Please, leave the x264 arguments in the video header. When I use MediaInfo to check for them, they are not there.
Like these:
Stream size : 416 MiB (85%)
Writing library : x264 core 138 r2358 9e941d1
Encoding settings : cabac=1 / ref=13 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=11 / psy=1 / psy_rd=0.50:0.00 / mixed_ref=1 / me_range=48 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=6 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=240 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=0 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=81 / qpstep=4 / vbv_maxrate=17500 / vbv_bufsize=17500 / crf_max=0.0 / nal_hrd=none / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:0.70
Like these:
Stream size : 416 MiB (85%)
Writing library : x264 core 138 r2358 9e941d1
Encoding settings : cabac=1 / ref=13 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=11 / psy=1 / psy_rd=0.50:0.00 / mixed_ref=1 / me_range=48 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=6 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=240 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=0 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=81 / qpstep=4 / vbv_maxrate=17500 / vbv_bufsize=17500 / crf_max=0.0 / nal_hrd=none / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:0.70