Progressive download in Phonon MMF backend: integrated with player

This commit integrates the Download class with the media playback
classes in the backend, to implement Progressive Download.

Note that this PDL implementation has one drawback: when video
playback is paused due to shortage of data (i.e. due to the download
being temporarily stalled), the display goes black.  This is because,
when the end of the currently-downloaded data is reached, the
playback session is closed.  When more data becomes available, the
clip is re-opened, a seek is done to reach the previous playback
position, and playback is re-started.  Closing the playback session
closes the video stack's connection to the display, thereby causing
the video widget to go black while more data is buffered.

This is a consequence of the level in the native video stack at which
the Phonon integration is done: managing a network stall without
requiring the playback session to be closed would require integration
below the MMF client API, specifically at the MMF controller level.

Task-number: QTBUG-10769
Reviewed-by: Derick Hawcroft

1 files changed, 134 insertions, 14 deletions

diff --git a/src/3rdparty/phonon/mmf/abstractmediaplayer.cpp b/src/3rdparty/phonon/mmf/abstractmediaplayer.cpp
index 3702560..a728423 100644
--- a/src/3rdparty/phonon/mmf/abstractmediaplayer.cpp
+++ b/src/3rdparty/phonon/mmf/abstractmediaplayer.cpp
@@ -51,10 +51,13 @@ MMF::AbstractMediaPlayer::AbstractMediaPlayer
         ,   m_parent(parent)
         ,   m_pending(NothingPending)
         ,   m_positionTimer(new QTimer(this))
+        ,   m_position(0)
         ,   m_bufferStatusTimer(new QTimer(this))
         ,   m_mmfMaxVolume(NullMaxVolume)
         ,   m_prefinishMarkSent(false)
         ,   m_aboutToFinishSent(false)
+        ,   m_download(0)
+        ,   m_downloadStalled(false)
 {
     connect(m_positionTimer.data(), SIGNAL(timeout()), this, SLOT(positionTick()));
     connect(m_bufferStatusTimer.data(), SIGNAL(timeout()), this, SLOT(bufferStatusTick()));
@@ -183,6 +186,7 @@ void MMF::AbstractMediaPlayer::seek(qint64 ms)
         }
 
         doSeek(ms);
+        m_position = ms;
         resetMarksIfRewound();
 
         if(wasPlaying && state() != ErrorState) {
@@ -207,6 +211,11 @@ bool MMF::AbstractMediaPlayer::isSeekable() const
     return true;
 }
 
+qint64 MMF::AbstractMediaPlayer::currentTime() const
+{
+    return m_position;
+}
+
 void MMF::AbstractMediaPlayer::doSetTickInterval(qint32 interval)
 {
     TRACE_CONTEXT(AbstractMediaPlayer::doSetTickInterval, EAudioApi);
@@ -247,6 +256,14 @@ void MMF::AbstractMediaPlayer::open()
             symbianErr = openFile(*file);
             if (KErrNone != symbianErr)
                 errorMessage = tr("Error opening file");
+        } else if (url.scheme() == QLatin1String("http")) {
+            Q_ASSERT(!m_download);
+            m_download = new Download(url, this);
+            connect(m_download, SIGNAL(lengthChanged(qint64)),
+                    this, SLOT(downloadLengthChanged(qint64)));
+            connect(m_download, SIGNAL(stateChanged(Download::State)),
+                    this, SLOT(downloadStateChanged(Download::State)));
+            m_download->start();
         } else {
             symbianErr = openUrl(url.toString());
             if (KErrNone != symbianErr)
@@ -288,6 +305,14 @@ void MMF::AbstractMediaPlayer::open()
     TRACE_EXIT_0();
 }
 
+void MMF::AbstractMediaPlayer::close()
+{
+    doClose();
+    delete m_download;
+    m_download = 0;
+    m_position = 0;
+}
+
 void MMF::AbstractMediaPlayer::volumeChanged(qreal volume)
 {
     TRACE_CONTEXT(AbstractMediaPlayer::volumeChanged, EAudioInternal);
@@ -374,7 +399,8 @@ void MMF::AbstractMediaPlayer::bufferingComplete()
 {
     stopBufferStatusTimer();
     emit MMF::AbstractPlayer::bufferStatus(100);
-    changeState(m_stateBeforeBuffering);
+    if (!progressiveDownloadStalled())
+        changeState(m_stateBeforeBuffering);
 }
 
 void MMF::AbstractMediaPlayer::maxVolumeChanged(int mmfMaxVolume)
@@ -385,13 +411,28 @@ void MMF::AbstractMediaPlayer::maxVolumeChanged(int mmfMaxVolume)
 
 void MMF::AbstractMediaPlayer::loadingComplete(int error)
 {
-    Q_ASSERT(Phonon::LoadingState == state());
-
-    if (KErrNone == error) {
-        updateMetaData();
-        changeState(StoppedState);
+    TRACE_CONTEXT(AbstractMediaPlayer::loadingComplete, EAudioApi);
+    TRACE_ENTRY("state %d error %d", state(), error);
+    if (progressiveDownloadStalled()) {
+        Q_ASSERT(Phonon::BufferingState == state());
+        if (KErrNone == error) {
+            bufferingComplete();
+            doSeek(m_position);
+            startPlayback();
+            m_downloadStalled = false;
+        }
     } else {
-        setError(tr("Loading clip failed"), error);
+        Q_ASSERT(Phonon::LoadingState == state());
+        if (KErrNone == error) {
+            updateMetaData();
+            changeState(StoppedState);
+        } else {
+            if (isProgressiveDownload() && KErrCorrupt == error) {
+                setProgressiveDownloadStalled();
+            } else {
+                setError(tr("Loading clip failed"), error);
+            }
+        }
     }
 }
 
@@ -415,8 +456,12 @@ void MMF::AbstractMediaPlayer::playbackComplete(int error)
         QMetaObject::invokeMethod(m_parent, "switchToNextSource", Qt::QueuedConnection);
     }
     else {
-        setError(tr("Playback complete"), error);
-        emit finished();
+        if (isProgressiveDownload() && KErrCorrupt == error) {
+            setProgressiveDownloadStalled();
+        } else {
+            setError(tr("Playback complete"), error);
+            emit finished();
+        }
     }
 }
 
@@ -425,15 +470,28 @@ qint64 MMF::AbstractMediaPlayer::toMilliSeconds(const TTimeIntervalMicroSeconds
     return in.Int64() / 1000;
 }
 
+bool MMF::AbstractMediaPlayer::isProgressiveDownload() const
+{
+    return (0 != m_download);
+}
+
+bool MMF::AbstractMediaPlayer::progressiveDownloadStalled() const
+{
+    return m_downloadStalled;
+}
+
 //-----------------------------------------------------------------------------
 // Slots
 //-----------------------------------------------------------------------------
 
 void MMF::AbstractMediaPlayer::positionTick()
 {
-    const qint64 current = currentTime();
-    emitMarksIfReached(current);
-    emit MMF::AbstractPlayer::tick(current);
+    const qint64 pos = getCurrentTime();
+    if (pos > m_position) {
+        m_position = pos;
+        emitMarksIfReached(m_position);
+        emit MMF::AbstractPlayer::tick(m_position);
+    }
 }
 
 void MMF::AbstractMediaPlayer::emitMarksIfReached(qint64 current)
@@ -458,7 +516,7 @@ void MMF::AbstractMediaPlayer::emitMarksIfReached(qint64 current)
 
 void MMF::AbstractMediaPlayer::resetMarksIfRewound()
 {
-    const qint64 current = currentTime();
+    const qint64 current = getCurrentTime();
     const qint64 total = totalTime();
     const qint64 remaining = total - current;
 
@@ -487,9 +545,71 @@ void MMF::AbstractMediaPlayer::startPlayback()
     changeState(PlayingState);
 }
 
+void MMF::AbstractMediaPlayer::setProgressiveDownloadStalled()
+{
+    TRACE_CONTEXT(AbstractMediaPlayer::setProgressiveDownloadStalled, EAudioApi);
+    TRACE_ENTRY("state %d", state());
+    Q_ASSERT(isProgressiveDownload());
+    m_downloadStalled = true;
+    doClose();
+    bufferingStarted();
+    // Video player loses window handle when closed - need to reapply it here
+    videoOutputChanged();
+#ifdef QT_PHONON_MMF_DOWNLOAD_DUMMY
+    m_download->resume();
+#endif
+}
+
 void MMF::AbstractMediaPlayer::bufferStatusTick()
 {
-    emit MMF::AbstractPlayer::bufferStatus(bufferStatus());
+    // During progressive download, there is no way to detect the buffering status.
+    // Phonon does not support a "buffering; amount unknown" signal, therefore we
+    // return a buffering status of zero.
+    const int status = progressiveDownloadStalled() ? 0 : bufferStatus();
+    emit MMF::AbstractPlayer::bufferStatus(status);
+}
+
+void MMF::AbstractMediaPlayer::downloadLengthChanged(qint64 length)
+{
+    TRACE_CONTEXT(AbstractMediaPlayer::downloadLengthChanged, EAudioApi);
+    TRACE_ENTRY("length %Ld", length);
+    Q_UNUSED(length)
+    if (m_downloadStalled) {
+        bufferingComplete();
+        int err = m_parent->openFileHandle(m_download->targetFileName());
+        if (KErrNone == err)
+            err = openFile(*m_parent->file());
+        if (KErrNone != err)
+            setError(tr("Error opening file"));
+    }
+}
+
+void MMF::AbstractMediaPlayer::downloadStateChanged(Download::State state)
+{
+    TRACE_CONTEXT(AbstractMediaPlayer::downloadStateChanged, EAudioApi);
+    TRACE_ENTRY("state %d", state);
+    switch (state) {
+    case Download::Idle:
+    case Download::Initializing:
+        break;
+    case Download::Downloading:
+        {
+        int err = m_parent->openFileHandle(m_download->targetFileName());
+        if (KErrNone == err)
+            err = openFile(*m_parent->file());
+        else if (KErrCorrupt == err)
+            // Insufficient data downloaded - enter Buffering state
+            setProgressiveDownloadStalled();
+        if (KErrNone != err)
+            setError(tr("Error opening file"));
+        }
+        break;
+    case Download::Complete:
+        break;
+    case Download::Error:
+        setError(tr("Download error"));
+        break;
+    }
 }
 
 Phonon::State MMF::AbstractMediaPlayer::phononState(PrivateState state) const