Grass Valley iTX System v.2.6 - Manual (Page 210)

Configuring the audio output for a playout channel
• If the output format is PCM stereo and there is only a PCM mono source track that is
untagged and cannot be set to Default, iTX assigns this track to both left and right
stereo outputs.
5. Use of a compatible source track
• If the previous steps fail to identify a suitable track, iTX selects the first source track if
it is compatible with the specified output type.
Track grouping
Tracks in a media file or live asset have numbers that indicate the relative positions of the
tracks; the first track is track 1, the second is track 2, and so on.
For mapping purposes, iTX gives each track a group number. The group number also indicates
the relative position of the track, but group numbers start at zero. So, track numbers and group
numbers correspond in a way shown by the table below.
Track number Group number
1 0
2 1
3 2
4 3
iTX can use multiple consecutive source tracks to provide the content for a single output track.
It may do this, for instance, to play out a PCM stereo track from two consecutive mono tracks.
In selecting the source tracks, it identifies them by their group numbers.
To enable iTX to use two non-consecutive PCM mono tracks for a stereo channel, the tracks
may be grouped together by giving them the same group number; the channels then act as a
stereo pair.
The grouping can be done automatically by the Media Watcher when a file is ingested, or
manually by an operator on the Asset layout. The Media Watcher operation is controlled by the
Group Mono Tracks configuration option on the service window (under the Setup tab).
For a media file with four mono tracks, for example, we may change the group number of track
4 to be the same as that of track 2. This table shows the modified group numbering:
Track number Group number
1 0
2 1
3 2
4 1
iTX can then use tracks 2 and 4 together, for a PCM stereo playout, by selecting group 1.
March 2015 System Administrator Guide Page 210 of 404