[mythtv-users] 0.24+fixes - tearing, /dev/rtc permissions and getting openGL to work

[Michael T. Dean]

On 02/26/2011 01:25 PM, Mike wrote:
> On 26 February 2011 13:12, Michael T. Dean wrote:
>> On 02/26/2011 11:01 AM, Mike wrote:
>>> On 26 February 2011 10:50, Brian J. Murrell wrote:
>>>> On 11-02-26 10:47 AM, Mike wrote:
>>>>> Thanks for everyones help and commentary on what my hardware can
>>>>> achieve.
>>>> I just wish I could get mine to stop tearing as easily as you did.
>> ...
>>> I've also tried to ensure I'm running 'good' NVIDIA drivers
>> And, TTBOMK, that is basically the approach you need to take to prevent
>> tearing.  AFAIU, tearing has nothing to do with /dev/rtc timing versus
>> usleep timing.  The video drivers prevent tearing, so you need good
>> drivers and need to configure them correctly for your chosen video
>> output method.
> I realised tearing is not related to the timing sources in my
> situation with GPU/Composite issue... I had understood from a mythtv
> wiki page that OpenGL (obselete) was better than RTC which was
> possibly better than usleep... overall, I figured since RTC
> configureable it may be useful or better than usleep for general
> timing issues wrt audio&  video and streaming from a separate backend
> vs frontend.  All speculation though and was just pinning my hopes on
> what I'd read and trying to figure out how to achieve RTC timing
> instead of usleep.  Maybe usleep is less important in the newer
> versions of hardware&  software?

 From what I understand, the timing is more about frame delivery than 
tearing.  A good-quality timer makes it more likely for us to have the 
frame ready when it's needed (presuming decoding/rendering hardware are 
able to keep up), so you don't end up dropping frames or whatever.

Mike