DirectShow: fix media player seeking.

Correctly handle seek requests happening when the media is not playing.

Change-Id: I82c508dae41792b75a26e86512da66a4871f6352
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

src/plugins/directshow/player/directshowplayercontrol.cpp

@@ -225,6 +225,8 @@ const QIODevice *DirectShowPlayerControl::mediaStream() const
 
 void DirectShowPlayerControl::setMedia(const QMediaContent &media, QIODevice *stream)
 {
+    m_pendingPosition = -1;
+
     m_media = media;
     m_stream = stream;
 
@@ -238,30 +240,35 @@ void DirectShowPlayerControl::setMedia(const QMediaContent &media, QIODevice *st
 
 void DirectShowPlayerControl::play()
 {
-    if (m_status == QMediaPlayer::NoMedia)
+    playOrPause(QMediaPlayer::PlayingState);
-        return;
-    if (m_status == QMediaPlayer::InvalidMedia) {
-        setMedia(m_media, m_stream);
-        if (m_error != QMediaPlayer::NoError)
-            return;
-    }
-    m_service->play();
-    if (m_pendingPosition != -1)
-        setPosition(m_pendingPosition);
-    emit stateChanged(m_state = QMediaPlayer::PlayingState);
 }
 
 void DirectShowPlayerControl::pause()
 {
-    if (m_status == QMediaPlayer::NoMedia)
+    playOrPause(QMediaPlayer::PausedState);
+}
+
+void DirectShowPlayerControl::playOrPause(QMediaPlayer::State state)
+{
+    if (m_status == QMediaPlayer::NoMedia || state == QMediaPlayer::StoppedState)
         return;
     if (m_status == QMediaPlayer::InvalidMedia) {
         setMedia(m_media, m_stream);
         if (m_error != QMediaPlayer::NoError)
             return;
     }
+
+    m_state = state;
+
+    if (m_pendingPosition != -1)
+        setPosition(m_pendingPosition);
+
+    if (state == QMediaPlayer::PausedState)
         m_service->pause();
-    emit stateChanged(m_state = QMediaPlayer::PausedState);
+    else
+        m_service->play();
+
+    emit stateChanged(m_state);
 }
 
 void DirectShowPlayerControl::stop()

src/plugins/directshow/player/directshowplayercontrol.h

@@ -114,6 +114,8 @@ private:
         PropertiesChanged = QEvent::User
     };
 
+    void playOrPause(QMediaPlayer::State state);
+
     void scheduleUpdate(int properties);
     void emitPropertyChanges();
     void setVolumeHelper(int volume);

src/plugins/directshow/player/directshowplayerservice.cpp

@@ -98,6 +98,7 @@ DirectShowPlayerService::DirectShowPlayerService(QObject *parent)
     , m_videoOutput(0)
     , m_rate(1.0)
     , m_position(0)
+    , m_seekPosition(-1)
     , m_duration(0)
     , m_buffering(false)
     , m_seekable(false)
@@ -217,6 +218,7 @@ void DirectShowPlayerService::load(const QMediaContent &media, QIODevice *stream
     m_error = QMediaPlayer::NoError;
     m_errorString = QString();
     m_position = 0;
+    m_seekPosition = -1;
     m_duration = 0;
     m_streamTypes = 0;
     m_executedTasks = 0;
@@ -665,8 +667,10 @@ void DirectShowPlayerService::play()
     if (m_executedTasks & Render) {
         if (m_executedTasks & Stop) {
             m_atEnd = false;
-            m_position = 0;
+            if (m_seekPosition == -1) {
+                m_seekPosition = 0;
                 m_pendingTasks |= Seek;
+            }
             m_executedTasks ^= Stop;
         }
 
@@ -709,8 +713,10 @@ void DirectShowPlayerService::pause()
     if (m_executedTasks & Render) {
         if (m_executedTasks & Stop) {
             m_atEnd = false;
-            m_position = 0;
+            if (m_seekPosition == -1) {
+                m_seekPosition = 0;
                 m_pendingTasks |= Seek;
+            }
             m_executedTasks ^= Stop;
         }
 
@@ -780,7 +786,7 @@ void DirectShowPlayerService::doStop(QMutexLocker *locker)
             control->Release();
         }
 
-        m_position = 0;
+        m_seekPosition = 0;
         m_pendingTasks |= Seek;
 
         m_executedTasks &= ~(Play | Pause);
@@ -884,7 +890,7 @@ void DirectShowPlayerService::seek(qint64 position)
 {
     QMutexLocker locker(&m_mutex);
 
-    m_position = position;
+    m_seekPosition = position;
 
     m_pendingTasks |= Seek;
 
@@ -894,8 +900,11 @@ void DirectShowPlayerService::seek(qint64 position)
 
 void DirectShowPlayerService::doSeek(QMutexLocker *locker)
 {
+    if (m_seekPosition == -1)
+        return;
+
     if (IMediaSeeking *seeking = com_cast<IMediaSeeking>(m_graph, IID_IMediaSeeking)) {
-        LONGLONG seekPosition = LONGLONG(m_position) * qt_directShowTimeScale;
+        LONGLONG seekPosition = LONGLONG(m_seekPosition) * qt_directShowTimeScale;
 
         // Cache current values as we can't query IMediaSeeking during a seek due to the
         // possibility of a deadlock when flushing the VideoSurfaceFilter.
@@ -919,13 +928,13 @@ void DirectShowPlayerService::doSeek(QMutexLocker *locker)
         m_position = currentPosition / qt_directShowTimeScale;
 
         seeking->Release();
-    } else {
-        m_position = 0;
-    }
 
         QCoreApplication::postEvent(this, new QEvent(QEvent::Type(PositionChange)));
     }
 
+    m_seekPosition = -1;
+}
+
 int DirectShowPlayerService::bufferStatus() const
 {
 #ifndef QT_NO_WMSDK

src/plugins/directshow/player/directshowplayerservice.h

@@ -194,6 +194,7 @@ private:
     int m_streamTypes;
     qreal m_rate;
     qint64 m_position;
+    qint64 m_seekPosition;
     qint64 m_duration;
     bool m_buffering;
     bool m_seekable;