Re: [linux-dvb] Multiproto API/Driver Update
From: Oliver Endriss
Date: Wed Sep 24 2008 - 12:55:53 EST
Julian Scheel wrote:
> Michael,
>
> On Monday 15 September 2008 17:42:06 Michael Krufky wrote:
> > In summary, the bottom line is this:
> >
> > Manu did a great job with the multiproto API, people were happy using
> > it, and all of the LinuxDVB developer community was happy with the
> > work that was done, and we all wanted to merge it ~ two years ago.
> >
> > Back then, Manu said that it wasnt ready, so for some time we waited
> > for him in hopes that he would agree that it was ready for merge.
> >
> > As more months went by, Manu was asked if he would be merging his
> > changes, and he kept answering to the effect of "it's not ready yet,
> > but should be in a few weeks"
> >
> > Months and months and months went by since then, with an occasional
> > ping to Manu, with the reply "not ready yet" ...
> >
> > Two years is a very long time to wait for a new API, especially
> > considering that it was functional from the start. It was looking
> > like Manu may not have had any intention at all to merge his work into
> > the master v4l/dvb development repository -- It should be not be
> > surprising at all that Steven Toth felt the need to come up with his
> > own solution.
> >
> > Steven posted a proposal for his API expansion solution, and he
> > received positive feedback. Immediately, Manu broke out of his
> > silence and sent in a pull request.
> >
> >
> > Is there malice here?? No. There is development, and developers
> > looking to move forward. Nobody is at fault.
> >
> >
> > I have posted the above just to clarify what the "politics" actually
> > are, here. The only real politics going around are those that are
> > accusing others of politics themselves.
> >
> > Had Manu been willing to merge his work earlier, this would have all
> > been a non-issue. However, now there is an alternative proposal on
> > the table, which appears to be more robust and may have more potential
> > that the multiproto proposal.
> >
> > Does that mean multiproto is disqualified? Absolutely not.
> >
> > Does the fact that multiproto was there first mean that it will be
> > merged without question now that it is suddenly available? No, not
> > necessarily.
> >
> > What does it mean? It means that now there are two proposals on the
> > table. Two ways to solve a problem using different ideas and methods.
> >
> > The end users that have piped into the discussion are mostly concerned
> > with which API demonstration repository already contains support for
> > their device. This should have no bearing whatsoever on the decision
> > of the linuxDVB API extension. All drivers will be ported to
> > whichever solution is decided upon.
> >
> > Now is the time to examine these solutions from a developer point of
> > view, in terms of how this affects kernel developers and application
> > developers alike. There is no reason to rush into things just because
> > a pull request has been made -- the outcome of this decision is highly
> > important, and we will have to live with the decision for a good long
> > time.
>
> Thanks for your version of the history. I just have to say I can't really
> agree with the way you describe the history. To point this out I looked up
> some of the old threads...
>
> So everything started in 2005 with initial proposals for a DVB-S2 extension of
> the API by Marcel. In early 2006 there were some discussions about it on the
> lists:
> http://thread.gmane.org/gmane.linux.drivers.dvb/23914/focus=24030
> http://thread.gmane.org/gmane.linux.drivers.dvb/24239
>
> At that thought not much (if any) capable hardware was available, so the idea
> was put off for the moment.
> Then in April 2006 Manu started to work at the things and provided a first
> draft based on the changes from Marcel:
> http://thread.gmane.org/gmane.linux.drivers.dvb/25401
>
> An initial driver for KNC cards was provided by Manu based on this API
> proposal. After some discussions on 05 May 2006 Manu requested for a pull of
> the API:
> http://www.linuxtv.org/pipermail/v4l-dvb-maintainer/2006-May/001006.html
>
> Immediately followed by Johannes stating that he is not satisfied with the API
> yet and suggested a rework:
> http://www.linuxtv.org/pipermail/v4l-dvb-maintainer/2006-May/001007.html
>
> At that time rework began while in parallel some people (including jusst
> technologies) started testing the first drivers. As expected they were still
> far away from running perfect.
>
> So it took a while to come to obvious progress. In January 2007 Manu announced
> the mp-stb0899-c5 tree - not even the current multiproto tree - which included
> the results of the rework. Some testing was done on that by more people.
> http://thread.gmane.org/gmane.linux.drivers.dvb/31146/focus=31159
>
> In February Steven came up with initial support for HVR 4000 in the multiproto
> tree.
> http://thread.gmane.org/gmane.linux.drivers.dvb/31605/focus=31644
>
> Furthermore at this time the dvb-apps (at least parts of) were started to be
> extended by multiproto support, so that more people (which do not write their
> own applications...) could start testing.
> http://thread.gmane.org/gmane.linux.drivers.dvb/31726/focus=31729
>
> In March Steven asked for the status of multiproto. Manu noted that the API
> should be fine, but also asked Steve to look into dvb_frontend where Manu was
> not sure of not having introduced new issues.
> http://thread.gmane.org/gmane.linux.drivers.dvb/31938/focus=32144
>
> End of May 2007 still problems in dvb-core, which were related to the new API
> came up and were fixed:
> http://thread.gmane.org/gmane.linux.drivers.dvb/33893
>
> Then in Sept 2007 discussions came up how to integrate the multiproto API,
> doing this as experimental or non-experimental.
> http://thread.gmane.org/gmane.linux.drivers.dvb/36082/focus=36411
>
> In Oct 2007 Steven abandons his support for multiproto, due to delays caused
> by several reasons. Political, surely also personal, but also technical.
> http://thread.gmane.org/gmane.linux.drivers.dvb/36583/focus=36670
>
> At the same time some more sophisticated DVB-S2 featues were requestes by the
> users:
> http://thread.gmane.org/gmane.linux.drivers.dvb/36785/focus=36789
>
> Finally in Nov 2007 Oliver did a full review of the new code, which was
> necessary for merging. Still he asked for more reviewers.
> http://article.gmane.org/gmane.linux.drivers.dvb/37665
>
> In January 2008 another user-initialised thread came up:
> http://thread.gmane.org/gmane.linux.drivers.dvb/38529/focus=38544
> Still testing is obviously needed as bugs still come up.
>
> In Apr 2008 VDR announced support for multiproto tree, so that more testing
> can be done by many users.
>
> End of May Manu left for travelling and personal stuff until August, just with
> short breaks apllying some minor patches. Still some users report issues with
> multiproro, which were not fully taken care of.
>
> After his vacation Manu came back on this topic and did another shot at a pull
> request.
>
> ---
>
> So this is how I see the history. Still 2 years is a very long time, but
> everyone should keep in mind that introduction of DVB-S2 support has been
> (still is) a big task with many problems. At first of course it is a big API
> extension, which is always problematic.
> Furthermore it is an API extension for a hardware which still is not spread
> too widely and especially was not spread in 2006. And even those who had
> proper cards for receiving DVB-S2 still were not able to make any use out of
> the received data. To properly do testing at user side it was really necessary
> to at least have a way to watch some of the distributed content, just to be
> sure it is working well.
> This was not possible for a long time due to lacing features in ffmpeg and
> missing alternatives. Still I think the only really working way is using a
> binary Windows codec named CoreAVC.
>
> Keeping all this in mind two years are not too long in my eyes.
>
> So this are just my 2 cents on this topic. All that I am interested in is a
> properly working API with wide application and driver support. Which proposal
> ever fits better - but decided on a technical base and not on historical or
> personal terms.
>
> Regards,
> Julian
Thanks for the detailed (and imho correct) description of the history.
CU
Oliver
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