Video Server Toolkit (VST) applications routinely open a TCP/IP connection to a host running VST on the MVCP port, normally 5250. The application sends MVCP commands to control VST.

The port value is set in the file /usr/vtr/config/control-in.conf. For example, to set the port to 5250, use the following line in the file:

mvcp tcp 5250

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Note: Do not change the port value from 5250 unless it is absolutely necessary.

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You can, however, manually control VST by opening a telnet connection to a host running VST and then issuing MVCP commands to control it. For example:

152% telnet server 5250
Trying 130.62.156.178...
Connected to server.
Escape character is `^]'.

100 VTR Ready

BYE

A unit is a virtual VTR. It can play and record video and audio just like a VTR.

Units can be created using the following command:

UADD DIVO_0 * SHAR

The UADD command returns the name of the unit, unitName, for example:

UADD DIVO_0 * SHAR
202 OK
U1

U1, in this case, controls the DIVO_0 video board, which includes both an input video port and an output video port.

For an explanation of the UADD options, see page 138. For more information about deleting a unit, see page 166.

UCLS unitName

Multiple Connections to a Unit

Once a unit has been created, it can be controlled by a number of MVCP connections by opening it:

UOPN unitName

When multiple MVCP connections are made to one unit, the unit is not deleted until all of the connections have deleted it.

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Warning: Opening a unit owned by a Sony, Louth, or Odetics port using MVCP commands (for example, UOPN) causes unpredictable behavior.

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To load and unload a clip into a unit, use the following commands, respectively:

LOAD unitName clipName OUT CRTE
UNLD unitName

unitName is the name of the unit on which the clip is loaded.

The OUT option means that the clip, clipName, can only be played, not recorded onto. Other valid values include IN, which means the clip will be recorded onto, and BOTH, which means the clip can be played or recorded onto.

CRTE creates the clip. Without a CRTE argument, the clip does not exist in the system.

If you do not know the name of a clip, you can list all of the clips by issuing the clip list command:

CLS

The IN and OUT edit points specify where the source video is to begin and end playing, and where the beginning and ending recording points are on the record deck, usually VST.

When a clip is played, by default the edit IN point is used as the starting point for PLAY.

To set edit points, use the CEDP command:

CEDP clipName inPoint outPoint

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Note: The media outside of the in and out points is not actually erased; its just not played.

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You can play and record on units without cueing them. There is, however, a good chance that the beginning of the playing or recording will not be clean: the frame count might be off by several frames or the audio might be garbled.

You can avoid these problems by cueing the units for playing or recording.

To cue a clip for playback, enter:

CUE unitName

To ca clip for recording, enter:

CUER unitName

CUE unitName <in-point> <out-point> <direction> <number-of-passes>

You can sequence more than one command to execute on a unit by using the append-sequential specification:

/APP /SEQ command unitName

This command specifies that the command, command, is appended (/APP) to the current list of commands queued for the unit, unitName, and the command will be executed after the previous command in the list completes (/SEQ). The alternative to waiting for completion is to preempt the previous command on the list using the flag, /IMM.

You can also:

For more information about command sequencing, see “Command Sequencing”.

To play a clip, use the following procedure:

You can also play the clip in other modes, such as:

For more information about the arguments for each of these commands, see “Unit Commands”.

VST configuration variables are called controls. The two major categories of controls are:

Device-specific—for which you use the SET and GET commands to specify and retrieve the control values for individual units.

System-wide—for which you use the SSET and SGET commands to specify and retrieve the control values for global, system values, for example, the log level.

There are two subsets of device-specific controls:

To set or get the configuration variables for a specific unit, you have to select the subset of controls you want to set by using STOR (storage) or MED (media). For example:

SET unitName MED vtr.media.video.input.compression.type DVCPRO
GET unitName MED vtr.media.video.output.*

These commands set the video compression type to DVCPRO, and return all of the video output controls for the specified unit.

To list all of the storage controls, use the asterisk (*) wildcard: GET unitName STOR *

For more information about the SET command, see page 165. For more information about the SSET command, see page 150

For more information about the GET command, see page 162. For more information about the SGET command, see page 150.

To display the configuration of video and deck control ports, use the port list command:

PLS

To identify which audio port to use by a given DIVO unit, use the SET command for a unit:

SET <unit> MED vtr.media.audio.input.port RAD1.AESIn
SET <unit> MED vtr.media.audio.output.port RAD1.AESOut

Alternately, you can configure a unit in /usr/vtr/config/device-defaults/*. For example, in DIVO_1 you would enter:

vtr.media.audio.input.port RAD1.AESIn
vtr.media.audio.output.port RAD1.AESOut

To record audio using VST, you must set the following controls:

The audio port can either be VideoIn, if the audio is embedded in the video signal, or the name of an audio port, for example, AnalogIn or AESIn.

For information about setting control values, see “Setting and Listing Configuration Values”.

To record video using VST, you must set the compression type using vtr.media.video.input.compression.type.

Valid values include JPEG, for O2, or, for machines using DIVO boards:

For information about setting control values, see “Setting and Listing Configuration Values”.

There are other commands that you might set according to your media format. For a list of those settings, see “Workflow to Generate a Single 4:2:2:4 Clip”.

To record a clip, use the following procedure:

You can edit clips on two levels of granularity:

Editing Frames

The following MVCP commands manipulate the frames within a clip that is already loaded in a unit:

• FRM—remove a frame. In film, the equivalent is cutting out frames of film and splicing the two parts of the film back together.

  FRM unitName inFrame outFrame

  
  

• FCLR—changes (clears) a frame to black but does not remove it.

  FCLR unitName inFrame outFrame

  
  

• FNEW—inserts a black frame into the clip.

  FNEW unitName inFrame outFrame

  
  

• FOVR—moves frames from one part of a clip and overwrites frames in another part of the clip.

  FOVR unitName sourceIn sourceOut destIn

  
  

• FINS—moves frames from one part of a clip and inserts them in another part of the clip.

  FINS unitName sourceIn sourceOut destIn

  
  

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Note: Frame editing is not supported on all clip formats. Currently, only vframe clips can be frame-edited.

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You can use the MVCP SET command with the following controls to display your company logo, or any image, when the video port is not playing a clip:

vtr.media.output.idle_mode image
vtr.media.video.output.image.type user
vtr.media.video.output.image.name <name of image>

Image files go in /usr/vtr/data/images.

The commands to execute a playlist can be performed over a single MVCP control connection. Some control implementations may find it easier to use a unique MVCP control connection for each unit. The commands and the order in which they are sent is identical in either case.

When executing a play list, it is common to also desire display of the state of the list execution. Using MVCP this can be accomplished via polling, but a more efficient solution is to utilize unit monitoring. Unit monitoring provides asynchronous events describing the change in state of a unit, such a execution state, loaded clips, or timecode location. Details of unit monitoring can be found in the MVCP documentation for the MON command. Typically a separate MVCP connection will be initiated for monitoring.

In the example play list algorithm above, a unit monitor could be started after the units are created to trace unit execution. This would allow a control application to trace which clip was being played and the timecode location of the unit in the clip. Note that the information provided by unit monitoring describes the unit state and locations. The actual video frame timecode leaving the server port will be some fixed number of frames behind that time due to codec delays. This delay is format dependent and can be found in the table below. The table shows the difference between the time reported by the unit and the actual video frame at the server port at a that time. For instance, with DVCPRO on record the unit status reports 3 frames behind the frame on the input of the server, and on play the unit status reports 7 frames ahead of the frame on the server output port.

VST provides the following ways to monitor the system:

The following sections explain each of these reports in further detail:

USTA unitName
ULS

MON [unitName] [/ eventType]

STLS [componentName [statisticsType]]

STLS * *

STST [componentName [statisticsType]]

STST *DIVO*

ERR 

UERR unitName