External Control Commands
Command Syntax
All commands shown in this section will be upper case. There are no spaces in the command argument itself. However, between commands there will be spaces. A sequence such as <command1>(space)<command2>(space)<command3>(space) <command4><CR> would indicate four separate commands to be executed. Some address arguments are optional and some are required to execute a command. Where an address is optional, it will be shown as “(address)”. Whenever an address is required for a command, it will be shown as “<address>”.
Address Arguments
Some commands permit or require address arguments. These arguments can be used to specify a position (frame or timecode) address within a video or an address which identifies the position or sequence order of a video within a list of videos. A list of videos playing back to back are commonly referred to as a playlist.
Laserdisc refers to a video playlist as a Chapter or CH. To specify a file address within a chapter, the sequential position is indicated by “x”. CH5, for example, would indicate the fifth file in the playlist or chapter. Designating the file position “x” is also accepted.
It is also possible to define an address within a video itself. FRx indicates a frame number within a video where “FR” denotes frame and “x” refers to the frame number. FR3000, for example, would refer to the frame 3000 of the current video. This equates to 100 seconds or 1 minute 40 seconds into the file. The frame number refers to actual video frames and calculating at 30 frames per second non drop, which is the NTSC standard, gives you the time elapsed at this frame of video.
TMx indicates a time code value using the format HHMMSSFF within the video.
H=Hour
M=Minute
S=Second
F=Frame
For example, TM1263212 would refer to the point at 1 hour, 26 minutes, 32 seconds and 12 frames in the video. The TM values will always be interpreted as a right justified value so TM 3415 would reference the position 34 seconds and 15 frames into the video.
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