stagefright: offload playback support

Offloading of compressed audio decoding to audio DSP
is implemented for audio only, non streamed content.
when the datasource is

AudioPlayer:
- Create an offloaded sink when playing a compressed
source
- Send metadata to audio HAL
- Return sink start error to AwesomePlayer so that a
new player for PCM audio can be created in case of problem.
- Forward stream end and tear down callback events to AwesomePlayer
- Stop the sink and wait for stream end callback when EOS is reached.
- Pause and restart the sink if needed before flushing when seeking
(otherwise flush is a no op).
- For current media time, directly query the render position from the
sink and offset by the start position (seek to time)

AwesomePlayer:

- When initializing the audio decoder, check with audio policy manager
if offloading is supported. If yes, create the software decoder in
case a reconfiguration is needed but connect the audio track directly
to the AudioPlayer.
- In case of error when starting the AudioPlayer, reconnect the software
decoder (OMXSource) and recreate a PCM AudioPlayer.
- Handle AudioPlayer tear down event by detroying and recreating the
AudioPlayer to allow transitions between situations were offloading
is supported or not.
- Force tear down of offloaded AudioPlayer when paused for a certain time:
This will close the sink and allow the DSP to power down.

Utils:
- Added helper methods:
    - send meta data to audio ia sink setParameters
    - query audio policy manager if offloading is supported for a
given audio content

Change-Id: I115842ce424f947b966d45e253a74d3fd5df9aae
Signed-off-by: Eric Laurent <elaurent@google.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/include/media/stagefright/AudioPlayer.h b/include/media/stagefright/AudioPlayer.h
index ec9f2df..912a43c 100644
--- a/include/media/stagefright/AudioPlayer.h
+++ b/include/media/stagefright/AudioPlayer.h
@@ -38,7 +38,10 @@ public:
 
     enum {
         ALLOW_DEEP_BUFFERING = 0x01,
-        USE_OFFLOAD = 0x02
+        USE_OFFLOAD = 0x02,
+        HAS_VIDEO   = 0x1000,
+        IS_STREAMING = 0x2000
+
     };
 
     AudioPlayer(const sp<MediaPlayerBase::AudioSink> &audioSink,
@@ -56,7 +59,7 @@ public:
     status_t start(bool sourceAlreadyStarted = false);
 
     void pause(bool playPendingSamples = false);
-    void resume();
+    status_t resume();
 
     // Returns the timestamp of the last buffer played (in us).
     int64_t getMediaTimeUs();
@@ -104,11 +107,13 @@ 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;
     int64_t mPinnedTimeUs;
 
+    bool mPlaying;
+    int64_t mStartPosUs;
+    const uint32_t mCreateFlags;
+
     static void AudioCallback(int event, void *user, void *info);
     void AudioCallback(int event, void *info);
 
@@ -126,6 +131,9 @@ private:
     uint32_t getNumFramesPendingPlayout() const;
     int64_t getOutputPlayPositionUs_l() const;
 
+    bool allowDeepBuffering() const { return (mCreateFlags & ALLOW_DEEP_BUFFERING) != 0; }
+    bool useOffload() const { return (mCreateFlags & USE_OFFLOAD) != 0; }
+
     AudioPlayer(const AudioPlayer &);
     AudioPlayer &operator=(const AudioPlayer &);
 };