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

Loren Merritt lorenm
Tue Feb 21 22:23:09 CET 2006

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.

--Loren Merritt

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