qtdemux: Initial chained support

This is similar to how asfdemux supports "chained" files. We detect that
by new STREAM_START events.

We put aside all old streams, and when we created all our new streams, we
push EOS on those old streams and finally remove them

2 files changed, 51 insertions, 9 deletions

diff --git a/gst/isomp4/qtdemux.c b/gst/isomp4/qtdemux.c
index b32385929..23be06171 100644
--- a/gst/isomp4/qtdemux.c
+++ b/gst/isomp4/qtdemux.c
@@ -1820,14 +1820,16 @@ gst_qtdemux_setcaps (GstQTDemux * demux, GstCaps * caps)
 }
 
 static void
-gst_qtdemux_reset (GstQTDemux * qtdemux, gboolean hard)
+gst_qtdemux_reset (GstQTDemux * qtdemux, gboolean hard, gboolean chaining)
 {
   gint n;
 
-  GST_DEBUG_OBJECT (qtdemux, "Resetting demux");
+  GST_DEBUG_OBJECT (qtdemux, "Resetting demux (hard:%d, chaining:%d)",
+      hard, chaining);
   gst_pad_stop_task (qtdemux->sinkpad);
 
-  if (hard || qtdemux->upstream_newsegment) {
+  /* On state changes, new TIME SEGMENT, or new headers */
+  if (hard || qtdemux->upstream_newsegment || chaining) {
     qtdemux->state = QTDEMUX_STATE_INITIAL;
     qtdemux->neededbytes = 16;
     qtdemux->todrop = 0;
@@ -1880,15 +1882,35 @@ gst_qtdemux_reset (GstQTDemux * qtdemux, gboolean hard)
   gst_adapter_clear (qtdemux->adapter);
   gst_segment_init (&qtdemux->segment, GST_FORMAT_TIME);
 
-  if (hard) {
+  if (hard || chaining) {
+    /* Remove old streams */
+    for (n = 0; n < qtdemux->n_old_streams; n++) {
+      GST_DEBUG_OBJECT (qtdemux, "Removing old stream %d", n);
+      gst_qtdemux_stream_free (qtdemux, qtdemux->old_streams[n]);
+      qtdemux->old_streams[n] = NULL;
+    }
+    qtdemux->n_old_streams = 0;
+
+    if (!hard) {
+      /* Save old streams (will be removed once we added new ones) */
+      GST_DEBUG_OBJECT (qtdemux, "Saving %d streams for later removal",
+          qtdemux->n_streams);
+      memcpy (qtdemux->old_streams, qtdemux->streams,
+          sizeof (qtdemux->streams));
+      qtdemux->n_old_streams = qtdemux->n_streams;
+      qtdemux->n_streams = 0;
+    }
+
     for (n = 0; n < qtdemux->n_streams; n++) {
       gst_qtdemux_stream_free (qtdemux, qtdemux->streams[n]);
       qtdemux->streams[n] = NULL;
     }
     qtdemux->n_streams = 0;
-    qtdemux->n_video_streams = 0;
-    qtdemux->n_audio_streams = 0;
-    qtdemux->n_sub_streams = 0;
+    if (!chaining) {
+      qtdemux->n_video_streams = 0;
+      qtdemux->n_audio_streams = 0;
+      qtdemux->n_sub_streams = 0;
+    }
     qtdemux->exposed = FALSE;
     qtdemux->fragmented = FALSE;
     qtdemux->mss_mode = FALSE;
@@ -2040,7 +2062,7 @@ gst_qtdemux_handle_sink_event (GstPad * sinkpad, GstObject * parent,
       guint64 dur;
 
       dur = demux->segment.duration;
-      gst_qtdemux_reset (demux, FALSE);
+      gst_qtdemux_reset (demux, FALSE, FALSE);
       demux->segment.duration = dur;
       break;
     }
@@ -2076,6 +2098,9 @@ gst_qtdemux_handle_sink_event (GstPad * sinkpad, GstObject * parent,
       gst_event_unref (event);
       goto drop;
     }
+    case GST_EVENT_STREAM_START:
+      gst_qtdemux_reset (demux, FALSE, TRUE);
+      break;
     default:
       break;
   }
@@ -2224,7 +2249,7 @@ gst_qtdemux_change_state (GstElement * element, GstStateChange transition)
 
   switch (transition) {
     case GST_STATE_CHANGE_PAUSED_TO_READY:{
-      gst_qtdemux_reset (qtdemux, TRUE);
+      gst_qtdemux_reset (qtdemux, TRUE, FALSE);
       break;
     }
     default:
@@ -9505,6 +9530,20 @@ qtdemux_expose_streams (GstQTDemux * qtdemux)
     gst_object_unref (oldpad);
   }
 
+  GST_DEBUG_OBJECT (qtdemux, "We have %d old streams to remove now",
+      qtdemux->n_old_streams);
+
+  for (i = 0; i < qtdemux->n_old_streams; i++) {
+    GST_DEBUG_OBJECT (qtdemux,
+        "Removing old stream %d, id %d, fourcc %" GST_FOURCC_FORMAT, i,
+        qtdemux->old_streams[i]->track_id,
+        GST_FOURCC_ARGS (qtdemux->old_streams[i]->fourcc));
+    gst_pad_push_event (qtdemux->old_streams[i]->pad, gst_event_new_eos ());
+    gst_qtdemux_stream_free (qtdemux, qtdemux->old_streams[i]);
+    qtdemux->old_streams[i] = NULL;
+  }
+  qtdemux->n_old_streams = 0;
+
   /* check if we should post a redirect in case there is a single trak
    * and it is a redirecting trak */
   if (qtdemux->n_streams == 1 && qtdemux->streams[0]->redirect_uri != NULL) {
diff --git a/gst/isomp4/qtdemux.h b/gst/isomp4/qtdemux.h
index 6345d9c45..a562e6263 100644
--- a/gst/isomp4/qtdemux.h
+++ b/gst/isomp4/qtdemux.h
@@ -66,6 +66,9 @@ struct _GstQTDemux {
   gint     n_audio_streams;
   gint     n_sub_streams;
 
+  QtDemuxStream *old_streams[GST_QTDEMUX_MAX_STREAMS];
+  gint     n_old_streams;
+
   GstFlowCombiner *flowcombiner;
 
   gboolean have_group_id;