[pvrusb2] mythtv: Failed to open the card

[roger]

On Wed, 2006-12-20 at 10:54 +0100, Tamas K Papp wrote:
> Thanks, I got it working.
> 
> At the moment it appears that mythtv is an overkill, so I will
> probably use mplayer to play and something like cat to record.
> 
> I would appreciate advice from people who use simple tools for
> recording and watching, especially about the following:
> 
> 1. how do you record?  cat /dev/video0 > film.mpg, or something more
> sophisticated?

See my web page:
http://www.eskimo.com/~roger/programming/pvrusb2.html


A simple test resulting in a playable MPEG2 file.

$ cat /dev/v4l/video0 > test.mpg

Here is the conantation for getting live playback using mplayer: 

$ mkfifo test.mpg
$ cat /dev/v4l/video0 > test.mpg | mplayer test.mpg

I'm guessing Mike's webpage is going to have this as well. 

> 2. how do you set the channel? cat frequency into the sysfs?

It's been awhile since I've read Mike's webpage thoroughly.  But
basically, echo "blah" > /sys/class/pvrusb2/sn-*/{one of the files
concerning channel changing}

Last I read, this required the channel frequency.  And you had to
reference you're channels number to frequencies within a script or
something (never done it here).

>3. is there any simple filtering one can do to remove fuzzy edges?
> something like
> cat /dev/video0 | mplayer magic > film.mpg

I would imagine using a crop feature of mplayer/mencoder?   How about
aspect feature (zoom)?  I think both mplayer & mythtv have an aspect
zoom feature.  The best is probably using a mpeg2 stream editor after
recording the stream to file.  I'm guessing mencoder or transcode
(transcode is multithreaded).

> Any other advice would be appreciated, and I am happy to try (and even
> compile) any tool you recommend.
> 
> Thanks,
> 
> Tamas

Tamas, I think mythtv is just great for player back only as well.
Granite, setup is over kill as most of us sometimes "just watch tv and
record only a few shows".  But once you setup mythtv, you only have to
fiddle with the settings every now & then.  Xawtv cvs version will
playback mpeg2 streams & perform some simple streaming, last I heard,
xawtv is currently inactive development (I could be wrong here).

There's a couple of other perks of mythtv for those of us who rarely
record.  There's a plugin called mythweb and pushes settings and program
data to your local http.  Although there are yahoo TV listings and TV
Guide data via web, the .com methods are usually bloated with scripts
and ADS taking >1 minutes to load into a browser.  With mythweb, the
tvguide program listings are already in your mysql database and are
readily displayed via your local http protocol (ie.
http://localhost/mythweb/ :-)

I still curse mythtv for it's methods of setting options as they are
complex menu systems.  But it has to be this way for IR cursor & field
selection movement.  I usually define a second display (ie. using
DISPLAY=":0.1" mythfrontend -l /dev/null & after setting up my xorg.conf
with a second tvout display).  This way, mythtv is on a second display
and out of the way of my usual working desktops.  It's there if I need
it, but I usually don't.  (Sorry, got a little carried away in my last
paragraph here. :-)



--
Roger
http://www.eskimo.com/~roger/index.html
Key fingerprint = 8977 A252 2623 F567 70CD 1261 640F C963 1005 1D61

Wed Dec 20 09:53:16 PST 2006