The database of FAB Teletext Network Controller consists of a simple directory structure in the NTFS file system.
Each directory contains teletext pages stored in .ETP file format which is a simple text file that can be opened with Notepad and therefore also allows full text search in the directory structure.
Example of a directory structure
- Channel1
- Channel2
- News
- National
- International
- Sports
- Football
- Basketball
- ExternalProviders
- Weather
- AutoSources
- ManualSources
Each of the above directories can contain .ETP files that contain teletext pages. Each .ETP file can contain up to 8192 subpages.
The mapping from files and directories to page numbers of TV channels is done through transmission list tables that are available for every channel
Transmission List for Channel 1
Page | Filename |
---|---|
100 | /Channel1/100.etp |
101 | /News/LatestNews.etp |
102 | /News/National/News1.etp |
… | … |
899 | /Channel1/Testpage.etp |
Transmission List for Channel 2
Page | Filename |
---|---|
100 | /Channel2/100.etp |
101 | /News/LatestNews.etp |
102 | /News/National/News1.etp |
… | … |
899 | /Channel2/Testpage.etp |
As you see the pages 101 and 102 point to the same file on both Channel 1 and Channel 2. This means that whenever the file /News/LatestNews.etp is changed this page is automatically distributed to Data Generators for Channel 1 and Channel 2.
Database Access
The files in the database can be accessed in the following ways:
- Directly over network (using the Windows Explorer for example)
- Using commands in FAB Teletext Editor
- Using the FAB Teletext REST API
All ways are possible and restricted to NTFS security rights as described below. It is completely legal to read, write or delete files in the directory structure directly over a shared network folder. FAB Network Controller is always monitoring all files and whenever a file change is detected (this may take from 0 to 5 seconds) the teletext page will be distributed to the Data Generators or exported in HTML format.
To avoid file sharing problems all file access functions in FAB Teletext Network Controller are written in a special way. If file access is not possible because the file is being accessed by another user/program FAB Teletext Network Controller will retry to access it with a short delay.
User Rights
The NTFS file system allows defining read/write access rights for files and directories. The Windows Active Directory User Manager is used to create users and Windows Explorer is used to define read/write access to files and directories.
This way any system administrator with knowledge of Windows Security Rights is able to define read/write access rights without the need to learn a new system.
Mask Pages
Every page has a mask page. All text that is present on the mask page will automatically overwrite the text on the main page.
This functionality allows very easy creation of banners on teletext pages.