VST - Video Server Toolkit


Video Server Toolkit is a software platform enabling developers to construct high-performance, scalable video server applications on Silicon Graphics servers.


The core VST software provides management of a simple database of clips (the Clip Cache), a control API for managing and operating VST, and a core library which supports various External Interface Modules.

A single VST instance manages all playback and record operations for a single video server. However, each VST instance supports multiple logical playback/record units. Each unit manages a single signal port but may be controlled by multiple control ports. A signal port may support multiple logical units subject to the device-sharing characteristics of that port.

External Interface Modules

The VST interface modules fall into five categories:

The storage interfaces provide access to the storage systems where the clip content is stored (the Clip Cache). The XFS-based disk interface module provided with the base VST software is sufficient for most applications.
The media I/O interfaces provide access to the "signal" ports of the video server. A signal port is any video or data networking I/O port over which the digital media will be transmitted or received. Each type of I/O port will typically have its own VST interface module.
The format interfaces provide handlers for accessing specific digital media storage formats. For instance, the base "stream" format handler is suitable for stream-based formats such as MPEG. The "vframe" format handler is specialized toward variable-length, frame-oriented video/audio material.
The control interfaces implement external control protocols to allow integration with a variety of automation controllers and digital media applications. The VST core control logic provides a wide variety of control capabilities which should be sufficient to implement most machine control protocols.
The archive interfaces provide support for content archiving (both storage and retrieval) on external archive systems.
Control Interfaces

The base VST software three external control protocols:

Louth Video Disk Communications Protocol
This protocol, defined by Louth Automation, provides full-featured control of the VST via RS-232, RS-422, and TCP/IP. The VST Louth processor supports back-to-back play and record (subject to restrictions imposed by the video I/O port capabilities) and archive management.
Multiport Video Computer Protocol (MVCP)
This protocol, defined by Silicon Graphics, provides full-featured control of VST via TCP/IP. The protocol processor supports archive management, multiple-unit control, and event monitoring. The protocol command set is documented in mvcp(5).
Industry-standard RS-422 VTR protocol (a.k.a. Sony protocol)
This protocol, implemented in varying flavors by nearly all broadcast- quality VTRs, provides VTR-emulation capability via RS-232 and RS-422.


vtrstart(1), vtrstop(1), vtrstat(1), vtrclip(1), mcpanel(1), mcclips(1), mcstat(1), mccompstats(1), vst-controls(5), mvcp(5), vvtr(1), vtrd(1), vtrvfutil(1)