[mythtv] Ticket #6938: smoother playback

Mark Spieth mark at digivation.com.au
Sun Aug 30 23:51:50 UTC 2009


>>
>>  using opengl vsync with no acceleration, audio controls timing.
>>
>>  xvideo, standard and linearblend/kernel deint on one.
>>  xvideo, standard and greedyx1/yadifx1 on FE.
>>
>>  1080i and 720i dvb source. display is 60Hz in both cases (TV's). 
>> original
>>  src material is 50Hz (aus DVB). various timestretch speedups between 1.0
>>  and 1.85.
>>
>>  ive been running this for a couple of years. gave it to a few people for
>>  eval. simon kenyon most recently. said it was much better.
>>
>>  most noticable in motor racing and news tickers. havent tried without 
>> for
>>  a long time.
>>  effect was 0.5 secs normal and then 0.5 secs hurry up for video out rate
>>  adaption.
>>  I suspect rtc is why you dont notice it.
>
>Are you using an nvidia card, and if so, do you have Xv sync to VBlank
>enabled or disabled?

yes nvidia 8400GS (cheap and fanless) in both machines.
option UseEvents is true
RenderAccel is off

in nvidiasettings
SyncToVBlank is 0

>I used to use opengl vsync with Xv sync to VBlank disabled for SD.  It
>was very smooth.  When I switched to HD, this configuration resulted
>in tearing and I had to enable XV sync to VBlank to get rid of it.
>Using opengl vsync with Xv sync to VBlank resulted in horrible
>jerkyness when timestretching.  To get rid of the jerkyness, I
>switched to RTC vsync and have running this way for about 2 years now.
>It's not ideal in that the timinig MythTV is using isn't exactly in
>sync with the display, but it's been close enough.

I have no tearing at all in HD or SD modes or mythvideo content with this 
config.

cheers
mark 



More information about the mythtv-dev mailing list