Add support for deep audio buffers

Allow AudioSink to use deep audio buffering when the
source is audio only and its duration is more than
a certain threshold.
This helps improve battery life but implies higher
audio latency.

Change-Id: Ie79915b61c370292f05aabda9779356570e03cbb

2 files changed, 8 insertions, 1 deletions

diff --git a/include/media/MediaPlayerInterface.h b/include/media/MediaPlayerInterface.h
index 9a8f4b0..a70fe8c 100644
--- a/include/media/MediaPlayerInterface.h
+++ b/include/media/MediaPlayerInterface.h
@@ -63,6 +63,9 @@ enum player_type {
 // when the channel mask isn't known, use the channel count to derive a mask in AudioSink::open()
 #define CHANNEL_MASK_USE_CHANNEL_ORDER 0
 
+// duration below which we do not allow deep audio buffering
+#define AUDIO_SINK_MIN_DEEP_BUFFER_DURATION_US 5000000
+
 // callback mechanism for passing messages to MediaPlayer object
 typedef void (*notify_callback_f)(void* cookie,
         int msg, int ext1, int ext2, const Parcel *obj);
@@ -98,7 +101,8 @@ public:
                 audio_format_t format=AUDIO_FORMAT_PCM_16_BIT,
                 int bufferCount=DEFAULT_AUDIOSINK_BUFFERCOUNT,
                 AudioCallback cb = NULL,
-                void *cookie = NULL) = 0;
+                void *cookie = NULL,
+                audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE) = 0;
 
         virtual void        start() = 0;
         virtual ssize_t     write(const void* buffer, size_t size) = 0;
diff --git a/include/media/stagefright/AudioPlayer.h b/include/media/stagefright/AudioPlayer.h
index 70c47ae..9e8e4bb 100644
--- a/include/media/stagefright/AudioPlayer.h
+++ b/include/media/stagefright/AudioPlayer.h
@@ -37,6 +37,7 @@ public:
     };
 
     AudioPlayer(const sp<MediaPlayerBase::AudioSink> &audioSink,
+                bool allowDeepBuffering = false,
                 AwesomePlayer *audioObserver = NULL);
 
     virtual ~AudioPlayer();
@@ -95,6 +96,8 @@ private:
     MediaBuffer *mFirstBuffer;
 
     sp<MediaPlayerBase::AudioSink> mAudioSink;
+    bool mAllowDeepBuffering;       // allow audio deep audio buffers. Helps with low power audio
+                                    // playback but implies high latency
     AwesomePlayer *mObserver;
 
     static void AudioCallback(int event, void *user, void *info);