event stream-start: GstEventStreamStart, flags=(GstStreamFlags)GST_STREAM_FLAG_NONE, group-id=(uint)1;
event caps: video/foo, variant=(string)test-custom;
event segment: format=BYTES, start=0, offset=0, stop=18446744073709551615, time=0, base=0, position=0
buffer: dts=0:00:00.000000000, pts=0:00:00.000000000, flags=discont
event eos: (no structure)