[mythtv-users] Using PVR-350 TV Out with Nebula DigiTV DVB Card

Stephen Longhurst steve at longsteve.com
Tue May 11 19:17:28 EDT 2004

Hi all,

I'm having an interesting issue with MythTV when using a Nebula DigiTV
DVB card with PVR-350 TV output.  My setup has a PVR-350, PVR-250 and
a DigiTV, all of which seem to be working pretty well.   

If I run mythfrontend on my monitor, everything works
as expected.  I can switch between the PVRs and DigiTV without
problems, use Picture-In-Picture, record from one input and
watch another etc, basically everything is great.  It's really exciting
seeing just how powerful and flexible mythtv really is.  It's a credit
to everyone working on it.

However, If I enable the PVR-350 tv out for video, the digital channels
don't work at all.  I continuously get this error on the backend  

DVB#0 WARNING - No data from card in 1 second.

with a black screen on the frontend.  Eventually things time out.  At
the same time, dmesg shows lots of the following message:
bt878(0): irq FDSR risc_pc=1746d210

Now to the interesting part. I can load the ivtv-fb module and enable
the tv output (using modprobe saa7127 enable_output=1 output_select=1   
pal=1) and bring up X.  This gives me two displays :0.0 and :0.1, as
normal.  To get mythtv on my TV, I do:
DISPLAY=:0.1 mythfrontend
Ths is how I get the above described problem.

However, if I just bring up mythfrontend on the monitor (and don't
enable pvr-350 out), then view a digital (dvb) channel and move the
mouse over to the TV display I get the following errors on the backend

DVB#0 WARNING - Transport Stream Continuity Error. PID = nnn

where nnn are both the audio and video pids I think.

I can see the mouse pointer moving on the TV, errors occuring in the
dvb stream and the picture breaking up, although not in a big way, just
stream failure artifacts (green blocks on the screen, etc).  Everything
goes back to normal when I stop moving the mouse on the TV (framebuffer)

It looks like there might be a conflict between the ivtv-fb and the
bttv/dvb modules.  I thought I'd post here and ask if anyone has seen
the same problem and may/may not have a fix for it?

System details are : kernel 2.4.26, patch-2.4.26-kraxel,
linux-2.4.26-i2c-2.8.4.patch (for lmsensors on 2.4 kernel), bttv-0.9.14,
ivtv-0.9.1, linux-tv-dvb-1.1.1, mythtv cvs

I'm going to try getting the nvidia tv-output working as an
alternative to the pvr-350, since I've got an MX440 card I can try.
Maybe this won't conflict?  I have a feeling it's something in the i2c
subsystem that's going wrong, but that's way out of my league!

Thanks very much,


Steve Longhurst
steve at longsteve.com

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