After doing gst_pad_push() in case of sync_streams and cache_buffers,
if the buffer can not be kept in cache, it should be unreffed to avoid
memory leackage.
https://bugzilla.gnome.org/show_bug.cgi?id=755141
if (selpad->segment.format != GST_FORMAT_TIME) {
GST_DEBUG_OBJECT (selpad, "Buffer %p with segment not in time format, "
"not caching", buffer);
if (selpad->segment.format != GST_FORMAT_TIME) {
GST_DEBUG_OBJECT (selpad, "Buffer %p with segment not in time format, "
"not caching", buffer);
+ gst_buffer_unref (buffer);