[mythtv] IVTV VBI reading

[f-myth-users at media.mit.edu]

    > Date: Sat, 20 Jan 2007 16:12:11 +0100
    > From: Hans Verkuil <hverkuil at xs4all.nl>

    > On Saturday 20 January 2007 15:34, Daniel Kristjansson wrote:
    > > On Fri, 2007-01-19 at 17:36 +0100, Hans Verkuil wrote:
    > > We use the V4L2_CAP_SLICED_VBI_CAPTURE ioctl if IVTV_IOC_S_VBI_MODE
    > > ioctl fails. But considering the problems I'll just drop support
    > > for captions unless the user is using the latest drivers. This
    > > isn't in the patch yet. I want to test the changes for this
    > > against the new drivers.

    > I think I would prefer that VBI is off by default for anything but the 
    > latest drivers (>= 0.10.0). If someone wants it for older drivers, then 
    > that is still possible. Completely removing it is overkill, I know that 
    > some people are using it to their satisfaction.

Yes, -please- don't -force- users with older drivers not to have
captions at all; make it possible to enable them.  Maybe issue a
warning about the sorts of issues seen when they -are- enabled, or
something if necessary.

I'm currently using ivtv 0.4.1 with a flock of PVR-250's and CC is
working just fine for me, and I'd be really annoyed if a working
configuration was forced to not work.

(Even very recent Ubuntu releases have moderately old kernels by the
standards of the very-fast-moving ivtv timeline, and the newest ivtv
won't work in kernels < 2.18.x, which would mean [if I understand you
correctly, and I'm not sure that I do] you'd force captions not to
work unless users are running distributions with kernels newer than
the distribution expects [hence users would be forced to compile their
own kernels, couldn't get automatic security updates for them, etc etc].
That in turn would mean that I, for one, would never run that version
of Myth until my distro could catch up to the kernel version required,
since my research requires the closed-captioning data.)