[MPlayer-users] Re: Help w/ Mencoder anyone? DVD->DivX + TVcapture->DivX + vop scale probs

[Rémi Guyomarch]

On Sat, Dec 14, 2002 at 08:19:32AM +0000, Diego Zuccato wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> D Richard Felker III wrote:
> 
> > The main way to speed things up for live encoding is not to use motion
> > vectors. You can use an intra-only codec like mjpeg (good for very
> > slow systems like mine) or mpeg1 or mpeg4 with vme=0 or keyint=0.
> > vme=0 will give better compression than keyint=0, but will take more
> > cpu time.
> Is it possible to acquire frames with lossless compression?
> So that there's no quality loss but the i/o bw is reasonable.

Let's say that you're capturing 25 fps at 320x240.
Each frame will probably be packed in YV12, which means 153600 bytes
per frame or 3.66 MBytes per second or ~13 GBytes per hour.

Multiply those numbers by 4 if you want to capture at 640x480 instead
of 320x200.

Any half-decent modern IDE hard drive can easily sustain 4 MBytes/s
but 15-16, that's another story ...

I don't know much about lossless video recording, but I bet such codec
won't be able to scrap more than 50% of that bandwidth ...

-- 
Rémi