[MPlayer-dev-eng] [PATCH] (mencoder) lavc option "notch_matrix"
Michael Niedermayer
michaelni at gmx.at
Sun Oct 19 21:26:39 CEST 2003
Hi
On Sunday 19 October 2003 21:04, Steven M. Schultz wrote:
[...]
> > btw, does anyone know why this matrix is supposed to be better then the
> > default? did anyone do any tests? PSNR?, double blind subjective?
>
> Comparing the tables they give to the default MPEG-2 tables
> it looks like the high frequencies are quantized very differently.
> "Roll off" isn't the right term but that's what comes to mind.
>
> I've used the Kvcd tables as well as the TMPGEnc tables in
> mpeg2enc (mpeg2 encoder from mjpegtools). Not double blind
> testing but the resulting video was fine to me (not having golden
> eyeballs, using an older TV set, etc ;)).
>
> The difference in bitrate was a big surprise. Using "-K kvcd"
> with mpeg2enc the average reduction in bitrate (as reported by
> mplex) was 20% (depends on the -q or quality setting - sometimes
> the savings was closer to 12%, other times 25%). The TMPGEnc
> tables split the difference between the default and Kvcd tables -
> usually around 10-15% savings over the default tables. Much
> depends of course on the source of the material being encoded.
yes, but thats meaningless, i mean just use 99 or 255 for all enries, dunno
which is tha largest which doesnt overflow, and u get a nice reduction of
bitrate at the same q but the quality will also suffer seriously
[...]
--
Michael
level[i]= get_vlc(); i+=get_vlc(); (violates patent EP0266049)
median(mv[y-1][x], mv[y][x-1], mv[y+1][x+1]); (violates patent #5,905,535)
buf[i]= qp - buf[i-1]; (violates patent #?)
for more examples, see http://mplayerhq.hu/~michael/patent.html
stop it, see http://petition.eurolinux.org & http://petition.ffii.org/eubsa/en
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