> Thanks Guennadi for your quick response , > > >Hi Alex > > > Hi Guennadi, > > > > We would like to use I.MX35 processor in new project. > > An important element of the project is to obtain life video from the camera and display it on display. > > For these purposes, we want to use mainline Linux kernel which supports all the necessary drivers for the implementation of this task. > > As I understand that soc_camera is not currently supported userptr method, in which case how I can configure the video pipeline in user space > > to get the live video on display, without the intervention of the processor. > > >soc-camera does support USERPTR, also the mx3_camera driver claims to > >support it. > > I based on soc-camera.txt document. > Yeah, I really have to update it... > The soc-camera subsystem provides a unified API between camera host drivers and > camera sensor drivers. It implements a V4L2 interface to the user, currently > only the mmap method is supported. > > In any case, I glad that this supported :-) > > What do you think it is possible to implement video streaming without > the intervention of the processor? >It might be difficult to completely eliminate the CPU, at the very least >you need to queue and dequeue buffers to and from the V4L driver. To avoid >even that, in principle, you could try to use only one buffer, but I don't >think the current version of the mx3_camera driver would be very happy >about that. You could take 2 buffers and use panning, then you'd just have >to send queue and dequeue buffers and pan the display. But in any case, >you probably will have to process buffers, but your most important >advantage is, that you won't have to copy data, you only have to move >pointers around. The method that you describe is exactly what I had in mind. It would be more correct to say it is "minimum" CPU intervention and not without CPU intervention. As far I understand, I can implement MMAP method for frame buffer device and pass this pointer directly to mx3_camera driver with use USERPTR method, then send queue and dequeue buffers to mx3_camera driver. What is not clear, if it is possible to pass the same pointer of frame buffer in mx3_camera, if the driver is using two buffers? Thanks, Alex Gershgorin -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
