debug output for pipeline

2017-03-16 20:45:04,864, hls.py, DEBUG, hls.py, 72, videomixer name=mixer sink_0::zorder=0 sink_1::zorder=99
                ! videoconvert
                ! x264enc
                ! mpegtsmux name=muxer
                ! hlssink playlist-root=/hls-test
playlist-location=/tmp/hlsstreams/hls-test/playlist.m3u8
location=/tmp/hlsstreams/hls-test/seg%05d.ts
playlist-length=999
max-files=999
target-duration=3

            filesrc location=sample_videos/VID09_2435_Service_BYO_FINAL_GENERIC_960X540_04-14-16_JN.mp4 ! decodebin name=demuxer ! video/x-raw,height=540 ! mixer.sink_0
            filesrc location=subtitles.srt ! subparse ! textrender ! video/x-raw,height=540 ! mixer.sink_1
            demuxer. ! audioconvert ! audioresample ! faac ! muxer.
2017-03-16 20:45:04,868, hls.py, DEBUG, hls.py, 171, ['src', 'sink_0', 'sink_1']
0:00:00.049882700 11662      0x2338c60 INFO       gstcontrolbinding gstcontrolbinding.c:143:gst_control_binding_constructor:<mixer:sink_1> trying to put property 'alpha' under control
0:00:00.049941761 11662      0x2338c60 DEBUG      gstcontrolbinding gstcontrolbinding.c:149:gst_control_binding_constructor:<mixer:sink_1>   psec->flags : 0x000002e3
0:00:00.049971532 11662      0x2338c60 DEBUG   gstdirectcontrolbinding gstdirectcontrolbinding.c:234:gst_direct_control_binding_constructor:   using type gdouble
2017-03-16 20:45:04,871, hls.py, DEBUG, hls.py, 211, set fade-in from 2440000000 to 3440000000
2017-03-16 20:45:04,871, hls.py, DEBUG, hls.py, 211, set fade-out from 2375000000 to 4375000000
2017-03-16 20:45:04,871, hls.py, DEBUG, hls.py, 211, set fade-in from 7476000000 to 8476000000
2017-03-16 20:45:04,871, hls.py, DEBUG, hls.py, 211, set fade-out from 9501000000 to 11501000000