# ---------------------------------------------------------------------------
#
#  VBI playback tool documentation
#
#  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. You find a copy of this
#  license in the file COPYRIGHT in the root directory of this release.
#
#  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
#  GNU General Public License for more details.
#
#
#  Description:
#
#    User's documentation in Perl "POD" format. The content is
#    converted into various other formats by use of different scripts:
#    UNIX manpage by pod2man; HTML web page by pod2html (needs manual
#    adjustments) and the online help by a self-made script. The releases
#    should contain the converted files, so that the user is not forced
#    to install Perl.
#
#  Author: Tom Zoerner
#
# $Id: vbiplay.pod,v 1.5 2004/03/23 15:54:54 tom Exp tom $
# ---------------------------------------------------------------------------

=head1 NAME

vbiplay - Playback of recorded EPG teletext packets


=head1 SYNOPSIS

B<vbiplay>


=head1 DESCRIPTION

B<vbiplay> allows to play back a series of teletext packets received
on a designated EPG page, even in regions of the world where the EPG
provider normally can not be received.  It can connect to I<nxtvepg>
and transfer the data into it's VBI input buffer as if they had been
received life on air (however with a much higher data rate).
It's a small tool that's intended for debugging EPG reception problems
or decoding errors.


=head1 USAGE

B<vbiplay> takes the the place of a TV application in the communication
with I<nxtvepg>, i.e. no TV application (which supports EPG interaction)
must be running at the same time or the tool will immediately exit
with an error message.

B<vbiplay> opens a file named I<ttx.dat> which must be previously
generated by B<vbirec>.  If I<nxtvepg> isn't already running, the program
waits until it is attached.  As soon as nxtvepg is attached and acquisition
is enabled, playback starts.  It's recommended to check the reception
by nxtvepg in the I<View acq statistics> window, which can be opened in
the Control menu.

The teletext packets are played back as fast as possible.  However since
nxtvepg only polls the teletext buffer once every second (which is enough
for regular Nextview transmissions) and the buffer holds a maximum of
512 packets, the maximum data rate is limited to shortly above 20 pages
per second, i.e. apx. 20 times the normal data rate.


=head1 FILES

=over 4

=item B<ttx.dat>

This is the fixed name of the input file.
It must be generated by B<vbirec>.

=back


=head1 SEE ALSO

See also the manuals for B<vbirec> and B<nxtvepg>.


=head1 AUTHOR

Th. "Tom" Zoerner, Nuremberg, Germany.

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


=head1 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
B<WITHOUT ANY WARRANTY>; without even the implied warranty of
merchantability or fitness for a particular purpose. See the
file F<COPYRIGHT> for more details.

