hlsdemux: Always flush the internal proxy pads before downloading

hlsdemux can't rely on the source to push flushes on a seek on ready
as that might not make sense. So always resort to flushing the
internal proxy pads by pushing flush events from the source's src pad.

Also as the seeking is not required anymore, only seek if there is
really a byte range to be used. And store a ref to the source's
src pad to avoid doing get_static_pad for every fragment.

2 files changed, 39 insertions, 14 deletions

diff --git a/ext/hls/gsthlsdemux.c b/ext/hls/gsthlsdemux.c
index b835acb78..bbd6bdd76 100644
--- a/ext/hls/gsthlsdemux.c
+++ b/ext/hls/gsthlsdemux.c
@@ -144,6 +144,11 @@ gst_hls_demux_dispose (GObject * obj)
 
   gst_hls_demux_reset (demux, TRUE);
 
+  if (demux->src_srcpad) {
+    gst_object_unref (demux->src_srcpad);
+    demux->src_srcpad = NULL;
+  }
+
   g_mutex_clear (&demux->download_lock);
   g_cond_clear (&demux->download_cond);
   g_mutex_clear (&demux->updates_timed_lock);
@@ -1011,13 +1016,11 @@ switch_pads (GstHLSDemux * demux)
   GstEvent *event;
   gchar *stream_id;
   gchar *name;
-  GstPad *target;
   GstPadTemplate *tmpl;
   GstProxyPad *internal_pad;
 
   GST_DEBUG_OBJECT (demux, "Switching pad (oldpad:%p)", oldpad);
 
-  target = gst_element_get_static_pad (demux->src, "src");
   if (oldpad) {
     gst_ghost_pad_set_target (GST_GHOST_PAD_CAST (oldpad), NULL);
   }
@@ -1025,10 +1028,10 @@ switch_pads (GstHLSDemux * demux)
   /* First create and activate new pad */
   name = g_strdup_printf ("src_%u", demux->srcpad_counter++);
   tmpl = gst_static_pad_template_get (&srctemplate);
-  demux->srcpad = gst_ghost_pad_new_from_template (name, target, tmpl);
+  demux->srcpad =
+      gst_ghost_pad_new_from_template (name, demux->src_srcpad, tmpl);
   gst_object_unref (tmpl);
   g_free (name);
-  gst_object_unref (target);
 
   /* set up our internal pad to drop all events from
    * the http src we don't care about. On the chain function
@@ -1799,9 +1802,11 @@ gst_hls_demux_update_source (GstHLSDemux * demux, const gchar * uri,
     new_protocol = gst_uri_get_protocol (uri);
 
     if (!g_str_equal (old_protocol, new_protocol)) {
+      gst_object_unref (demux->src_srcpad);
       gst_element_set_state (demux->src, GST_STATE_NULL);
       gst_bin_remove (GST_BIN_CAST (demux), demux->src);
       demux->src = NULL;
+      demux->src_srcpad = NULL;
       GST_DEBUG_OBJECT (demux, "Can't re-use old source element");
     } else {
       GError *err = NULL;
@@ -1852,6 +1857,7 @@ gst_hls_demux_update_source (GstHLSDemux * demux, const gchar * uri,
 
     gst_element_set_locked_state (demux->src, TRUE);
     gst_bin_add (GST_BIN_CAST (demux), demux->src);
+    demux->src_srcpad = gst_element_get_static_pad (demux->src, "src");
   }
   return TRUE;
 }
@@ -1902,16 +1908,33 @@ gst_hls_demux_get_next_fragment (GstHLSDemux * demux,
 
   if (gst_element_set_state (demux->src,
           GST_STATE_READY) != GST_STATE_CHANGE_FAILURE) {
-    gst_element_send_event (demux->src, gst_event_new_seek (1.0,
-            GST_FORMAT_BYTES, (GstSeekFlags) GST_SEEK_FLAG_FLUSH,
-            GST_SEEK_TYPE_SET, range_start, GST_SEEK_TYPE_SET, range_end));
+    if (range_start != 0 || range_end != -1) {
+      if (!gst_element_send_event (demux->src, gst_event_new_seek (1.0,
+                  GST_FORMAT_BYTES, (GstSeekFlags) GST_SEEK_FLAG_FLUSH,
+                  GST_SEEK_TYPE_SET, range_start, GST_SEEK_TYPE_SET,
+                  range_end))) {
+
+        /* looks like the source can't handle seeks in READY */
+        *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_NOT_IMPLEMENTED,
+            "Source element can't handle range requests");
+        demux->last_ret = GST_FLOW_ERROR;
+      }
+    }
+
+    if (G_LIKELY (demux->last_ret == GST_FLOW_OK)) {
+      /* flush the proxypads so that the EOS state is reset */
+      gst_pad_push_event (demux->src_srcpad, gst_event_new_flush_start ());
+      gst_pad_push_event (demux->src_srcpad, gst_event_new_flush_stop (TRUE));
 
-    demux->download_start_time = g_get_monotonic_time ();
-    gst_element_sync_state_with_parent (demux->src);
+      demux->download_start_time = g_get_monotonic_time ();
+      gst_element_sync_state_with_parent (demux->src);
 
-    /* wait for the fragment to be completely downloaded */
-    g_cond_wait (&demux->fragment_download_cond,
-        &demux->fragment_download_lock);
+      /* wait for the fragment to be completely downloaded */
+      GST_DEBUG_OBJECT (demux, "Waiting for fragment download to finish: %s",
+          next_fragment_uri);
+      g_cond_wait (&demux->fragment_download_cond,
+          &demux->fragment_download_lock);
+    }
   } else {
     demux->last_ret = GST_FLOW_CUSTOM_ERROR;
   }
@@ -1919,8 +1942,9 @@ gst_hls_demux_get_next_fragment (GstHLSDemux * demux,
 
   if (demux->last_ret != GST_FLOW_OK) {
     gst_element_set_state (demux->src, GST_STATE_NULL);
-    *err = g_error_new (GST_RESOURCE_ERROR, GST_RESOURCE_ERROR_FAILED,
-        "Failed to download fragment");
+    if (*err == NULL)
+      *err = g_error_new (GST_RESOURCE_ERROR, GST_RESOURCE_ERROR_FAILED,
+          "Failed to download fragment");
   } else {
     gst_element_set_state (demux->src, GST_STATE_READY);
     if (demux->segment.rate > 0)
diff --git a/ext/hls/gsthlsdemux.h b/ext/hls/gsthlsdemux.h
index 98daec948..988965c40 100644
--- a/ext/hls/gsthlsdemux.h
+++ b/ext/hls/gsthlsdemux.h
@@ -115,6 +115,7 @@ struct _GstHLSDemux
 
   /* fragment download tooling */
   GstElement *src;
+  GstPad *src_srcpad; /* handy link to src's src pad */
   GMutex fragment_download_lock;
   GCond fragment_download_cond;
   GstClockTime current_timestamp;