[mythtvnz] Video Motion Blur

[Steven Ellis]

Duncan Kennington wrote:
> Quoting Steven Ellis <steven@openmedia.co.nz>:
>
>> David Zanetti wrote:
>> > Fairly common problem, most TV encoders are trying to do progressive
>> to
>> > interlaced conversions and not neccecarily doing a great job of it.
>> The
>> > video doesn't always line up with the scan lines, and conversion
>> between
>> > the two is ugly, so the whole thing gets a bit soft.
>> >
>> > And the original content was interlaced, so you've really got
>> > interlaced->progressive->interlaced in there.
>> >
>> > One of the drivers I have for getting a decent HD set is not really
>> all
>> > that HD content out there, but so I can drive it over HDMI in a
>> > progressive mode and bypass a few conversion steps.
>>
>> Tried a number of HD screens over DVI->HDMI and the blur is still high.
>> Got a de-interlacer enabled to perform
>>
>>  interlaced->progressive
>>
>> Still isn't as clear as a DVD player.
>
> I find this with the the (non-HD) plasma I have.  It is a
> progressive/interlace
> problem as David says.  If you drive your display with an interlaced
> signal
> (TV-out off the video card) then the card will be interlacing a
> progressive
> signal which is probably showing a deinterlaced version of an interlaced
> recording.
>
> To eliminate some of this conversion, driving the display digitally is
> obviously
> a better option, hence using DVI or HDMI.  You can even use VGA or
> component out
> (if you have one of those $400+ NVidia cards) to drive the display
> progressively.  This will make your menus and non-recorded stuff look
> better
> (should do, anyway!)

Ok I've tried all of the following in a range of resolutions from

Inputs - Component/Composite/SVideo/VGA/DVI

Video Output Format -480i/576i/576p/720p/1080i/1080p/1200p

Deinterlacer - Interlaced/Bob/Kernel/lavc

MPEG2 Library - standard/libmpeg2/XvMC

I've also tried a variety of PAL/NTSC video source both SD, 720p and 1080i.

In the end 1080i -> 1080i/p is the best.

Even 720p -> 1080i/p has the same motion issues.

Anything lower down at SD resolutions is shocking.

There is no video tearing an playback as vsync is locked correctly.


The other side of this it the problem isn't Linux specific. I've seen it
with WinMCE and XBox360.


>
> Progressive scan DVDs do some up-conversion anyway, I think, doubling
> frames up
> for a faster frame rate?

This would be the equivalent to Bob deinterlacing.

>
> Personally I'm going to try a better graphics card, as rendering of
> downloaded
> HD content (like the WMV samples) is *almost* spot on.  And only over
> VGA...

Been playing with some of the HD movie trailers as samples. They do look
gorgeus, especially some of the QuickTime 1080 trailers.

Steve