[mythtv-users] XvMC and libmpeg2 to be dropped in 0.25

Brian Wood beww at beww.org
Thu Dec 2 19:52:03 UTC 2010


On Thursday, December 02, 2010 12:05:44 pm Robert McNamara wrote:
> We'd like to warn users that we are planning to drop XvMC and
> libmpeg2 decoding support from forthcoming MythTV releases. MythTV
> 0.25 will be the first release without these features, so you still
> have several months to upgrade hardware if you wish to continue
> running the latest MythTV releases. Of course the newly released
> 0.24 will remain available if either XvMC or libmpeg2 are important
> to you.
> Why are we doing this?
> 
> XvMC - The primary reason is that the XvMC code is very hard to
> maintain. It requires a lot special handling and does not support the
> features which many of our other video rendering methods provide. Far
> superior alternative hardware decoders such as Nvidia's VDPAU are now
> supported. Crystal HD, ATI and Intel support are also on the MythTV
> roadmap.
> 
> libmpeg2 - A high proportion of problems reported to us can be traced
> back to libmpeg2, we want MythTV to be as stable as possible and the
> advantages of libmpeg2 are outweighed by the negatives. Like XvMC, it
> complicates the code in ways that make it harder to maintain.
> 
> Both - Additionally, the need for both features is largely gone. Even
> the lowest cost CPUs which have been available in recent years can
> easily manage playback of Standard and High-Definition mpeg2. Low
> power CPUs such Intel's atom are usually supplied with Nvidia's ION
> platform or can be used with discrete hardware decoding solutions
> such as Crystal HD.
> 
> We believe that leaving these features behind will allow us to focus
> our time more productively, making the improvements and adding the
> features that a majority of users want to see.
> 
> N.B At some point in time, beyond 0.25, we'd like to drop XVideo
> support in favour of OpenGL rendering. There will be more on that
> subject when we have finalised our plans. Rest assured that we are
> considering embedded platforms and work on supporting OpenGL ES is
> already underway.

These moves are quite understandable.

The problem with VDPAU is with older AGP motherboards, for which the 
only alternative to XvMC for hardware acceleration is to use a PCI card 
supporting VDPAU, but in that case you are screwed if you have a codec 
not supported by VDPAU, but of course XvMC only helps with MPEG2 in any 
case,

CrystalHD support would be great (since I own a couple of the modules).

I've seen a lot of Atom platforms with Intel graphics, not ION, that 
problem has caused me to pass up several hardware options. Being able to 
use Intel graphics hardware would nice, especially as a lot of laptops 
use it.

But, as I said, your moves make sense, and the long warning time is 
greatly appreciated. I also understand that trying to continue to 
support "legacy" hardware will delay other improvements to Myth in 
general.

Thanks again for the heads up.


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