[mythtv-users] pcHDTV 5500 not working with 0.24

[Daniel Kristjansson]

On Mon, 2011-05-23 at 22:20 -0500, Saul A Peebsen wrote:
> Thank you for your help. What is the outlook, V4L1 is dead for kernel
> developers, is analog dead for MythTV?

No, there was a big push starting last year to convert the last of the
V4L1 drivers to the V4L2 API. MythTV has been using V4L2 whenever
possible for years, with fall-backs to the older V4L1 API being used
only when the V4L2 calls failed (since many cards were not converted
to the V4L2 API until recently). The change between MythTV 0.23 and 0.24
was that we started using the distro headers for both V4L1 and V4L2
APIs. We made the decision to do so because they had been stable a
for years and we didn't foresee any big changes on the horizon.

The event that caused 0.24 to fail for some was that Ubuntu 11.04
dropped the V4L1 API in their distro headers (possibly other recent
distro's did as well). The Linux kernel itself doesn't actually matter
since MythTV will use the V4L2 API by default, and if you use the V4L1
API with a new kernel the calls just fail. But as of 0.24 we depend
on the distro providing a both V4L1 and V4L2  headers. If either header
is missing we disable V4L entirely, this is what has been causing
problems. As of last week I fixed this in the git master branch and
as of today Michael T Dean has prepared a patch for 0.24/fixes which
just needs a bit of testing before it can be applied to the branch.

Note: I'm not blaming Ubuntu. We could have made the changes to
allow V4L2 support without V4L1 years ago. We just didn't realize
V4L1 was going to be pushed out until after it happened and were
caught flat footed.

-- Daniel