deinterlacing [was: Re: [MPlayer-dev-eng] Re: ccache]

[Arpi]

Hi,

> The Timeline of an Analog VCR/Camcorder is no different from a digital
> VCR/Camcorder. Only the storage format differs.
afair it mentiones some newer digital camcorder with ability to record
at 15/25 fps progressive.

> 2)
> It is not possible to capture fields with higher vertical resolution
> than 288 scanlines (PAL) because only 288 scanlines are transmitted
> in the video signal. So the digitizers we have are already doing the
> best that can be done. (Well, maybe they are a bit on the noisy side,
> at least my Hauppauge is...)
agree.
but what about DVB?
there are broadcasts at 480x576x25fps progressive sometimes.

> 3)
> The "color interlacing" can happen if an YUV411 Signal is converted to RGB
> or vice versa. You have to use different algorithms for interlaced and
> progressive material. For progressive material the first UV-Line
> contains color information for Y-Line 1+2, for interlaced material it is
> for Y-Line 1+3.
hmm. do our postproc filters handle this proeprly?
probably not, since it was designed for YV12 mpegs.

> 5)
> Area based, Motion blur -> Different adaptive deinterlacing Methods
> Blending Fields and Discarding Fields are closely related.
> With both you half the vertical resolution and scale it back up.
yep
btw it mentioned an adaptive virtualdub filter at the end of the page for
producing the best results.
maybe we could port it to mplayer:
DeinterlaceSmoothSrc.zip (it's only a 20k .cpp file)

> 6)
> PAL vs. NTSC:
> PAL has a slightly higher luma resolution, but a halfed chroma
> resolution because of the Phase Alternating Line Color Encoding.
> IIRC NTSC is information wise comparable to YUV422 while PAL carries
> only as much information as an YUV411 picture...
hmm.
in DV world, PAL uses Y420 while NTSC uses Y411

> 7)
> The best deinterlacing method is not deinterlacing at all. I'd like to
:)

> have a player that can display 25interlaced as 50progressive by filling

yep i agree that it's better deinterlacing at playback time.
but if you have a codec incapable of (well) compressing interlaced material?

> the even/odd lines for the odd/even fields with black lines, just the
> way it works in your Television set. :-)
> (Well the lower afterglow of the Monitor might be problematic, I
> think filling the missing lines with the last frame in 1/2 or 1/4 the
> brightness might compensate for that)

we should make a filter for mplayer which can emulate TV :)

btw, what about the 100Hz TVs? they don't display 50 fields per secs.
recently I've decided to buy a new TV (my current one is ~15 years old :)),
and i've 'tested' severals models, including the newest ones from sony, jvc
and grundig. The most surprising was that they show interlaced pictures!
Ok, some very expensive models has 'motion compensation' feature. I've seen
a Samsung one with this feature, hey, it was funny. There was a scene on
eurosport, sky running/jmping whatever. the camera follwoed the skier,
so the background quickly moved (panning). There were no interlacing
artifacts, but sometimes some part of the background 'sticked' to the skier
and moved with him for a while :) it was very funny.


A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu