Bookshelf Contents Previous Next Glossary Index Search

Videomedia V-LAN

The Videomedia V-LAN is available in several formats:

This section describes only external V-LAN. Refer to the specific sections for frame buffer-based V-LAN configurations.

Tip: Some V-LAN transmitters need a special cable to access the GPI trigger signal to capture video from a VTR. Currently, the SGI Galileo supports GPI trigger input. See the frame buffer device entry for details about the GPI trigger signal.

Syntax

A configuration entry is required for each V-LAN receiver on your V-LAN network that you want to control. The syntax is:

device video controller name
          server_name server
          server_id socket
          server_host host
          buffer buffer
          display display
          defn
                    node node
                    format format
                    preroll preroll
                    ttydev device
          enddefn
enddevice
device video controller name

The name is the name you want to assign to this device. If your V-LAN receiver is connected to your Sony Betacam, you may want to call it BVW75SP.

server_name server

The server is the name of the executable that controls the various V-LANs. The server resides in the product_bin. The server should be vtcvlan for external V-LAN. (If you relocate the server executable, or if the server is running on a different host than your application, you must specify the server as a full UNIX pathname.)

server_id socket

The socket is the socket number through which your application communicates with the V-LAN server process. This number must be unique to your UNIX system for each defined device and (Alias|Wavefront and non-Alias|Wavefront) server process. If you are defining configuration entries for multiple V-LAN receivers, they must have unique socket numbers.

server_host host

The host is the name of the workstation to which the V-LAN is connected. This is typically the workstation on which you are running your application, but can be any of the workstations on your Ethernet network. If you are using one workstation for your application and another for the V-LAN, you must install your application on both machines. The host can be localhost if the V-LAN is connected to your workstation.

buffer buffer

The buffer is optionally used to specify the name of a frame buffer device that is related to the V-LAN device being configured. If defined, this corresponding frame buffer is opened whenever the V-LAN device is opened.

display display

The display entry is optionally used to specify how you want the tape location to be displayed. The default, timecode, displays tape locations using time code. To display tape locations as frame numbers, specify frame.

Device-specific statements

node node

The node is the unique V-LAN identification number which your V-LAN receiver recognizes. If this line is omitted, a node number of 1 is used by default.

format format

The format indicates whether your V-LAN recognizes NTSC or PAL video. If this line is omitted, NTSC is used by default.

preroll preroll

The preroll indicates the duration of the pre-roll and post-roll time for edits. It must be specified in standard SMPTE timecode format, enclosed in double quotes. For NTSC output, it is suggested that "00:00:05:00" be used. For PAL output, it is suggested that "00:00:07:00" be used. When accessing an Abekas video disk, it is suggested that "00:00:00:15" be used, regardless of the video format. If this line is omitted, "00:00:05:00" is used by default.

ttydev device

The device indicates the name of the UNIX device port through which the workstation communicates with the V-LAN. This is required for the stand-alone V-LAN. On SGI workstations, it is typically ttyd1, ttyd2, ttyd3, or ttyd4, which corresponds to the RS-232 ports on the back of the machine. For additional information about connecting serial ports, see appendix A, "Connecting RS-232 Devices."

If you have multiple receivers connected to your V-LAN network, it is best to create multiple configuration entries. Create one per receiver, with unique names and node numbers, so that they can be easily referenced.



Bookshelf Contents Previous Next Glossary Index Search

[email protected]
Copyright © 1998, Alias|Wavefront, a division of Silicon Graphics Limited. All rights reserved.