Re: [PATCH] Image capturing driver for Basler eXcite smart camera

From: Ãric Piel
Date: Mon Aug 14 2006 - 11:51:10 EST

08/12/2006 07:27 PM, Thomas Koeller wrote/a Ãcrit:
Alan Cox <alan <at>> writes:

Ar Iau, 2006-08-10 am 23:18 +0200, ysgrifennodd Thomas Koeller:
This is a driver used for image capturing by the Basler eXcite smart camera
drivers/media/video and the Video4Linux2 API deal with image capture in
Linux. It provides a common API for video and thus image capture. Any
reason that interface is not suitable.


This is not a driver for grabbing live video streams. The eXcite platform using it is a smart camera running linux, and the driver is for a very special piece of hardware designed into this camera. Its purpose is grabbing single image frames for processing within the camera itself, which is quite different from what the v4l2 API has been designed for.

For more information about the device, see

Maybe I just completely misunderstood you point, in which case I apologize... However from what it seems, you are proposing a kernel driver for the hardware which is inside the product described on the webpage. This driver will run on a processor embedded into this camera. It will allow some user-space programs which also run on this processor to acquire pictures generated by the captor. Am I right so far?

If so then the Video4Linux2 API is still the best way to implement the protocol to pass data between the user-space programs and the driver. The V4L2 API doesn't says that the camera must be far away from the processor, it can work for USB webcams, for Firewire video camera, PCI TV tuners, and probably also for your device. Using the V4L2 not only has the advantage of being a well tested API for communicating video related information with the user-space but it also buys you the fact that any program available on Linux for video should be able to directly detect and use the captor!

That said, thank you already very much for submitting your driver to the Linux kernel. Your code seems already good quality and conformant with the coding style of the kernel. Still, some people will review your code, and let you know what they think might be problematic. This is the normal process for driver acceptance, for the good both of your driver and of the kernel. When you have answered the different suggestion, please resubmit your new version of the driver with the change. I suggest also CCing video4linux-list@xxxxxxxxxx :-)

See you,

I am not subscribed to lkml, so please cc my address thomas at koeller dot dyndns dot org on all replies.
Please, also keep the CC: in your answers.
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