From 575a5361fc970476cd7979638ee3ac00cc6e5024 Mon Sep 17 00:00:00 2001
From: Andreas Huber <andih@google.com>
Date: Wed, 3 Oct 2012 10:16:58 -0700
Subject: Better power savings with wifi display code.

No more polling the encoder for work to do, the encoder instead notifies
if there's activity.

Change-Id: Ia707211b4f5c5a6e6b70d750233d204a2d6bb778
related-to-bug: 7248248
---
 media/libstagefright/MediaCodec.cpp                | 43 ++++++++++++++++++++++
 .../wifi-display/source/Converter.cpp              | 39 +++++++++++++++++---
 .../libstagefright/wifi-display/source/Converter.h |  2 +
 3 files changed, 78 insertions(+), 6 deletions(-)

(limited to 'media/libstagefright')

diff --git a/media/libstagefright/MediaCodec.cpp b/media/libstagefright/MediaCodec.cpp
index 7f97430..56e6df0 100644
--- a/media/libstagefright/MediaCodec.cpp
+++ b/media/libstagefright/MediaCodec.cpp
@@ -333,6 +333,12 @@ status_t MediaCodec::requestIDRFrame() {
     return OK;
 }
 
+void MediaCodec::requestActivityNotification(const sp<AMessage> &notify) {
+    sp<AMessage> msg = new AMessage(kWhatRequestActivityNotification, id());
+    msg->setMessage("notify", notify);
+    msg->post();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 void MediaCodec::cancelPendingDequeueOperations() {
@@ -498,6 +504,7 @@ void MediaCodec::onMessageReceived(const sp<AMessage> &msg) {
                             sendErrorReponse = false;
 
                             mFlags |= kFlagStickyError;
+                            postActivityNotificationIfPossible();
 
                             cancelPendingDequeueOperations();
                             break;
@@ -508,6 +515,7 @@ void MediaCodec::onMessageReceived(const sp<AMessage> &msg) {
                             sendErrorReponse = false;
 
                             mFlags |= kFlagStickyError;
+                            postActivityNotificationIfPossible();
                             break;
                         }
                     }
@@ -600,6 +608,7 @@ void MediaCodec::onMessageReceived(const sp<AMessage> &msg) {
                             (new AMessage)->postReply(mReplyID);
                         } else {
                             mFlags |= kFlagOutputBuffersChanged;
+                            postActivityNotificationIfPossible();
                         }
                     }
                     break;
@@ -638,6 +647,7 @@ void MediaCodec::onMessageReceived(const sp<AMessage> &msg) {
 
                     mOutputFormat = msg;
                     mFlags |= kFlagOutputFormatChanged;
+                    postActivityNotificationIfPossible();
                     break;
                 }
 
@@ -669,6 +679,8 @@ void MediaCodec::onMessageReceived(const sp<AMessage> &msg) {
                                   err);
 
                             mFlags |= kFlagStickyError;
+                            postActivityNotificationIfPossible();
+
                             cancelPendingDequeueOperations();
                         }
                         break;
@@ -680,6 +692,8 @@ void MediaCodec::onMessageReceived(const sp<AMessage> &msg) {
                         ++mDequeueInputTimeoutGeneration;
                         mFlags &= ~kFlagDequeueInputPending;
                         mDequeueInputReplyID = 0;
+                    } else {
+                        postActivityNotificationIfPossible();
                     }
                     break;
                 }
@@ -709,7 +723,10 @@ void MediaCodec::onMessageReceived(const sp<AMessage> &msg) {
                         ++mDequeueOutputTimeoutGeneration;
                         mFlags &= ~kFlagDequeueOutputPending;
                         mDequeueOutputReplyID = 0;
+                    } else {
+                        postActivityNotificationIfPossible();
                     }
+
                     break;
                 }
 
@@ -1145,6 +1162,15 @@ void MediaCodec::onMessageReceived(const sp<AMessage> &msg) {
             break;
         }
 
+        case kWhatRequestActivityNotification:
+        {
+            CHECK(mActivityNotify == NULL);
+            CHECK(msg->findMessage("notify", &mActivityNotify));
+
+            postActivityNotificationIfPossible();
+            break;
+        }
+
         default:
             TRESPASS();
     }
@@ -1210,6 +1236,8 @@ void MediaCodec::setState(State newState) {
         mFlags &= ~kFlagOutputFormatChanged;
         mFlags &= ~kFlagOutputBuffersChanged;
         mFlags &= ~kFlagStickyError;
+
+        mActivityNotify.clear();
     }
 
     mState = newState;
@@ -1477,4 +1505,19 @@ status_t MediaCodec::setNativeWindow(
     return OK;
 }
 
+void MediaCodec::postActivityNotificationIfPossible() {
+    if (mActivityNotify == NULL) {
+        return;
+    }
+
+    if ((mFlags & (kFlagStickyError
+                    | kFlagOutputBuffersChanged
+                    | kFlagOutputFormatChanged))
+            || !mAvailPortBuffers[kPortIndexInput].empty()
+            || !mAvailPortBuffers[kPortIndexOutput].empty()) {
+        mActivityNotify->post();
+        mActivityNotify.clear();
+    }
+}
+
 }  // namespace android
diff --git a/media/libstagefright/wifi-display/source/Converter.cpp b/media/libstagefright/wifi-display/source/Converter.cpp
index f044666..a9b4c23 100644
--- a/media/libstagefright/wifi-display/source/Converter.cpp
+++ b/media/libstagefright/wifi-display/source/Converter.cpp
@@ -274,8 +274,17 @@ void Converter::onMessageReceived(const sp<AMessage> &msg) {
             break;
         }
 
-        case kWhatDoMoreWork:
+        case kWhatEncoderActivity:
         {
+#if 0
+            int64_t whenUs;
+            if (msg->findInt64("whenUs", &whenUs)) {
+                int64_t nowUs = ALooper::GetNowUs();
+                ALOGI("[%s] kWhatEncoderActivity after %lld us",
+                      mIsVideo ? "video" : "audio", nowUs - whenUs);
+            }
+#endif
+
             mDoMoreWorkPending = false;
 
             if (mEncoder == NULL) {
@@ -328,7 +337,17 @@ void Converter::scheduleDoMoreWork() {
     }
 
     mDoMoreWorkPending = true;
-    (new AMessage(kWhatDoMoreWork, id()))->post(1000ll);
+
+#if 1
+    if (mEncoderActivityNotify == NULL) {
+        mEncoderActivityNotify = new AMessage(kWhatEncoderActivity, id());
+    }
+    mEncoder->requestActivityNotification(mEncoderActivityNotify->dup());
+#else
+    sp<AMessage> notify = new AMessage(kWhatEncoderActivity, id());
+    notify->setInt64("whenUs", ALooper::GetNowUs());
+    mEncoder->requestActivityNotification(notify);
+#endif
 }
 
 status_t Converter::feedEncoderInputBuffers() {
@@ -375,15 +394,23 @@ status_t Converter::feedEncoderInputBuffers() {
 }
 
 status_t Converter::doMoreWork() {
-    size_t bufferIndex;
-    status_t err = mEncoder->dequeueInputBuffer(&bufferIndex);
+    status_t err;
+
+    for (;;) {
+        size_t bufferIndex;
+        err = mEncoder->dequeueInputBuffer(&bufferIndex);
+
+        if (err != OK) {
+            break;
+        }
 
-    if (err == OK) {
         mAvailEncoderInputIndices.push_back(bufferIndex);
-        feedEncoderInputBuffers();
     }
 
+    feedEncoderInputBuffers();
+
     for (;;) {
+        size_t bufferIndex;
         size_t offset;
         size_t size;
         int64_t timeUs;
diff --git a/media/libstagefright/wifi-display/source/Converter.h b/media/libstagefright/wifi-display/source/Converter.h
index 93ff72f..8d45395 100644
--- a/media/libstagefright/wifi-display/source/Converter.h
+++ b/media/libstagefright/wifi-display/source/Converter.h
@@ -58,6 +58,7 @@ struct Converter : public AHandler {
         kWhatRequestIDRFrame,
         kWhatShutdown,
         kWhatMediaPullerNotify,
+        kWhatEncoderActivity,
     };
 
     void shutdownAsync();
@@ -75,6 +76,7 @@ private:
     sp<AMessage> mOutputFormat;
 
     sp<MediaCodec> mEncoder;
+    sp<AMessage> mEncoderActivityNotify;
 
     Vector<sp<ABuffer> > mEncoderInputBuffers;
     Vector<sp<ABuffer> > mEncoderOutputBuffers;
-- 
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