[MPlayer-users] Re: Framerate vs. monitor refresh rate

[ACS]

----- Original Message ----- 
From: <sci-fi at hush.ai>
To: <mplayer-users at mplayerhq.hu>
Sent: Monday, November 20, 2006 09:00
Subject: [MPlayer-users] Re: Framerate vs. monitor refresh rate

> I might be o.t. here, but what would a DVI-D video system
> do, which usually does not report a refresh rate at all and
> can't be selected/changed inside the o.s. or video/X11
> driver/subsystem?  i.e. there is no such refresh rate as the
> entire video system is "pure digital" IIUC clear out to the
> pixels on the display.
As long as all individual pixels can't be addressed simultaneously, pixels 
have to be addressed sequentially.
Obvious, this way pixels can only be updated a limited times per second 
(bandwidth, max clock), which results in a refresh rate in the all digital 
world too.

> I'm just wondering about this, because when making mplayer
> use -vo macosx, I am seeing some "streaking" or "tearing" of
> the motion in all kinds of modes (std-def xvid, mpeg2, dv,
> hi-def .ts, whatever) -- and the streaks do not "freeze"
> with the '.' key so I can't even provide a snapshot of what
> I'm trying to describe.  ;)

Might be lack of double buffering.
Imagine your monitor is halfway displaying an frame, when a new output frame 
becomes available from the decoder.
Data from this new output shouldn't be displayed immediately, the monitor 
should finish the complete frame displaying the previous output.

Try to visualize what happens when display switches halfway in its scan from 
top to bottom from previous to next decoded frame.

Adrian