QuVIS Acuity, User Manual

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Audio clip files of different formats (QMF or WAVE) cannot be intermixed within the same virtual tape even if
their sample rate and bit depth are the same.
Subtitle Track Overview
The content owner (e.g. movie studio) or their authorized agent releasing a Digital Cinema Composition is
responsible for authoring subtitle asset files that will be incorporated into a Digital Cinema Package (DCP). QuVIS
does not provide authoring tools for subtitles creation. QuVIS does however provide the necessary tools (e.g.
QuVIS QuStudio and the Acuity’s VTP Editor) for authoring a DCP that includes subtitle files.
Subtitle track asset files are not frame-base media files or clips like video and audio track files. Subtitle asset files
are text-based XML files that contain no playable media properties as the timed-text or graphic files are rendered
during playback either by the server or the projector.
The Acuity’s VTP Editor does however provide the unique ability to visualize (display) Digital Cinema subtitles
during the mastering process by supporting real-time server-base rendering (QuVIS TitleMaster) or projector-based
rendering while the VTP (Composition) timeline is being played. This ability to preview subtitle, video and audio
reels allows the content producer the ability to preview subtitle placement and timing before the Composition is
finalized and packaged into a DCP for distribution.
Note: Digital Cinema Subtitles are currently authored in the CineCanvas
™
format according to Digital Cinema
accepted practices. The format of Digital Cinema subtitle files is in the active process of becoming a formalized
SMPTE standard. QuVIS will provide support for new SMPTE standards for both DCP mastering and playback
when the industry adopts the use of the new standards.
Subtitle Types
Digital Cinema subtitles can be in one of two forms: Timed-text and Image (PNG) overlay.
Timed-text subtitles consist of text-based XML files that store the appropriate subtitle dialog for each reel. Custom
font files may be used but the font file must be present for each reel that font is used. During playback of a Digital
Cinema Composition, subtitle assets are either locally rendered real-time on the server (e.g. QuVIS TitleMaster
™
)
or are uploaded to the Digital Cinema projector and rendered as the image track is displayed.
Pre-rendered PNG graphic files may be used to display the subtitle dialog onto the cinema screen during playback.
Server-based subtitle rendering (e.g. QuVIS TitleMaster) will overlay the image file onto the output video stream
and output by the projector. Projector-based rendering requires the projector to retrieve the subtitle image files from
the playback server and overlay the image at the projector during playback.
Subtitle Track Rules
Due to the non-media properties of subtitle asset files there are rules for how they are be used within the VTP
Editor.
•
Like video and audio track assets, subtitle XML files must be broken into reels (e.g. a separate XML file for
each separate reel).
•
The duration of each subtitle asset file cannot exceed the length of each defined video and audio reel of the
composition.
•
Placement of subtitle asset files should correspond with the defined In and Out points of video and audio track
assets. If the subtitle asset file contains subtitle spots that occur after the outpoint of the reel (video and audio)
it is associated with, it will result in that subtitle file being processed multiple times during playback in its
entirety.
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The In point of the subtitle asset file should line up with the In point of the video and audio reel.
•
The Out point of the subtitle asset file should line up with the Out point of the video and audio reel.
QuVIS Acuity
™
Page 148 QSR Version 3.3