queue2: Process SEEKING query

Add QUERY_SEEKING handling to queue2, so RTMP live streams become
seekable when a queue2 in download or ringbuffer mode is inserted:

rtmpsrc ! queue2 ! flvdemux

https://bugzilla.gnome.org/show_bug.cgi?id=733351

diff --git a/plugins/elements/gstqueue2.c b/plugins/elements/gstqueue2.c
index 7ac1e4e..28d7e5e 100644 (file)
--- a/plugins/elements/gstqueue2.c
+++ b/plugins/elements/gstqueue2.c
@@ -3092,6 +3092,55 @@ gst_queue2_handle_src_query (GstPad * pad, GstObject * parent, GstQuery * query)
       gst_query_add_scheduling_mode (query, GST_PAD_MODE_PUSH);
       break;
     }
+    case GST_QUERY_SEEKING:
+    {
+      gint64 segment_start, segment_end;
+      GstFormat format;
+      gboolean seekable, peer_success;
+
+      peer_success = gst_pad_peer_query (queue->sinkpad, query);
+
+      gst_query_parse_seeking (query, &format, &seekable, &segment_start,
+          &segment_end);
+
+      if (peer_success && seekable) {
+        GST_DEBUG_OBJECT (queue, "peer seekable (%s) from %" G_GINT64_FORMAT
+            " to %" G_GINT64_FORMAT, gst_format_get_name (format),
+            segment_start, segment_end);
+        break;
+      }
+
+      if (format != GST_FORMAT_BYTES) {
+        GST_DEBUG_OBJECT (queue, "query in %s (not BYTES) format, cannot seek",
+            gst_format_get_name (format));
+        return FALSE;
+      }
+
+      GST_QUEUE2_MUTEX_LOCK (queue);
+      if (queue->current) {
+        if (QUEUE_IS_USING_RING_BUFFER (queue)) {
+          segment_start = queue->current->rb_offset;
+          segment_end = queue->current->rb_writing_pos;
+        } else if (QUEUE_IS_USING_TEMP_FILE (queue)) {
+          segment_start = queue->current->offset;
+          segment_end = queue->current->writing_pos;
+        } else {
+          segment_start = -1;
+          segment_end = -1;
+        }
+      }
+      GST_QUEUE2_MUTEX_UNLOCK (queue);
+
+      seekable = ! !(segment_start < segment_end);
+
+      GST_DEBUG_OBJECT (queue, "segment from %" G_GINT64_FORMAT " to %"
+          G_GINT64_FORMAT " %sseekable", segment_start, segment_end,
+          seekable ? "" : "not ");
+
+      gst_query_set_seeking (query, format, seekable, segment_start,
+          segment_end);
+      break;
+    }
     default:
       /* peer handled other queries */
       if (!gst_pad_query_default (pad, parent, query))