Re: zvbi-atsc-cc device node conflict

[David Liontooth <lionteeth@cogweb.net>]

HoP wrote:
> 2010/4/17 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?
>>
>>     
>
> Very dump way is simply feed zvbi with resulting test-cat3.mpeg.
> If this page is correct: http://www.digipedia.pl/man/doc/view/zvbi-atsc-cc.1/
> using -t command line option you can get CC by issuing something like
> "cat test-cat3.mpeg > zvbi-atsc-cc -ts -C test-cc.txt"
>
> Of course I'm assuming that CC pid is included in recording.
> But dunno if azap is demuxing pids others then A/V.
>
> /Honza
>
>   
That's promising but no cigar:

 cat test-cat3.mpeg > zvbi-atsc-cc --ts

just feeds the output of the cat into a file called zvbi-atsc-cc (not 
surprisingly).

  cat test-cat3.mpeg | zvbi-atsc-cc --ts

also doesn't work. zvbi-atsc-cc's --ts switch is designed to "Decode a 
DVB Transport Stream on stdin", so if the file created with

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

qualifies as a DVB Transport Stream, then there's a way to pipe it to 
zvbi-atsc-cc.  How do we get the syntax for this?

I'm also wondering if zvbid, the zvbi daemon, could be used to get a 
text file output from zvbi-atsc-cc. This would seem the more elegant 
solution.

Cheers,
Dave