User Manual

Preserving HD Closed Captioning and Ancillary Data
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For details on how Meridien systems support VBI, see the Preserving Information in the Vertical
Blanking Interval white paper on the Avid Knowledge Base.
Preserving HD Closed Captioning and Ancillary Data
Unlike SD closed captioning data, which is transferred in the vertical blanking interval (VBI),
HD closed captioning and ancillary data packets are transferred in the HD-SDI data stream.
In certain circumstances, your Avid editing application lets you capture closed captioning and
other ancillary data in HD, preserve this data during editing, and output the data through the
HD-SDI port of your Avid input/output hardware. Your Avid editing application lets you turn
ancillary data preservation on and off and to control which data is preserved.
Depending on your input/output hardware and the version of software you have, there are two
methods for preserving ancillary data. The Legacy method embeds the ancillary data in a
DNxHD video file, and the Data Track method adds a separate data track to the Timeline and lets
you capture and store ancillary data as a separate MXF file. You need to choose whether you
want to use the new Data Track method or the legacy embedded method.
For both methods, you can only monitor and view the data on a client monitor capable of
handling ancillary data.
Your Avid editing application can capture and preserve any of the following four types of
ancillary data by default:
• Closed Captioning (CEA 608, CEA 708): Closed captioning ancillary data packets are
captured from the HD-SDI source according to the SMPTE 334M standard.
• Program Description (AFD): AFD ancillary data packets are captured from the HD-SDI
source according to the SMPTE 334M standard.
• Ancillary Time Code (ATC): Ancillary time code packets are captured from the HD-SDI
source.
The options that you set for ancillary data preservation are associated with the project. When you
create a new project, you must set the ancillary data options you need for that project.
Can VBI information affect compression quality? Yes Yes
Can compression affect VBI quality? Yes Yes
Feature Meridien Current