[mythtv] Idea for interlaced playback
bjornko at ifi.uio.no
Mon Oct 2 09:42:58 UTC 2006
Harri Järvi wrote:
> bjornko wrote in Nov 2005:
>> What's happening is that the video refresh is at 50Hz, and the
>> framebuffer is updated every 2nd refresh with two new fields.
>> Sometimes this is out of synch with the tv-out which causes fields to be
>> shown out of order.
>> (Both fields being refreshed in the framebuffer and the TV-out has only
>> displayed one of them).
>> This is why I would like a playback option which updates at 50Hz, but
>> only updates one of the interlaced fields at a time. Unfortunately this is
>> harder than I had hoped. I'd also get an audio offset as I would have to
>> buffer at least one field pair.
> I'm interested in knowing if you or someone else has solved these
> problems. Is your filter available for download somewhere?
Sorry. I really haven't had the time to move forwards on this. I'm
pretty sure the idea is sound,
because I created a videoclip using the algorithm described, and it
plays well using mplayer,
but MythTV's playback uses XV which defaults to the video overlay
hardware for scaling, and
it isn't clean enough, causing bleeding between video fields, at least
on my nvidia-card. Disabling
XV works, but is too slow.
In mplayer i can use an opengl-based playback which does not suffer from
The normal mythtv filter interface is not flexible enough to implement
the filter, (as far as I could tell.)
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