...
While the preview is based on 2 channels, the publish phase will haven more options based on the output format. For example, imagine a output into a XDCAMHD file that has 8 audio channels. In this scenario it might make sense to store the mix on channel 1 and 2, but the voice over on channel 3 and 4. This can be done in the transcoder preset (shape tag) configuration. Please refer to Publish Transcoding Preset Configuration [VE 21.3 OG] and https://vidispine.atlassian.net/wiki/pages/createpage.action?spaceKey=ITSFP&title=Direct%20Out%20Publish%20Configuration%20%5BINT%20VE%2021.3%20OG%5D Direct Out Publish Configuration [VE 21.3 OG] for an introduction about this configuration.
...