Properly detect whether a stream is seekable

Don't make assumptions about the gstreamer source element, the rtspsrc
is for example not a regular GstBaseSrc. Instead use a query on the
pipeline to determine whether our stream is seekable.

Fixes: QTBUG-97121
Change-Id: I935ea9fe399172a26b0fef6879d491cadadc47f3
Reviewed-by: Piotr Srebrny <piotr.srebrny@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
(cherry picked from commit 9bb626d19f001ab7cf7719555f80ffe9837cd6b9)
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

2 files changed, 13 insertions, 5 deletions

diff --git a/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer.cpp b/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer.cpp
index 6ebfb703b..999d3ba19 100644
--- a/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer.cpp
+++ b/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer.cpp
@@ -357,6 +357,17 @@ bool QGstreamerMediaPlayer::processBusMessage(const QGstreamerMessage &message)
 
                 emit tracksChanged();
                 mediaStatusChanged(QMediaPlayer::LoadedMedia);
+
+                GstQuery *query = gst_query_new_seeking(GST_FORMAT_TIME);
+                gboolean canSeek = false;
+                if (gst_element_query(playerPipeline.element(), query)) {
+                    gst_query_parse_seeking(query, NULL, &canSeek, nullptr, nullptr);
+                    qCDebug(qLcMediaPlayer) << "    pipeline is seekable:" << canSeek;
+                } else {
+                    qCDebug(qLcMediaPlayer) << "    query for seekable failed.";
+                }
+                gst_query_unref(query);
+                seekableChanged(canSeek);
             }
 
             break;
@@ -620,10 +631,6 @@ void QGstreamerMediaPlayer::uridecodebinElementAddedCallback(GstElement */*uride
     if (G_OBJECT_TYPE(child) == that->decodebinType) {
         qCDebug(qLcMediaPlayer) << "     -> setting post-stream-topology property";
         c.set("post-stream-topology", true);
-    } else if (!qstrcmp(gst_element_get_name(child), "source")) {
-        GstBaseSrc *src = GST_BASE_SRC(child);
-        bool seekable = src && GST_BASE_SRC_GET_CLASS(src)->is_seekable(src);
-        that->seekableChanged(seekable);
     }
 }
 
diff --git a/src/multimedia/playback/qmediaplayer.cpp b/src/multimedia/playback/qmediaplayer.cpp
index f65b6a2a1..5c11d8e81 100644
--- a/src/multimedia/playback/qmediaplayer.cpp
+++ b/src/multimedia/playback/qmediaplayer.cpp
@@ -600,7 +600,8 @@ void QMediaPlayer::setPosition(qint64 position)
 
     if (d->control == nullptr)
         return;
-
+    if (!d->control->isSeekable())
+        return;
     d->control->setPosition(qMax(position, 0ll));
 }