Opened 6 years ago

Closed 6 years ago

#261 closed defect (fixed)

ffmpeg now sets libx264 open_gop=1 by default

Reported by: rectalogic Owned by:
Priority: normal Component: avcodec
Version: git-master Keywords:
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no


x264 default is closed gop (open_gop=0), ffmpeg defaults to open gop unless -flags +cgop is specified.

This commit e25c67108a77b2dbf13de1339b5314d07e3ffa02 applies the ffmpeg setting to libx264, and changed all the libx264 ffpresets to specify +cgop so the x264 default remained the same.

Now that ffpresets aren't used and the new -preset (libx264 internal presets) is used, open_gop=1 is set for libx264 by default unless -flags +cgop is passed explicitly to ffmpeg.

ffmpeg -i -acodec libfaac -ab 64k -ar 44100 -ac 1 -pass 2 -threads 0 -vcodec libx264 -preset slow -wpredp 0 -r 1200/40 -g 8*1200/40 -b 700k -bt 700k -f mp4 -y output.mp4
ffmpeg: [libx264 @ 0x150b5c0] profile High, level 3.0
ffmpeg: [libx264 @ 0x150b5c0] 264 - core 115 d0d6ea718 - H.264/MPEG-4 AVC codec - Copyleft 2003-2011 - - options: cabac=1 ref=5 deblock=1:0:0 analyse=0x3:0x113 me=umh subme=8 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=18 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=2 b_bias=0 direct=3 weightb=1 open_gop=1 weightp=0 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=50 rc=2pass mbtree=1 bitrate=700 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 cplxblur=20.0 qblur=0.5 ip_ratio=1.40 aq=1:1.00

I'm not sure if this is considered a bug, but it's a change in behavior and the intention of that commit was clearly to preserve the x264 default.

Change History (1)

comment:1 Changed 6 years ago by michael

  • Resolution set to fixed
  • Status changed from new to closed

Fixed locally

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