[pvrusb2] mythtv and wintv-hvr-1950 - analog/digital scanning

[Mike Isely]

On Sun, 4 Jan 2009, fivenote wrote:

> Thanks Mike.
> 
> I think I am telling it QAM mode. In myth TV backend config I choose
> "us-cable" as the "Channel frequency table". I'm doing exactly as I
> did yesterday when it found all the cable channels. Only thing I
> changed was to compile the latest v4l drivers from
> http://linuxtv.org/hg/v4l-dvb. After that the DVB/broadcast channels
> started working and MPEG/cable channels disappeared.
> 
> My developer's sense (I'm a web app developer) says the fix for the
> DVB broke the analog side. Please feel free to pass this on to the DVB
> develpoers.
> 
> BTW... overall the developers that contribute here are doing a great
> job. I'm excitied to be so close to having this all work.
> 
> -vincent
> 
> On Sun, Jan 4, 2009 at 9:39 PM, Mike Isely <isely at isely.net> wrote:
> > On Sun, 4 Jan 2009, fivenote wrote:
> >
> >> Mike,
> >>
> >> Thanks so much. Your explanation made sense. I got the latest v4l
> >> driver source from linuxtv.org. It compiled and installed ok. I
> >> noticed it came with a version of pvrusb2 so I used that instead of
> >> the pvrisb2 I had compiled separately before.
> >>
> >> Now I get tons of HD ATSC channels. But I lost my cable channels. I
> >> scanned the input connection for [MPEG : /dev/video0] and get all "no
> >> signal". I had all my expected channels before upgrading the v4l
> >> drivers and now none. I checked the myth and system logs,but nothing
> >> obvious.

  [...]

Vincent:

Ah, I misread your post.  I thought you were trying to scan for digital 
cable channels.  But you said analog and you had clearly stated 
/dev/video0, the V4L device entry point.  While it's possible that there 
might be problem in the tuner chip's driver, there's another more likely 
possibility:  You can't run the DVB and V4L sides at the same time.  If 
something is holding the DVB side open, the V4L side will be prevented 
from tuning or streaming - it can't run because the hardware resources 
needed are busy servicing the DVB side.

If you're running this completely under MythTV and you've told MythTV 
that the two devices are related to one another (have you?) then this 
collision should not have happened.  If MythTV doesn't know that the two 
sides map to the same hardware then it might erroneously try to operate 
both sides at once.  Alternatively if you might have had something else 
holding the DVB side open when you tried to touch the V4L side (for 
example an instance of the DVB azap utility), then the V4L side won't 
operate.

Knowing that, does this help?

  -Mike

-- 

Mike Isely
isely @ pobox (dot) com
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