libmedia: offloaded playback support

- start() returns a status so that upper layers can
recreate a non offloaded track in case of error.

- Added states to handle offloaded tracks specific:
  - waiting for stream end (drain) notification by
audio flinger
  - allow pause while waiting for stream end notification

- getPosition() queries the render position directly from
audio HAL.

- disable APIs not applicable to offloaded tracks

- Modified track restoring behavior for invalidated
offloaded tracks: just send the callback and wait for
upper layers to create a new track.

- Added wait for stream end management in audio track client
proxy. Similar to obtainBuffer and should be factored in.

Change-Id: I0fc48117946364cb255afd653195498891f622bd
Signed-off-by: Eric Laurent <elaurent@google.com>

1 files changed, 27 insertions, 5 deletions

diff --git a/media/libmedia/IAudioPolicyService.cpp b/media/libmedia/IAudioPolicyService.cpp
index 57de58f..4be3c09 100644
--- a/media/libmedia/IAudioPolicyService.cpp
+++ b/media/libmedia/IAudioPolicyService.cpp
@@ -137,6 +137,12 @@ public:
         data.writeInt32(static_cast <uint32_t>(format));
         data.writeInt32(channelMask);
         data.writeInt32(static_cast <uint32_t>(flags));
+        if (offloadInfo == NULL) {
+            data.writeInt32(0);
+        } else {
+            data.writeInt32(1);
+            data.write(offloadInfo, sizeof(audio_offload_info_t));
+        }
         remote()->transact(GET_OUTPUT, data, &reply);
         return static_cast <audio_io_handle_t> (reply.readInt32());
     }
@@ -379,9 +385,11 @@ public:
 
     virtual bool isOffloadSupported(const audio_offload_info_t& info)
     {
-        // stub function
-        return false;
-    }
+        Parcel data, reply;
+        data.writeInterfaceToken(IAudioPolicyService::getInterfaceDescriptor());
+        data.write(&info, sizeof(audio_offload_info_t));
+        remote()->transact(IS_OFFLOAD_SUPPORTED, data, &reply);
+        return reply.readInt32();    }
 };
 
 IMPLEMENT_META_INTERFACE(AudioPolicyService, "android.media.IAudioPolicyService");
@@ -450,12 +458,17 @@ status_t BnAudioPolicyService::onTransact(
             audio_channel_mask_t channelMask = data.readInt32();
             audio_output_flags_t flags =
                     static_cast <audio_output_flags_t>(data.readInt32());
-
+            bool hasOffloadInfo = data.readInt32() != 0;
+            audio_offload_info_t offloadInfo;
+            if (hasOffloadInfo) {
+                data.read(&offloadInfo, sizeof(audio_offload_info_t));
+            }
             audio_io_handle_t output = getOutput(stream,
                                                  samplingRate,
                                                  format,
                                                  channelMask,
-                                                 flags);
+                                                 flags,
+                                                 hasOffloadInfo ? &offloadInfo : NULL);
             reply->writeInt32(static_cast <int>(output));
             return NO_ERROR;
         } break;
@@ -662,6 +675,15 @@ status_t BnAudioPolicyService::onTransact(
             return status;
         }
 
+        case IS_OFFLOAD_SUPPORTED: {
+            CHECK_INTERFACE(IAudioPolicyService, data, reply);
+            audio_offload_info_t info;
+            data.read(&info, sizeof(audio_offload_info_t));
+            bool isSupported = isOffloadSupported(info);
+            reply->writeInt32(isSupported);
+            return NO_ERROR;
+        }
+
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }