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

2 files changed, 53 insertions, 1 deletions

diff --git a/include/private/media/AudioEffectShared.h b/include/private/media/AudioEffectShared.h
new file mode 100644
index 0000000..a3a99a4
--- /dev/null
+++ b/include/private/media/AudioEffectShared.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_EFFECTCBASESHARED_H
+#define ANDROID_EFFECTCBASESHARED_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <utils/threads.h>
+
+namespace android {
+
+// ----------------------------------------------------------------------------
+
+// Size of buffer used to exchange parameters between application and mediaserver processes.
+#define EFFECT_PARAM_BUFFER_SIZE 1024
+
+
+// Shared memory area used to exchange parameters between application and mediaserver
+// process.
+struct effect_param_cblk_t
+{
+                Mutex       lock;
+    volatile    uint32_t    clientIndex;    // Current read/write index for application
+    volatile    uint32_t    serverIndex;    // Current read/write index for mediaserver
+                uint8_t*    buffer;         // start of parameter buffer
+
+                effect_param_cblk_t()
+                    : lock(Mutex::SHARED), clientIndex(0), serverIndex(0) {}
+};
+
+
+// ----------------------------------------------------------------------------
+
+}; // namespace android
+
+#endif // ANDROID_EFFECTCBASESHARED_H
diff --git a/include/private/media/AudioTrackShared.h b/include/private/media/AudioTrackShared.h
index cd47fdf..1510f87 100644
--- a/include/private/media/AudioTrackShared.h
+++ b/include/private/media/AudioTrackShared.h
@@ -78,7 +78,8 @@ struct audio_track_cblk_t
                 uint16_t    bufferTimeoutMs; // Maximum cumulated timeout before restarting audioflinger
                 uint16_t    waitTimeMs;      // Cumulated wait time
 
-                uint32_t    reserved;
+                uint16_t    sendLevel;
+                uint16_t    reserved;
                 // Cache line boundary (32 bytes)
                             audio_track_cblk_t();
                 uint32_t    stepUser(uint32_t frameCount);