Modifications in audio effect engine state management.

- Separate the updating of effect engine state from the process call in EffectModule so that the state
of all effects in the same effect chain is updated simultaneusly before all process functions are called.
- Added a mechanism for the effect engine to continue being called for processing after receiving the disable
commands untils it considers that the framework can stop calling the process function without causing
a glitch or loosing some effect tail.
- Updated test reverb and equalizer to support this new feature

Change-Id: Icb56ae2c84c076d4dbad6cf733b1a62f823febe7

diff --git a/libs/audioflinger/AudioFlinger.cpp b/libs/audioflinger/AudioFlinger.cpp
index e6f46ce..97eb6c0 100644 (file)
--- a/libs/audioflinger/AudioFlinger.cpp
+++ b/libs/audioflinger/AudioFlinger.cpp
@@ -17,8 +17,7 @@
 
 
 #define LOG_TAG "AudioFlinger"
-//
-#define LOG_NDEBUG 0
+//#define LOG_NDEBUG 0
 
 #include <math.h>
 #include <signal.h>
@@ -5085,15 +5084,53 @@ void AudioFlinger::EffectModule::disconnect(const wp<EffectHandle>& handle)
     }
 }
 
+void AudioFlinger::EffectModule::updateState() {
+    Mutex::Autolock _l(mLock);
+
+    switch (mState) {
+    case RESTART:
+        reset_l();
+        // FALL THROUGH
+
+    case STARTING:
+        // clear auxiliary effect input buffer for next accumulation
+        if ((mDescriptor.flags & EFFECT_FLAG_TYPE_MASK) == EFFECT_FLAG_TYPE_AUXILIARY) {
+            memset(mConfig.inputCfg.buffer.raw,
+                   0,
+                   mConfig.inputCfg.buffer.frameCount*sizeof(int32_t));
+        }
+        start_l();
+        mState = ACTIVE;
+        break;
+    case STOPPING:
+        stop_l();
+        mDisableWaitCnt = mMaxDisableWaitCnt;
+        mState = STOPPED;
+        break;
+    case STOPPED:
+        // mDisableWaitCnt is forced to 1 by process() when the engine indicates the end of the
+        // turn off sequence.
+        if (--mDisableWaitCnt == 0) {
+            reset_l();
+            mState = IDLE;
+        }
+        break;
+    default: //IDLE , ACTIVE
+        break;
+    }
+}
+
 void AudioFlinger::EffectModule::process()
 {
     Mutex::Autolock _l(mLock);
 
-    if (mEffectInterface == NULL || mConfig.inputCfg.buffer.raw == NULL || mConfig.outputCfg.buffer.raw == NULL) {
+    if (mEffectInterface == NULL ||
+            mConfig.inputCfg.buffer.raw == NULL ||
+            mConfig.outputCfg.buffer.raw == NULL) {
         return;
     }
 
-    if (mState != IDLE) {
+    if (mState == ACTIVE || mState == STOPPING || mState == STOPPED) {
         // do 32 bit to 16 bit conversion for auxiliary effect input buffer
         if ((mDescriptor.flags & EFFECT_FLAG_TYPE_MASK) == EFFECT_FLAG_TYPE_AUXILIARY) {
             AudioMixer::ditherAndClamp(mConfig.inputCfg.buffer.s32,
@@ -5101,33 +5138,15 @@ void AudioFlinger::EffectModule::process()
                                         mConfig.inputCfg.buffer.frameCount);
         }
 
-        // TODO: handle effects with buffer provider
-        if (mState != ACTIVE) {
-            switch (mState) {
-            case RESET:
-                reset_l();
-                mState = STARTING;
-                // clear auxiliary effect input buffer for next accumulation
-                if ((mDescriptor.flags & EFFECT_FLAG_TYPE_MASK) == EFFECT_FLAG_TYPE_AUXILIARY) {
-                    memset(mConfig.inputCfg.buffer.raw, 0, mConfig.inputCfg.buffer.frameCount*sizeof(int32_t));
-                }
-                return;
-            case STARTING:
-                start_l();
-                mState = ACTIVE;
-                break;
-            case STOPPING:
-                mState = STOPPED;
-                break;
-            case STOPPED:
-                stop_l();
-                mState = IDLE;
-                return;
-            }
-        }
-
         // do the actual processing in the effect engine
-        (*mEffectInterface)->process(mEffectInterface, &mConfig.inputCfg.buffer, &mConfig.outputCfg.buffer);
+        int ret = (*mEffectInterface)->process(mEffectInterface,
+                                               &mConfig.inputCfg.buffer,
+                                               &mConfig.outputCfg.buffer);
+
+        // force transition to IDLE state when engine is ready
+        if (mState == STOPPED && ret == -ENODATA) {
+            mDisableWaitCnt = 1;
+        }
 
         // clear auxiliary effect input buffer for next accumulation
         if ((mDescriptor.flags & EFFECT_FLAG_TYPE_MASK) == EFFECT_FLAG_TYPE_AUXILIARY) {
@@ -5216,6 +5235,10 @@ status_t AudioFlinger::EffectModule::configure()
     if (status == 0) {
         status = cmdStatus;
     }
+
+    mMaxDisableWaitCnt = (MAX_DISABLE_TIME_MS * mConfig.outputCfg.samplingRate) /
+            (1000 * mConfig.outputCfg.buffer.frameCount);
+
     return status;
 }
 
@@ -5292,21 +5315,19 @@ status_t AudioFlinger::EffectModule::setEnabled(bool enabled)
         switch (mState) {
         // going from disabled to enabled
         case IDLE:
-            mState = RESET;
+            mState = STARTING;
+            break;
+        case STOPPED:
+            mState = RESTART;
             break;
         case STOPPING:
             mState = ACTIVE;
             break;
-        case STOPPED:
-            mState = STARTING;
-            break;
 
         // going from enabled to disabled
-        case RESET:
-            mState = IDLE;
-            break;
+        case RESTART:
         case STARTING:
-            mState = STOPPED;
+            mState = IDLE;
             break;
         case ACTIVE:
             mState = STOPPING;
@@ -5325,7 +5346,7 @@ status_t AudioFlinger::EffectModule::setEnabled(bool enabled)
 bool AudioFlinger::EffectModule::isEnabled()
 {
     switch (mState) {
-    case RESET:
+    case RESTART:
     case STARTING:
     case ACTIVE:
         return true;
@@ -5772,6 +5793,9 @@ void AudioFlinger::EffectChain::process_l()
     for (size_t i = 0; i < size; i++) {
         mEffects[i]->process();
     }
+    for (size_t i = 0; i < size; i++) {
+        mEffects[i]->updateState();
+    }
     // if no track is active, input buffer must be cleared here as the mixer process
     // will not do it
     if (mSessionId > 0 && activeTracks() == 0) {

diff --git a/libs/audioflinger/AudioFlinger.h b/libs/audioflinger/AudioFlinger.h
index ec3d7f1..507c9ac 100644 (file)
--- a/libs/audioflinger/AudioFlinger.h
+++ b/libs/audioflinger/AudioFlinger.h
@@ -905,7 +905,7 @@ private:
 
         enum effect_state {
             IDLE,
-            RESET,
+            RESTART,
             STARTING,
             ACTIVE,
             STOPPING,
@@ -914,6 +914,7 @@ private:
 
         int         id() { return mId; }
         void process();
+        void updateState();
         status_t command(int cmdCode, int cmdSize, void *pCmdData, int *replySize, void *pReplyData);
 
         void reset_l();
@@ -948,6 +949,9 @@ private:
 
     protected:
 
+        // Maximum time allocated to effect engines to complete the turn off sequence
+        static const uint32_t MAX_DISABLE_TIME_MS = 10000;
+
         EffectModule(const EffectModule&);
         EffectModule& operator = (const EffectModule&);
 
@@ -973,6 +977,9 @@ private:
         status_t mStatus;               // initialization status
         uint32_t mState;                // current activation state (effect_state)
         Vector< wp<EffectHandle> > mHandles;    // list of client handles
+        uint32_t mMaxDisableWaitCnt;    // maximum grace period before forcing an effect off after
+                                        // sending disable command.
+        uint32_t mDisableWaitCnt;       // current process() calls count during disable period.
     };
 
     // The EffectHandle class implements the IEffect interface. It provides resources