VBI recorder - TV application interaction debugging tool
This is the manual page for the VBI recorder which is part of the
nxtvepg software package.
vbirec - TV application interaction monitor and EPG recorder
vbirec
vbirec is a tool that helps in debugging TV application's interaction
with nxtvepg. vbirec takes the place of nxtvepg in the communication.
It monitors the shared memory which is used for communication with the
TV app. and displays all TV app controlled values in it's main window.
The following shared memory elements are displayed
and updated every 500 millyseconds:
- TTX pkg count
-
The total number of teletext packets the TV app. has received since the
last channel change.
- TTX pkg per frame avg.
-
A running average of the number of VBI lines containing teletext packets
per video frame.
- VPS lines count
-
The total number of VPS lines the TV app. has received since the
last channel change. For networks that transmit VPS there should
be one VPS line in each frame.
- EPG page count
-
The number or EPG pages since the last channel change, i.e. the number
of teletext packets with packet address zero on the designated EPG
teletext page.
- EPG packet count
-
The total number or teletext packets on the designated EPG teletext page
since the last channel change.
- VPS CNI and PIL
-
The last received and confirmed VPS network and program identifiers.
VPS is only used by German, Austrian and Swiss networks.
- PDC CNI and PIL
-
The last received and confirmed PDC (teletext packet 8/30/2) network
and program identifiers. If the network transmits only a network
identifier value of zero, but does include a status display text
(which usually contains channel name and sometimes also the title
of the current programme) it's displayed here instead.
VPS is mainly used by British and French networks.
- Packet 8/30/1
-
The last received and confirmed packet 8/30/1 network identifier.
If the network transmits only a network identifier value of zero
but does include a status display text it's displayed here instead.
- EPG teletext page no
-
The teletext page number on which EPG is tranmitted according to the
provider. Note: the default page is 0x1DF; other page numbers can be
specified in the teletext magazine inventory page of each magazine.
- Teletext header
-
The text part of the last received teletext packet with address 0.
Usually the text contains the teletext page number, network name,
clock and date. This element is provided here mainly to allow detecting
which TV network was tuned by the TV application.
- Network by VPS/PDC/NI
-
A human readable network identification derived from the VPS, PDC or
P8/30/2 CNI codes (in this order, if several alternatives are available).
The following shared memory elements are displayed
and updated whenever updates are signalled by the TV application:
- TV app. channel name
-
The TV application's station name for the currently tuned channel.
This element should be updated after ever channel change.
- TV app. channel CNI
-
The TV application's numerical network identifier for the currenlty
tuned channel. If unavailable it should be set to zero.
- TV app. input source
-
The TV application's current video input source (0=TV tuner, 1=composite,
2=S-Video or Composite #2).
- TV app. tuner freq.
-
The current TV tuner frequency from which VBI data is forwarded. This
value must be updated after every channel change.
- TV app. grants tuner
-
Boolean flag that indicates if the TV application currently honors
the EPG application's input source and tuner frequency requests.
The TV application should grant the tuner when video capturing is
disabled of the TV window minimized or completely obscured by other
windows.
Packets received on the designated EPG teletext page can be stored
into a file for later playback by vbiplay. The intended use is
to allow me debugging decoding errors, e.g. for providers that I
cannot receive at my location.
The name of the output file is specified by the entry field at the
bottom of the window. The file is created as soon as recording is
enabled by checking the Enable teletext recorder button.
- ttx.dat
-
Default output file name for recorded teletext packets.
- vbi_map.dat
-
This hidden file is used to set up shared memory to allow information
exchange between vbirec and an attached TV application. It's
automatically removed when vbirec terminates and should never be
accessed (i.e. being written to or removed) by external applications.
See also the manuals for nxtvepg, tvsim and vbiplay.
Th. ``Tom'' Zoerner, Erlangen, Germany.
Email: tomzo (at) users (dot) sourceforge (dot) net
Copyright (C) 2002 by Th. 'Tom' 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.