[mythtv] MythUI OSD branch and the way forward

[Yeechang Lee]

Mark Kendall <mark.kendall at gmail.com> says:
> There has been some discussion on irc recently regarding the
> libmythui-osd branch and how to support XVideo (and XvMC) going
> forward.

This is the branch that was at one point going to be merged into 0.23,
right?

> On linux VDPAU will handle the rendering basics well enough but in
> the future we may want to use OpenGL rendering directly. Any VDPAU
> capable card also has sufficient OpenGL horsepower.

I am displaying my ignorance here, but are you talking about someday
bypassing the VDPAU functionality entirely? Or some sort of
VDPAU-accelerated OpenGL?

I ask because the combination of my frontend and VDPAU-capable video
card isn't fast enough to play using the Standard decoder and the
OpenGL renderer. I realize this is because my frontend's CPU is so
old, but I'd hate to have to upgrade a frontend that is otherwise
perfectly adequate for all foreseeable MythTV uses thanks to
VDPAU. Again, I hope I'm misunderstanding what you're saying.

> Option 6 - Drop XVideo/XvMC support and standardise around OpenGL

I knew this was coming as soon as I read the first sentence in your
message. I agree Xv is on its way out, but to drop it so soon would
be, well, too soon. I'd bet that Xv is still the most-popular
decoder/renderer used, with VDPAU second; even if I'm wrong and VDPAU
is nowadays the most popular, Xv can't be too far behind. It's still
remarkably usable on low-end gear; if my VDPAU-capable card were to
die today I could pop in a non-VDPAU Nvidia card and revert to the
software-decoder/Xv-renderer that was the status quo for 1080i HD
playback for more than three years before VDPAU came along in early
2009.

I know VDPAU-capable cards are very inexpensive. I know ION-based
frontends are $200. I know that ultimately the decision is up to what
the commit-enabled developers are interested in using and supporting;
we saw that with 0.22's dropping of PVR-350 output. Unlike the
PVR-350, though, any Xv-support drop wouldn't be because no one still
has an Xv-capable card, or because Xv output is insufficient to play
current (MPEG-2) HD recordings.

The Xv "problem," such as it is, is inherently a self-solving one. As
more and more MythTV users buy HD-PVRs or in some other way move to
h.264 recordings, Xv will suddenly be inadequate. The masses aren't
there yet, though, and it would be a pity to drop too soon a
well-tested and popular video-output solution.

-- 
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