audio policy: add deep audio buffering flag.

Add a value in audio policy flags to indicate an output
stream providing deep audio PCM buffers. Such an output
helps reducing the power consumption at the expense of audio latency.

Stagefright will indicate a preference for such an output when playing music
only (no video) and the audio duration is more than a given threshold.

Change-Id: I0e6a9f5746a22d2bfea2b21dd182489a34a4b528

1 files changed, 11 insertions, 10 deletions

diff --git a/include/system/audio.h b/include/system/audio.h
index 382fc36..3807317 100644
--- a/include/system/audio.h
+++ b/include/system/audio.h
@@ -351,16 +351,17 @@ typedef enum {
  * (when getOuput() is called) to an available output stream.
  */
 typedef enum {
-    AUDIO_OUTPUT_FLAG_NONE = 0x0,    // no attributes
-    AUDIO_OUTPUT_FLAG_DIRECT = 0x1,  // this output directly connects a track
-                                     // to one output stream: no software mixer
-    AUDIO_OUTPUT_FLAG_PRIMARY = 0x2, // this output is the primary output of
-                                     // the device. It is unique and must be
-                                     // present. It is opened by default and
-                                     // receives routing, audio mode and volume
-                                     // controls related to voice calls.
-    AUDIO_OUTPUT_FLAG_FAST = 0x4,    // output supports "fast tracks",
-                                     // defined elsewhere
+    AUDIO_OUTPUT_FLAG_NONE = 0x0,       // no attributes
+    AUDIO_OUTPUT_FLAG_DIRECT = 0x1,     // this output directly connects a track
+                                        // to one output stream: no software mixer
+    AUDIO_OUTPUT_FLAG_PRIMARY = 0x2,    // this output is the primary output of
+                                        // the device. It is unique and must be
+                                        // present. It is opened by default and
+                                        // receives routing, audio mode and volume
+                                        // controls related to voice calls.
+    AUDIO_OUTPUT_FLAG_FAST = 0x4,       // output supports "fast tracks",
+                                        // defined elsewhere
+    AUDIO_OUTPUT_FLAG_DEEP_BUFFER = 0x8 // use deep audio buffers
 } audio_output_flags_t;
 
 static inline bool audio_is_output_device(audio_devices_t device)