[MPlayer-users] Re: lavc vs. xvid (and improving lavc quality)

[Evgueni V. Gavrilov]

In article <20040530005848.GU26953 at brightrain.aerifal.cx> of mplayer-users you wrote:

DRFI> Anyway this is interesting if it's correct. At same quant, the two
DRFI> should give comparable bitrates.
this comparison isn't correct because by default lavc doesn't create B-frames, but xvid does.

here is a small example:

$ mencoder -dvd-device /big/Video/Star\ Wars/Episode\ II\ -\ Attack\ Of\ The\ Clones dvd://7 -chapter 4 -endpos 30 -oac mp3lame -ovc xvid -xvidencopts fixed_quant=3:psnr -vf filmdint -fps 29.97 -ofps 23.976023976024 -noautoexpand -o test.xvid

$ cq psnr_115135.log
1:            57            7.96%           2.81%
2:           189           26.40%          18.67%
3:           290           40.50%          42.96%
4:           180           25.14%          35.56%

VIDEO:  [XVID]  720x480  24bpp  23,976 fps  1774,5 kbps (216,6 kbyte/s)

$ mencoder -dvd-device /big/Video/Star\ Wars/Episode\ II\ -\ Attack\ Of\ The\ Clones dvd://7 -chapter 4 -endpos 10 -oac mp3lame -ovc lavc -lavcopts vqscale=3:psnr -vf filmdint -fps 29.97 -ofps 23.976023976024 -noautoexpand -o test.avi

$ cq psnr_115322.log
3:           719          100.00%         100.00%

VIDEO:  [DIVX]  720x480  24bpp  23,976 fps  948,6 kbps (115,8 kbyte/s)

$ ls -l test*
-rw-r--r--  1 aquatique  wheel  4369446 30 ÍÁÊ 11:53 test.avi
-rw-r--r--  1 aquatique  wheel  7474052 30 ÍÁÊ 11:52 test.xvid

shots, psnr files and video available on http://aquatique.rusunix.org/qscale/

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