add native IPlayer interface implementation

Generalized the IPlayer implementation done for OpenSL ES
so that it can be used by other native audio players
Created two classes:
 - PlayerBase implementing the interfacin native AudioManager and
 IPlayer methods
 - TrackPlayerBase, a derived class specialized for AudioTrack.

Bug: 62027849
Test: verify regressions with OpenSL ES buffer queue player

Change-Id: If5ad21a3c1a243fba0b312001c5034102e6d6672
diff --git a/media/libaudioclient/TrackPlayerBase.cpp b/media/libaudioclient/TrackPlayerBase.cpp
new file mode 100644
index 0000000..48cd803
--- /dev/null
+++ b/media/libaudioclient/TrackPlayerBase.cpp
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#include <media/TrackPlayerBase.h>
+
+namespace android {
+
+//--------------------------------------------------------------------------------------------------
+TrackPlayerBase::TrackPlayerBase() : PlayerBase(),
+        mPlayerVolumeL(1.0f), mPlayerVolumeR(1.0f)
+{
+    ALOGD("TrackPlayerBase::TrackPlayerBase()");
+}
+
+
+TrackPlayerBase::~TrackPlayerBase() {
+    ALOGD("TrackPlayerBase::~TrackPlayerBase()");
+    doDestroy();
+}
+
+void TrackPlayerBase::init(AudioTrack* pat, player_type_t playerType, audio_usage_t usage) {
+    PlayerBase::init(playerType, usage);
+    mAudioTrack = pat;
+}
+
+void TrackPlayerBase::destroy() {
+    doDestroy();
+    baseDestroy();
+}
+
+void TrackPlayerBase::doDestroy() {
+    if (mAudioTrack != 0) {
+        mAudioTrack->stop();
+        // Note that there may still be another reference in post-unlock phase of SetPlayState
+        mAudioTrack.clear();
+    }
+}
+
+void TrackPlayerBase::setPlayerVolume(float vl, float vr) {
+    {
+        Mutex::Autolock _l(mSettingsLock);
+        mPlayerVolumeL = vl;
+        mPlayerVolumeR = vr;
+    }
+    doSetVolume();
+}
+
+//------------------------------------------------------------------------------
+// Implementation of IPlayer
+status_t TrackPlayerBase::playerStart() {
+    status_t status = NO_INIT;
+    if (mAudioTrack != 0) {
+        status = mAudioTrack->start();
+    }
+    return status;
+}
+
+status_t TrackPlayerBase::playerPause() {
+    status_t status = NO_INIT;
+    if (mAudioTrack != 0) {
+        mAudioTrack->pause();
+        status = NO_ERROR;
+    }
+    return status;
+}
+
+
+status_t TrackPlayerBase::playerStop() {
+    status_t status = NO_INIT;
+    if (mAudioTrack != 0) {
+        mAudioTrack->stop();
+        status = NO_ERROR;
+    }
+    return status;
+}
+
+status_t TrackPlayerBase::playerSetVolume() {
+    return doSetVolume();
+}
+
+status_t TrackPlayerBase::doSetVolume() {
+    status_t status = NO_INIT;
+    if (mAudioTrack != 0) {
+        float tl = mPlayerVolumeL * mPanMultiplierL * mVolumeMultiplierL;
+        float tr = mPlayerVolumeR * mPanMultiplierR * mVolumeMultiplierR;
+        mAudioTrack->setVolume(tl, tr);
+        status = NO_ERROR;
+    }
+    return status;
+}
+
+
+void TrackPlayerBase::applyVolumeShaper(
+        const sp<VolumeShaper::Configuration>& configuration,
+        const sp<VolumeShaper::Operation>& operation) {
+    if (mAudioTrack != 0) {
+        ALOGD("TrackPlayerBase::applyVolumeShaper() from IPlayer");
+        VolumeShaper::Status status = mAudioTrack->applyVolumeShaper(configuration, operation);
+        if (status < 0) { // a non-negative value is the volume shaper id.
+            ALOGE("TrackPlayerBase::applyVolumeShaper() failed with status %d", status);
+        }
+    } else {
+        ALOGD("TrackPlayerBase::applyVolumeShaper()"
+                " no AudioTrack for volume control from IPlayer");
+    }
+}
+
+} // namespace android