[mythtv-users] Getting lots of jitter with version 0.24

[John P Poet]

On Mon, Nov 22, 2010 at 4:23 PM, Justin Johnson
<justin.johnson3 at gmail.com> wrote:
> On Sun, Nov 14, 2010 at 4:06 PM, Justin Johnson
> <justin.johnson3 at gmail.com> wrote:
>> On Sat, Nov 13, 2010 at 8:25 PM, Kevin Ross <kevin at familyross.net> wrote:
>>>
>>> Unfortunately, no I haven't.  I haven't had time to try to diagnose the
>>> problem, so I've just been putting up with it.  I wonder how many other
>>> HD-PVR users are observing the same.
>>
>> I've investigated this a little further, after having a couple
>> recordings take place. I only see the jitter in LiveTV on progressive
>> scan video, my recordings are fine. In fact, if I enter livetv, I
>> observe the jitter. If I then hit the record button, then play the
>> same recording from the recording list, the jitter is gone. I've
>> confirmed this in the logs as well as visually.
>> It looks like the framerate in LiveTV is being detected as 25fps, and
>> the display is set to match. But the video is actually 30fps and so
>> the display is at the wrong refresh rate. If I force the display rate
>> to 60Hz then it displays fine, of course 24fps content is wrong.
>> So, the question is, why does myth incorrectly detect the framerate of
>> progressive content in LiveTV only?
>> As a temporary workaround, I've removed the 50Hz modeline from
>> xorg.conf and the issue is fixed. Since I don't plan on watching any
>> PAL content, I don't think this should be a problem, but it would be
>> nice if it were fixed in the future.
>>
>> --Justin Johnson
>>
>
> OK, I lied, this does not work around the issue, at least not fully. I
> still see the same behavior when playing back at 1.5x (I like to watch
> most shows sped up, it dramatically decreases the amount of time in
> front of the tv). Again, only with progressive content. Mythfrontend
> drops a number of frames every 0.02 seconds, which causes significant
> stutter. Any ideas for troubleshooting, users?


Try these patches against 0.24:

http://svn.mythtv.org/trac/attachment/ticket/7964/mythtv_smoothsync.13.patch
http://svn.mythtv.org/trac/attachment/ticket/7964/smoother-vsync-audio.11.patch
http://svn.mythtv.org/trac/attachment/ticket/7964/smoother-vsync-vsync-opt.11.patch

They do wonders for progressive frame-rate timestretch playback.

Unfortunately, something in trunk has broken the effectiveness of
these patches, but they work great with 0.24.


John
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