[linux-dvb] Is anyone else running a CX18 in 64bit OS?

Andy Walls awalls at radix.net
Sat May 10 03:48:08 CEST 2008


On Fri, 2008-05-09 at 21:10 -0400, Brandon Jenkins wrote:
> On Fri, May 9, 2008 at 8:14 PM, Andy Walls <awalls at radix.net> wrote:
> > On Fri, 2008-05-09 at 15:55 -0400, Brandon Jenkins wrote:
> >
> > Brandon,
> >
> > Yes I'm running the cx18 driver with an HVR-1600 on a 64 bit OS.
> >
> >> I have noticed an appreciable difference in video capture quality.
> >
> > The first analog capture after a modprobe of the cx18 is usually
> > terrible and unwatchable due to apparently lost frames or no initial
> > audio followed by audio and lost frames.  The work around is to stop the
> > analog capture and restart.
> >
> > Would you characterize the analog capture quality problems as being only
> > on weak channels or strong channels as well?
> >
> >>  The
> >> timeline for the change is exactly the same time that development
> >> ceased on the IVTV version of CX18 and moved to V4L.
> >
> > I'm not clear on exactly what versions you mean.  Do you have hg
> > repository names and change ID's?
> >
> >
> >>  I see heavy
> >> pixelation in analog capture and the dvb tuner module returns far
> >> fewer channels on a scan than before. I would like to troubleshoot,
> >> please let me know what is needed.
> >
> >
> > Since you have the two particular source trees at hand, could you do a
> > recursive diff so we can see the changes?  That hopefully will narrow
> > the search for potential causes.
> >
> > Regards,
> > Andy
> >
> >> I am attaching dmesg/channel.conf/channel scan output for v4l drivers
> >> comparing the results from a cx18 and a cx23885 card. (hvr-1600 and
> >> hvr-1800) If I switch back to the older ivtv and mxl500s dvb tuner all
> >> works fine.
> >>
> >> Thanks in advance
> >>
> >> Brandon
> >
> >
> >
> Andy,
> 
> Thanks for the response.
> 
> I am running the following command in rc.local to start a capture and
> then kill it.
> 
> cat /dev/video3 > /dev/null & sleep 8 && kill $!
> 
> Is that sufficient for an initial capture?

Without testing it, I'm going to say, I imagine it would be from the
look of it.


> I am recording via svideo from a DirecTV signal. All signal levels are
> consistent.

OK.  I looked at the cx28885 channels.conf, after I sent the questions,
and noticed you didn't have terrestrial over the air source.  I saw you
have the same local channels on QAM that I get over 8-VSB: WETA-HD,
WUSA-HD, 9-Radar, CW50, etc.

> The driver base which works for me is cx18-8788bde67f6c it is the
> older cx18-ivtv branch

This is precisely the version (with a small change for auto chroma
subcarrier locking) that I use when I need to leave my machine with a
reliable cx18 driver with digital capability for use with MythTV.
("General Hospital" *must* be recorded properly daily!)


> The version I am having issues with was built from a v4l-dvb pull this morning.
> 
> I did not mention this in my email but it was in the log files; I am
> scanning QAM for DVB. With the mxl500x.ko frontend everything works
> well. With mxl5005s.ko in the new v4l-dvb scanning is broken.

OK.  Steve just introduced that mxl5005s driver from a separate code
base.  I've copied him on this e-mail to let him know of the problem.

I'll have to do the pull and test scanning my 8VSB stations.

-Andy

> rdiff -r cx18-8788bde67f6c v4l-dvb output attached.
> 
> Brandon




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