GStreamer: fix GstAppSrc usage.

Allow our GstAppSrc wrapper to be reconfigured with a new GstAppSrc
object. This is necessary because that object changes every time
playback is restarted, even for the same source. The consequence of
not allowing the reconfigure was that playback for a given qrc media
would only work the first time; any subsequent calls to play() would
not work since our wrapper wouldn't know about the new GstAppSrc object
and therefore wouldn't be able to produce any data.

Also improved management of the wrapper lifecycle.

Task-number: QTBUG-49531
Change-Id: I905afb6848cc7e9a563b4edc2c5875cdd7e53d21
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

src/gsttools/qgstappsrc.cpp

@@ -41,7 +41,6 @@ QGstAppSrc::QGstAppSrc(QObject *parent)
     ,m_appSrc(0)
     ,m_sequential(false)
     ,m_maxBytes(0)
-    ,m_setup(false)
     ,m_dataRequestSize(~0)
     ,m_dataRequested(false)
     ,m_enoughData(false)
@@ -60,11 +59,13 @@ QGstAppSrc::~QGstAppSrc()
 
 bool QGstAppSrc::setup(GstElement* appsrc)
 {
-    if (m_setup || m_stream == 0 || appsrc == 0)
-        return false;
-
-    if (m_appSrc)
+    if (m_appSrc) {
         gst_object_unref(G_OBJECT(m_appSrc));
+        m_appSrc = 0;
+    }
+
+    if (!appsrc || !m_stream)
+        return false;
 
     m_appSrc = GST_APP_SRC(appsrc);
     gst_object_ref(G_OBJECT(m_appSrc));
@@ -79,32 +80,35 @@ bool QGstAppSrc::setup(GstElement* appsrc)
     gst_app_src_set_stream_type(m_appSrc, m_streamType);
     gst_app_src_set_size(m_appSrc, (m_sequential) ? -1 : m_stream->size());
 
-    return  m_setup = true;
+    return true;
 }
 
 void QGstAppSrc::setStream(QIODevice *stream)
 {
-    if (stream == 0)
-        return;
     if (m_stream) {
         disconnect(m_stream, SIGNAL(readyRead()), this, SLOT(onDataReady()));
         disconnect(m_stream, SIGNAL(destroyed()), this, SLOT(streamDestroyed()));
+        m_stream = 0;
     }
-    if (m_appSrc)
+
+    if (m_appSrc) {
         gst_object_unref(G_OBJECT(m_appSrc));
+        m_appSrc = 0;
+    }
 
     m_dataRequestSize = ~0;
     m_dataRequested = false;
     m_enoughData = false;
     m_forceData = false;
+    m_sequential = false;
     m_maxBytes = 0;
 
-    m_appSrc = 0;
-    m_stream = stream;
-    connect(m_stream, SIGNAL(destroyed()), SLOT(streamDestroyed()));
-    connect(m_stream, SIGNAL(readyRead()), this, SLOT(onDataReady()));
-    m_sequential = m_stream->isSequential();
-    m_setup = false;
+    if (stream) {
+        m_stream = stream;
+        connect(m_stream, SIGNAL(destroyed()), SLOT(streamDestroyed()));
+        connect(m_stream, SIGNAL(readyRead()), this, SLOT(onDataReady()));
+        m_sequential = m_stream->isSequential();
+    }
 }
 
 QIODevice *QGstAppSrc::stream() const
@@ -135,7 +139,7 @@ void QGstAppSrc::streamDestroyed()
 
 void QGstAppSrc::pushDataToAppSrc()
 {
-    if (!isStreamValid() || !m_setup)
+    if (!isStreamValid() || !m_appSrc)
         return;
 
     if (m_dataRequested && !m_enoughData) {
@@ -242,6 +246,9 @@ void QGstAppSrc::destroy_notify(gpointer data)
 
 void QGstAppSrc::sendEOS()
 {
+    if (!m_appSrc)
+        return;
+
     gst_app_src_end_of_stream(GST_APP_SRC(m_appSrc));
     if (isStreamValid() && !stream()->isSequential())
         stream()->reset();

src/multimedia/gsttools_headers/qgstappsrc_p.h

@@ -54,7 +54,6 @@ public:
     ~QGstAppSrc();
 
     bool setup(GstElement *);
-    bool isReady() const { return m_setup; }
 
     void setStream(QIODevice *);
     QIODevice *stream() const;
@@ -93,7 +92,6 @@ private:
     GstAppStreamType m_streamType;
     GstAppSrcCallbacks m_callbacks;
     qint64 m_maxBytes;
-    bool m_setup;
     unsigned int m_dataRequestSize;
     bool m_dataRequested;
     bool m_enoughData;

src/plugins/gstreamer/audiodecoder/qgstreameraudiodecodersession.cpp

@@ -142,9 +142,6 @@ void QGstreamerAudioDecoderSession::configureAppSrcElement(GObject* object, GObj
     if (!self->appsrc())
         return;
 
-    if (self->appsrc()->isReady())
-        return;
-
     GstElement *appsrc;
     g_object_get(orig, "source", &appsrc, NULL);
 
@@ -350,9 +347,8 @@ void QGstreamerAudioDecoderSession::start()
             return;
         }
 
-        if (m_appSrc)
-            m_appSrc->deleteLater();
-        m_appSrc = new QGstAppSrc(this);
+        if (!m_appSrc)
+            m_appSrc = new QGstAppSrc(this);
         m_appSrc->setStream(mDevice);
 
         g_object_set(G_OBJECT(m_playbin), "uri", "appsrc://", NULL);

src/plugins/gstreamer/mediaplayer/qgstreamerplayersession.cpp

@@ -241,6 +241,10 @@ QGstreamerPlayerSession::QGstreamerPlayerSession(QObject *parent)
         g_signal_connect(G_OBJECT(m_playbin), "video-changed", G_CALLBACK(handleStreamsChange), this);
         g_signal_connect(G_OBJECT(m_playbin), "audio-changed", G_CALLBACK(handleStreamsChange), this);
         g_signal_connect(G_OBJECT(m_playbin), "text-changed", G_CALLBACK(handleStreamsChange), this);
+
+#if defined(HAVE_GST_APPSRC)
+        g_signal_connect(G_OBJECT(m_playbin), "deep-notify::source", G_CALLBACK(configureAppSrcElement), this);
+#endif
     }
 }
 
@@ -274,7 +278,7 @@ void QGstreamerPlayerSession::configureAppSrcElement(GObject* object, GObject *o
     Q_UNUSED(object);
     Q_UNUSED(pspec);
 
-    if (self->appsrc()->isReady())
+    if (!self->appsrc())
         return;
 
     GstElement *appsrc;
@@ -298,16 +302,14 @@ void QGstreamerPlayerSession::loadFromStream(const QNetworkRequest &request, QIO
     m_lastPosition = 0;
     m_isPlaylist = false;
 
-    if (m_appSrc)
-        m_appSrc->deleteLater();
-    m_appSrc = new QGstAppSrc(this);
+    if (!m_appSrc)
+        m_appSrc = new QGstAppSrc(this);
     m_appSrc->setStream(appSrcStream);
 
     if (m_playbin) {
         m_tags.clear();
         emit tagsChanged();
 
-        g_signal_connect(G_OBJECT(m_playbin), "deep-notify::source", (GCallback) &QGstreamerPlayerSession::configureAppSrcElement, (gpointer)this);
         g_object_set(G_OBJECT(m_playbin), "uri", "appsrc://", NULL);
 
         if (!m_streamTypes.isEmpty()) {
@@ -330,6 +332,13 @@ void QGstreamerPlayerSession::loadFromUri(const QNetworkRequest &request)
     m_lastPosition = 0;
     m_isPlaylist = false;
 
+#if defined(HAVE_GST_APPSRC)
+    if (m_appSrc) {
+        m_appSrc->deleteLater();
+        m_appSrc = 0;
+    }
+#endif
+
     if (m_playbin) {
         m_tags.clear();
         emit tagsChanged();