[mythtv-users] Extracting QAM streams outside of Myth

[Brian Wood]

On Jun 14, 2006, at 2:05 PM, Preston Crow wrote:

> On Wed, 2006-06-14 at 13:59 -0600, Brian Wood wrote:
>> On Jun 14, 2006, at 1:36 PM, Preston Crow wrote:
>>
>>> On Wed, 2006-06-14 at 13:22 -0600, Greg Woods wrote:
>>>> On Wed, 2006-06-14 at 14:44 -0400, Preston Crow wrote:
>>>>
>>>>> Not all of the streams are watchable channels.  I still want to
>>>>> extract
>>>>> them to find out what they are.
>>>>
>>>> I found the qamscan.sh script recently posted here to be useful for
>>>> this. It finds tunable channels and makes a channels.conf file
>>>> that can
>>>> be used by azap. You still have to go through the channels one  
>>>> by one
>>>> afterward to identify them, but at least it narrows down the
>>>> streams to
>>>> those that are tunable channels.
>>>>
>>>> http://www.tux.org/~peterw/#qamscan
>>>
>>> I'm trying to get the opposite of that.  I can get the watchable
>>> streams.  I want to look at the data in the unwatchable streams.
>>>
>>
>> azap and the like will find all the streams,not just the watchable
>> ones. If you find that a strem is not watchable video couldn't you
>> just save it to a file and look at it with various tools (hex editor,
>> or try to interpret it as an image etc.).
>
> Right, that's my question.  How do I do that?  I can tune with  
> azap, and
> see the streams with dvbtraffic.  How do I extract one of those  
> streams
> and save it in a file?

Maybe I'm being too obvious here, but couldn't you  just cat the  
output of the demuxer to a file ??

cat /dev/dvb/adapter0/demux0 > testfile

This assumes it is muxed in a form that your card can understand of  
course, but it's what I would try first.

Or am I way off base here, I haven't had much sleep lately :-)