PUBLIC MARKS with tags later & gstreamer

The max-lateness property affects how the sink deals with buffers that arrive too late in the sink. A buffer arrives too late in the sink when the presentation time (as a combination of the last segment, buffer timestamp and element base_time) plus the duration is before the current time of the clock. If the frame is later than max-lateness, the sink will drop the buffer without calling the render method. This feature is disabled if sync is disabled, the get_times_vfunc() method does not return a valid start time or max-lateness is set to -1 (the default). Subclasses can use set_max_lateness() to configure the max-lateness value.