[linux-dvb] AverTV Hybrid Volar HX

Michael Krufky mkrufky at linuxtv.org
Mon Dec 31 19:56:12 CET 2007

Steven Toth wrote:
> Michael Krufky wrote:
>> Manu Abraham wrote:
>>> This device might be supported soon. Other than that, I guess the 
>>> TDA18271 driver doesn't support DVB-T as of now.
>> Actually, I have heard reports from some people that they have gotten
>> the tda18271 to work for DVB-T in their tests.  I haven't been able to
>> successfully test that yet myself, but I welcome patches if there are
>> any problems with the driver.
> Mike,
> Is their something Hauppauge can do to help with this?


If there are no bug reports, then there are no bugs to be fixed. (do you like the satire?)

If someone REPORTS a bug, then we can look at the problem.

Let me re-phrase -- Hauppauge can help, if interested, by finding somebody to write a GPL'd driver for a DVB-T demod found on a board that also uses the tda18271 -- after that, I'll be able to test DVB-T.

Until now, AFAIK, the tda18271 module works in all analog modes, ATSC / QAM, and has only been tested for use with DVB-T (and DMB-T) in a closed circuit.

There are a few obvious places that need adjusting to improve the tuning quality -- I am working on improving the tuning algorithm and rf tracking filter calibration scheme.

If there is any bug anywhere preventing DVB-T from working, it would be related to the std bits / IF (all found in tda18271_set_params).  I believe that there may be some device-specific configuration that I've been thinking of moving into an attach-time parameter, but until I see a need for it ( bug reports ? ) I'll leave it as-is.

I have not spend much time with DVB-T support on this tuner, since I don't have any devices with all known supported hardware except for the new tuner.  If there were drivers available for newer demods that are usually found with this tuner on DVB-T boards, then maybe I'd have an easier time testing it.

Right now, I am working on adding support for the C2 revision of this device.  I already have digital mode working, tested with QAM256 so far, and I have a rock-solid signal.  Analog works too, but it's really just limping for now.  I have not pushed up the c2 support yet -- my tda18271c2 tree is just a staging area, and still only supports the c1 tuner.

If the "mystery vendor X" has a C2 tuner, it _will_not_ work with the driver in my public repository.

I will not merge in C2 support until after I clean up my patches here in my local sandbox, unless anybody out there is specifically interested in testing it... If so, send me an email and I'll push up today's snapshot to a test repository.  Even still, I'd rather clean it up first -- should just take a few more hours of work.

Manu Abraham wrote:
> Some of the vendors (more than one) wrote to me that the TDA18271 driver 
> doesn't work. That was the basis of my statement.

Silly vendors.  Why write to _you_ about somebody else's work?

If they are interested in participating in the open source community, they should file their own bug reports, and be sure that they are received by the author of said driver.

-Mike Krufky

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