On Saturday 09 May 2009 19:39:37 Andy Walls wrote:
> On Sat, 2009-05-09 at 08:54 -0700, Jim Stichnoth wrote:
> > On Fri, May 8, 2009 at 5:28 PM, Andy Walls <[email protected]> wrote:
> > > 'osc', a test utility that comes with the libzvbi source code, is a
> > > great tool for seeing what the raw VBI lines look like that the
> > > PVR-150 is seeing.
> > >
> > > See this recent thread for how to use osc with the cx18 driver. It
> > > should be no different than the ivtv driver, except perhaps the ivtv
> > > driver will not need a video capture running at the same time.
> > >
> > > http://www.gossamer-threads.com/lists/ivtv/users/39891?page=last
> > >
> > > With my STB I have for ATSC to NTSC conversion, only the 2 CC lines
> > > in each frame are inserted in the VBI. Those lines are very clean
> > > and all the other lines are blank.
> > >
> > > My PVR-150MCE, which has a CX25843 A/V decoder, is showing VBI just
> > > fine in osc, and closed captioning signals from analog over the air
> > > show up on the proper lines (21 & 284):
> > >
> > > $ ~/build/zvbi-0.2.30/test/osc -2 -d /dev/vbi1 -v
> > >
> > > See attached GIF.
> > >
> > > Regards,
> > > Andy
> >
> > Thanks Andy, that is very helpful.
> >
> > Here is what dmesg says about my card:
> > ivtv: Start initialization, version 1.1.0
This is quite old. Sliced VBI was broken for quite some time and it wasn't
fixed until ivtv version 1.3 if I'm not mistaken. I recommend upgrading to
a newer kernel first (from memory: 2.6.26 or up).
> > ivtv0: Initializing card #0
> > ivtv0: Autodetected Hauppauge card (cx23416 based)
>
> Do you know what A/V decoder your board has: CX25843, MSPnnn, SAAnnnn,
> etc.?
>
> > I ran osc, and it looks like the DISH VIP211 is inserting 2 very clean
> > lines in the VBI with the rest blank.
> >
> > When I try to examine the raw VBI data (zvbi-ntsc-cc --cc -d
> > /dev/vbi0), I get good caption text. This is consistent with what
> > shows up on a direct TV connection.
>
> That's consistent with STB's. OK, so raw VBI capture and software
> decoding of CC works.
>
> What lines did osc say the CC waveforms were on?
>
> > When I try to examine sliced VBI data (v4l2-ctl -d /dev/video0
> > --set-fmt-sliced-vbi=cc ; zvbi-ntsc-cc -S --cc -d /dev/vbi0), I get
> > nothing at all. No errors, no warnings, no cc text printed. Just no
> > activity/output until I kill it.
> >
> > If I try either of these zbi-ntsc-cc commands while a MythTV capture
> > is going on, I get a series of messages "VBI read timeout (ignored)".
> > In addition, running with the -S option gives an initial error
> > message: "VIDIOC_S_FMT failed: Device or resource busy." I suppose
> > that confirms that MythTV is actively looking at the vbi device.
> >
> > So it looks to me like the driver is having troubles with the sliced
> > VBI. Any suggestions on diagnosing this?
>
> Nope. I'll have to test with my PVR-150MCE. If I can't reproduce the
> problem, I'll come up with suggestions.
>
> It looks like the VBI slicer in the CX25843 (if that's what you have) is
> not being set up properly, or the lines aren't being captured and
> decoded properly.
>
> I just fixed this for the cx18 driver for NTSC and am going to fix it
> for PAL this weekend (hopefully).
>
>
> Once I fix that, I'll try to look at the cx25840 module and ivtv module
> next weekend. The cx18's integrated A/V decoder is very much like a
> CX25843. What I would do will fix cx25840 and ivtv, but it might break
> sliced VBI in ivtv for other digitizers, or break sliced VBI for chips
> that do sliced VBI with a CX2584x.
>
>
> Hans,
>
> Does any other v4l module apart from ivtv use the cx25840 module for
> sliced VBI?
I don't think so. I believe ivtv is the only one.
Regards,
Hans
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG Telecom
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