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

James Courtier-Dutton james.dutton at gmail.com
Mon Dec 6 12:11:37 UTC 2010

On 5 December 2010 19:43, Brian Wood <beww at beww.org> wrote:
> On Sunday, December 05, 2010 12:26:57 pm BP wrote:
>> A cheap Atom based computer should be able to decode SD content
>> without GPU assistance.  How old is your hardware in that it cannot
>> decode SD content with the CPU?  Even seven years ago when I was
>> running .11 I didn't require XvMC for any SD content.  I think I was
>> using an Athlon XP 2500 at that time.
> As a datapoint, Dell stopped putting hardware mpeg decoders in their
> DVD-equipped laptops at the time their CPUs hit 500Mhz.
> Of course they were using highly-optimized code for the DVD player, so
> it might be better to say that 750 Mhz. is required to decode SD mpeg2
> in software. Myth does more than just play the file, so it would need a
> little more than just decoding would require.

The mpeg2 decode on the CPU is not the issue with old PCs.
The problem area is the transfer of data from the CPU to the graphics card.
XV makes considerable savings in this area over plain RGB putimage.
XvMC makes even further savings by instead just sending the macro
blocks to the video card.

I think that another approach might be to have myth 0.24 in a
maintenance mode, whereby it can always talk to the latest
myth-backend database.
So, old PCs can continue to use 0.24 mythfrontend.
Is this a workable way forward?

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