lkml.org 
[lkml]   [2006]   [Jun]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
Subjectv4l device in userspace
>>>>> "Salvatore" == Salvatore Sanfilippo <antirez@gmail.com> writes:

Salvatore> Hello, I'm trying to implement a v4l device driver for
Salvatore> symbian based smart phones. In theory it is very
Salvatore> simple:

Salvatore> I've a little program running in the phone, capturing
Salvatore> images from the camera and sending it to the linux box
Salvatore> via bluetooth.

Salvatore> In the linux box side, I've a deamon capturing this
Salvatore> images (via a bluetooth SP channel), and.... I've to
Salvatore> pass the images to a fake v4l device driver that
Salvatore> actually gets the images form userspace.
Salvatore> Basically I've to pass by the kernel just for the
Salvatore> interface, and not to do real kernel-side work (like to
Salvatore> access to the some kind of hardware).

Salvatore> So I've some questions ( thanks in advance for any
Salvatore> reply).

Salvatore> 1) What's the best way to pass relatively high-band
Salvatore> data between the v4l fake driver and userspace? A char
Salvatore> device will do the work? ioctl?

Salvatore> 2) What about some way to handle ioctl directly from
Salvatore> userspace? Given this support I may implement the whole
Salvatore> code in userspace. And I guess there are a lot of
Salvatore> other real world problems that can be handled in
Salvatore> userspace given the ability to handle ioctl from there.

Salvatore> If you think 2) is reasonable I may actually implement
Salvatore> some simple form of generic char driver that just
Salvatore> allows userspace programs to handle read/write/ioctl
Salvatore> opreations, and then use this to fix my real issue.

Salvatore> Thank you very much for the help, and sorry if there is
Salvatore> something conceptually wrong in my questions.

Sounds like you should take a look at the v4l loopback device
(http://www.lavrsen.dk/twiki/bin/view/Motion/VideoFourLinuxLoopbackDevice).
Otherwise it may be better to ask the question on the v4l mailing list
(https://listman.redhat.com/mailman/listinfo/video4linux-list).

Anyway, since you already capture the video, why do you have to pipe
it through a v4l device?

Marcus

--
/--------------------------------------------------------------------\
| Dr. Marcus O.C. Metzler | |
| mocm@metzlerbros.de | http://www.metzlerbros.de/ |
\--------------------------------------------------------------------/
|>>> Quis custodiet ipsos custodes <<<|
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2006-06-16 13:46    [from the cache]
©2003-2011 Jasper Spaans