Changes to QMediaPlayer GStreamer backend to allow setPosition before pause

Do not display prerolled frames in stopped state.
Instead store prerolled frame and display it only after switching to
pause or playback state.
Added new unit test with a sample video file to check this functionality.

Change-Id: I3fd159a199b65ca10fdf9843af5675c5ae9dad05
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/src/plugins/gstreamer/mediaplayer/qgstreamerplayercontrol.cpp b/src/plugins/gstreamer/mediaplayer/qgstreamerplayercontrol.cpp
index 3ce1e9cd3..ec3e5dd92 100644
--- a/src/plugins/gstreamer/mediaplayer/qgstreamerplayercontrol.cpp
+++ b/src/plugins/gstreamer/mediaplayer/qgstreamerplayercontrol.cpp
@@ -259,6 +259,10 @@ void QGstreamerPlayerControl::playOrPause(QMediaPlayer::State newState)
 
         bool ok = false;
 
+        // show prerolled frame if switching from stopped state
+        if (newState != QMediaPlayer::StoppedState && m_state == QMediaPlayer::StoppedState && m_pendingSeekPosition == -1)
+            m_session->showPrerollFrames(true);
+
         //To prevent displaying the first video frame when playback is resumed
         //the pipeline is paused instead of playing, seeked to requested position,
         //and after seeking is finished (position updated) playback is restarted
@@ -299,6 +303,7 @@ void QGstreamerPlayerControl::stop()
 
     if (m_state != QMediaPlayer::StoppedState) {
         m_state = QMediaPlayer::StoppedState;
+        m_session->showPrerollFrames(false); // stop showing prerolled frames in stop state
         if (m_resources->isGranted())
             m_session->pause();
 
@@ -342,7 +347,7 @@ void QGstreamerPlayerControl::setMedia(const QMediaContent &content, QIODevice *
     m_state = QMediaPlayer::StoppedState;
     QMediaContent oldMedia = m_currentResource;
     m_pendingSeekPosition = -1;
-    m_session->showPrerollFrames(true);
+    m_session->showPrerollFrames(false); // do not show prerolled frames until pause() or play() explicitly called
 
     if (!content.isNull() || stream) {
         if (!m_resources->isRequested() && !m_resources->isGranted())
@@ -767,7 +772,8 @@ void QGstreamerPlayerControl::updatePosition(qint64 pos)
         //seek request is complete, it's safe to resume playback
         //with prerolled frame displayed
         m_pendingSeekPosition = -1;
-        m_session->showPrerollFrames(true);
+        if (m_state != QMediaPlayer::StoppedState)
+            m_session->showPrerollFrames(true);
         if (m_state == QMediaPlayer::PlayingState) {
             m_session->play();
         }