qtmux: Chain up when releasing pad, and fix some locking.

Release pads by calling up into aggregator so it can do the right
things. Don't clean up the pad until after that.

 Add some missing locks around some accesses to shared pad state.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/800>

1 files changed, 15 insertions, 3 deletions

diff --git a/gst/isomp4/gstqtmux.c b/gst/isomp4/gstqtmux.c
index 6a5c72053..cf48e65a3 100644
--- a/gst/isomp4/gstqtmux.c
+++ b/gst/isomp4/gstqtmux.c
@@ -3377,6 +3377,7 @@ gst_qt_mux_start_file (GstQTMux * qtmux)
         gst_aggregator_update_segment (GST_AGGREGATOR (qtmux), &segment);
       }
 
+      GST_OBJECT_LOCK (qtmux);
       qtmux->current_chunk_size = 0;
       qtmux->current_chunk_duration = 0;
       qtmux->current_chunk_offset = -1;
@@ -3384,7 +3385,6 @@ gst_qt_mux_start_file (GstQTMux * qtmux)
       qtmux->current_pad = NULL;
       qtmux->longest_chunk = GST_CLOCK_TIME_NONE;
 
-      GST_OBJECT_LOCK (qtmux);
       for (l = GST_ELEMENT_CAST (qtmux)->sinkpads; l; l = l->next) {
         GstQTMuxPad *qtpad = (GstQTMuxPad *) l->data;
 
@@ -6486,18 +6486,25 @@ static void
 gst_qt_mux_release_pad (GstElement * element, GstPad * pad)
 {
   GstQTMux *mux = GST_QT_MUX_CAST (element);
+  GstQTMuxPad *muxpad = GST_QT_MUX_PAD_CAST (pad);
 
   GST_DEBUG_OBJECT (element, "Releasing %s:%s", GST_DEBUG_PAD_NAME (pad));
 
-  gst_element_remove_pad (element, pad);
+  /* Take a ref to the pad so we can clean it up after removing it from the element */
+  pad = gst_object_ref (pad);
+
+  /* Do aggregate level cleanup */
+  GST_ELEMENT_CLASS (parent_class)->release_pad (element, pad);
 
+  GST_OBJECT_LOCK (mux);
   if (mux->current_pad && GST_PAD (mux->current_pad) == pad) {
     mux->current_pad = NULL;
     mux->current_chunk_size = 0;
     mux->current_chunk_duration = 0;
   }
 
-  GST_OBJECT_LOCK (mux);
+  gst_qt_mux_pad_reset (muxpad);
+
   if (GST_ELEMENT (mux)->sinkpads == NULL) {
     /* No more outstanding request pads, reset our counters */
     mux->video_pads = 0;
@@ -6505,6 +6512,8 @@ gst_qt_mux_release_pad (GstElement * element, GstPad * pad)
     mux->subtitle_pads = 0;
   }
   GST_OBJECT_UNLOCK (mux);
+
+  gst_object_unref (pad);
 }
 
 static GstAggregatorPad *
@@ -6572,9 +6581,12 @@ gst_qt_mux_request_new_pad (GstElement * element,
   g_free (name);
 
   /* set up pad */
+  GST_OBJECT_LOCK (qtmux);
   gst_qt_mux_pad_reset (qtpad);
   qtpad->trak = atom_trak_new (qtmux->context);
+
   atom_moov_add_trak (qtmux->moov, qtpad->trak);
+  GST_OBJECT_UNLOCK (qtmux);
 
   /* set up pad functions */
   qtpad->set_caps = setcaps_func;