track->isPaused()) {
@@ -3661,6 +3668,12 @@
mActiveTrack = t;
mixerStatus = MIXER_TRACKS_READY;
} else {
+ // clear effect chain input buffer if an active track underruns to avoid sending
+ // previous audio buffer again to effects
+ if (!mEffectChains.isEmpty()) {
+ mEffectChains[0]->clearInputBuffer();
+ }
+
//ALOGV("track %d u=%08x, s=%08x [NOT READY]", track->name(), cblk->user, cblk->server);
if (track->isTerminated() || track->isStopped() || track->isPaused()) {
// We have consumed all the buffers of this track.
@@ -8978,6 +8991,25 @@
return 0;
}
+void AudioFlinger::EffectChain::clearInputBuffer()
+{
+ Mutex::Autolock _l(mLock);
+ sp<ThreadBase> thread = mThread.promote();
+ if (thread == 0) {
+ ALOGW("clearInputBuffer(): cannot promote mixer thread");
+ return;
+ }
+ clearInputBuffer_l(thread);
+}
+
+// Must be called with EffectChain::mLock locked
+void AudioFlinger::EffectChain::clearInputBuffer_l(sp<ThreadBase> thread)
+{
+ size_t numSamples = thread->frameCount() * thread->channelCount();
+ memset(mInBuffer, 0, numSamples * sizeof(int16_t));
+
+}
+
// Must be called with EffectChain::mLock locked
void AudioFlinger::EffectChain::process_l()
{
@@ -9002,8 +9034,7 @@
// 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));
+ clearInputBuffer_l(thread);
if (mTailBufferCount > 0) {
mTailBufferCount--;
}
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index 51cbae7..19390b1 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -1717,6 +1717,8 @@
void checkSuspendOnEffectEnabled(const sp<EffectModule>& effect,
bool enabled);
+ void clearInputBuffer();
+
status_t dump(int fd, const Vector<String16>& args);
protected:
@@ -1744,6 +1746,8 @@
// types or implementations from the suspend/restore mechanism.
bool isEffectEligibleForSuspend(const effect_descriptor_t& desc);
+ void clearInputBuffer_l(sp<ThreadBase> thread);
+
wp<ThreadBase> mThread; // parent mixer thread
Mutex mLock; // mutex protecting effect list
Vector< sp<EffectModule> > mEffects; // list of effect modules