NAME

tvsim - TV application interaction simulator


SYNOPSIS

tvsim [ options ]


DESCRIPTION

tvsim is a demo application that shows in which ways nxtvepg can cooperate with TV applications on the Micro$oft Windows operating system. It's also a reference implementation of the communication protocol and offers most of the source code (under the GPL license) that would be required to add EPG support to a TV application.


OPTIONS

Summary of command line options (it's a sub-set of the options supported by nxtvepg):

-geometry geometry
Specifies the position of the main window, e.g. -geometry -0+0 to put the main window in the upper right corner of the visible screen. The size of the window cannot be changed.

-iconic
Start with the main window iconified (i.e. minimized).

-rcfile path
Specify an alternate configuration file. Default: nxtvepg.ini in the current directory. tvsim only loads the TV card configuration from this file (with the exception of the card index)

-card index
Specify which tuner card to use, if you have more than one. Default: index 0, i.e. the ``best'' card in the order Brooktree Bt878, Bt878A, Bt848, Bt849, Philips SAA7134, Conexant 23881 (aka Bt811). If you have more than one TV card with the same chip, the order between those is undefined, but still constant (i.e. depends on the driver, not tvsim or nxtvepg).

-help
List all available command line options.

tvsim uses the nxtvepg INI file, i.e. by default it searches for a file named nxtvepg.ini in the current working directory. If this file is located elsewhere, you need to specify the -rcfile option. Please refer to GETTING STARTED below for configuration information.


INTERACTION FEATURES

tvsim can demonstrate all TV application interaction features which currently are supported by nxtvepg:

Automatically freeing the TV card
When nxtvepg is running with acquisition enabled when the TV application is started, it automatically frees the TV card to allow the TV application to access to the hardware. When the TV application is stopped, nxtvepg automatically accesses the TV card again. This allows the user to keep nxtvepg permanently running in the background without bothering to remember to switch acquisition off manually before starting the TV application.

Look-up of program info in the EPG database
The TV application can pass a network name to nxtvepg to look up the title, start and stop times and PDC theme codes of the current programme on that network. Usually the TV application will display that information on screen or in a popup windows next to the live TV image. In tvsim it's displayed in the three text fields below that channel table.

nxtvepg following channel changes
When the TV channel is changed inside the TV application, nxtvepg will follow with its cursor in the browser window, i.e. it'll set the cursor on the program title that's currently running on that network so that the detailed program information becomes displayed. (Channels are identified firstly by their name, but also by VPS/PDC which is forwarded from the TV application to nxtvepg.)

Changing channels from inside nxtvepg
When a TV application is connected to nxtvepg, there's a Tune TV button in the main window that allows to tune in the network of the program that's currently selected in nxtvepg. This allows the user to comfortably select his/her favorite program inside nxtvepg.

EPG data acquisition while watching TV
Even while the TV card is ``owned'' by the TV application, it's possible for nxtvepg to keep acquiring EPG information if it's connected to a TV application that forwards incoming teletext packets on the designated EPG page.


GETTING STARTED

The software is called a ``simulator'' because it doesn't display a TV image. But still it does read in a channel table and tune in the respective TV channels when they are selected in the channel table; this is required to demonstrate forwarding of VPS/PDC and EPG packets.

tvsim does not have its own INI file, instead it uses the nxtvepg INI file. Hence you should configure nxtvepg first before using tvsim. Please refer to the nxtvepg manual, section ``GETTING STARTED'' for detailed documentation of the initial configuration process. tvsim only uses the configuration settings of the TV card input and TV app. interaction dialogs, with the exception of the card index.

If your TV application's channel table format is not supported by nxtvepg and you don't have any of the supported freeware TV applications, you can set up a minimal channel table manually. The simplest format is that of the DScaler channel table; so create a file named program.txt somewhere with the following format:

   Name: First Channel
   Freq2: 2020
   Name: Second Channel
   Freq2: 2132

where you replace ``First Channel'' etc. with the actual channel names and the numbers with the respective TV tuner frequencies in MHz times 16 (i.e. 2020 means tuner frequency 126.25 MHz). Then open the TV app. interaction dialog in nxtvepg, choose TV app. name DScaler and specify the path to the channel table you've just creatd. Then quit the dialog with Ok and start tvsim (you don't need to quit nxtvepg). Your channels should appear in the tvsim channel table.


FILES

nxtvepg.ini
Configuration file from which TV card setup and TV application interaction settings are read. By default it is expected in the working directory, but a different path and file name can be specified with the -rcfile option. tvsim never writes to this file; configuration changes have to be made with nxtvepg.


SEE ALSO

Please refer to the manual of nxtvepg for information on TV card and TV application interaction configuration. See also the manuals for vbirec and vbiplay for further debugging possibilities.


AUTHOR

Th. ``Tom'' Zoerner, Erlangen, Germany.

Email: tomzo (at) users (dot) sourceforge (dot) net

Thanks to e-nek for reviewing the design of the communication protocol, alpha testing and most importantly for being the first to implement interaction with nxtvepg in a TV application.


COPYRIGHT

Copyright (C) 2002 by Th. Zoerner. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License Version 2 as published by the Free Software Foundation, e.g. at http://www.fsf.org/

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of merchantability or fitness for a particular purpose. See the file COPYRIGHT for more details.