User`s guide

145
Appendix
Description File
Command Directives
An external description file or an on screen Text I/O Window (Macintosh only) can contain all of
the information necessary to create closed captions, program rating, and interactive television
links for a video program.
When processing a command line the following rules are followed:
Lines that contain no characters, including no blank characters, are ignored.
Lines that begin with a single asterisk ‘*’ character are keyword lines.
Lines that start with two asterisk characters ‘**’ are treated as comments and can be
used for file annotation.
All other lines are text data lines.
Keywords may be entered in upper case or lowercase characters. For example, the
keywords “*DROPFRAME”, “*dropframe” and “*DropFrame” are equivalent.
The time code data fields are of the form HH:MM:SS:FF or +HH:MM:SS:FF. Time
codes are interpreted from right to left so a time code data field with one number, such
as 15, indicates 15 frames and a time code data field with two numbers, such as +45:15,
indicates an additional 45 seconds and 15 frames from the current time marker.
The bracket characters, ‘[‘ and ‘]’, indicate optional parameters in each of the keywords and they
should not be typed. A summary of all of the keywords can be found in Appendix.
MacCaption recognizes the following keywords:
*DROPFRAME
*DF
Indicates the time code values in this file are to be interpreted as drop frame time codes.
Example: *DF
This command causes subsequent absolute time code data to be interpreted as drop frame
time code values.
*NONDROPFRAME