Xawtv usage

A place for discussion of topics that are not specific to ZoneMinder. This could include Linux, Video4Linux, CCTV cameras or any other topic.
Post Reply
decibel83
Posts: 80
Joined: Tue Dec 06, 2005 5:22 pm

Xawtv usage

Post by decibel83 »

Hi.

How I can use Xawtv or Vlc to test a multichannel bt878 card?
I don't understand what is the command and what are the parameters to specify the input channel to view (my card has 4 channels).

Anyone could explain me this thing, please?

Thank you very much!
Bye.
nakedfarmanimals
Posts: 20
Joined: Fri Jun 15, 2007 9:46 pm

Post by nakedfarmanimals »

From their FAQ : http://linux.bytesex.org/xawtv/faq3.html

Q: xawtv doesn't show anything
xawtv supports a wide range of hardware. Chances are good that xawtv simply tries to talk to another device than you expect. That is a common problem with nvidia cards which have a video port (for nvidia's composite input maybe?). xawtv picks that one instead of the TV card by default.

Try "xawtv -hwscan" to get a list of devices xawtv is aware of. Every device you can ask xawtv to use has the command line option needed to do that listed in brackets. The first device in the list is the default which xawtv will use if no other device is specified on the command line. Example:

eskarina kraxel ~# xawtv -hwscan
This is xawtv-3.91, running on Linux/x86_64 (2.6.5-rc1)
looking for available devices
port 69-69 [ -xvport 69 ]
type : Xvideo, video overlay
name : video4linux

port 70-70 [ -xvport 70 ]
type : Xvideo, video overlay
name : video4linux

port 71-71
type : Xvideo, image scaler
name : ATI Radeon Video Overlay

/dev/video0: OK [ -device /dev/video0 ]
type : v4l2
name : BT878 video (Hauppauge (bt878))
flags: overlay capture tuner

/dev/video1: OK [ -device /dev/video1 ]
type : v4l2
name : Proteus Pro [philips reference
flags: overlay capture tuner


Default device in that case is Xvideo port 69, which is a video port driven by the X-Server's v4l module. If I want xawtv speak directly to the WinTV card using the v4l2 API I'll have to start xawtv with the "-device /dev/video0" switch.



Hope that this helps. Damn... did I really hit "bytesex.org" from work?
Jim March
Posts: 88
Joined: Thu Oct 04, 2007 8:31 am

Post by Jim March »

Unless somebody can explain otherwise, what my testing says...

OK, I have a pair of ImpactVCB cards with three ports each.

I have three cameras per card.

I can start two terminal windows, and on each do:

xawtv -device /dev/video0

xawtv -device /dev/video1

...and then in each instance, pick a composite input port to view.

What I cannot do is one or the other twice, and view one composite input on one window, another on another.

Each card has just one graphics processor chip, is the problem. I can view inputs from two different cards at close to 30fps in my rig no problem, but...to continuously view and/or record all six inputs even at crippled frame rates, ZM is allegedly the answer. I'm close to making it work, just got some performance tuning to do...

http://www.zoneminder.com/forums/viewtopic.php?t=10484
User avatar
Lee Sharp
Posts: 1069
Joined: Sat Mar 31, 2007 9:18 pm
Location: Houston, TX

Post by Lee Sharp »

In most cases you can not watch 2 channels at once on a TV as well. You have one capture chip, and 4 channels. ZM works around this by polling each channel in turn.
Post Reply