libmediaplayerservice: offload playback support

Main change is to how recycled tracks are used for gapless
playback. If we are playing offloaded tracks that can't be
recycled we don't open a new offloaded output until we have
closed the previous one. This is because offloaded tracks
are a limited resource so we don't want to spuriously create
unnecessary instances. If the tracks cannot be recycled
this means that the formats are incompatible and so the
hardware most likely will also be unable to use the existing
output channel for the new track. If we already have the
maximum number of hardware offload channels open (which could
be only one) then creation of the next output would fail if
we attempted it while the previous output was still open.

Change-Id: I4f5958074e7ffd2e17108157fee86329506730ea
Signed-off-by: Eric Laurent <elaurent@google.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/media/libmediaplayerservice/MediaPlayerService.h b/media/libmediaplayerservice/MediaPlayerService.h
index f7076cc..7d27944 100644
--- a/media/libmediaplayerservice/MediaPlayerService.h
+++ b/media/libmediaplayerservice/MediaPlayerService.h
@@ -94,7 +94,7 @@ class MediaPlayerService : public BnMediaPlayerService
                 audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
                 const audio_offload_info_t *offloadInfo = NULL);
 
-        virtual void            start();
+        virtual status_t        start();
         virtual ssize_t         write(const void* buffer, size_t size);
         virtual void            stop();
         virtual void            flush();
@@ -112,11 +112,14 @@ class MediaPlayerService : public BnMediaPlayerService
                 void            setNextOutput(const sp<AudioOutput>& nextOutput);
                 void            switchToNextOutput();
         virtual bool            needsTrailingPadding() { return mNextOutput == NULL; }
+        virtual status_t        setParameters(const String8& keyValuePairs);
+        virtual String8         getParameters(const String8& keys);
 
     private:
         static void             setMinBufferCount();
         static void             CallbackWrapper(
                 int event, void *me, void *info);
+               void             deleteRecycledTrack();
 
         sp<AudioTrack>          mTrack;
         sp<AudioTrack>          mRecycledTrack;
@@ -196,7 +199,7 @@ class MediaPlayerService : public BnMediaPlayerService
                 audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
                 const audio_offload_info_t *offloadInfo = NULL);
 
-        virtual void            start();
+        virtual status_t        start();
         virtual ssize_t         write(const void* buffer, size_t size);
         virtual void            stop();
         virtual void            flush() {}