Add callback for codec format change.

When creating native audio track, a IAudioTrackCallback will be created
systematically. All callbacks will be cached in Threads and protected by
a lock. Whenever there is a callback event from audio HAL, it will
finally trigger callback to native audio track. Currently, there is only
one callback event, which is codec format change.

Bug: 150301890
Test: manual
Change-Id: I32293627ed923b17dd25f11f0ee0a0c35cd7c01f
diff --git a/media/libaudioclient/AudioTrack.cpp b/media/libaudioclient/AudioTrack.cpp
index d5690fb..2f95886 100644
--- a/media/libaudioclient/AudioTrack.cpp
+++ b/media/libaudioclient/AudioTrack.cpp
@@ -217,7 +217,8 @@
       mPreviousSchedulingGroup(SP_DEFAULT),
       mPausedPosition(0),
       mSelectedDeviceId(AUDIO_PORT_HANDLE_NONE),
-      mRoutedDeviceId(AUDIO_PORT_HANDLE_NONE)
+      mRoutedDeviceId(AUDIO_PORT_HANDLE_NONE),
+      mAudioTrackCallback(new AudioTrackCallback())
 {
     mAttributes.content_type = AUDIO_CONTENT_TYPE_UNKNOWN;
     mAttributes.usage = AUDIO_USAGE_UNKNOWN;
@@ -248,7 +249,8 @@
       mState(STATE_STOPPED),
       mPreviousPriority(ANDROID_PRIORITY_NORMAL),
       mPreviousSchedulingGroup(SP_DEFAULT),
-      mPausedPosition(0)
+      mPausedPosition(0),
+      mAudioTrackCallback(new AudioTrackCallback())
 {
     mAttributes = AUDIO_ATTRIBUTES_INITIALIZER;
 
@@ -281,7 +283,8 @@
       mPreviousPriority(ANDROID_PRIORITY_NORMAL),
       mPreviousSchedulingGroup(SP_DEFAULT),
       mPausedPosition(0),
-      mSelectedDeviceId(AUDIO_PORT_HANDLE_NONE)
+      mSelectedDeviceId(AUDIO_PORT_HANDLE_NONE),
+      mAudioTrackCallback(new AudioTrackCallback())
 {
     mAttributes = AUDIO_ATTRIBUTES_INITIALIZER;
 
@@ -1527,6 +1530,7 @@
     input.notificationFrameCount = mNotificationFramesReq;
     input.selectedDeviceId = mSelectedDeviceId;
     input.sessionId = mSessionId;
+    input.audioTrackCallback = mAudioTrackCallback;
 
     IAudioFlinger::CreateTrackOutput output;
 
@@ -3376,4 +3380,23 @@
     mPausedNs = ns;
 }
 
+binder::Status AudioTrack::AudioTrackCallback::onCodecFormatChanged(
+        const std::vector<uint8_t>& audioMetadata)
+{
+    AutoMutex _l(mAudioTrackCbLock);
+    sp<media::IAudioTrackCallback> callback = mCallback.promote();
+    if (callback.get() != nullptr) {
+        callback->onCodecFormatChanged(audioMetadata);
+    } else {
+        mCallback.clear();
+    }
+    return binder::Status::ok();
+}
+
+void AudioTrack::AudioTrackCallback::setAudioTrackCallback(
+        const sp<media::IAudioTrackCallback> &callback) {
+    AutoMutex lock(mAudioTrackCbLock);
+    mCallback = callback;
+}
+
 } // namespace android