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pyther

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Registered: 2008-01-21

Posts: 1,395

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Record from Tv Tuner (Composite)

I need to record from the composite port of my tv tuner. I have the KWorld ATSC 115. I am able to see the video in tvtime, but I'm not sure how to record it. I tried xawtv but the quality was just awful!

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pyrrhicvictory

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From: Rradhat e UCK-se

Registered: 2007-12-21

Posts: 39

Re: Record from Tv Tuner (Composite)

Hey pyther. I have a hauppage card, and hopefully this command gives you a better idea of what you should do.

cat /dev/video0 > file.mpg

But I think mine encodes to mpg on the fly... Not really sure how it works. See what happens (your card location may be different)

pyther

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Registered: 2008-01-21

Posts: 1,395

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Re: Record from Tv Tuner (Composite)

Thank you, however I get this error

[pyther@tux ~]$ sudo cat /dev/video0 > file.mpeg
cat: /dev/video0: Invalid argument

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pyrrhicvictory

Member

From: Rradhat e UCK-se

Registered: 2007-12-21

Posts: 39

Re: Record from Tv Tuner (Composite)

You have to know where the device is mouinted for that command to work. For me, its /dev/video0 for you it may be something else. stry different number combinations like video1 or just try /dev/video

pyther

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Registered: 2008-01-21

Posts: 1,395

Website

Re: Record from Tv Tuner (Composite)

Yes, but I only have video and video0, both which give the same error...

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Arch User since March 2005

pyrrhicvictory

Member

From: Rradhat e UCK-se

Registered: 2007-12-21

Posts: 39

Re: Record from Tv Tuner (Composite)

Oddly enough, after looking at the mythtv howtos for your card, it should be /dev/videoX

This may be a loooong shot, but try /dev/vbi0

If at this point you still get nothing, you may want to consult your kernel logs

(you DID modprobe, right?)

azleifel

Member

Registered: 2007-10-28

Posts: 486

Re: Record from Tv Tuner (Composite)

I know nothing much about ATSC cards but I'm sure that they are not that different from "normal" TV cards:

Is the card set up properly?  The mythtv wiki article at http://www.mythtv.org/wiki/index.php/Kworld_ATSC_110 seems to be reasonable and it's telling me that this is an saa7134 card and so should work easily on Linux.

Check dmesg to make sure that the card is being recognised correctly at boot.  For alsa sound, add

"options saa7134 alsa=1"

to /etc/modprobe.conf.

The other thing that wiki article tells me is that the card does not have a hardware mpeg encoder, so a "cat /dev/video0 > somefile.mpg" won't work for analogue signals.  In any event, the card needs to be tuned to a channel or set to use the composite input first.

Can the card be controlled with v4lctl (comes with xawtv)?  Try

v4lctl -c /dev/video0 list

If the output includes a line that's similar to this from my MSI TV@Anywhere saa7134 card

input      | choice | Televis | Televis | Television Composite1 Composite2 S-Video

then you're in business.  A command like

v4lctl -c /dev/video2 setinput Composite1

can be used to set the card to the correct input.  Mencoder or transcode are possible candidates for recording the card's output.

Last edited by azleifel (2008-06-27 19:40:06)