[mythtv-users] New deinterlacer for perfect image quality when using an interlaced display, mode that matches the source

Paul Gardiner lists at glidos.net
Wed Apr 1 08:07:27 UTC 2009

Tom Dexter wrote:
> On Mon, Mar 30, 2009 at 4:39 AM, Paul Gardiner <lists at glidos.net> wrote:
>> Paul Gardiner wrote:
>>> Tom Dexter wrote:
>>>> I noticed some flickering of translucent portions of the OSD (the
>>>> playback menu for example) while this deinterlacer was in use (unless
>>>> video is paused).  On 720p stations where it gets disabled this
>>>> doesn't occur at all.
>>> I think I've just sussed what is causing this. The deinterlacer gets
>>> given each frame twice. Each time it overwrites the bottom field,
>>> but leaves the top field unchanged. After each call the OSD will
>>> be rendered over the frame. The fact that I don't update the
>>> top field in the second call to the deinterlacer means the OSD gets
>>> rendered over the top of a previous rendering. That doesn't matter
>>> for a solid OSD, but if translucent the top field will be
>>> darker than the bottom.
>>> Should be easy to fix:
>> ...
>> Hmmm, so much for that idea! Doesn't seem to make any difference.
>> P.
> It's definitely a side affect I can live with for sure...it's not even
> all that noticeable.

I've just tried yadif and see exactly the same thing, so I guess it's
a general problem with doubleprocess deinterlacers on an interlaced
display. As you say, it's not that noticeable in any case.

> The deinterlacer really does work great though.  Watching the 1080i
> content I'm starting to notice more and more just how much better it
> looks...that almost 3D-like clarity I just wasn't getting before.

I'm really pleased. I imagined it would make a significant difference
to 1080i. I've been suspicious for some time that most people running
MythTv aren't getting full quality 1080i. Good to hear you are now.

BTW, what graphics card are you using, and what method of connection?


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