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[linux-dvb] Re: FF cards alter PTS'?



Oliver Endriss wrote:
On Thursday 20 November 2003 20:56, Holger Waechtler wrote:

Oliver Endriss wrote:

On Thursday 20 November 2003 15:59, Robert Schlabbach wrote:


From: "Klaus Schmidinger" <Klaus.Schmidinger@cadsoft.de>

Robert Schlabbach wrote:


AFAIK, the specs for the TT designs have never been published either,
and the drivers you have now are the result of guessing and reverse
engineering. I don't see why this shouldn't be repeated for more
up-to-date designs than the old TT ones...
True - but soembody actually has to _do_ this ;-)
Apparently the interest in this isn't high enough, yet...
Maybe the incentives just aren't high enough - why bother reverse
engineering a design that's technically no improvement over the TT ones?
Now if there was a card that was actually a technical advance (e.g. a
DVB-S2 card, or a hybrid DVB-C/T card, or a card with a better suited PCI
bridge with a deep FIFO, or a card with a much quicker sync'ing
demodulator), I'm sure someone would get into reverse engineering it...

Exactly, that's the point.

IIRC some recent budget cards also require closed-source firmware,
which has to be taken from the windows driver.
This is a step in the wrong direction.
Get real. These cards are again Technotrend cards. Or do you know another design which is using the TDA10045 demod?

? Hm, I think you got me wrong.
If I may choose between two comparable cards,
- one card with a closed-source firmware and
- another card with a complete open-source driver
I would definitely select the second one, even if it is more expensive.
Furthermore, I will prefer a vendor who provides us with card specs.
Well, the Technotrend cards are the one you woould never ever buy, is this correct?
*g*

Btw: understand firmware as part of the hardware, you don't have the sources of the BIOS of your mainboard and graphics card, you don't even know which other hardware components need some codelets from their drivers or from onboard EEPROMs to operate. A firmware is just something required for the hardware to operate, if it's done well you don't even want to know that it's there.


There is no advantage except that these cards are really cheap.
?!? sorry, I don't understand you. They do their job and are cheap, isn't this advantage enough?

I was targeting at budget cards with closed-source firmware.
From what I have read so far, they are not working very reliable (yet).
There are no specs, and I2C communication has to be sniffed.
It's not easy to implement features like error recovery correctly,
if the firmware is a black box...
Well, as far I know the TDA10045 based DVB-T cards are working just fine, the Avermedia cards have problems at weak receiption conditions or with many reflections. But since the Windows driver is appearently doing fine with the same firmware it's a driver issue that can and will get fixed.


The situation with full-featured cards is completely different:
o Basically there is only one card design available.
guess why.

o While the firmware is closed-source, there are some trustworthy guys
  who maintain the source code and do a great job. ;-)
none of them likes this job, scroll back in the mailing list archive. These are the guys trying to convince Klaus and the other VDR freaks to implement a software decoder. guess why.

end of thread.

Holger




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