faq FAQ: Frequently Asked Questions faq

Last update december 2004

  • This error message appears at startup, how to correct it?
*** AUDIO DEVICE TYPE = alsa
*** GRABBER DEVICE TYPE = v4l2
xdtv: simple.c:1785: snd_mixer_selem_get_capture_switch: Assertion `elem' failed.

This error could happened if Alsa is not configured correctly:
Go to the  "Alsa for dummies" section and follow all advices:

You can also try to stop alsa with this specific command line (with root rights): /etc/init.d/alsa stop
delete the /etc/asound.state file (with root rights: rm /etc/asound.state)
restart alsa with this specific command line (with root rights): /etc/init.d/alsa start

If, after doing all these steps, the problem is not resolved, try to start XdTV like that: xdtv -noalsa

  • This error message appears at startup, how to correct it?

WARNING: video memory base unknown, may be caused by a problem

  with xdtv_v4l-conf or a non-availability of DGA
  and frame buffer devices: CLASSICAL OVERLAY IS DISABLED !
 
With root right, launch this command line xdtv_v4l-conf:

xdtv_v4l-conf: using X11 display :0.0
dga: version 2.0
mode: 1024x768, depth=16, bpp=16, bpl=2048, base=0xf0000000
/dev/video [v4l2]: configuration done
done

When the configuration is done, you can restart XdTV.

  • Since XdTv 2.0, old Nxtvepg versions (<=2.7.3) don't work with XdTV (because of the renaming). To solve this problem you have to launch these command lines:
cd /home/xxxxx/ ( xxxxx is your own user profil)
ln -s .xawdecode .xdtv
cd .xdtv
ln -s xawdecoderc xdtvrc

XdTV is totally supported by Nxtvepg with the version  2.7.4pre1 or higher.

  • I have a blackborders problem. When I switch into the fullscreen mode, blackborders appear around the TV zone.  How to solve this problem?
With the overlay mode, the max. video resolution is 768x576. So it's adviced to choose a "768x576" or a "640x480" video resolution. Open the GUI and go to:
 
"open X11 options">"Fullscreen resolution"

Since the 1.9.2 version, a new overlay method appears. With it, you can switch the video resolution above this high limit (very interesting if you use the fullscreen). To verify if your TV card works fine with this method, try these command lines and give us all the results:

Test the overlay mode:

-noxv -capture overlay
-v4l1 -capture overlay
-xvtv -capture overlay
-xvtv_overlay on -capture overlay
-xvtv_overlay off -capture overlay

Test the grabdisplay mode:

-noxv -capture grabdisplay
-v4l1 -capture grabdisplay
-xvtv -capture grabdisplay
-xvtv_overlay on -capture grabdisplay
-xvtv_overlay off -capture grabdisplay

Be careful: the fullscreen works fine with overlay only is you use the -xvtv_overlay on option (by default) & only if you use the v4l2 drivers.

Information:
> xdtv -noxv
If your video card has a buggy Xv support, you can use this parameter. By default the X-server Xv support is activated.
> xdtv -xvtv_overlay off
The old overlay system is used. XdTV window can't be resized over 768x576. DGA support is needed.
> xdtv -xvtv
The only way to have the new overlay support in v4l1 mode. Grabdisplay is not available. No recording can be launched. AleVT can't be used.

  • When I restart my Linux Mandrake 10.0, the TV doesn't work. How to solve this problem?
You just have to edit the /etc/modprobe.preload file and add this line : bttv

  • When I launch XdTV, I can't use the overlay mode because I can't load any DGA module. How to solve this problem?
Try to use one of these two parameters:

 -d disable the usage of X11 DGA extension.
-D adr set  framebuffer  address to adr. Needed for overlay mode if DGA is not available (needs root privileges, use with caution !).

  • With the Xaw GUI, I can't use successfully any cursors? How to correct that?
Try to use the right & left buttons of your mouse (before and after the cursor).
The lef button -> it increases the parameters, the right button -> it decreases the parameters.

This problem is not an XdTV bug but a Xaw limitation. Try to install the neXtaw library which is better that the Xaw one (better cursors management).

  • This error message appears at startup, how to correct it?
ALSA lib pcm_hw.c:549:(snd_pcm_hw_start) SNDRV_PCM_IOCTL_START failed: Broken pipe

This error can appears because of a bad ALSA version. Try to recompile an older ALSA version. It can resolve your problem. (We meet this error on a Linux MDK 10.1)

  • Is it possible to keep the audio frequency value equal to 44kHz with a 48kbps bitrate (mono)?
Normally Lame choose the good bitrate. With this patch you do that:

--- src/divx.c  2004-06-08 22:15:17.000000000 +0200
+++ src/divx.c.new      2004-09-03 23:46:53.037679720 +0200
@@ -1453,6 +1453,7 @@
      lame_set_num_channels(gfp, achans);
 
      lame_set_in_samplerate(gfp, DEC_FREQ);
+    lame_set_out_samplerate(gfp, DEC_FREQ);
      lame_set_compression_ratio(gfp, 0.0);
      if(!divx.mp3_vbr)
        lame_set_brate(gfp, divx.mp3_bitrate);

  • When I use XdTV, only the high quality mode (image with 2 frames) is proposed by default. How to modify this parameter?

It's possible to choose the grab resolution. First, open the GUI and go to this menu: "XFree Options"> "Max size of the grabbed frames" second modify the default value.

  • I already installed XdTV, but I want to activate the debug mode. How can I do that?
First you have to recompile XdTV as follow:
./configure --disable-nodebug && make

Second you can launched XdTV with this specific parameter:
xdtv -v 2

  • Since the installation of the newest nvidia 1.0-6111 drivers, XdTV crashed my Linux system. Does someone meet this problem?
There is a bug with the overlay management into the last nvidia drivers. All driver versions 1.0-6xxx have this bug. We also meet such problems with all ATI drivers when the  DGA is activated.




july 2003 FAQ

  • I can't change channels, why?
If you can't change channels with XdTV means, your selected tuner is not the good one. With new distributions, this selection is automatic, but with old TV cards the result could be wrong. So you have to select manually the good tuner. Edit (with root rights) the /etc/modules.conf file (kernel 2.4.x)  or the  modprobe.conf file (kernel 2.6.x), select the good tuner and record the new configuration:

An example for a Miro PCTV BT848 card:

######### Tuner TV ############
alias char-major-81-0 video
alias video bttv
options bttv pll=0 radio=0 card=1 tuner=3
######### End Tuner TV #########

If you have this problem with a very recent TV card, please refer to the BTTV supported cards list.
Actually some very new tuners are not supported. If your card and tuner are in that list, please remember them and modify (with root rights) the /etc/modules.conf file
(kernel 2.4.x)  or the  modprobe.conf file (kernel 2.6.x as it is explained higher (options bttv card=x tuner=y).
 
  • What are Overlay and grabdisplay modes?
When you use overlay mode, with XdTV or Xawtv, the video display is sent directly from the TV card on the screen: in that case, the display is managed by BTTV drivers.
This method is very CPU friendly, this is the only advantage, the drawback being that we can't make any video processing on the TV images.
When you use grabdisplay mode, display is entirely managed by XdTV itself..
Nevertheless, video stretching is managed by the graphic card itself thanks to the Xv extensions from the XFree / X.org drivers.
 
  • CPU load and deinterlace filter:
Greedy and linear blend filters use a lot of CPU power.
Bob filter uses much less CPU and will give you good results.
 
  • At startup, this error message appears: "no video grabber device available": What can I do?
XdTV looks for the /dev/vbi device. If in your /dev folder there are neither /dev/vbi0 nor /dev/vbi1 nor /dev/v4l/vbi0 nor /dev/v4l/vbi1 device, then you will have to make a symbolic link as:

ln -s /dev/v4l/vbix /dev/vbi
After this, XdTV will work.

Actually XdTV could discover automatically all video used devices. But, this method could be used with strange configurations that can't use this autodiscover method.
 
  • Some graphic resolutions (for example 640x480) don't display correctly with gabdisplay fullscreen mode, Why?
XFree4.x / X.org can extract automatically preset EDID data from screen. For example these video resolutions: 640x480, 800x600, 1024x768, 1280x1024
On some old screens, this extraction might be wrong.
To resolve this problem you can:
Firstly, add
in your XF86config-4 / xorg.conf file the video resolutions modelines you need.
Secondly, if you have a Mandrake distribution, copy needed resolutions from XFree86config (version 3) to XFree86config-4
/ xorg.conf (version 4).
 
  • Deinterlace filters don't work, why?
You have to select grabdisplay mode to make a video processing. Go to the main options panel and modify the capture mode from overlay to grabdisplay.
 
  • What is nxtvepg software?
Nxtvepg is a software supported by XdTV. It is a decoder for nexTView signals and can transmit useful informations to XdTV.
To install it, you just have to type
(with root rights) in a shell, these commands:

urpmi nxtvepg (For those of you who use a Mandrake distribution)

or this one (for RPM distributions):

rpm -Uvh nxtvepg-x.y.z.1mdk.i586.rpm
 
  • The .xdtv folder explained:
The first time you start XdTV a .xdtv folder is created into your $HOME folder:
In this folder, you can find these files:

xdtvrc:
This is the XdTV configuration file. It can be created manually or by XdTV itself.

last_channel:
This file records, when you close the application, the last channel you used. The next time you'll start XdTV it will immediately select the last used channel.

memcpy_method:
memcpy is a C function which copies the content of a memory area to another memory area. It is abusively used for buffer transfers and the more this function is efficient, the smoother the images are. At the very first launch, different memcpy implementations are tested by XdTV : the C library one, the kernel one, a MMX optimised one, etc... the fastest is selected and the result is stored in the .xdtv/memcpy_method file in order not to run the test every time XdTV is started.
 
  • Keyboard shortcuts don't work!

To make XdTV keyboard shortcuts work correctly, you must:
1 ) install XdTV with this command: make install (or with a RPM file). The installation process copy the "X11 ressources file" named XdTV.ad into the "X11 ressources system folder": /usr/X11R6/lib/X11/app-defaults (this folder can be different from one distribution to another). This process also rename the file as "XdTV".

2) Give the focus to your TV window with your mouse (your mouse must be inside the window).
 

  • XdTV crash at startup with this error message:

No Xv port available.
Successfully find YUY2 XvImage port : -1
X Error of failed request: XvBadPort

We suggest you to start XdTV with this option -no-xv or noxv.

Xv means Extension Video. These extensions are used by XFree 4.x / X.org server.
With these extensions, you can do great things as using better video hardware acceleration capacities. That makes your video more fluid.
In fact, with Xv extensions, all the hardware transformations YUY2 -> RGB are made by the graphic card itself. If you don't use Xv, theses transformations are made by XdTV itself (fortunately, with MMX instructions).
If you don't use Xv, some functionnalities are not supported by XdTV (for example deinterlace filters).
To verify if your system supports these extensions, you can type this command into a shell:

xvinfo

http://linuxcommand.org/man_pages/xvinfo1.html

If XdTV crash because of no Xv support, you can start it with this parameter:

xdtv -noxv
 

  • XdTV crash at startup with this error message:

The app-defaults file is not correctly installed.
Your fault (core dumped)

The reason of this crash is the X11 ressource file. XdTV doesn't find it into the X11 ressource system folder (/usr/X11R6/lib/X11/app-defaults).
Rename XdTV.ad as XdTV and copy it this folder. That will resolve your problem!
 

  • When I switch in fullscreen mode, the image is small and positionned on the center of the screen:

This is a XdTV or a X11 configuration problem.

1) Into ~/.xdtv/xdtvrc file, add this line:

fullscreen=640x480 or that one
fullscreen=768x576

2) We suggest you to use XFree86 4.0.x (or the version 4.2.x) / X.org  rather than XFree86 3.3.6.
Why?
For these 3 reasons:
* Firstly, because XFree4.x / X.org can extract automatically preset EDID screen data like 640x480, 800x600, 1024x768, 1280x1024, etc.. 
video resolutions.

* Secondly, because XFree4.x / X.org  has a better support for v4l (video for linux) devices. Don't forget to add Load "v4l" into the "Module" section of the XFree configuration file (/etc/X11/XF86Config-4 or /etc/X11.xorg.conf)

* Thirdly, because with XFree4.x / X.org, you can now use XVideo extension which allows an hardware acceleration for video YVU display. As all graphic cards don't support this extension, we suggest you to verify if you can use Xv.

If you use XVideo extension, overlay streching is possible. Be careful on Mandrake distribution there is a bug: XFree4.x / X.org is very slow when you use XVideo with YVU display. So if it is the case, we suggest you to use XdTV with the -noxv parameter (this problem doesn't exist any more on version 9.0).

So, if you use XFree4.x / X.org with the parameter fullscreen=640x480, you won't have anything to modify in your X11 configuration file.
But if you want to activate fullscreen in 768x578 mode, you must add the good modeline into the config file as your screen can't extract this resolution!
To build this modeline, you must get all the technical features of your screen.
After getting them, go to
Colas XFree Modeline Generator web site:

http://www-sop.inria.fr/cgi-bin/koala/nph-colas-modelines: this site will help you to build correct modelines.

If you use XFree86 version 3.3.6, the EDID screen extraction is not possible: you must manually add all the modelines for all needed resolutions.

3) Adding modelines into your X11 configuration file is not enough! You must also activate the video resolutions you are going to use:

This modifications must be done into the "Screen" section. For example:

Subsection "Display"
Depth 16
Modes "1280x1024" "1024x768" "800x600" "768x576" "640x480"
ViewPort 0 0
EndSubsection

We also suggest you to launch XFree / X.org in 16bpp rather than 24 or 32bpp.

With all these suggestions, XdTV fullscreen will be perfect even if you don't use Xv extensions.
 

  • How to know if I use XFree4.x / X.org or version 3?

Check the existence of that log file: /var/log/XFree86.0.log or /var/log/Xorg.0.log
 

  • Can I use XdTV with root rights?

This is not advised!!!! You must start XdTV (or XFree / X.org) only as a normal user. This is a general rule on all Unix Operating System.
Root user must only be used to administrate your system.

  • When I launch XdTV these messages appear: "can't acces mixer" and / or "can't access vbi":

This is a general access right problem for these devices: /dev/dsp, /dev/vbi, /dev/video, /dev/mixer, etc...
firstly, you must verify if /dev/video device exists and if it's a symbolic link for /dev/video0 device.
If needed, you can create this symbolic link: ln -s /dev/video0 /dev/video (with root rights).
You can do the same thing for /dev/vbi device: ln -s
/dev/vbi0 /dev/vbi 

Now we are going to resolve problems with groups...
In recent Linux distributions, if you want to access to some specific devices, your account must be added into a specific group, one group for each device.
For example, the audio device /dev/dsp belongs to root and to the audio group. So, if someone wants to use this device (listenning to music for example) he must be included into the audio group.
To access to the TV card, you could meet the same problem as with the /dev/video0 device. This device belongs to root and to the video group.
The CDROM device (/dev/cdrom) belongs to the cdrom group.
The printer owner group is lp or printer
The modem owner group is either modem or uucp or dialup.
.......
So to use all these devices, you must belong to all these groups: cdrom, audio, video, lp, uucp....

This method allows the administrator to thightly control all access rights!

Nevertheless, the group must have the rights to use devices. So you just type these commands into a shell with root rights:

$ chmod g+rw /dev/video0
$ chmod g+rw /dev/vbi0
$ chmod g+rw /dev/audio0
$ chmod g+rw /dev/mixer
$ chmod g+rw /dev/dsp

You can also check to which group these devices belongs to. For example, on a Mandrake 8.0 distribution, for the video and audio devices:

$ ls -l /dev/video0

=> crw-rw---- 1 root sys 81, 0 Apr 14 13:06 /dev/video0

$ls -l /dev/audio0

=> crw-rw---- 1 root audio 14, 4 Apr 14 13:06 /dev/audio0

So, you must belong to sys and audio groups if you want to get video and sound.

How to add a user into a group?
For this example, lets assume your user name is USER1. Firstly, we are going to verify in which groups you belong to. Type this command in a shell

$ id -a USER1

This command gives this answer:

uid=993(USER1) gid=21(USER1) groups=21(USER1),22(cdrom),43(usb),80(cdwriter),504(xgrp)

USER1 is a user which default group is "USER1" and which belongs to the cdrom, usb, cdwriter and xgrp groups.
To let this user USER1 belong to sys and audio group, you have to type this command in a shell with, of course, root rights:

$ usermod -g USER1 -G USER1,cdrom,usb,cdwriter,xgrp,sys,audio USER1

"-g USER1" parameter meens that USER1 is its principal and default group
"-G USER1,cdrom, .... ,audio" parameter means that USER1 belongs to all these other groups. Be careful, when you want to add a user in a new group, you have to write all the groups he used to belong to as well as the new ones.

To activate these modifications, USER1 have to logoff then logon in the system.
 

  • What is "memcpy":

Memcpy is a C function which copies the content of a memory area to another memory area. It is abusively used for buffer transfers and the more this function is efficient, the smoother the images are. At the very first start, different memcpy implementations are tested by XdTV : the C library one, the kernel one, a MMX optimised one, etc... the fastest is selected and the result is stored in the .xdtv/memcpy_method file in order not to run the test every time XdTV is started.
 

  • Which sound driver should I use?

There are two sound drivers: OSS and ALSA. Alsa is an OSS GPL compatible sound driver. We suggest you to use ALSA driver. Why?

  • Because, this driver can give you a Full Duplex sound
  • Because, the synchronization between sound and video is very good 
 
  • How to get, for my graphic card, informations on Xv, V4L (Video for Linux) and BTTV?

Start Xawdecode with this parameter: -hwscan
This option gives you that near result:

This is xawdecode 1.3.10 running on Linux/i686 (2.4.8-26mdk).
looking for available devices
MIT Shm extension available
Number of Xv adaptors available: 1
port 58-58 [ -xvport 58 ]
name : Matrox G-Series Backend Scaler
type : Xvideo, image scaler
format supported on port 58 : YUY2 YV12 I420
v4l: bttv version 0.7.72
/dev/video0: OK [ -c /dev/video0 ]
type : v4l
name : BT848(MIRO PCTV)
flags: capture tuner overlay clipping frameram scales

This option doesn't exist any more with XdTV.
You can also start XdTV in a debug session. To do that, type into a shell this command : gdb /usr/bin/xdtv
This method gives you that near result:

[user1@localhost user1]$ gdb /usr/local/bin/xdtv
GNU gdb 20010813 (MI_OUT)
Copyright 2001 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-mandrake-linux"...
(gdb) run
Starting program: /usr/local/bin/xdtv
[New Thread 1024 (LWP 2003)]

This is xdtv 2.0.0 running on Linux/i686 (2.6.8.1-20mdk).
wmhooks: netwm
DGA: server=2.0, include=2.0
VidMode: server=2.1, include=2.1
available video mode(s): 1024x768 800x600 768x576 640x480
Selected XvImage adaptor with YUY2 support: Matrox G-Series Backend Scaler on port 58
x11: 1024x768, 16 bit/pixel, 2048 byte/scanline
v4l: 1024x768, 16 bit/pixel, 2048 byte/scanline
v4l: framebuffer base=0xe3000000
v4l: mmap()'ed buffer size = 0x410000
......

.......
MMX and SSE detected.
......


  • My fps (Frame per second) is very bad: How can I correct it?

With some linux distributions (like Mandrake 7.2 distribution), you could meet this problem. We suggest you to install XvBogus (you can download it from xawdecode download section) or launching, at startup, Xawdecode with the -noxv option. (Xv method is better than noxv. noxv need more CPU).

This problem doesn't exist any more with XdTV.

  • XdTV is very slow: why?

Best results are obtained with XFree4.x / X.org and Xvideo extensions. If you can't use Xv, we suggest you to launch XFree / X.org with 16bpp rather than 24 or 32 bpp. You can also activate MTRR support in your kernel. If you use XFree86 version 3.x, you will have to indicate to the kernel where to find graphic card memory. This method is explained into the "Linux DVD HowTo".
   

  • On my screen, I have some white parasitic points when I switch from a grabdisplay channel to an overlay one (and vice-versa):

You have to activate, in your xdtvrc configuration file, this parameter: colorkey = 123456. This problem is related to the Xvideo colorkey which uses black color as color of transparency. So it is not a XdTV issue but a Xv one.
 

  • When I reduce window size, image is more and more deformed. What must I do?

If the bottom of the image disappear when you upwards stretch this image (this problem could appear when you switch from Xawtv to Xawdecode), the reason could be a non Scalling support of your Xv video driver. To correct it, you can:
Firstly, upgrade XFree86 from version 3 to version 4
Secondly, add, in your xawdecoderc configuration file, this parameter:
hw_scaling = off

This problem doesn't exist any more with XdTV.
 

  • Could you explain us what are the differences between each deinterlace filters?

Explanations about XdTV filters can be found into the DScaler project documentation web site: (http://deinterlace.sourceforge.net)...

  • Video Deinterlace (Bob) (This is the BOB filter used in XdTV)

 This method is based on Gunnar Thalin's VirtualDub filter. If it detects weaving artifacts in the current image it uses bob to get rid of them.
This method has a tendency to bob rather too much and gives poor results on fine static images.
 

  • Video Deinterlace (Weave) (This is the WEAVE filter used in XdTV)

 Similar to Video Deinterlace (Bob), however this method has a tendency to weave on moving images.
 

  • Video Deinterlace (2-Frame)

 This method uses the current frame and the last two to determine whether to bob or weave a given pixel. This gives better results on both stationary and moving images than the above two methods however it uses more CPU.
 

  • Simple Weave

 This method just combines the most recent even and odd fields. This causes motion artifacts and is provided for comparison.
 

  • Simple Bob

 This uses only the most recent field and fills the lines in between with interpolated pixels. This method has in may ways been superceded by Scaler BOB.
 

  • Blended Clip

 The BLENDED CLIP Deinterlace method is designed mostly for experimentation by those interested in what works for video deinterlacing. When it is selected it will pop up a control panel with many controls to adjust various parameters.
 These all correspond to Blc... parameters in the [Deinterlace] section of the DScaler.ini file and are documented there. It is probably not the single best method for anything but it can be used to create custom deinterlace methods for special purposes. These can be saved in a separate ini file and invoked by a command line parameter when starting DScaler.exe. Somewhat CPU intensive
 

  • Scaler Bob

 Uses the DirectDraw hardware bob feature (if available), this uses the current field and lets the video card scaler size the picture to fit the screen.
 Produces good results for fast moving images.
 

  • Even Fields Only

 Odd Fields Only (This is the ONE FIELD filter used in XdTV)
 These use only one field out of each pair and use hardware scaling. This reduces bob artifacts at the cost of loss of information. These were originally intended to be used with game consoles.
 

  • Adaptive Deinterlace

 This method uses the amount of motion detected to select the best deinterlacing alogoritm. Currently by default it switches between 2-Frame and weave.
 

  • Greedy deinterlace method

 The GREEDY Deinterlace method is designed to give good results on low motion video source, using less CPU than some others. Good on slower machines but it will give awful results on high motion video material like sports. Quite by accident, it can also do a decent job on poorly mastered 3:2 or 2:2 pull down film source material like some anime movies, regardless of low or high motion.
 Try it if you have a movie source that is not giving good results with normal Auto Pull Down processing.
 

  • Greedy 2 Frame method (This the GREEDY filter used in XdTV)

 This method tries to combine the best features of the 2-frame algorithm with the looking ahead ability of the greedy method. I find this methods works well on sports and other high motion material. With static images and low quality
 sources there may be unacceptable levels of bobbing.

  • Linear Blend method (This the LINEAR BLEND filter used in XdTV)

Linear Blend operates by taking a line, then averaging the pixel values in it with the line below, effectively blurring the frame. This almost completely eliminates the effects of interlacing - at times you may notice slight ghosting (instant transition from one thing to another), the image appears to persist for a fraction of a second. This is absolutely not a serious issue, as far as I am concerned - in fact it's really only noticeable if you are me, and a perfectionist.
 

  • I have some strange colors on screen when I play a Xawdecode avi file. How to correct this problem?

We suggest you to use the last version of your favorite avi file player (mplayer, aviplay or xine). If you still have the problem, you can force the avi player to use the divx4 codec: option -vc divx4 for aviplay or mplayer, and for xine, modify your xine config file (~/.xine/config) with "codec.divx4_priority:6".

This problem doesn't exist with XdTV.
 

  • I can't select any deinterlace filter: why?

In fact this problem is very simple. If you start Xawdecode with -noxv option you can't use deinterlace filters. You can only use these filters with Xv and Grabdisplay mode. These filters have been extracted from xine and dscaler source code. To use them you must be able to display YVU images, so, as it is not the case with the noxv mode, we can't use them. Also, in noxv mode all references about deinterlacing are discarded.

This problem doesn't exist with XdTV.

  • With devfs, video devices numbers are distributed automatically without any order. How can I force devices numbers?


options bttv pll=0 radio=0 card=1 tuner=3 video_nr=1 vbi_nr=1 gbuffers=4 fieldnr=1
######### End Tuner TV #########

You could do the same thing with Webcam. Use this parameter: dev_hint:

For example:
######### USB Webcam #########
alias char-major-81-0 pwc
alias sound-service-1-0 audio
alias sound-service-1-3 audio
alias sound-service-1-8 audio
alias sound-service-1-12 audio
options pwc dev_hint=0
post-install pwc /sbin/insmod --force /lib/modules/2.4.19-16mdk/kernel/drivers/usb/pwcx-i386.o.gz >/dev/null 2>&1 || :
pre-remove pwc /sbin/rmmod pwcx >/dev/null 2>&1 || :
######### End USB Webcam ######

  • XdTV compilation and optimization:

If you compile XdTV on you own PC, it will be optimized for your own CPU. It's possible to avoid this and to make (to build rpm or deb packages) a standard compilation. To do this you just need to add this option to the ./configure script :  --disable-cpu-detection

  • How to move or resize a window without any "window decoration"?


It's very easy. You just have to read this article (into this help file): "test window decoration"

  • I have some sound problems: sometimes there are some conflicts between XdTV and Xmms and XdTV sound become mute:

If you use Kde, this problem could be an artsd problem (artsd daemon). I advice you to never use this daemon and to desactivate it!

  • XdTV / Xawtv freeze after several minutes:


here is one explication:
"IRQ sharing is known to cause problems in some cases. It works just fine in theory and many configurations. Neverless it might be worth a try to shuffle around the PCI cards to give bttv another IRQ or make it share the IRQ with some other piece of hardware. IRQ sharing with VGA cards seems to cause trouble sometimes. I've also seen funny effects with bttv sharing the IRQ with the ACPI bridge (and apci-enabled kernel)."

So you just have to add this option to bttv in your modules.conf file: triton1=1
"The triton1 insmod option sets the EN_TBFX bit in the control register. The vsfx insmod option does the same for EN_VSFX bit. If you have stability problems you can try if one of these options makes your box work solid." (Thanks to Mat)

  • How to install nvtv (TV out pour nvidia) to watch XdTV on your TV:
Add this to the  /etc/x11/xf86config-4 file or to the  /etc/x11/xorg.conf file:

Section "Monitor"
Identifier "TV"
VendorName "GOLDSTAR"
ModelName "55cm"
HorizSync 30.0 - 50.0
VertRefresh 60

into "device" section:

Option "TwinView" "1"
Option "SecondMonitorHorizSync" "30-50"
Option "SecondMonitorVertRefresh" "60"
Option "MetaModes" "1024x768,1024x768;800x600,800x600;640x480,640x480"
Option "TVStandard" "PAL-N"

or that method:

Option "ConnectedMonitor" "CRT, TV"
Option "SecondMonitorHorizSync" "30-50"
Option "TwinView" "on"
Option "MetaModes" "1024x768 ,1024x768 ; 800x600 ,800x600 ; 640x480 , 640x480"
Option "TVStandard" "PAL-B"
Option "SecondMonitorVertRefresh" "60"
Option "TwinViewOrientation" "Clone"
Option "TVOutFormat" "Composite"

(Thanks to Mat and pourtout6)


Copyright (c) 2002 Keuleu - Pingus - BlindMan
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1
or any later version published by the Free Software Foundation;
with the Invariant Sections being LIST THEIR TITLES, with the
Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
A copy of the license is included in the section entitled "GNU
Free Documentation License".