Re: v4l2_buffer with PBO mapped memory

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Thomas,

On Wednesday 02 April 2014 17:10:42 Thomas Scheuermann wrote:
> Hello,
> 
> I've written a program which shows my webcam with the v4l2 interface.
> In the v4l2_buffer I use the type V4L2_BUF_TYPE_VIDEO_CAPTURE and the
> memory is V4L2_MEMORY_USERPTR.
> Everything works if I use malloced memory for frame buffers.
> Now I want to get the frames directly in OpenGL. I've mapped a pixel
> buffer object with glMapBuffer and wanted to use this as a frame buffer.
> But if I use this memory, the ioctl VIDIOC_QBUF fails with 'invalid
> argument'.
> 
> What can I do to use the pixel buffer object together with the v4l2
> interface?
> I want to use as less copy steps as possible.

The use case is reasonable (although V4L2_MEMORY_DMABUF would be better, but 
we're not there yet on the OpenGL side I believe), so let's try to debug this. 
First of all, what webcam driver do you use ?

-- 
Regards,

Laurent Pinchart