User`s manual
Alcorn McBride Digital Video Machine HD User’s Manual Rev 1.0
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Play
Description: This command causes the DVMHD to play a file that has been searched using the
Search File command. This command is also used to resume playback of a clip that
has been stilled or paused. If this command is issued while a Playlist is being played,
the DVMHD will advance to the next Playlist entry. When this command is sent after
a successfully Search, playback will begin immediately (with less than 1 frame of
latency).
Command bytes: PL
Message Response: R
Comments: When playback of a video is complete, the DVMHD holds the last decoded frame of
video on-screen. This means that if the video ends with a non-black screen, that
picture will be displayed until another video file is played.
Example: Search File 22: 22SE
Play Searched File: PL
Loop Play
Description: This command works exactly like the Play command in every way except that the
searched video or playlist file will continue to loop back to the beginning of the file
whenever the end is reached.
Command bytes: LP
Message Response: R
Example: Select File 35: 35SE
Loop Currently Selected File: LP
Play File
Description: This command is very similar to the Play command, except that the file number or
name is included in the command. This means that no prior Search File command is
required. The other key difference is that this command does not result in
instantaneous playback due to the search time that is required prior to playback.
Command bytes: nnnnnPL or “<filename>”PL
Parameters: nnnnn is the ASCII file number between 0-99999.
<filename> is an ASCII file name surrounded by quotation marks.
Message Response: R
Comments: If the video material ends with a non-black screen, that picture will be displayed until
another video file is played. Also, this command is not recommended for use with
applications that require precise synchronization with other DVMHD’s or other
products. Since this command has the Search built-in, there will be an inconsistent
delay between the time the command is received and playback actually begins. For
synchronous applications, you should use the Search command in conjunction with
the Play command.
Examples: Play file 215: 215PL
Play file 4: 4PL or “vid00004.mpg”PL
Play files alcorn.mpg: “alcorn.mpg”PL