FREQUENTLY ASKED QUESTIONS
~~~~~~~~~~~~~~~~~~~~~~~~~~

1.  GENERAL TROUBLESHOOTING

1.1  When switching the TV on, I can see only part of my screen.
1.2  When I switch my DVD player into fullscreen mode, only part of the 
     image appears on the TV.
1.3  When my application switches X modes while the TV is active, the screen
     gets messed up. 
1.4  I don't get an image on the TV at all.
1.5  I can see an image on the TV, but no image on the monitor in some or
     in all modes, even though I have dualview enabled.
1.6  The image on my TV is only black and white. How can I get color?
1.7  While using TV-out, after some time (10, 20 or 30 minutes) something
     happens to the image: There may be some disturbances (black lines),
     or the image may even disappear completely. What's wrong here?
1.8  When switching back to the monitor, I see 'waves' on the screen,
     or only half of the screen.
1.9  The computer freezes after some time, the cursor disappears, or there
     are strange patterns on the screen.This happen especially in
     modes with low overscan.
1.10 When I switch back to the monitor, the image is slightly horizontally
     shifted.
1.11 Can I connect a SCART connector and get real RGB?

2.  ISSUES WITH SOME CARD TYPES

2.1 I have a GeForce4 MX, GeForce4 GO or GeForce MX GPU card, and nvtv 
    doesn't work. 
2.2 I have a Voodoo3 card, and the image "tilts" when I move the cursor
    as soon as I have enabled TV out. What's wrong?
2.3 I have a Riva128, and nothing works. Are these cards not supported?
2.4 Can I use nvtv on my Laptop with an LCD display/flatpanel?
2.5 I have a TNT2 card, and the border of the TV image is pink.
2.6 I have a GeForce4 card, and with Twinview activated, there is no image
    at all on the TV.

3.  ISSUES WITH SOME ENCODER CHIPS

3.1 I have a Chrontel chip, and the image on the screen is either too
    large, or too small.
3.2 I have the Chrontel chip, and the "Macrovision" button on the Settings
    page is grayed and off. Why can't I enable Macrovision?
3.3 I have a Philips chip, and the colors are all wrong.
3.4 I have a Chrontel chip, and on some resolutions, the color flickers
    (e.g. between blue and red).
3.5 The colors are wrong (e.g. purple background), and I have a Brookree
    or Conexant chip, or the suggestions to the questions above didn't
    help.

4.  THE DEMON, PLUGINS, AND OTHER ACCESS ISSUES

4.1 The new version of nvtv doesn't work with the xine plugin. What can
    I do?
4.2 I am using the closed source 'nvidia' driver, but the -N option doesn't
    work.
4.3 How can I automatically run nvtvd after booting?

5.  CUSTOMIZING AND SPECIAL USAGE

5.1 Can I use two X servers, one for the TV, and one for the monitor,
    and switch between them by switching between the virtual terminals?
5.2 It's tiring to always have to start nvtv, pick a mode, and switch on
    the tv, and then to start an application. Can I automatize that?
5.3 Can I have true dualhead view with one image on the monitor and a 
    different image on the TV?
5.4 My TV can show images in true 16:9 widescreen format. How can I use
    this feature, for example to view DVDs in this format?
5.5 I am using a second graphics card, and nvtv is not able to detect
    it.
5.6 I have trouble getting a stable TV image while trying my own settings,
    and I do not want to reboot all the time.
5.7 I need to adjust the position, the color carrier frequency or something
    else that is not covered by the command line switches. How can I automate
    thus?
5.8 When I try to watch videos on the TV, the aspect ration is distorted.

6.  CONTRIBUTING

6.1 I have one of the cards that are not fully supported by nvtv. How
    can I help?
6.2 How can I include a new mode or a modefied mode into the database?

7.  RESSOURCES

7.1 Are any other web ressources available?
7.2 Is there a list of cards together with the encoder type they use,
    so I can make a choice before I buy a new card?

======================================================================

1.1 When switching the TV on, I can see only part of my screen.

The reason is probably that your X screen has a much larger 'virtual'
resolution than what is displayed on the TV. This is a 'feature' of X;
even if you switch X modes, the overall size of the screen stays the
same.

There are several things you can do:

1) If you have modes for smaller resolutions in your XF86Config file,
   you can switch to those with the 'X Video mode' button *before*
   enabling TV out. This will allow you to move the visible part
   of the screen on your TV. If the application you want to use on the TV
   uses a window (recommended), you can resize and center this window
   on the TV with the nvtv GUI or command line options, or of course with 
   the command line options of the application. Don't try to switch to
   'fullscreen', it will be too large.

   The documentation about XFree explains how to make a mode with a special 
   resolution. Resolutions like 800x600 or 640x480 are often preconfigured, 
   or can be selected with the setup programs of XFree. 

   This is the recommended way that I use myself.

2) Change you XF86Config file so that it doesn't contain any resolutions
   larger than the mode you want to use. If you want to keep higher 
   resolutions, you can use a second X server, and switch between both
   servers with the keyboard.

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1.2 When I switch my DVD player into fullscreen mode, only part of the 
    image appears on the TV.

To understand this, you have to keep in mind that X always has the
same 'maximal' resolution (which corresponds to the size of the
virtual screen). So 'fullscreen' does not mean 'all that is visible'
but 'all that is drawable in the video memory' (see question 1.1 above).

Solution: Don't use fullscreen mode, but resize the window to the
correct size instead, either using nvtv or the command line options of
your player program.

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1.3 When my application switches X modes while the TV is active, the screen
    gets messed up. 

Don't switch X modes while TV out is active. This is a no-no, Nvtv was
not designed to support that. Switch X modes *before* you enable the
TV, either with your application, or with Nvtv from the GUI or command
line.

Some applications like mplayer under some circumstances (e.g. with vesa
fb driver) seem to insist on switching video modes. The only way to fix 
that is to patch the application (or to add a command line switch) to 
prevent them from switching. If you cannot program yourself, send a 
support request to the developers of that application.

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1.4 I don't get an image on the TV at all.

Maybe the connector autodetection doesn't work for you, because the
line is not properly terminated in your TV. Switch the connector to
'both', and try again. Of course, there may be lots of different
reasons, like a damaged connector cable, etc.

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1.5 I can see an image on the TV, but no image on the monitor in some or
    in all modes, even though I have dualview enabled.

Some monitors don't like the low frequencies (50 Hz/60 Hz vertical for
PAL/NTSC, and 30-40 kHz horizontal) the dual view mode has to use. If
you cannot get an image on the monitor in nearly all modes, you should
disable dualview completely. (Remember, if you destroy your monitor,
it's your responsibility, not mine). However, most modern monitors
should cope with that.

The second reason is that in some modes, especially those with large
overscan (i.e., small overscan percantage, and a large image) don't
leave the monitor enough time to 'retrace'. In that case, if you
really need dualview, you should use a different mode (or even make a
new one if you have the Brooktree chip).

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1.6 The image on my TV is only black and white. How can I get color?

There are many possible reasons for this. 

(a) You have chosen the wrong color encoding system (PAL/NTSC/...), 
    or your TV uses a color encoding system that is not supported yet.

(b) You have a SVideo (S-VHS) to Composite connector that uses only
    the luminance (Y) line of the SVideo connection. If you have a
    Brooktree chip, try selecting 'Convert' on the 'Config'-page as
    connector setting. This will output the composite (FBAS) signal on
    the Y-line.
    If you have a Chrontel chip, however, this setting will not help; 
    'Convert' in this case is the same as the 'SVideo' setting. You will 
    need a proper connector that 'mixes' both the Y-line and the C-line
    of the SVideo output. See http://tvtool.info/english/cablefaq3_e.htm
    for some details. Other helpful links may be
    http://www.hut.fi/Misc/Electronics/circuits/svideo2cvideo.html
    or the schematics for a couple of converters from sandberg
    http://www.sandberg.it/img/prod/autocad/502-34.pdf
    http://www.sandberg.it/img/prod/autocad/503-65.pdf

(c) The cable connecting your TV with your computer is too long, or
    external electrical signals interfere with the color signal.

(d) On some systems, especially with Chrontel encoders, the frequency of
    the color carrier is wrong. You can change this frequency with the 
    two 'fsci' spinbuttons on the Chrontel register page, and similarly
    with the 'msc' spinbuttons on the Brooktree register page. Don't
    forget to 'Apply' or 'AutoApply' your changes. If you need to change
    this value and find ones that work for you, please mail me the mode 
    and the values. There is also a 'pseudo' TV system called 'PAL-X' 
    which has a few modes with different color carrier. Maybe those work 
    for you, maybe they don't.

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1.7 While using TV-out, after some time (10, 20 or 30 minutes) something
    happens to the image: There may be some disturbances (black lines),
    or the image may even disappear completely. What's wrong here?

This is probably the X screen saver. You can disable it with
'xset -dpms s off'. Don't forget to enable it later on if you need
it. Read the manpage for details.

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1.8 When switching back to the monitor, I see 'waves' on the screen,
    or only half of the screen.

Try switch to the virtual text console and back. With the closed source
'nvidia' driver, this should help; with the 'nv' driver, it might.

The reason for this effect is probably that the newer cards (like
GeForce3 or GeForce4) use some additional registers that are not
programmed correctly. If anybody finds out what these registers are,
please send me an email (I don't have any of those cards, I cannot
test it.)

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1.9  The computer freezes after some time, the cursor disappears, or there
     are strange patterns on the screen. This happen especially in
     modes with low overscan.

The NVidia cards need some time during the vertical refresh phase.  If
this time is too short, the above effects may happen, especially if
you have a somewhat slower system (I have observed this on a 700MHz
AMD K6). 

You can use a software cursor instead of a hardware cursor by using
the options "SWCursor" or "HWCursor" in your XF86Config file as
described in the README of the NVidia driver, or use the open source
'nv' driver instead of the closed source 'nvidia' driver.

If this does not help, use a different mode with more overscan (or
make your own).

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1.10 When I switch back to the monitor, the image is slightly horizontally
     shifted.

The 'nvidia' and the 'nv' driver don't agree on the way they interpret
the X modeline. Nvtv interprets it the way 'nvidia' does (because I
supposed they would be doing it correctly); so compared to the 'nv'
driver it will be always shifted.

You can correct that by switching X modes, e.g with CTRL-+ followed by CTRL--
on the numberpad. (This will of course only work if you have more than
one valid modeline).

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1.11 Can I connect a SCART connector and get real RGB?

In principle, yes. It depends on the encoder chip, and in most cases
you will have to solder additional connectors to the board. For
the Chrontel chip, for example, have a look at 

http://tvtool.info/english/rgb_chrontel_e.htm

Nvtv has not setting yet to enable RGB, but if you enable 'Bypass', you
can for example enable the RGB mode by setting the 'scart' flag on
the CH Regs1 page. Please contact me if you have modified your hardware
and want an additional setting to make it easier to use.

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2.1 I have a GeForce4 MX card, and nvtv doesn't work. 

The GeForce4 MX, GeForce4 GO and GeForce4 MX GPU cards sometimes use
an internal TV encoder chip (which shows up as 'NVIDIA', 'NV17' or
'NV18' as the name of the TV encoder in the XFree log). This encoder
is not supported at all by nvtv yet, and without the hardware it's
impossible to figure out how to do it.

But even if there is an external encoder chip on the card, the
GeForce4 MX might use some extra registers, which need to be
configured to make TV work. You can try cheating by activating TV
with the nvidia driver, and then using nvtv. Or, even better, if
someone helps finding those extra registers, we can include support
in nvtv. (The GeForce4 support was done in that way.)

The GeForce4 GO card has not been tested at all, and may very likely
crash the program.

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2.2 I have a Voodoo3 card, and the image "tilts" when I move the cursor
    as soon as I have enabled TV out. What's wrong?

If you are using a X mode with a large resolution (dot clock greater
than 135 MHz, i.e. a horizontal resolution of 1024 or 1280 etc.)  and
a hardware cursor, the X driver will write a wrong value into a
register when it shows or hides the cursor.

Solution: Either disable the hardware cursor with the "SWCursor"
option in your XF86Config file, or switch to a smaller X mode before
enabling TV out.

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2.3 I have a Riva128, and nothing works. Are these cards not supported?

The Riva128 card uses a completely different way to produce TV-out.
Also, as far as I know, it can send a picture either to the monitor or
to the TV, but not both, because it uses the same chip pins to supply
the data, and decides which one to choose at power-on time. So if
someone can figure out a way to switch between TV and monitor output
later, I'd be happy to hear about it, but at the moment it seems it
just won't work.

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2.4 Can I use nvtv on my Laptop with an LCD display/flatpanel?

In principle, yes. But be careful: The program does not know how to
control the flatpanel. It tries to disable it, if it is one the same
head that is used for tv-out, but it might completely turn it off.

Also, switching the TV head when the flatpanel is active will
currently probably not work. 

It might help if you connect your Laptop to an external monitor, and
disable the flatpanel before starting nvtv.

Generally speaking, nvtv doesn't work very well on Laptops/GeForce2 GO 
cards at the moment. I got it working with TwinView on a laptop,
but I didn't have the laptop long enough to try different ways.

Experiments are at your own risk. 

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2.5 I have a TNT2 card, and the border of the TV image is pink.

This happens on some cards for unknown reasons. I tried to zero every
register I can think of that could influence the color, but I haven't
found the right one yet, and without the card this is not so easy.

If someone figures out which registers to change, please tell me.

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2.6 I have a GeForce4 card, and with Twinview activated, there is no image
    at all on the TV.

Try "TV on", "TV off", and then again "TV on". Yes, that is probably
a bug, and might be fixed in the next release.

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3.1 I have a Chrontel chip, and the image on the screen is either too
    large, or too small.

The Chrontel encoder chip only has a limited number of modes; all of
them are accessible with nvtv. So if you really want an image that
exactly fits on your TV, you need another encoder chip. (However,
remember that for 'normal' TV, the image is always too large, and you
don't notice that at all).

If you *really* want fine control over the size of the image, you can
cheat a bit. Take a mode that is too large for your screen, reduce the
Display CRTC values, and adjust the Sync and Total values until the
image is centered again. You will end up with a non-standard
resolution, but the image will fit. (This is how the 768x576 modes were
made).

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3.2 I have the Chrontel chip, and the "Macrovision" button on the Settings
    page is grayed and off. Why can't I enable Macrovision?

It is not possible to enable Macrovision in all modes, because we do
not have enough information how to do that. Therefore, the Macrovision
button will be insensitive and off for those modes, and sensitive (and
also off by default) for the others. Since most people do not want
Macrovision anyway, this is not a serious drawback.

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3.3 I have a Philips chip, and the colors are all wrong.

Try the colorfix setting.

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3.4 I have a Chrontel chip, and on some resolutions, the color flickers
    (e.g. between blue and red).

Try the colorfix setting.

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3.5 The colors are wrong (e.g. purple background), and I have a Brookree
    or Conexant chip, or the suggestions to the questions above didn't
    help.

Try moving the image horizontally. Activate AutoApply, and change
HTotal, HSyncStart, and HSyncEnd on the NV Regs page, or h_blanki and
hsynoffset on the BT or CX pages. First try setting hsynoffset to zero;
then play with the other values to center your image.

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4.1 The new version of nvtv doesn't work with the xine plugin. What can
    I do?

The xine plugin is contained in the xine source tree and uses the
client backend of the nvtv source, but it has to connect to the nvtv
server demon (nvtvd). If the latter changes (which happens from time
to time; remember that nvtv is still alpha), they won't work
together. So choose one:

a) Use the version of nvtv for which the xine plugin was compiled;
b) Get the xine source, replace the nvtv client file in src/xine-engine/nvtv
   with the newer files from the nvtv source, and compile xine;
c) Wait until the xine plugin updates to the new nvtv version.

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4.2 I am using the closed source 'nvidia' driver, but the -N option doesn't
    work.

NVidia changed and may keep chainging the internal data structures of
the driver. Currently, nvtv should work with version upto 1.0-3123,
but the next change by NVidia might break this again, of course.

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4.3 How can I automatically run nvtvd after booting?

Unfortunately, this varies wildy for different Linux distributions.
On Debian, you should copy /etc/init.d/skeleton into /etc/init.d/nvtvd. 
Replace the appropiate variables in the top of the file with the path 
to nvtvd. Add the --make-pidfile option to the lines beginning with

  start-stop-daemon --start

Then run "/usr/sbin/upate-rc.d nvtvd defaults 80".

For other systems, look for /etc/init.d/boot.local, or S99Local 
in /etc/rc.d/rc.local, or something similar. Read your distribution's
documentation, or ask in a newsgroup related to this distribution.

(If you have any detailed information how this works in other 
distributions, please drop me an email.)

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5.1 Can I use two X servers, one for the TV, and one for the monitor,
    and switch between them by switching between the virtual terminals?

Not really. The open source 'nv' X driver doesn't know that the card
is in TV mode, and therefore does not save all the state that is
necessary. With the closed source 'nvidia' driver, you can do this,
but the driver will reprogram the encoder chip every time, so you'll
have to run nvtv again after each switch.

The only way to get this to work properly is to integrate nvtv in the 
XFree server (which is a long term goal).

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5.2 It's tiring to always have to start nvtv, pick a mode, and switch on
    the tv, and then to start an application. Can I automatize that?

You can use the command line options. For example,

  nvtv -r 800,600 -s Normal -t

switches to 800x600 tv mode with 'Normal' overscan size. Type 'nvtv -?'
to see all the command line options. Write a simple shell script that
swicthes to tv mode, runs your application, and switches back to monitor
mode. There are some examples in doc/scripts.txt.

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5.3 Can I have true dualhead view with one image on the monitor and a 
    different image on the TV?

Yes, if you have a GeForce2 MX/Quadro2 MX/GeForce2 GO card (NV11
architecture). These cards have two heads, and you can choose which
one to use on the 'Head' GUI page, or with the command line switches.
However, the video overlay will only work on one of those heads, and
there are some other restrictions on the usage.

It is also possible on a TNT2 to display the video overlay on the TV,
while keeping the normal framebuffer display on the monitor, but this
has not been implemented yet.

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5.4 My TV can show images in true 16:9 widescreen format. How can I use
    this feature, for example to view DVDs in this format?

You should be able to switch your TV manually in the 16:9 mode. It
will then take the normal TV signal and display it in widescreen. To
make this work with DVD player programs, you have to prevent the
program from scaling the anamorphic DVD, or for true widescreen formats, 
you have to horizontally scale down the image, in both cases by a
factor of 1.3333. The xine subdirectory contains a patch to xine which
allows you to do this with the --display-ratio command line switch.

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5.5 I am using a second graphics card, and nvtv is not able to detect
    it.

The problem might be that the I/O memory of the card is not enabled.
You can try enabling it with setpci. However, this won't initialize
the card, so it might not work. First, use lspci to find out what PCI
bus address your card is on, for this example 0:0a.0. Then do
something like

$ setpci -s 0:0a.0 command
<some output, say 1234>
$ setpci -s 0:0a.0 command=1237

where the last digit should be replaced by 7 if it was 0-7, and 
by f if it was 8,9, or a-f. (In other words, logically or 0x7 to it).

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5.6 I have trouble getting a stable TV image while trying my own settings,
    and I do not want to reboot all the time.

The keyboard accelerators are really helpful in this case. Pressing F2
should restore the normal settings. If this doesn't help, and you are
using the closed source NVidia driver, you can also try to switch X
modes (Ctrl-Alt and + and - on the keypad) or virtual consoles.

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

5.7 I need to adjust the position, the color carrier frequency or something
    else that is not covered by the command line switches. How can I automate
    thus?

You need to create a new mode (or modify an existing one) and include it
in the database. See question 6.2.

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5.8 When I try to watch videos on the TV, the aspect ration is distorted.

There is a number of possible reasons. All of them are not related to
nvtv.

1) You don't use the video overlay, but (for example) shared memory access.
   Run xvinfo to find out if your X server supports a video overlay at
   all; if it doesn't, setup the X server properly.   
   Read the docs to find out how to force the program to use the video
   overlay (e.g. -vo xv for mplayer, -V xv for xine).

2) The playback program chooses the wrong aspect, for example because
   your X mode or virtual desktop is not 4:3. Read to docs to find
   out how to force the correct aspect (e.g. -monitoraspect 4:3 for 
   mplayer)

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6.1 I have one of the cards that are not fully supported by nvtv. How
    can I help?

The easiest way to support new card types for me is to have the card
in front of me, so I can test everything myself. This has worked in
most cases so far. So consider making the card available to me in some
way or other. (I also thought about organizing some way of collecting
money so I can *buy* the card. If everybody who wants nvtv to support
a GeForce4 donates about 5 EUR, say, I'd have enough money to do
this. But I haven't tried that seriously yet.)

I have found it very difficult to do 'remote debugging', so I am
reluctant to try it again (it's just too slow). Besides the problem
with NV17 encoder chip, what's wrong most often are just some
uninitialized registers. So if you can get it to work with the closed
source nvidia driver, or otherwise, try to compare the register dumps
(you can get those with 'nvtv -P'). Then try changing the existing
writeCrtNv calls in tv_nv.c (or insert new ones). This file also
contains most of the information about what is known about the
registers (as C code, of course).

Additionally, you can compile the program 'nvdump' from the source
release, which can dump all the NVidia registers (besides the CRTC).
You can use it if you suspect there might be register changes that 
are to output with 'nvtv -P'.

If you succeed in any way, please tell me about your results.

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6.2 How can I include a new mode or a modefied mode into the database?

See 'Inserting a new mode in the database' in doc/USAGE.

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7.1 Are any other web ressources available?

I recommend the TVTool web-site, which hosts the corresponding tool for
Windows. The archive can be found here:

http://tvtool.info/english/archive_e.htm

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7.2 Is there a list of cards together with the encoder type they use,
    so I can make a choice before I buy a new card?

Yes, there's a card database at the website of TVTool:

http://tvtool.info/cardbase.htm

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