[MEncoder-users] new doom9 codec comparission

[Guillaume POIRIER]

Hi,

On 11/24/05, Michael Niedermayer <michaelni at gmx.at> wrote:

> doom9 is planning to do a new codec comparission, and they are asking me
> to provide them with 2pass settings (lavc mpeg4 & lavc snow) for the
> "qualification round" against xvid 1.03 with the matrix as movie
> they need a single set of options not a mix of possible good ones from
> which they would have to select, thats also why they refuse to ask here,
> they are also askng which binary of mencoder they should use
> iam not forwarding their mail as it was in german ...
>
> so we need a volunteer who has some experience with encoding, can
> provide them with all that and furthermore could double check that
> nothing silly goes wrong like using a player with postprocessing disabled
> for viewing the mencoder encoded video while one with pp enabled is used
> in the other cases
>
> if you want to volunteer just reply to the list ...
> if you dont do that, then shut up and dont complain about what doom9 will
> say about libav*/mencoder

> PS: also dont forget to ask if the test is just quality wise or speed wise too

I don't use libavcodec much those days, that's why I did not propose
an encoding option line. All I can offer is the encoding line that
I've used before switching to x264:
pass1:
vcodec=mpeg4:mbd=2:trell:v4mv:last_pred=2:dia=-1:vmax_b_frames=2:vb_strategy=1:cmp=3:subcmp=3:precmp=0:vqcomp=0.6:turbo:vpass=1:vbitrate=xx
pass2:
vcodec=mpeg4:mbd=2:trell:v4mv:last_pred=2:dia=-1:vmax_b_frames=2:cmp=3:subcmp=3:precmp=0:vqcomp=0.6:vpass=2:vbitrate=xx

I worked reasonably well for live action content.

As far as Snow is concerned, I really have not used it much to feel
like I should give any advice
Here is the encoding option line that you seemed to agree yield the
best quality with Snow:
pass1:
vqscale=2:vcodec=snow:cmp=1:subcmp=1:vqcomp=0.6:mbcmp=1:pred=0:psnr:vstrict=-2:vpass=1
pass2:
vbitrate=xx:vcodec=snow:cmp=1:subcmp=1:vqcomp=0.6:mbcmp=1:pred=0:psnr:vstrict=-2:vpass=2

I have not tested them though, so I guess I or someone should do that
before the deadline (I just can't do it tonight).

Also, I believe that the SIMD routines I'm working on may speed-up the
encoding process. If Doom9 is wants us to provide binaries, it may be
a good idea to apply that patchset too. However, the problem is that
apparently when mencoder is built on on win32 platform all sse code is
disabled (rich says it's because mingw malloc functions can't be
trusted to give well aligned memory).

Guillaume
--
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