Re: zvbi-atsc-cc device node conflict

[David Liontooth <lionteeth@cogweb.net>]

HoP wrote:
> 2010/4/17 Devin Heitmueller <dheitmueller@kernellabs.com>:
>   
>> On Fri, Apr 16, 2010 at 7:19 PM, David Liontooth <lionteeth@cogweb.net> wrote:
>>     
>>> I'm using a HVR-1850 in digital mode and get good picture and sound using
>>>
>>>  mplayer -autosync 30 -cache 2048 dvb://KCAL-DT
>>>
>>> Closed captioning works flawlessly with this command:
>>>
>>> zvbi-atsc-cc -C test-cc.txt KCAL-DT
>>>
>>> However, if I try to run both at the same time, I get a device node
>>> conflict:
>>>
>>>  zvbi-atsc-cc: Cannot open '/dev/dvb/adapter0/frontend0': Device or resource
>>> busy.
>>>
>>> How do I get video and closed captioning at the same time?
>>>       
>> To my knowledge, you cannot run two userland apps streaming from the
>> frontend at the same time.  Generally, when people need to do this
>> sort of thing they write a userland daemon that multiplexes.
>> Alternatively, you can cat the frontend to disk and then have both
>> mplayer and your cc parser reading the resulting file.
>>
>>     
>
> Usually there is some way, for ex. command line option,
> how to say to "second" app that frondend is already locked.
> Then second app simply skips tuning at all.
>
> Rest processing is made using demux and dvr devices,
> so there is not reason why 2 apps should tune in same
> time.
>
> /Honza
>   
Thanks! I'm trying to create separate recordings of the video/audio file 
on the one hand and the closed captioning on the other.

In one console, I issue
 
  azap -r KOCE-HD

In a second, I issue

  cat /dev/dvb/adapter0/dvr0 > test-cat3.mpeg

I cannot at the same time run this in a third:

  zvbi-atsc-cc -C test-cc.txt KOCE-HD

because of resource conflict.

Using cat works, but how do I get closed captioning from the resulting 
mpeg file?

If I can get that to work, that would be great -- but not particularly 
elegant. Does someone have an example of a multiplexing userland daemon 
that allows me to spit out video to one file and text to another?

Cheers,
Dave