[mythtv-users] PVR 350 TV out

Chris Martin council.tax at gmail.com
Tue Jan 18 07:28:41 EST 2005


On Tue, 18 Jan 2005 10:55:44 -0000, Nick <pvr at insidethex.co.uk> wrote:
> > I've been following Jarod's guide for FC3, and have got most things
> > working.  Unfortunately I'm having great difficulty getting my PVR
> > 350's TV out to work.
> >
> > If I run the commands
> >
> > # /sbin/rmmod saa7127
> > # /sbin/modprobe saa7127 test_image=1
> >
> > I see the test pattern correctly,  however if I try to pipe video
> > through the tv out, with the commands:
> >
> > # /usr/bin/ivtvfbctl /dev/fb1 -noglobalalpha -localalpha
> > # dd if=/dev/video0 of=/dev/video16 bs=64k
> > I just get what looks like a blank screen with a load of interference
> overlayed.
> 
> First unload the test image. Which input have you selected for output - you
> may be seeing the tuner which is likely not yet tuned to a signal. Can you
> see any movement on the TV or just snow?
> 
> Check to make sure your devices exist:
> 
> # ls -l /dev/video*
> 
> Also, check your system logs for the ivtv init output, this can provide
> useful info on what's happening.
> 
> Now repeat these two commands, changing x in the first command for values
> between 0 and 9:
> 
> # /usr/bin/ivtvctl -p x
> # dd if=/dev/video0 of=/dev/video16 bs=64k
> 
> This will go through the card's inputs in turn - hopefully you'll see
> something on the TV on one of them - have you got a composite or S-Video
> source hooked up to the card?
> 
> If /dev/fb1 is your ivtv framebuffer you can also try:
> 
> # /usr/bin/ivtvfbctl /dev/fb1 -globalalpha -nolocalalpha
> 
> or
> 
> # /usr/bin/ivtvfbctl /dev/fb1  -alpha -on -globalalpha -nolocalalpha (I have
> to use this one)
> 
> to try to get rid of the lines on the screen when ivtv loads.
> 
> > I've also tried to run X through the tv out, using the appropriate
> > xorg.conf file.  In this case I get a static screen made up of lots of
> > tiny dots that looks pink/purple/blue from a distance.
> 
> Try and get normal TV-out working first, then X once this is working
> normally.
> 
> Check here for ivtv help:
> http://www.gossamer-threads.com/lists/ivtv/devel/ - lots of valuable info.
> 
> Nick
> 
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> 

Thanks for your reply,

Here's a better explanation of what happens:

# /sbin/rmmod saa7127 [completely blank screen on tv]
# /sbin/modprobe saa7127 test_image=1 [test image of coloured lines on tv]
# /sbin/rmmod saa7127 [back to blank screen]
# /sbin/modprobe saa7127 [black and white fuzzy background, overlaid
with 5-6 horizontal and diagonal flickering lines]
#/usr/bin/ivtvfbctl /dev/fb1 -noglobalalpha -localalpha [background
goes darker, still have flickering lines]
#dd if=/dev/video0 of=/dev/video16 bs=64k [sound comes out of the tv's
speakers.  No change to the screen]
ctrl-c
# /usr/bin/ivtvfbctl /dev/fb1  -alpha -on -globalalpha
-nolocalalpha[background goes black, still have the flickering lines
but not so bad].
#dd if=/dev/video0 of=/dev/video16 bs=64k [sound comes out of the tv's
speakers.  the background changes to something that could be a very
distorted black and white tv signal, but could not be, still have
those flickering lines]
ctrl-c

Just to check that my tv signal is ok
#cat /dev/video0 > /tmp/test_capture.mpg
#mplayer -vo xv /tmp/test_capture.mpg

results in a perfect picture through the monitor.

I couldn't find anything in the logs and # ls -l /dev/video* shows
that my devices exist.  I'm in the UK, so I'm using an S Video ->
Scart cable going into a PAL TV.  Am I right in thinking that as the
test patter displays ok, I can rule out a problem with my cable?

Thanks,

Chris


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