Issue 2667801: [Audio Effect Framework] AudioFlinger, AudioMixer AudioTrack modifications.

First drop of audio framework modifications for audio effects support.

- AudioTrack/AudioRecord:
Added support for auxiliary effects in AudioTrack
Added support for audio sessions
Fixed left right channel inversion in setVolume()

- IAudioFlinger:
Added interface methods for effect enumeraiton and instantiation
Added support for audio sessions.

- IAudioTrack:
Added method to attach auxiliary effect.

- AudioFlinger
Created new classes to control effect engines in effect library and manage effect connections to tracks or
output mix:
  EffectModule: wrapper object controlling the effect engine implementation in the effect library. There
	is one EffectModule per instance of an effect in a given audio session
  EffectChain: group of effects associated to one audio session. There is one EffectChain per audio session.
	EffectChain for session 0 is for output mix effects, other chains are attached to audio tracks
	with same session ID. Each chain contains a variable number of EffectModules
  EffectHandle: implements the IEffect interface. There is one EffectHandle object for each application
	controlling (or using) an effect module. THe EffectModule maintians a list of EffectHandles.

Added support for effect modules and effect chains creation in PlaybackThread.
modified mixer thread loop to allow track volume control by effect modules and call effect processing.

-AudioMixer
Each track now specifies its output buffer used by mixer for accumulation
Modified mixer process functions to process tracks by groups of tracks with same buffer
Modified track process functions to support accumulation to auxiliary channel

Change-Id: I26d5f7c9e070a89bdd383e1a659f8b7ca150379c

1 files changed, 22 insertions, 2 deletions

diff --git a/media/libmedia/IAudioTrack.cpp b/media/libmedia/IAudioTrack.cpp
index 01ffd75..bc8ff34 100644
--- a/media/libmedia/IAudioTrack.cpp
+++ b/media/libmedia/IAudioTrack.cpp
@@ -34,7 +34,8 @@ enum {
     STOP,
     FLUSH,
     MUTE,
-    PAUSE
+    PAUSE,
+    ATTACH_AUX_EFFECT
 };
 
 class BpAudioTrack : public BpInterface<IAudioTrack>
@@ -97,7 +98,21 @@ public:
             cblk = interface_cast<IMemory>(reply.readStrongBinder());
         }
         return cblk;
-    }    
+    }
+
+    virtual status_t attachAuxEffect(int effectId)
+    {
+        Parcel data, reply;
+        data.writeInterfaceToken(IAudioTrack::getInterfaceDescriptor());
+        data.writeInt32(effectId);
+        status_t status = remote()->transact(ATTACH_AUX_EFFECT, data, &reply);
+        if (status == NO_ERROR) {
+            status = reply.readInt32();
+        } else {
+            LOGW("attachAuxEffect() error: %s", strerror(-status));
+        }
+        return status;
+    }
 };
 
 IMPLEMENT_META_INTERFACE(AudioTrack, "android.media.IAudioTrack");
@@ -138,6 +153,11 @@ status_t BnAudioTrack::onTransact(
             pause();
             return NO_ERROR;
         }
+        case ATTACH_AUX_EFFECT: {
+            CHECK_INTERFACE(IAudioTrack, data, reply);
+            reply->writeInt32(attachAuxEffect(data.readInt32()));
+            return NO_ERROR;
+        } break;
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }