[mythtv-users] PVR-250 composite-in gives black video---why?

Nick knowledgejunkie at gmail.com
Fri Dec 9 06:00:43 EST 2005

On 09/12/05, f-myth-users at media.mit.edu <f-myth-users at media.mit.edu> wrote:
> In 0.18.1, ivtv 0.4.1:
> I'm convinced I'm doing something dumb, but I can't see it.
> I'm trying to set up a PVR-250 such that it can record from either
> analog cable via its RF-in, or from digital cable via its composite
> input, which is connected to a cable box.  I defined two different
> lineups at zap2it, one corresponding to each, with the digital lineup
> having only one channel enabled (since I'm not trying to change
> channels on the cable box under machine control yet---I'm just trying
> to get the video signal path working first).  I assigned the digital
> lineup to the Composite 0 input of card #0 (e.g., /dev/video0), so
> that card now had both Composite 0 and Tuner 0 assigned.
> If I try to record an analog channel via RF, it works as it always
> did.  If I try to record the single digital channel, I get black
> video.  I'm running the backend with "-v all" and see the logging
> below, which sure looks like it's trying to change to composite-in.
> I've tried plugging the end of the cable that's plugged into the
> PVR-250 directly into a TV, and I see video.  I verified that I knew
> which card was card 0 by unplugging the RF input while recording via
> RF, and sure enough the recording went to snow.
> So why am I seeing nothing but black video?  It -does- work to have a
> single card set so it switches between RF-in and composite-in, right?

I do this on my PVR-x50 cards without a problem. I'd guess the problem
you are experiencing is likely because in input connections setup, you
are using the incorrect Composite input (my -350 card has 4 of these,
and choosing the wrong one gives either b/w picture or nothing) When I
set my -350 card up last year, I tested the various inputs using
ivtvctl from the command line, but you could just select each one in
turn in Input Connections and see which gives you a colour picture.

Also, when setting up a PVR-x50, the correct input (S-Video or
composite) is not always necessarily #0 for the first card.

Good luck,

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