[mythtv-users] High timestretch speeds with VDPAU

David Engel david at istwok.net
Sat Dec 13 18:05:39 UTC 2008

On Fri, Dec 12, 2008 at 09:36:33AM -0800, Brad DerManouelian wrote:
> On Dec 12, 2008, at 9:23 AM, David Engel wrote:
> > I like to watch most news and talking heads shows and occasionally
> > some sports at fairly high timestretch speeds.  I'd like to hear if
> > anyone has been able to achieve at or near 2x timestretch speeds using
> > VDPAU on H.264/HD-PVR recordings?  I'd particularly like to hear what
> > speeds others can get on 9300/9400 IGP systems since that's what I've
> > been eyeing for a frontend upgrade.
> > [...]
> On 13.5 Mbps 720p content, I can time stretch to 1.25, but 1.3+ has  
> audio dropouts that make it too annoying to use. I haven't seen much  
> mention of time stretching with VDPAU so I don't know if it's been  
> optimized at all. There's likely some work still left to be done with  
> it.

With which GPU is that?  If your drop off for 1080i is comparable to
mine with my 9500, that wouldn't leave you much room to do anything
more than 1.0x.  I don't know that there's much optimization Myth can
do.  I would expect the timestretch speed to be almost entirely
dependent on the speed of the GPU, but I'll defer to Mark Kendall who
appears to be the MythTV expert on VDPAU.

Could someone with an integrated 9300 or 9400 please see what maximum
timestretch speed they can reach.  I can't imagine either would beat
an add-in 9500, though.

David Engel
david at istwok.net

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