[MPlayer-users] advice on mencoder options

D Richard Felker III dalias at aerifal.cx
Tue Nov 18 15:52:42 CET 2003


On Tue, Nov 18, 2003 at 12:53:45PM +0300, Vladimir Mosgalin wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> On Mon, 17 Nov 2003, D Richard Felker III wrote:
> 
> DRFI>> E.g. 640*480 resolution video at 25 frames per second at bitrate
> DRFI>> 2000 kbit/s would be 2000000/(640*480*25) = 0.26042 bits per
> DRFI>> pixel.
> DRFI>
> DRFI>Then your recommendation of 0.26 is insane. 640x480 video is fine
> DRFI>with ~1100 kbit/sec from my experience. In fact constant qscale=2
> DRFI>only gave me 1500 kbit/sec!! Of course if you have hideous noisy
> DRFI>input from TV then you'll need more bits (or preferably you'll need
> DRFI>to denoise), but for clean-source video, properly cropped, I expect
> DRFI>2000 will always be overkill.
> 
> I've got 3.5-minute video coded from dvd, most of the scenes have _very_
> fast motion. In 640x480, with bitrate 2000 average vq is higher than 3,
> video looks quite good. With vq=2, average bitrate was over 3000, and
> higher (4000 or so) in some moments. AFAIR quality with bitrage=1000 was
> noticeable worse. Well, its size is 60m now, so it doesn't matter...

I agree you may need these rates for your particular situation, but
it's a VERY unusual situation and not one to make general
recommendations on. Normally one is coding between 20 minutes and 2
hours of video with both high and low motion scenes, and average of
1100 kbit/sec is a plenty!

Rich



More information about the MPlayer-users mailing list