my $pixel_format = 'rgb24';
    my $file = 0; # device number 0, or .avi file, for reproducible testing
    my ($pid,$stream) = $self->spawn(sprintf qq{%s -f vfwcap -r 30 -i %s -f rawvideo -pix_fmt %s - |},
        $self->ffmpeg, $file, $pixel_format
    );