[MPlayer-users] Re: Low bitrate using 2-pass with libavcodec

[Arpi]

Hi,

> > pass2.avi has lower quality than pass1.avi having about the same size.
> 
> Well, an alternate 2pass mode has just been committed to mplayer &
> libavcodec. Perhaps you can try it ? Be sure to check the latest CVS
> version of each. I didn't have time to really test it, but it seems
> better than the old (divxnetwork) code. At least it sticks to the
> desired bitrate quite well in -pass 2.

nope. -pass still uses divx4 2psss code. to use lavc's one, use -lavcopts
vpass=1 and -lavcopts vpass=2

my first test is nice, quality is acceptable and for vbitrate=600 i got:
Video stream:  600.062 kbit/s  (75007 bps)  size: 627774738 bytes  8369.464
secs

it was vcd sized video, coded with options:
-lavcopts vcodec=mpeg4:vhq:vpass=2:vmax_b_frames=2:vqmin=2:vbitrate=600
-vop crop=336:224:16:0

note that blockiness was reduced, but still visible for fats motion scenes :(
i'll make a test with higher resolution and bitrate tomorrow.

what's the status of B frame support? it seems to work, but dunno if it
really helps or it's not yet finished.


A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu