[Ffmpeg-devel] Differences between mencoder and ffmpeg whenencoding using x264

[Robert Swain]

On Tuesday 21 February 2006 21:23, Loren Merritt wrote:
> On Tue, 21 Feb 2006, Robert Swain wrote:
> > -ac -loop -partitions parti4x4+partp8x8+partb8x8 -me_method 7 -subq 5
> > -me_range 16 -chroma -trellis 1 -gop_size 250 -keyint_min 25
> > -sc_threshold 40 -bit_rate_tolerance 3000 -rc_eq 'blurCplx^(1-qComp)'
> > -qcompress 0.60 -qmin 10 -qmax 51 -max_qdiff 2 -rc_buffer_size 8000000
> > -i_quant_factor 0.71
> >
> > ...should bring them into line. me_method 7 corresponds to hex. I think
> > qpstep is 4 in the x264 cli. ip_ratio = 1/abs(i_quant_factor). The rest
> > of the differences you should be able to see. I think these command line
> > options are correct but I may be wrong. Also, I don't know if the
> > mencoder options are synced to the x264 cli precisely. They're pretty
> > close though.
>
> Warning: some options are both supported by ffmpeg.c and auto generated
> from avcodec.h, but only one of the copies works.
> e.g. "-g 250" works, but "-gop_size 250" does nothing.
> This applies to any option printed by `ffmpeg` that has a version without
> the "EDV.." field.

Hmm, OK. Why are such options present? Should they be removed if they are 
naught but placebos? :)

Rob