DVB-API v5 questions and no dvb developer answering ?

DVB-API v5 questions and no dvb developer answering ?

[wk]

The last week two guys were kindly asking here on the list where to find 
a written DVB-API v5 documentation,
but nobody of the dvb driver community was answering.

http://www.mail-archive.com/linux-media@vger.kernel.org/msg01350.html
http://www.mail-archive.com/linux-media@vger.kernel.org/msg01300.html

Does that mean that:
- dvb developers are currently not interested in application developers 
integrating new DVB-API v5? or..
- no dvb developer reading that list knows something about 
documentation? or..
- does it simply not exist, so who is working on that api documentation 
stuff?


The offical documentation found on linuxtv.org is outdated and already 5 
years old, and describes only api v3.
See http://www.linuxtv.org/downloads/linux-dvb-api-1.0.0.pdf

Please read also the announcements on linuxtv:
http://www.linuxtv.org/news.php?entry=2008-09-23.mchehab
[quote]
Some improvements were proposed by the LinuxTV developers, in order to 
improve the S2API, including:
...
* Update DVB API documentation to reflect the API changes;"
[/quote]

But also this statement is already now five months old,
so i guess documentation should be finished meanwhile or at least 
started and usable/redistributable..

Is it possible to get some information on that topic?

-Winfried

Re: DVB-API v5 questions and no dvb developer answering ?

[Hans Verkuil]

On Monday 16 February 2009 18:48:13 wk wrote:
> The last week two guys were kindly asking here on the list where to find
> a written DVB-API v5 documentation,
> but nobody of the dvb driver community was answering.
>
> http://www.mail-archive.com/linux-media@vger.kernel.org/msg01350.html
> http://www.mail-archive.com/linux-media@vger.kernel.org/msg01300.html
>
> Does that mean that:
> - dvb developers are currently not interested in application developers
> integrating new DVB-API v5? or..
> - no dvb developer reading that list knows something about
> documentation? or..
> - does it simply not exist, so who is working on that api documentation
> stuff?

I do know that the main dvb devs involved in this api are very busy lately, 
but that's no excuse for not providing a document in the Documentation/dvb 
directory.

Steve, Mike, spend a few hours in a weekend to document this API!

Proper documentation should be a hard requirement before allowing new APIs 
in the kernel IMHO.

Regards,

	Hans

>
>
> The offical documentation found on linuxtv.org is outdated and already 5
> years old, and describes only api v3.
> See http://www.linuxtv.org/downloads/linux-dvb-api-1.0.0.pdf
>
> Please read also the announcements on linuxtv:
> http://www.linuxtv.org/news.php?entry=2008-09-23.mchehab
> [quote]
> Some improvements were proposed by the LinuxTV developers, in order to
> improve the S2API, including:
> ...
> * Update DVB API documentation to reflect the API changes;"
> [/quote]
>
> But also this statement is already now five months old,
> so i guess documentation should be finished meanwhile or at least
> started and usable/redistributable..
>
> Is it possible to get some information on that topic?
>
> -Winfried
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Hans Verkuil - video4linux developer - sponsored by TANDBERG

Re: DVB-API v5 questions and no dvb developer answering ?

[VDR User]

On Mon, Feb 16, 2009 at 10:08 AM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
> On Monday 16 February 2009 18:48:13 wk wrote:
>> The last week two guys were kindly asking here on the list where to find
>> a written DVB-API v5 documentation,
>> but nobody of the dvb driver community was answering.
>>
>> http://www.mail-archive.com/linux-media@vger.kernel.org/msg01350.html
>> http://www.mail-archive.com/linux-media@vger.kernel.org/msg01300.html
>>
>> Does that mean that:
>> - dvb developers are currently not interested in application developers
>> integrating new DVB-API v5? or..
>> - no dvb developer reading that list knows something about
>> documentation? or..
>> - does it simply not exist, so who is working on that api documentation
>> stuff?
>
> I do know that the main dvb devs involved in this api are very busy lately,
> but that's no excuse for not providing a document in the Documentation/dvb
> directory.
>
> Steve, Mike, spend a few hours in a weekend to document this API!
>
> Proper documentation should be a hard requirement before allowing new APIs
> in the kernel IMHO.

I couldn't agree more with the last sentence in the above quote.  It's
ridiculous at best that after months now there is _still_ no proper
documentation, yet there was plenty of time when the task-at-hand was
making up s2api and pushing it into the kernel as fast as possible.
I'd love to hear a good reason why this documentation doesn't exist,
or why the people politely asking for help are being completely
ignored since the  "I've been busy" excuse is laughable.

Sorry, I've seen many people expressing frustration over this and many
other things from recent times.

Re: DVB-API v5 questions and no dvb developer answering ?

[Devin Heitmueller]

On Mon, Feb 16, 2009 at 1:37 PM, VDR User <user.vdr@gmail.com> wrote:
> I couldn't agree more with the last sentence in the above quote.  It's
> ridiculous at best that after months now there is _still_ no proper
> documentation, yet there was plenty of time when the task-at-hand was
> making up s2api and pushing it into the kernel as fast as possible.
> I'd love to hear a good reason why this documentation doesn't exist,
> or why the people politely asking for help are being completely
> ignored since the  "I've been busy" excuse is laughable.
>
> Sorry, I've seen many people expressing frustration over this and many
> other things from recent times.

As always we continue to welcome patches, including for the
documentation.  Instead of bitching and moaning, how about you roll up
your sleeves and actually help out?

Let's try to remember that pretty much all the developers here are
volunteers, so berating them for not doing things fast enough for your
personal taste is not really very productive.

Regards,

Devin

-- 
Devin J. Heitmueller
http://www.devinheitmueller.com
AIM: devinheitmueller

Re: DVB-API v5 questions and no dvb developer answering ?

[VDR User]

On Mon, Feb 16, 2009 at 11:33 AM, Devin Heitmueller
<devin.heitmueller@gmail.com> wrote:
> As always we continue to welcome patches, including for the
> documentation.  Instead of bitching and moaning, how about you roll up
> your sleeves and actually help out?

Interesting you would suggest people who did not develop s2api be the
ones to write the documentation for it.

> Let's try to remember that pretty much all the developers here are
> volunteers, so berating them for not doing things fast enough for your
> personal taste is not really very productive.

Ahh yes, because everyone is a volunteer nobody is entitled to
opinions that aren't akin to sending flowers.  Sorry, it slipped my
mind that only 'approved' opinions are welcome.

I would say that neglecting something as important as proper
documentation for several months extends beyond "personal taste" and
into the realm of common sense.  Especially when people trying to
actively develop software have requested such information on many
occasions, only to be ignored.  Call me crazy but that is what I
consider to be 'not really very productive'.  Certainly far more then
my measly little ol' opinion on the matter.

I guess we'll agree to disagree on some key points.  Thanks for
sharing none-the-less.  And hopefully those who have been so patiently
and politely asking for help will finally get it.  Unless, of course,
you think that's a bad idea?

Re: DVB-API v5 questions and no dvb developer answering ?

[wk]

Devin Heitmueller wrote:
> As always we continue to welcome patches, including for the
> documentation.  Instead of bitching and moaning, how about you roll up
> your sleeves and actually help out?
>
> Let's try to remember that pretty much all the developers here are
> volunteers, so berating them for not doing things fast enough for your
> personal taste is not really very productive.
>
> Regards,
>
> Devin
>
>   
Devin,

can you please explain, how others should contribute to an dvb api if
- the only DVB API file to be found is a pdf file, and therefore not 
editable. Which files exactly to be edited you are writing of?
- one doesn't know which ioctls exist for what function, which return 
codes and arguments, how to understand and to use..?

What you suggest is almost impossible to someone not perfectly familiar 
with the drivers, only for dvb experts who have written at least a bunch 
of drivers.
Its something different than sending patches for one single driver where 
some bug/improvement was found.

On the other hand, in principle a driver without existing api doc is 
useless. Nobody can use it, the same for drivers with undocumented new 
features.

Regards,
Winfried

Re: DVB-API v5 questions and no dvb developer answering ?

[Hans Verkuil]

On Monday 16 February 2009 22:39:44 wk wrote:
> Devin Heitmueller wrote:
> > As always we continue to welcome patches, including for the
> > documentation.  Instead of bitching and moaning, how about you roll up
> > your sleeves and actually help out?
> >
> > Let's try to remember that pretty much all the developers here are
> > volunteers, so berating them for not doing things fast enough for your
> > personal taste is not really very productive.
> >
> > Regards,
> >
> > Devin
>
> Devin,
>
> can you please explain, how others should contribute to an dvb api if
> - the only DVB API file to be found is a pdf file, and therefore not
> editable. Which files exactly to be edited you are writing of?

10 minutes searching revealed that the sources are still available in the 
old CVS repository:

http://www.linuxtv.org/cgi-bin/viewcvs.cgi/DVB/doc/dvbapi/

So we need a volunteer to take this, merge it into the current v4l-dvb 
master repository (just as I did recently with the v4l2 API spec) and then 
start updating the docs bit by bit.

Regards,

	Hans

> - one doesn't know which ioctls exist for what function, which return
> codes and arguments, how to understand and to use..?
>
> What you suggest is almost impossible to someone not perfectly familiar
> with the drivers, only for dvb experts who have written at least a bunch
> of drivers.
> Its something different than sending patches for one single driver where
> some bug/improvement was found.
>
> On the other hand, in principle a driver without existing api doc is
> useless. Nobody can use it, the same for drivers with undocumented new
> features.
>
> Regards,
> Winfried
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Hans Verkuil - video4linux developer - sponsored by TANDBERG

Re: DVB-API v5 questions and no dvb developer answering ?

[VDR User]

On Mon, Feb 16, 2009 at 1:39 PM, wk <handygewinnspiel@gmx.de> wrote:
> Devin,
>
> can you please explain, how others should contribute to an dvb api if
> - the only DVB API file to be found is a pdf file, and therefore not
> editable. Which files exactly to be edited you are writing of?
> - one doesn't know which ioctls exist for what function, which return codes
> and arguments, how to understand and to use..?
>
> What you suggest is almost impossible to someone not perfectly familiar with
> the drivers, only for dvb experts who have written at least a bunch of
> drivers.
> Its something different than sending patches for one single driver where
> some bug/improvement was found.
>
> On the other hand, in principle a driver without existing api doc is
> useless. Nobody can use it, the same for drivers with undocumented new
> features.

Exactly!  Should be entertaining to hear the answers to everything but
the first 'what files do you edit', though the rest of the questions
will likely continue to be ignored.  It seems some think those not
familiar with s2api technical structure should reverse engineer it and
write the documentation rather then the people who actually created
it.  To even suggest such a thing is absurd in my humble opinion.
Talk about counter-productive...

Re: DVB-API v5 questions and no dvb developer answering ?

[Andy Walls]

On Mon, 2009-02-16 at 16:03 -0800, VDR User wrote:
> On Mon, Feb 16, 2009 at 1:39 PM, wk <handygewinnspiel@gmx.de> wrote:
> > Devin,
> >
> > can you please explain, how others should contribute to an dvb api if
> > - the only DVB API file to be found is a pdf file, and therefore not
> > editable. Which files exactly to be edited you are writing of?
> > - one doesn't know which ioctls exist for what function, which return codes
> > and arguments, how to understand and to use..?
> >
> > What you suggest is almost impossible to someone not perfectly familiar with
> > the drivers, only for dvb experts who have written at least a bunch of
> > drivers.
> > Its something different than sending patches for one single driver where
> > some bug/improvement was found.
> >
> > On the other hand, in principle a driver without existing api doc is
> > useless. Nobody can use it, the same for drivers with undocumented new
> > features.
> 
> Exactly!  Should be entertaining to hear the answers to everything but
> the first 'what files do you edit', though the rest of the questions
> will likely continue to be ignored.

It's actually not that hard.  I was unfamiliar and looked at the header
file and the code that processed the requests.  I whipped up a little
tuning app in a short time:

http://www.mail-archive.com/linux-media@vger.kernel.org/msg00734.html

(but of course longer than it would have taken if an up to date document
were available.)

>   It seems some think those not
> familiar with s2api technical structure should reverse engineer it and
> write the documentation rather then the people who actually created
> it.

Actually, I had been toying with the idea since it should be a simple
addition to the v3 spec, but I got too busy (day job).

V5 is only a single ioctl() for mucking with the frontend IIRC.  The
rest is the same as the DVB V3 API unmodified, again IIRC.  With V5, you
issue a list of frontend properties to set and/or a command to do the
tune in that list and submit it via ioctl().  This list is returned with
a return status for each item in the list you submitted.  It reminded me
of database transactions.

It was actually more complex to extract the current frontend status with
the DVB V3 API events and whatnot, but the documentation spares some of
the headache there.

Regards,
Andy

> To even suggest such a thing is absurd in my humble opinion.
> Talk about counter-productive...

Re: DVB-API v5 questions and no dvb developer answering ?

[Mauro Carvalho Chehab]

On Mon, 16 Feb 2009 23:01:47 +0100
Hans Verkuil <hverkuil@xs4all.nl> wrote:

> On Monday 16 February 2009 22:39:44 wk wrote:
> > Devin Heitmueller wrote:
> > > As always we continue to welcome patches, including for the
> > > documentation.  Instead of bitching and moaning, how about you roll up
> > > your sleeves and actually help out?
> > >
> > > Let's try to remember that pretty much all the developers here are
> > > volunteers, so berating them for not doing things fast enough for your
> > > personal taste is not really very productive.
> > >
> > > Regards,
> > >
> > > Devin
> >
> > Devin,
> >
> > can you please explain, how others should contribute to an dvb api if
> > - the only DVB API file to be found is a pdf file, and therefore not
> > editable. Which files exactly to be edited you are writing of?
> 
> 10 minutes searching revealed that the sources are still available in the 
> old CVS repository:
> 
> http://www.linuxtv.org/cgi-bin/viewcvs.cgi/DVB/doc/dvbapi/
> 
> So we need a volunteer to take this, merge it into the current v4l-dvb 
> master repository (just as I did recently with the v4l2 API spec)

Done. The DVB API specs are under /dvb-spec dir. I've imported the DVB original
changesets by using hg convert extension with cvsps.

It compiles fine but it requires tetex-latex and Xfig packages. I didn't check
if the produced pdf is equal to the one at the linuxtv website.

I didn't bother to recover the original author names when importing from CVS,
so, it will show the author aliases used on CVS.

> and then start updating the docs bit by bit.

Volunteers?

Cheers,
Mauro