Chapter 1
Working With Oracle Media Data Store Files

This chapter discusses using Oracle Video Server utilities on Oracle Media Data Store files. Topics in this chapter are:

The MDS_CWD Environment Variable

If you wish to specify files without specifying the MDS pathname, you must set the MDS_CWD environment variable.

MDS_CWD prefixes the MDS path information to relative pathnames. If the MDS_CWD environment variable is set, the media data store and video server utilities use this path anytime you specify a relative pathname to a file.

Note

For Windows NT, the syntax for MDS_CWD is MDS.CWD.

If the MDS_CWD environment variable is not set and you do not specify a path in your filename, the media data store and video server utilities search for input files using /mds/*/filename.

You must specify the full path for all output files when MDS_CWD is not set.

Examples

These examples use vstagprint to print the tag information in the tag file lost_children.mpi from the volume video.

First use mdsdir to show all files in all volumes on the server:

% mdsdir

Volume /mds/ref (ir): 2 matches

cover.mpg          cover.mpi 
Volume /mds/video (ir): 2 matches

lost_children.mpg         lost_children.mpi

Example 1

In this example, MDS_CWD is used as the path name to find the tag file lost_children.mpi:

% setenv MDS_CWD /mds/video

% vstagprint lost_children.mpi

Tag file version: 3.4 

Current code is version 3.4, back-compatible to version 3.4 

[etc.]

Example 2

In this example, MDS_CWD is pointing to the wrong volume, therefore the tag file lost_children.mpi is not found:

% setenv MDS_CWD /mds/ref

% vstagprint lost_children.mpi

error while attempting to print tag file

Unable to continue due to errors, see log for more details

Example 3

In this example, MDS_CWD is not set and the MDS path is not specified. This finds the first occurance of the tag file lost_children.mpi in all MDS volumes mounted on the server:

% unsetenv MDS_CWD

% vstagprint lost_children.mpi

Tag file version: 3.4 

Current code is version 3.4, back-compatible to version 3.4 

[etc.]

Files and Filenaming in this Guide

The syntax rules in this section apply to all Video Server utilities unless otherwise noted.

Media data store and video server utilties can be used on files residing in an MDS volume, on a host computer, or both. Throughout this chapter, files are referred to in one of the following ways:

filename

a file residing on either a host computer or an MDS volume

host-filename

a file residing on a host computer

mds-filename

a file residing in an MDS volume

Referencing Files on the MDS Filesystem

/mds/volume/file

a file in an MDS volume. MDS volume names can be from 1 to 32 characters long. MDS file names can be from 1 to 36 characters long, including the period (.) and file extension if any.

Referencing Files on a Host Filesystem

/path/file

the absolute path and name of a file on the server host.

./path/file

a file and its path relative to your current working directory on the server host.

../path/file

a file and its path relative to the directory above your current working directory on the server host.

Case of Files and Volumes

Names of MDS volumes and files are not case-sensitive, although they are
case-retentive. For example:

Once you create an MDS volume named Classics, the Video Server utilities always return the name as "Classics", rather than "CLASSICS" or "classics". However, you cannot create another volume named CLASSICS or classics.
If you copy the file sleuth.mpg into the Classics volume, mdsdirsrv and its clients always return its name as "sleuth.mpg". However, copying Sleuth.mpg into the same volume overwrites sleuth.mpg.
File naming conventions are more restrictive as of Release 2.1. The only legal characters for new filenames are:
- letters A-Z, both upper and lowercase
- numbers 0-9
- underscore (_), hyphen (-), and period (.)

If you have an MDS volume created prior to Release 2.1 which uses earlier file naming conventions you will still be able to read those files with their previous names.

System-Wide Options

Each Oracle Video Server utility accepts these switches in addition to the ones listed:

-h

shows syntax for a utility.

-T

enables verbose mode. Verbose mode returns more information about actions performed by utilities.

-V

shows the release version.

Chapter 1 Working With Oracle Media Data Store Files