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

[Oliver Endriss <o.endriss@gmx.de>]

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.

So if I need a budget card, I will not buy one with closed-source
firmware, because there *are* budget cards available without this
restriction.

> > 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...

The situation with full-featured cards is completely different:
o Basically there is only one card design available.
o While the firmware is closed-source, there are some trustworthy guys
  who maintain the source code and do a great job. ;-)

I chose a full-featured card, because for me the full-featured card
has more advantages than disadvantages:
  + excellent TV out
  + teletext re-insertion
  + virtually no cpu load
  + cam support
  + stable and reliable
  - OSD limitations
  - no HDTV support
  - bandwidth limitations
  - closed-source firmware
BTW, you can buy a new full-featued sat card for 150..200 euros.

Sorry, after considering everything, there is no real alternative for
a full-featured card. IMHO. Your mileage might vary. ;-)

> You accept silently all the limitations of the av711x: a OSD that is far 
> from what you expect for a modern STB (the OSD is not even able to 
> display 8bit DVB subtitles correctly), no way to pass a high-bandwidth 
> stream to the host and process it there, no way to decode HDTV or even 
> MPEG4 sources. Their cheap alternatives provide you all this, they don't 
> force you to do anything on the card what can get done much easier and 
> better on the host processor.

Well, I'm aware of these limitations. But until now it's the best
compromise I have seen. I need a pc-based STB, I do not watch TV on
the computer monitor.

The main advantage of the av7110 is the high quality of the TV out.
I haven't seen any reasonable-priced graphics adapter with a TV out
which can be compared with this. AFAIK some older matrox cards had a
pretty good TV out, but we are talking about current hardware...

Oliver


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