[mythtv] 20180705 Android Observations

David Engel david at istwok.net
Tue Jul 10 18:31:44 UTC 2018


On Tue, Jul 10, 2018 at 01:58:09PM -0400, Peter Bennett wrote:
> On 07/08/2018 03:15 PM, David Engel wrote:
> > I bumped the number of buffers up a little bit and 1080i at 1x was
> > very smooth, but any timestretching made it more jerky than it should
> > be.  I think something in the video display timing doesn't know that
> > the video is being deinterlaced at 2x.  720p content at 60 fps is as
> > smooth as it can be at any speed, so 1080i content deinterlaced to 60
> > fps should be the same.  The only thing that could prevent that is if
> > the decoder or deinterlacer can just barely do their jobs at 1x with
> > no extra margin. and don't believe that's the case.
> 
> David
> 
> Please share with me what you found to be the best buffer values. For the
> meantime I should add them to the patch with an #ifdef for android.
> Then I can work on timestretch with those buffer values.

I don't have the best values yet.  Bumping them by roughly 50 to 100%
(vbuffers.Init(8, true, 1, 4, 3, 2)) got the 1x playback smooth, but
didn't make any difference at speeds greater than 1x.  I've since
changed course and want to try to get the >1x playback smooth first.
To do that, I reset the buffer values back to original and captured
some playback logs at 1x and 1.5x for 720p and 1080i yesterday.  I
still need to analyze those logs.

David
-- 
David Engel
david at istwok.net


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