AVFoundation: implement bufferState

This add support for the buffer status with
AVPlayerItem.playbackLikelyToKeepUp. It only supports
buffer status values of 0 and 100.

Change-Id: I5779ea360fe9c497ecc0236e442850422d96ac87
Reviewed-by: Christian Stromme <christian.stromme@qt.io>

3 files changed, 37 insertions, 3 deletions

diff --git a/src/plugins/avfoundation/mediaplayer/avfmediaplayercontrol.mm b/src/plugins/avfoundation/mediaplayer/avfmediaplayercontrol.mm
index 5f7bae1c8..bf7ebb4a0 100644
--- a/src/plugins/avfoundation/mediaplayer/avfmediaplayercontrol.mm
+++ b/src/plugins/avfoundation/mediaplayer/avfmediaplayercontrol.mm
@@ -60,6 +60,7 @@ void AVFMediaPlayerControl::setSession(AVFMediaPlayerSession *session)
 
     connect(m_session, SIGNAL(positionChanged(qint64)), this, SIGNAL(positionChanged(qint64)));
     connect(m_session, SIGNAL(durationChanged(qint64)), this, SIGNAL(durationChanged(qint64)));
+    connect(m_session, SIGNAL(bufferStatusChanged(int)), this, SIGNAL(bufferStatusChanged(int)));
     connect(m_session, SIGNAL(stateChanged(QMediaPlayer::State)),
             this, SIGNAL(stateChanged(QMediaPlayer::State)));
     connect(m_session, SIGNAL(mediaStatusChanged(QMediaPlayer::MediaStatus)),
diff --git a/src/plugins/avfoundation/mediaplayer/avfmediaplayersession.h b/src/plugins/avfoundation/mediaplayer/avfmediaplayersession.h
index ef854e23f..1e4311140 100644
--- a/src/plugins/avfoundation/mediaplayer/avfmediaplayersession.h
+++ b/src/plugins/avfoundation/mediaplayer/avfmediaplayersession.h
@@ -105,10 +105,14 @@ public Q_SLOTS:
 
     void processLoadStateChange();
     void processLoadStateFailure();
+
+    void processBufferStateChange(int bufferStatus);
+
 Q_SIGNALS:
     void positionChanged(qint64 position);
     void durationChanged(qint64 duration);
     void stateChanged(QMediaPlayer::State newState);
+    void bufferStatusChanged(int bufferStatus);
     void mediaStatusChanged(QMediaPlayer::MediaStatus status);
     void volumeChanged(int volume);
     void mutedChanged(bool muted);
@@ -176,6 +180,7 @@ private:
     qint64 m_requestedPosition;
 
     qint64 m_duration;
+    int m_bufferStatus;
     bool m_videoAvailable;
     bool m_audioAvailable;
     bool m_seekable;
diff --git a/src/plugins/avfoundation/mediaplayer/avfmediaplayersession.mm b/src/plugins/avfoundation/mediaplayer/avfmediaplayersession.mm
index f4eb8a4ea..923aeabe6 100644
--- a/src/plugins/avfoundation/mediaplayer/avfmediaplayersession.mm
+++ b/src/plugins/avfoundation/mediaplayer/avfmediaplayersession.mm
@@ -52,7 +52,8 @@ static NSString* const AVF_TRACKS_KEY       = @"tracks";
 static NSString* const AVF_PLAYABLE_KEY     = @"playable";
 
 //AVPlayerItem keys
-static NSString* const AVF_STATUS_KEY       = @"status";
+static NSString* const AVF_STATUS_KEY                   = @"status";
+static NSString* const AVF_BUFFER_LIKELY_KEEP_UP_KEY    = @"playbackLikelyToKeepUp";
 
 //AVPlayer keys
 static NSString* const AVF_RATE_KEY         = @"rate";
@@ -60,6 +61,7 @@ static NSString* const AVF_CURRENT_ITEM_KEY = @"currentItem";
 
 static void *AVFMediaPlayerSessionObserverRateObservationContext = &AVFMediaPlayerSessionObserverRateObservationContext;
 static void *AVFMediaPlayerSessionObserverStatusObservationContext = &AVFMediaPlayerSessionObserverStatusObservationContext;
+static void *AVFMediaPlayerSessionObserverBufferLikelyToKeepUpContext = &AVFMediaPlayerSessionObserverBufferLikelyToKeepUpContext;
 static void *AVFMediaPlayerSessionObserverCurrentItemObservationContext = &AVFMediaPlayerSessionObserverCurrentItemObservationContext;
 
 @interface AVFMediaPlayerSessionObserver : NSObject
@@ -70,6 +72,7 @@ static void *AVFMediaPlayerSessionObserverCurrentItemObservationContext = &AVFMe
     AVPlayerItem *m_playerItem;
     AVPlayerLayer *m_playerLayer;
     NSURL *m_URL;
+    BOOL m_bufferIsLikelyToKeepUp;
 }
 
 @property (readonly, getter=player) AVPlayer* m_player;
@@ -100,6 +103,7 @@ static void *AVFMediaPlayerSessionObserverCurrentItemObservationContext = &AVFMe
         return nil;
 
     self->m_session = session;
+    self->m_bufferIsLikelyToKeepUp = FALSE;
     return self;
 }
 
@@ -139,6 +143,7 @@ static void *AVFMediaPlayerSessionObserverCurrentItemObservationContext = &AVFMe
 {
     if (m_playerItem) {
         [m_playerItem removeObserver:self forKeyPath:AVF_STATUS_KEY];
+        [m_playerItem removeObserver:self forKeyPath:AVF_BUFFER_LIKELY_KEEP_UP_KEY];
 
         [[NSNotificationCenter defaultCenter] removeObserver:self
                                                     name:AVPlayerItemDidPlayToEndTimeNotification
@@ -216,6 +221,11 @@ static void *AVFMediaPlayerSessionObserverCurrentItemObservationContext = &AVFMe
                       options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
                       context:AVFMediaPlayerSessionObserverStatusObservationContext];
 
+    [m_playerItem addObserver:self
+                   forKeyPath:AVF_BUFFER_LIKELY_KEEP_UP_KEY
+                      options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
+                      context:AVFMediaPlayerSessionObserverBufferLikelyToKeepUpContext];
+
     //When the player item has played to its end time we'll toggle
     //the movie controller Pause button to be the Play button
     [[NSNotificationCenter defaultCenter] addObserver:self
@@ -329,6 +339,15 @@ static void *AVFMediaPlayerSessionObserverCurrentItemObservationContext = &AVFMe
             break;
         }
     }
+    else if (context == AVFMediaPlayerSessionObserverBufferLikelyToKeepUpContext)
+    {
+        const bool isPlaybackLikelyToKeepUp = [m_playerItem isPlaybackLikelyToKeepUp];
+        if (isPlaybackLikelyToKeepUp != m_bufferIsLikelyToKeepUp) {
+            m_bufferIsLikelyToKeepUp = isPlaybackLikelyToKeepUp;
+            QMetaObject::invokeMethod(m_session, "processBufferStateChange", Qt::AutoConnection,
+                                      Q_ARG(int, isPlaybackLikelyToKeepUp ? 100 : 0));
+        }
+    }
     //AVPlayer "rate" property value observer.
     else if (context == AVFMediaPlayerSessionObserverRateObservationContext)
     {
@@ -386,6 +405,7 @@ AVFMediaPlayerSession::AVFMediaPlayerSession(AVFMediaPlayerService *service, QOb
     , m_rate(1.0)
     , m_requestedPosition(-1)
     , m_duration(0)
+    , m_bufferStatus(0)
     , m_videoAvailable(false)
     , m_audioAvailable(false)
     , m_seekable(false)
@@ -526,11 +546,10 @@ qint64 AVFMediaPlayerSession::duration() const
 
 int AVFMediaPlayerSession::bufferStatus() const
 {
-    //BUG: bufferStatus may be relevant?
 #ifdef QT_DEBUG_AVF
     qDebug() << Q_FUNC_INFO;
 #endif
-    return 100;
+    return m_bufferStatus;
 }
 
 int AVFMediaPlayerSession::volume() const
@@ -892,6 +911,15 @@ void AVFMediaPlayerSession::processLoadStateFailure()
     Q_EMIT stateChanged((m_state = QMediaPlayer::StoppedState));
 }
 
+void AVFMediaPlayerSession::processBufferStateChange(int bufferStatus)
+{
+    if (bufferStatus == m_bufferStatus)
+        return;
+
+    m_bufferStatus = bufferStatus;
+    Q_EMIT bufferStatusChanged(bufferStatus);
+}
+
 void AVFMediaPlayerSession::processPositionChange()
 {
     if (m_state == QMediaPlayer::StoppedState)