[mythtv-users] PVR-150 Tuner Quality Issues

Brian Wood beww at beww.org
Sun Apr 16 18:42:31 UTC 2006


On Apr 16, 2006, at 11:19 AM, Michael T. Dean wrote:

> On 04/16/2006 04:41 AM, Michael Horn wrote:
>> First of all it looks like I mis-spoke in my last reply. It wasn't
>> that my tuner wasnt detected properly, it was that its type was being
>> set incorrectly. I've been playing around with the setup, and if all
>> tuner=xx options are removed,  it is detected as type 4. However,  
>> type
>> 4 seems to be equivilent to tuner not found or something of the sort
>> (at least according to
>> /usr/src/Documentation/video4linux/CARDLIST.tuners) So if I leave it
>> without a tuner=xx option, or try to set it to 4, its unsuccessful,
>> and I can only tune the channel that was last tuned, with no ability
>> to change it. When set as type=50, which I chose originally as it was
>> the closest match to my TCL M2523_5N_E. With that option, I can tune
>> all my channels, but with the quality issues.
>
> Tuner type 4 is "No Tuner."  It's used by cards without tuners.  Also,
> when a card has a tuner whose tuning characteristics have not yet been
> "identified," it's type is set to 4.  Therefore, the tveeprom module
> (which contains mappings of card data to tuner module characteristics)
> did not have any information to allow /auto-detection/ of your  
> tuner type.
>
> Your tuner's (TCL M2623_5N_E) characteristics were not yet  
> identified as
> of ivtv 0.4.4 and 0.5.x and 0.6.x rely on the in-kernel tveeprom  
> for all
> autodetection.  The tveeprom in the V4L CVS (which is slightly newer
> than the most-recent in-kernel module) has not yet identified the  
> tuner
> characteristics for your tuner, either.
>
> Therefore, you must pass a "tuner=" module option to ivtv ("options  
> ivtv
> tuner=xx") to select the closest match (at this point, there are  
> only 75
> to choose from--and you've already tried #4 ;)--but you can narrow  
> that
> down by selecting only the NTSC or PAL tuners as appropriate).  Your
> best bet for finding the right tuner is the IvyTV mailing lists.   
> There,
> you would likely find the closest matches (and, whether that's a true
> match or whether you need to patch your tuner module for proper  
> reception).
>

I guess I can understand why there might be 100 or more tuner  
modules, even though it seems ridiculous, but why on earth are there  
that many control protocols, since they all seem to need something  
different to control them.

Can you imagine if there were 75 or more different control protocols  
for hard drives? or serial ports? Even with things like scanners and  
printers, where every maker seems to want to have their own protocol,  
there are not *that* many different ones.

It seems like the video capture card manufacturers would revolt about  
having to have 75 - 100 different protocols, although if the  
characteristics are just loaded into an eeprom maybe they just don't  
care.

Still it seems like an incredible waste of resources, I guess that's  
what happens when nobody can/will force some consistency.


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