[mythtv-users] Cropping with PVR-150

Bobby Gill bobbygill at rogers.com
Wed Oct 1 23:40:49 UTC 2008


On Wed, Oct 1, 2008 at 2:40 PM, Jim Stichnoth <stichnot at gmail.com> wrote:

> On Thu, Sep 25, 2008 at 9:59 AM, Jim Stichnoth <stichnot at gmail.com> wrote:
>
>> I recently installed a Hauppauge PVR-150 to complement my two HDHomeRun
>> boxes, with the s-video input connected to a DirecTiVo box.  I have closed
>> captioning enabled in the mythtv setup, which works great, except that the
>> PVR-150 seems to be cropping around 10 lines from the top, and inserting a
>> horizontal black bar at the bottom.  Doing "cat /dev/video > /tmp/foo.mpg"
>> and then playing foo.mpg with xine or mplayer also shows the black bar (as
>> well as a smaller vertical black bar on the left), and foo.mpg is at 720x480
>> resolution.
>>
>> If I first execute "v4l2-ctl -b off", then the bottom black bar is no
>> longer there in foo.mpg (though the small black bar on the left is the
>> same).  I'm guessing that the PVR-150 and/or ivtv are helpfully stripping
>> the VBI information.  But this is not really necessary since I already have
>> global settings to deal with the flickering VBI line in the picture that the
>> HDHR picks up from digital SD broadcasts.
>>
>> Is there a way to get rid of this bottom black bar and also keep closed
>> captions?
>>
>> I'm running MythDora 5.  I'm not quite sure how to figure out what version
>> of ivtv I have.
>>
>> Jim
>>
>
> I took a couple of screen shots to show the problem more clearly.  I paused
> the input source (an SD DirecTiVo), then ran either "v4l2-ctl -b cc" or
> "v4l2-ctl -b off" to turn closed captioning on or off, and then captured a
> frame using xine.  If you flip back and forth between the two images, it's
> clear that the first several lines are being cropped and everything shifted
> up when cc is enabled.  It's also interesting that even with the uncropped
> picture, the VBI stuff has apparently already been removed.  If I had to
> guess, I would say that VBI removal is being done twice when cc is on.  (I
> would prefer that VBI were not removed at all, so that MythTV overscan or
> whatever could be applied consistently to all inputs.)
>
> cc on: http://www.flickr.com/photos/37377999@N00/2905480460/sizes/o/
> cc off: http://www.flickr.com/photos/37377999@N00/2905480878/sizes/o/
>
> Any ideas on this?
>
> On a barely related note, I was also experiencing the PVR-150 "tinny audio"
> problem on many recordings, but the various tweaks suggested on mailing
> lists weren't fixing it.  (I was trying to add the extra commands to my
> channel changing script.)  I finally realized that mythtv doesn't start
> capturing from the PVR-150 until after the channel change script completes.
> The solution was to run a background command from the channel change script
> that delays a few seconds and then executes the command.  In my bash script,
> the last line is this:
>         ( sleep 5; v4l2-ctl --set-audio-input 1 -d /dev/video0 > /dev/null
> 2>&1 ) &
> I'm sure there's something similar for people using perl scripts.
>
> Jim
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
>

What is the "tinny audio" problem? I have a PVR150 and get a wierd little
sound that I don't quite know how to describe, on certain channels,
wondering if this is what you're talking about.

Thanks
Bob
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mythtv.org/pipermail/mythtv-users/attachments/20081001/08c3d18f/attachment.htm 


More information about the mythtv-users mailing list