Update for Version 0.02 (February 2005)
---------------------------------------

Why a new release after 6 years of inactivity? There have been indeed some
people using JVtxView, especially for viewing VTX files produced by some
DVB packages, and there are still a few bugs out there :-)

- JVtxView now is quite forgiving on errors in the vtx file header, which
  means it should now work better with files not produced from vbidecode.
- I fixed one more error in vbidecode (vbidecode now saves pages >= 800 with
  the right file name

Please note that to compile vbidecode, you definitly need a g++ that is older
than version 3.0, e.g. the g++ from gcc-2.95. I changed the Makefile to make 
g++-2.95 the compiler of choice; you may have to change that in the first line
of the Makefile if your compiler executable has another name.

Martin Denn <mdenn@unix-ag.uni-kl.de>, February 2005.



Some notes to JVtxView
----------------------

1) What does it do?

JVtxView is a program to display *.vtx files. It has been built to show
those files that are created by vbidecode (vbidecode uses the bttv driver
and generates teletext pages in software from the current channel).

I wrote JVtxView for two reasons:
first I had severe problems to get Martin Buck's videotext program to work
with spool files, and second I just wanted to surf through my pages the
same way as through the internet...

2) Now, how do I get it up and running?

JVtxView is a Java applet. That means you need a Java enabled browser
(I know it works with Netscape 4.05) or you use "appletviewer" from the
Java Development Kit.
Next you need to run vbidecode, to get fresh teletext pages.

vbidecode uses the following file structure:
(you have to make those directories manually...)

starting_directory/
        ARD/
                100_01.vtx
                101_00.vtx
                102_00.vtx 
                ...
        hessentext/
                100_00.vtx
                101_00.vtx
                102_00.vtx 
                ...
        next_channel/
                ...
        ...

The channel directories (ARD, hessentext, etc.) have to have names that
appear in the first line of the teletext page; vbidecode searches that
line to put the pages in the right directory.

Next you have to copy the *.class, *.gif and JVtxView.html files to the
starting_directory.

Then you have to edit JVtxView.html, to tell the Java applet what channels
are available. This is done by manipulating the line
<param name="channels" value="x">
and replacing the "x" with the available channel names, separated by a
blank. For example
<param name="channels" value="ARD hessentext">

After that, you have three possibilities:

  a) using appletviewer:

  just cd to the starting_directory and type
  appletviewer JVtxView.html

  b) local Netscape:

  start Netscape and point it to
  file:/starting_directory/JVtxView.html
  You have to give the full path name for starting_directory.

  c) remote Netscape:

  You may of course use a web server to access the teletext data.
  In this case the starting_directory has to be reachable by the
  web server. Of course you can use symbolic links.

I prefer appletviewer, because it is much faster than the Nescape method.  

3) How do I change the fonts?

Three fonts come with JVtxView:

vtx10x12.gif (width=400 height=300)
vtx15x18.gif (width=600 height=4500)
vtx20x24.gif (width=800 height=600)

You can tell JVtxView with the "font" parameter in JVtxView.html which font
to use. You have to change the "with" and "height" arguments in the 
<applet ...> line to tell Netscape the applet's size.

4) And how to use it?

JVtxView starts with page 100, which is usually a channels starting page.
You may use the keyboard to enter page numbers, or you may simply click
on a displayed number to jump to that page. Subpages can be accessed
clicking on a ">>" in the last line or on a "x/y" (meaning page x from y)
somewhere on the page. Additionally the "command line" at the bottom
offers some features.

5) What's that vbidecode.patch?

The patch fixes a few problems from vbidecode-1.0:
- vbidecode compiles now with glibc-2
- there are no more "garbage lines"
- the numbering of subpages works
- foreign code pages are displayed correctly.

There are new vbidecode versions, but they make some troubles on my machine.
Therefore I bundled vbidecode-1.0 together with this software. To build
a new executable, please do the following:

patch -p0 < vbidecode.patch
cd vbidecode-1.0
make

-------------------

Have fun with this software and please drop me a mail if something does not
work, or if you have some more ideas...

The source code is enclosed (*.java), you may fix the problems for yourself :-)
The code is distributed under the GPL.

Thanks to Martin Buck <martin-2.buck@student.uni-ulm.de> for its
videotext program, I borrowed some code from it.
Thanks also to Ralph Metzler <rjkm@thp.uni-koeln.de> for vbidecode.

Martin Denn <mdenn@unix-ag.uni-kl.de>, January 1999
