Re: [GnomeMeeting-list] [PATCH] Better integration with Video4Linux for PWLIB

[Derek Smithies <derek indranet co nz>]

Hi,
 Yes, a patch could be sent to the maintainer - you are correct. This does 
then percolate to all users (which means for the next 2 years people are 
having the same problems with your drivers)

Asking people to upgrade to the latest kernel, use a new kernel rpm is 
excessive. Fine for a developer. As Damien said, asking people to modify 
/etc/modules.conf can be too hard. 

=====
It is definately a bad idea to put too much camera specific stuff in the 
program. The camera specific stuff that is in pwlib is specific to each 
driver.  Thus, the hint system means that the code change only applies to 
that particular type of camera. The hint system we use detects the driver 
name, as returned by
  ::ioctl(videoFd, VIDIOCGCAP, &videoCapability)
and reading videoCapability.name)

============================================

<rant>
 One of the goals of linux people the world over is to replace MS with 
Linux. This is fine. Consequently, for linux to be usable by the masses,
things like cameras, programs, drivers etc have to be installed simply.
No requirements for fiddling around with new kernels, editing conf files,
building from source.

It should be 
   rpm -Uvh gnomemeeting.rpm
   gnomemeeting

Now, cameras (usb ones in particular) are easy to install. Just plug it in. 
Non usb camera may require a grabber card.

You see - just plug it in and it goes. This is what the Microsoft 
interface is aiming for. 

In the four years that I have been involved in openh323, reading the 
list, helping people, 
my view is the biggest pain in the ass is camera and sound.

Buggy drivers, (drivers that fail to meet the spec)
Authors who say, my driver meets the spec - it works with xawtv.
This is  a stupid and obnoxious comment.

   
STOP the crap software. fix the driver. make the driver meet the spec.
work harder. get it right.

openh323 is criticised because it does not work. Why does openh323 not 
work? Cause the driver writer did not do his/her job correctly.

I don't want to know about adding extra options to conf files. The default 
option should always work.

If linux video and sound drivers cannot work "out of the box", then there
is no hope of overtaking microsoft.

Yes, I know that microsoft code has many drivers that "don't work right".
That is no excuse. 
The goal for linux is for all drivers to work.
If we can achieve that goal, linux has a chance.

</rant>


Derek.

P.S. sorry for venting/ranting, but I am sick of substandard driver code.
    it wastes so much developer time, getting applications to work with 
     buggy drivers.


 On Mon, 22 Sep 2003, Nemosoft Unv. wrote:

> Hello,
> 
> On Monday 22 September 2003 00:02, Derek Smithies wrote:
> > Chris,
> >  Modifying kernel code, or adding module parameters, are a pain.
> 
> Not really. You can always send a patch to the apropriate maintainer (that 
> would be me :))) It will then eventually percolate into kernels on user's 
> systems. The most important thing is not to break (too many) existing 
> applications.
> 
> [...]
> 
> >  You see, it means that anyone else who uses the QuickCam has to do the
> > same.
> >
> > Your patch is "fine", in that it works.
> > However, I really really don't want to add it, cause that will change the
> > operation of the pwlib v4l code for all cameras.
> >
> > Can I suggest that you modify your patch, so that it uses the hint table,
> > line 200 of video4linux.cxx
> > Modify the hint table so it includes a section for your QuickCam camera.
> > and put a new hint in the hint table.
> >
> > The new hint is
> >     HINT_USE_CURRENT_HARDWARE_SIZE 0x0400
> >
> > Then,  you have in your changes.
> > if (HINT (HINT_USE_CURRENT_HARDWARE_SIZE)) {
> >    your code;
> >  } else {
> >     previous code;
> >  }
> >
> >
> > Thus, if the camera is QuickCam, it uses your code.
> >      if the camera is anything else, nothing changes.
> 
> If I may? First off, I think it's a bad idea to put too much camera specific 
> code in your program. Second, if you do it, try to do it in the most 
> general way possible. The QuickCam is using my PWC driver, and although I 
> admit that driver is slightly "broken" in this case, your code should then 
> work on all PWC supported cams, since they all suffer from the same 
> problem, in which case I'm happy to point you to my API document on 
> http://www.smcc.demon.nl/webcam/api.html which includes a PWC detection 
> routine. 
> 
>  - Nemosoft
> 
> 

-- 
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