stagefright: Resurrect PCM offload

 * Forward-port the open-source code from L which was moved to closed-source
   in M. This is being done out of necessity- the architecture chosen by
   Qualcomm is not optimal and doesn't work well with a singular
   codebase which attempts to service a large number of devices.
 * This patch brings in the code to support PCM offload (AudioFlinger
   bypass). This allows for playback of high resolution clips without
   decimation stages, and enables reduced power consumption for audio
   pipelines which take advantage of the Hexagon DSP (effects).

Change-Id: I0ef15fc3df538ab723f3c12ce0ed71d0e607c99e

1 files changed, 58 insertions, 5 deletions

diff --git a/media/libmediaplayerservice/nuplayer/NuPlayer.cpp b/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
index de507f1..678db8e 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
@@ -189,6 +189,7 @@ NuPlayer::NuPlayer(pid_t pid)
       mPID(pid),
       mSourceFlags(0),
       mOffloadAudio(false),
+      mOffloadDecodedPCM(false),
       mAudioDecoderGeneration(0),
       mVideoDecoderGeneration(0),
       mRendererGeneration(0),
@@ -1133,10 +1134,12 @@ void NuPlayer::onMessageReceived(const sp<AMessage> &msg) {
 
             mResetting = true;
 
-            mDeferredActions.push_back(
-                    new FlushDecoderAction(
-                        FLUSH_CMD_SHUTDOWN /* audio */,
-                        FLUSH_CMD_SHUTDOWN /* video */));
+            if (mAudioDecoder != NULL && mFlushingAudio == NONE) {
+                mDeferredActions.push_back(
+                        new FlushDecoderAction(
+                            FLUSH_CMD_SHUTDOWN /* audio */,
+                            FLUSH_CMD_SHUTDOWN /* video */));
+            }
 
             mDeferredActions.push_back(
                     new SimpleAction(&NuPlayer::closeAudioSink));
@@ -1228,9 +1231,16 @@ void NuPlayer::onResume() {
     } else {
         ALOGW("resume called when source is gone or not set");
     }
+    if (mOffloadAudio && !mOffloadDecodedPCM) {
+          // Resuming after a pause timed out event, check if can continue with offload
+          sp<AMessage> videoFormat = mSource->getFormat(false /* audio */);
+          sp<AMessage> format = mSource->getFormat(true /*audio*/);
+          const bool hasVideo = (videoFormat != NULL);
+          tryOpenAudioSinkForOffload(format, hasVideo);
+    } 
     // |mAudioDecoder| may have been released due to the pause timeout, so re-create it if
     // needed.
-    if (audioDecoderStillNeeded() && mAudioDecoder == NULL) {
+    if (audioDecoderStillNeeded() && mAudioDecoder == NULL && !mOffloadDecodedPCM) {
         instantiateDecoder(true /* audio */, &mAudioDecoder);
     }
     if (mRenderer != NULL) {
@@ -1282,6 +1292,7 @@ void NuPlayer::onStart(int64_t startPositionUs) {
     }
 
     mOffloadAudio = false;
+    mOffloadDecodedPCM = false;
     mAudioEOS = false;
     mVideoEOS = false;
     mStarted = true;
@@ -1292,8 +1303,10 @@ void NuPlayer::onStart(int64_t startPositionUs) {
         flags |= Renderer::FLAG_REAL_TIME;
     }
 
+    ALOGV("onStart");
     sp<MetaData> audioMeta = mSource->getFormatMeta(true /* audio */);
     AVNuUtils::get()->setSourcePCMFormat(audioMeta);
+    audioMeta->dumpToLog();
     audio_stream_type_t streamType = AUDIO_STREAM_MUSIC;
     if (mAudioSink != NULL) {
         streamType = mAudioSink->getAudioStreamType();
@@ -1690,6 +1703,18 @@ void NuPlayer::flushDecoder(bool audio, bool needShutdown) {
         return;
     }
 
+    FlushStatus *state = audio ? &mFlushingAudio : &mFlushingVideo;
+
+    bool inShutdown = *state != NONE &&
+                      *state != FLUSHING_DECODER &&
+                      *state != FLUSHED;
+
+    // Reject flush if the decoder state is not one of the above
+    if (inShutdown) {
+        ALOGI("flush %s called while in shutdown", audio ? "audio" : "video");
+        return;
+    }
+
     // Make sure we don't continue to scan sources until we finish flushing.
     ++mScanSourcesGeneration;
     if (mScanSourcesPending) {
@@ -2433,4 +2458,32 @@ void NuPlayer::performTearDown(const sp<AMessage> &msg) {
     processDeferredActions();
 }
 
+bool NuPlayer::ifDecodedPCMOffload() {
+    return mOffloadDecodedPCM;
+}
+
+void NuPlayer::setDecodedPcmOffload(bool decodePcmOffload) {
+    mOffloadDecodedPCM = decodePcmOffload;
+}
+
+bool NuPlayer::canOffloadDecodedPCMStream(const sp<MetaData> audioMeta,
+            bool hasVideo, bool isStreaming, audio_stream_type_t streamType) {
+    const char *mime = NULL;
+
+     //For offloading decoded content
+    if (!mOffloadAudio && (audioMeta != NULL)) {
+        audioMeta->findCString(kKeyMIMEType, &mime);
+        sp<MetaData> audioPCMMeta =
+                AVNuUtils::get()->createPCMMetaFromSource(audioMeta);
+
+        ALOGI("canOffloadDecodedPCMStream");
+        audioMeta->dumpToLog();
+        mOffloadDecodedPCM =
+                ((mime && !AVNuUtils::get()->pcmOffloadException(audioMeta)) &&
+                canOffloadStream(audioPCMMeta, hasVideo, isStreaming, streamType));
+        ALOGI("PCM offload decided: %d", mOffloadDecodedPCM);
+    }
+    return mOffloadDecodedPCM;
+}
+
 }  // namespace android