No Galicaster preview when using backup audio track

[RaiG6]

We are using a Shure X2U record a separate backup audio file. When previewing a recording in the Galicaster Media Manager, all the preview windows are black, and the preview does not start.

We have defined a custom flavour in conf-dist.ini:
custom_flavors=presenter4k presentation2 backupaudio

The separate audio track from conf.ini:
[track5]
name = backupaudio
device = pulse
flavor = backupaudio
location = alsa_input.usb-Shure_Incorporated_Shure_Digital-00.analog-stereo
file = backup_audio.flac
#vumeter = True
amplification = 1.0
player = True
audioencoder = deinterleave name=d d.src_0 ! audioconvert ! flacenc
active = True
delay = 0

Galicaster logs:

galicaster      2019-08-22 12:51:18,653 INFO    classui/listing ON_action >> play_action
galicaster      2019-08-22 12:51:18,654 INFO    classui/listing Play: 9c50e6a2-43c9-458b-aa3a-403340920738
galicaster      2019-08-22 12:51:18,659 INFO    player/player   Player deleted
galicaster      2019-08-22 12:51:18,725 INFO    player/player   Duration ON_DISCOVERED: 751
galicaster      2019-08-22 12:51:18,725 INFO    player/player   playing '/usr/share/galicaster-repository/gc_obs_20190822T10h47m09/audio.flac'
galicaster      2019-08-22 12:51:18,725 INFO    player/player   playing '/usr/share/galicaster-repository/gc_obs_20190822T10h47m09/presenter.mkv'
galicaster      2019-08-22 12:51:18,725 INFO    player/player   playing '/usr/share/galicaster-repository/gc_obs_20190822T10h47m09/backup_audio.flac'
galicaster      2019-08-22 12:51:18,726 INFO    player/player   playing '/usr/share/galicaster-repository/gc_obs_20190822T10h47m09/presentation.avi'
galicaster      2019-08-22 12:51:18,726 INFO    player/player   Player playing
galicaster      2019-08-22 12:51:18,729 INFO    player/player   new decoded pad: 'audio/x-raw, format=(string){ S8, S16LE, S24_32LE, S32LE }, layout=(string)interleaved, rate=(int)[ 1, 655350 ], channels=(int)[ 1, 8 ]' in 'track-2'
galicaster      2019-08-22 12:51:18,731 INFO    player/player   new decoded pad: 'audio/x-raw, format=(string){ S8, S16LE, S24_32LE, S32LE }, layout=(string)interleaved, rate=(int)[ 1, 655350 ], channels=(int)[ 1, 8 ]' in 'track-0'
galicaster      2019-08-22 12:51:18,735 ERROR   player/player   gstbaseparse.c(3608): gst_base_parse_loop (): /GstPipeline:galicaster_player/GstDecodeBin:decode-track-0/GstFlacParse:flacparse5:
streaming stopped, reason not-linked (-1)
galicaster      2019-08-22 12:51:18,736 INFO    player/player   Player deleted
galicaster      2019-08-22 12:51:22,532 INFO    plugins/obs     handling timer

When we disable the backup track, the recording previews as usual

[RaiG6]

We discovered a workaround for this issue, by setting the backup audio track flavour to "other" allows Galicaster Media Manager preview to display as required.

flavour = other