[MEncoder-users] Mencoder params

[John Doe]

> Well, there's already suggested "encoding profiles" here:
> http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-x264.html#menc-feat-x264-example-settings

I tested both the HD and the VHD params from the page but I cannot really see much difference, apart from the slower encoding...

> Also, you shouldn't have to manually change the "me=" option between
> 1st and 2nd pass, "turbo" option already takes care of that.

Thx, I changed it.

> > (1) You don't need to encode audio on the first pass. To save cpu
> >     cycles, rather use -oac copy
> 
> Quite the contrary.  Changing the audio encoder will very likely cause
> different frames to be dropped, resulting in lower quality 2-pass
> encoding, and potentially the second-pass crashing as well.

Indeed, I put -oac copy in the 1st pass and got:
x264 [error]: 2nd pass has more frames than 1st pass (400):0.023 [1019:102]]
x264 [error]: continuing anyway, at constant QP=36
.... Segmentation fault

> (3) -sws isn't really needed as long as you don't scale the video
> You might want to ask yourself though what the pressing reason exactly is forresampling the audio to 41kHz.

I do have to rescale if the input is too big.
And I do have to resample because the flash player I use only handles 11025, 22050 and 44100.
As a side note, some 3gp files transcode well to 11025 or 44100; but not with 22050 for some reason.
And the sizes difference was low, so I just chose 44100.

> vbitrate and vqscale at the same time makes no sense. Also, two pass makes no sense if you have vqscale.

I removed vbitrate when I put qscale in the past but mencoder complained, so I put it back...
But now it does not complain anymore, I must have made a typo or something.

> I think x264 will even refuse to do anything when both bitrate and vqscale is specified

In fact, another copy/paste error; there is no vqscale option with -x264encopts; only with -lavcopts...
I did put "bitrate=1000:vbv_maxrate=2000:vbv_bufsize=2400" instead.
Is the bufsize value supposed to be "a little bit higher" than maxrate?

Thx to everybody.

I must admit that I am still a bit confused with fixed/variable bitrates, 2 passes.
vbitrate with 1 pass is fixed and with 2 pass is variable, is that it?
The thing is, the quality of the videos done with qscale seems a lot better quality than with 2pass vbitrate.
So, there's no equivalent to qscale in x264?
I guess I still have more testing to do...

JD