VDPAU playback of interlaced content starts to be jumpy when user enables
glamor and DI is set to 2x.
Issue is seen under MythTV. Playback log reports:

2014-11-13 13:47:01.013753 I Player(1): Video is 3.18365 frames behind audio
(too slow), dropping frame to catch up.
2014-11-13 13:47:01.013783 I AOBase: Pause 1
2014-11-13 13:47:01.014047 I Player(1): Video is 3.45023 frames behind audio
(too slow), dropping frame to catch up.
2014-11-13 13:47:01.014064 I AOBase: Pause 1
2014-11-13 13:47:01.014171 I Player(1): Video is 3.40015 frames behind audio
(too slow), dropping frame to catch up.
2014-11-13 13:47:01.014188 I AOBase: Pause 1
2014-11-13 13:47:01.014286 I Player(1): Video is 3.1126 frames behind audio
(too slow), dropping frame to catch up. 

2x DI problem manifests only with enabled glamor. On Brazos with EXA, 2x DI
works perfect while enabling glamor triggers 2x DI issue. 
On Kabini issue is always present as Kabini mandatory requires glamor. 

Tests were done with mesa 10.2.8/10.3.3 and xserver 1.16.1/1.16.2