[Mplayer-advusers] Deinterlacing at full frame rate.

[Francois SIMOND]

Hello to every mplayer-user and developper !

MPlayer contains useful deinterlacing techniques, but i've
noticed the lack of a full frame rate deinterlacing method,
that output 50fps with PAL, and 60fps with NTSC.
This is the simplest and efficient way to obtain fluent animations
and scrollings.
Mostly TV sources, camecorders sources, and some badly encoded DVDs
(poorly NTSC->PAL reencoded), are interlaced to be seen on a TV.
So, they look much nicer when viewed at teir original frame rate.

DScaler, a great ( win32 only :`| ) program does this job realtime,
grabbing video from a bt8x8 card. It use highly optimized deinterlace
filters (like Greedy High Motion / GPL, written by trbarry -
 see http://www.xvid.org/forum/viewtopic.php?topic=384&forum=2 ),
or Simple BOB. ( or 3:2 / 2:2 pulldown for film sources, autodetected )
The result is often visualy better than what does a 100Hz tv.

It could be very cool if you implement (one of) these techniques,
the simplest is BOB, i think it can be implemented in minutes ;)

as you know, TV displays alternatively odd and even lines,
simple BOB does the same:

->the man goes this way->

-----------time----------->

 @25fps
 ---------       ---------
|     O   |     |     O   |
|  --|--  |     |  --|--  |
|     |   |     |     |   |
|   /_\ _ |     |   /_\ _ |
 ---------       ---------
interlaced       the same
image / 25fps


 @50fps
 ---------       ---------
|         |     |     O   |
|  --|--  |     |         |
|         |     |     |   |
|   / \   |     |    _  _ |
 ---------       ---------
  even            odd lines
lines only          only

lines not displayed becomes black ( or dark )
with simple bob, animation is smooth :)


I wrote this long mail because I really want this display mode
( or deinterlacing techniques ) to be inclued with MPlayer !

Not any linux software does it, xaw-deinterlace, xawdecode, xine
always output at 25fps instead of 50 ( these software took
their deinterlacing techniques from DScaler, but didn't implement
it correctly )
Not any avi-player does this under win32, but in some configurations
powerdvd does.
These functionnalities are usefull with DVDs, MJPEG, V4L, interlaced XVID..

I hope i'll get your attention. if not I will learn C and send you a
patch .. after 1 or 2 years :)

thx for this powerfull piece of software

curio