Re: bttv 0.8.xx and V4L2

[Stephen Davies <steve@xxxxxxxxxxxxx>]

On Tue, 22 Jan 2002, Andrea Oddera wrote:

> I tried to use PROT_READ|PROT_WRITE but I got a permission denied error
> even if I was superuser.

Did you also change your open to O_RDWR?

My working code goes:

        vct->fd = open(fdev, O_RDWR);

and then later:

                vct->bufs[i * vct->planes] = (unsigned char *)mmap(NULL,
                  vct->cbuf.length, PROT_READ|PROT_WRITE, MAP_SHARED,
                  vct->fd, vct->cbuf.offset);

This code does work here (bttv0.8.28 with some minor local changes, though
I'm pretty sure not material here).  You must have the MAP_SHARED I
believe.

Steve