Tech Support > Microsoft Windows > Drivers > avshws & rwiso
avshws & rwiso
Posted by DamL on February 22nd, 2008


Hi,

I've written firmware and modified the rwiso code for an isochronous USB
camera. Streaming from camera via rwiso -g command is also ok.
In this code, I construct n (typically 2) Buffers representing
consecutive frames from camera. This works quite well (images complete
and correct rythm)

I'd like to include this usb part in avshws sample and idea would be to
remove the "simulated" hardware and pictures by the contents of these
frame buffers.

For now I've "summed" the 2 projects rwiso and avshws (just to see if it
was possible), but I encounter major issues :

1) KsInitializeDriver reroute the different IRP_XXs defined in rwiso and
pnp driver of this cannot be used anymore.

2) How to make the Pnp for camera working : in avshws there is no
hardware defined but what is to be done to integrate the pnp detection
of usb camera, and precisely at plug of it ?

Is there some samples available to describe this ?

3) Is BDA a better option for this or is it similar to avshws at it seems ?

Thank you for your help,
Best Regards

Posted by Tim Roberts on February 23rd, 2008


DamL <damien.lebrun@cynove.com> wrote:
This has already been asked and answered on the "ntdev" mailing list.

Right. You won't use ioctls to talk to the driver. Instead, you'll use
the DirectShow proxy filter, and IT will talk to the driver.

Yes, rwiso for example. It is the INF file that determines when your
driver is loaded. You just have to make the avshws INF match your device's
VID and PID. Then, your PnPStart callback can go fetch the descriptors, or
do whatever needs to be done.

BDA is a thin layer on top of AVStream, needed only if you need to support
digital television signals.
--
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.


Similar Posts