adaptivedemux: Implement GST_SEEK_TYPE_END usage for live

When dealing with live streams, we can't rely on GstSegment calculation
since it uses the segment duration to calculate the absolute values.

But since we are dealing with live *and* we know the ranges, we can
compute the absolute seeking values using the range stop (i.e. "now")
as the END position.

Allows seeking back to "live" by using start_type:GST_SEEK_TYPE_END
and start:0

https://bugzilla.gnome.org/show_bug.cgi?id=782228

diff --git a/gst-libs/gst/adaptivedemux/gstadaptivedemux.c b/gst-libs/gst/adaptivedemux/gstadaptivedemux.c
index a5e517b..c3f4cd6 100644 (file)
--- a/gst-libs/gst/adaptivedemux/gstadaptivedemux.c
+++ b/gst-libs/gst/adaptivedemux/gstadaptivedemux.c
@@ -1502,6 +1502,7 @@ gst_adaptive_demux_handle_seek_event (GstAdaptiveDemux * demux, GstPad * pad,
 
   if (gst_adaptive_demux_is_live (demux)) {
     gint64 range_start, range_stop;
+    gboolean changed = FALSE;
     if (!gst_adaptive_demux_get_live_seek_range (demux, &range_start,
             &range_stop)) {
       GST_MANIFEST_UNLOCK (demux);
@@ -1510,6 +1511,18 @@ gst_adaptive_demux_handle_seek_event (GstAdaptiveDemux * demux, GstPad * pad,
       return FALSE;
     }
 
+    /* Handle relative positioning for live streams (relative to the range_stop) */
+    if (start_type == GST_SEEK_TYPE_END) {
+      start = range_stop + start;
+      start_type = GST_SEEK_TYPE_SET;
+      changed = TRUE;
+    }
+    if (stop_type == GST_SEEK_TYPE_END) {
+      stop = range_stop + stop;
+      stop_type = GST_SEEK_TYPE_SET;
+      changed = TRUE;
+    }
+
     if (!(flags & GST_SEEK_FLAG_ACCURATE)) {
       /* If the accurate flag is not set, we allow seeking before the start
        * to map to the start for live cases, since those can return a "moving
@@ -1523,6 +1536,7 @@ gst_adaptive_demux_handle_seek_event (GstAdaptiveDemux * demux, GstPad * pad,
         start = range_start;
         if (stop != GST_CLOCK_TIME_NONE)
           stop += dt;
+        changed = TRUE;
       }
     }
 
@@ -1533,6 +1547,14 @@ gst_adaptive_demux_handle_seek_event (GstAdaptiveDemux * demux, GstPad * pad,
       gst_event_unref (event);
       return FALSE;
     }
+
+    if (changed) {
+      gst_event_unref (event);
+      event =
+          gst_event_new_seek (rate, format, flags,
+          start_type, start, stop_type, stop);
+
+    }
   }
 
   seqnum = gst_event_get_seqnum (event);