Johannes Stezenbach wrote:
On Mon, May 22, 2006, Manu Abraham wrote:
Johannes Stezenbach wrote:
Anyway, one last try. Let's go back to the very beginning:
- we need to extend frontend API for DVB-S2, DVB-H etc.
- we cannot do so without breaking backward compatibility
because of mistakes made when defining the current API
- so now that we define new API, we don't want to repeat
the same mistake, but design in a way that make future
extensions possible without too much pain for
driver and application developers
- right from the beginning my position was to do the
*minimal* work necessary to support the *current*
requirements -- keep it simple and stupid
- and add other stuff later when the need arises
- and all along you totally ignored this and instead
want to cram every last detail into the API that
you think *might* be necessary
- wrt requirements: you need to think through how
an application will work (how does dvbscan discover
DVB-S2 transmission? where do the tuning parameters
come from?)
currently the tuning parameters come from the
s2_satellite_delivery_system_descriptor
what i have in there is the sis-mis flag and the transport stream
identifier to select the streams
Anyone seen a s2_satellite_delivery_system_descriptor in any broadcast?
There are DVB-S2 braodcasts on Astra 19.2E, do they have
s2_satellite_delivery_system_descriptors?
Well on Arabsat some of the broadcasters does name all the providers as
DEFAULT PROVIDER
So should i say that the current usage too is wrong ?
Remember: You cannot remove anything from the API
once it is in there. But you can always add stuff later.
Please ask yourself who are doing this API design for, and
how people are going to benefit from your work.
IMHO:
- users just expect to be able to buy a DVB-S2 card and
watch the services broadcast *today* via DVB-S2
- application developers want to support DVB-S2 with
as little hassle as possible
With the new API "as little hassle as possible" for
apps already means:
- testing for support for the new API
- fallback to using the old API for backwards compatibility
:-(
IMHO it is of no use to further complicate the matter by
adding lots of unnecessary stuff to the API.
Johannes, you are just accusing me with blunt statements like that. I
really don't know what to say on your accusations.
There isn't any accusation or "blunt statement" in my writing.
I just wanted to give you stuff to think about.
I asked myself those questions and reached some conclusions
(which I think were reflected in my postings already). Those
questions should show you how I reached my conclusions, so
you can folloow them.
Ok, tell me how do you get a Low Priority stream. Ask yourself this
question. Since you say that i was wrong, i won't say anything, just
waiting for your answer.
I too agree with not adding unwanted stuff into the API.
Good.
BTW, I don't claim to be right on my interpretation of the
DVB-S2 spec, however as long as we can't agree (i.e.
no one can give a good explanation why his version
of the DVB-S2 API is the correct one, and *everyone*
can agree on it), I think the while DVB-S2 API is useless.
Are there any other versions ?
There are few different versions of your proposal,
and my proposal, and Felix' or Mws' original proposal.
I thought updating the patch was the same thing. moeover Mws did clarify
things on his post.
Manu
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