[MPlayer-users] How to pause mencoder

[Adam Nielsen]

> Sometime nice -19 is not sufficent.
> On my 1GHz athlon, I'm not able to grab from analog tv at 25fps while
> mencoding other video, even at nice -19.

Yes, I can agree with you there.  I capture from a digital TV source, so I can 
grab 50fps data if I want on a PII/400 running mencoder, but the problem for 
me is with mplayer.  If I'm running mencoder (on a 750MHz Athlon) and I try 
to use mplayer at the same time, it is very difficult to get a full 
framerate.  I have to use -framedrop to avoid A/V desync, and then every 
minute or so the video freezes completely for a second or so.  Even -cache 
8192 doesn't help (I'm playing the file over a network, and it works fine 
when mencoder isn't running.)

I think the problem is that Linux doesn't seem to have a true idle priority 
scheduler (although I've seen interesting conversations about the possibility 
of this in newer kernel versions.)  The problem is that even when running 
mencoder at nice -19, it still steals enough CPU power to cause problems 
elsewhere.  For example, running mencoder at nice -19, and then running 
another CPU intensive program (like a second copy of mencoder) at normal 
priority, the normal priority program only gets something like 80% of the 
CPU.  Ideally the nice -19 process should be as good as suspended if 
something else is using the CPU (and this is the 'batch' priority they were 
discussing.)

> So, sometime, mencoder take longer then I expected and if it's time for
> tv recording I suspend it and resume it later.

So yes, I have to suspend mencoder too if I want to watch something in mplayer 
without it being annoyingly jerky.

> Finally, there is at least two good reasons to suspend mencoder :)

But of course, since pressing Ctrl+Z and later typing "fg" seems to work 
perfectly, there's not really any reason to add this feature to mencoder.

Cheers,
Adam.