[MPlayer-dev-eng] Re: MPlayer-dev-eng digest, Vol 1 #1573 - 18 msgs
dtoso at optushome.com.au
Thu Dec 5 14:18:14 CET 2002
D Richard Felker III <dalias at aerifal.cx> wrote:
> > Actually, they are avi files with MPEG1 codec. I mention it just in case that makes a difference
> > to what would have to be hacked in the demuxer (probably not).
> It'll definitely make things trickier. With plain mpeg files you could
> probably just pipe the data to mplayer through a fifo and have a
> program switch which stream is getting sent into the fifo.
Hmmm, I like this fifo idea... (better than stupid symlink switching :-).
> > Here is the (snipped) output of 'mplayer -identify':
> > Detected AVI file format!
> > VIDEO: [mpg1] 352x240 24bpp 25.00 fps 856.0 kbps (104.5 kbyte/s)
> > VIDEO: MPEG1 352x240 (aspect 1) 25.00 fps 1000.0 kbps (125.0 kbyte/s)
> > Clip info:
> > Software: MEncoder CVS-021124-23:55-2.95.4
> Who on earth made such nonsense files? The only point of mpeg1 is for
> stuff that doesn't support mpeg4, but the only thing that will play
> mpeg1-in-avi is mplayer!!
Well I chose MPEG1 specifically because of the extremely low amount (0.3% according
to 'top' - but with some substantial I/O) of CPU mplayer uses when playing it back. I will
have 6 of these mplayer playing concurrently (maybe one more for an animated logo :-).
The problem then becomes that the machine could also be capturing MJPEG from a
capture card at 720x576 @30fps, and there still needs to be CPU/IO left to run all the
menu code that makes up the PVR display. I am not sure, but the MJPEG stream may
_also_ have to be transcoded to DivX 5 or WMV8 on the fly.
With this in mind, MPEG4 does not seem a viable candidate for the 6 concurrent
preview movies on the "recorded movies" menu page.
I would _love_ to have plain MPEG files, however (yes I have RTFM) I have not
been able to figure out how to get mencoder to encode such beasts. I currently use
mencoder ... -lavcopts vcodec=mpeg1video ...
in order to create the preview files. It encodes extremely fast (uses 5% CPU to do
so) and as I said, the playback of the files uses very little CPU.
Any advice here (either on mencoder, or on different codec ideas) would be very
More information about the MPlayer-dev-eng