Audio Processing and Flow

Unlike video, the switcher does not handle audio signals independently. An audio signal is embedded into the ancillary data of a video signal before is comes into the switcher. As the signal comes into the switcher and is manipulated, you must ensure not to perform an operation that will force the ancillary data to be stripped.

Figure 1. Embedded Audio Flow Through the Switcher


The following restrictions apply to ancillary data being included in the output:

  • All ME program buses pass ancillary data.
  • MultiViewer outputs do not include any ancillary data.
  • MiniME and MultiScreen outputs do not include any ancillary data unless an ME with ancillary data is re-entered onto the background bus.
  • ME Preview does not include ancillary data unless the background is not selected as part of the next transition.
  • A MiniME or MultiScreen can include ancillary data if an ME is re-entered onto the background.
  • Any format conversion on the input video signal.
  • Setting ancillary data to be stripped.

When you are performing a transition, or keying, the embedded audio is carried in the ancillary data of the background video signal. The ancillary data from the background source is replaced with the ancillary data from the preset source, and the ancillary data for keyed sources is stripped.