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View Full Version : Files encoded with x264 preset slow + B-adapt 2 are shown as b-adapt=1


numaios
27th November 2017, 18:21
Hello to everyone.

I've been encoding several files in MeGUI 2774, with x264 codec, using preset Slow, and ticking the "show advanced settings" checkbox only to change ME method from hex to uneven multihex, so the commandline is:

program --preset slow --tune film --crf 21.0 --me umh --output "output" "input"

In the encoder GUI, in Frame-type tab, "adaptive b-frames" is set to 2 (Optimal), I understand this setting won't appear in the command line since it's the default setting for slow preset.

But when the file is encoded and analyzed with Mediainfo, it shows this info:

Writing library : x264 core 152 r2851 ba24899
Encoding settings : cabac=1 / ref=5 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=umh / subme=8 / psy=1 / psy_rd=1.00:0.15 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-3 / threads=3 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=crf / mbtree=1 / crf=21.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

Any ideas? Is this some kind of bug? Let me know if you need any further information.

Thank you very much.

sneaker_ger
27th November 2017, 18:25
Preset slow was changed last year.

http://git.videolan.org/?p=x264/x264-sandbox.git;a=commit;h=4e5adb87070c82b937c03e0cc030eae3578c251d

numaios
27th November 2017, 18:31
Thanks for your answer.

I understand default b-adapt setting was changed to 1 (fast). In this case, then the problem must be that MeGUI doesn't add the "--b-adapt 2" to the command line in spite of being selected in the GUI. Isn't it supposed to work that way?

sneaker_ger
27th November 2017, 18:40
Yes, I suppose so.

numaios
27th November 2017, 18:52
Thank you. Is this the proper place to warn about a bug and suggest a fix in the next MeGUI version?

numaios
27th November 2017, 18:58
Sorry, I just saw this thread: MeGUI: bug reports and feature requests