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  1. Hi guys,

    I just saw this video and I was very impressed about the quality for the size.

    http://player.vimeo.com/video/83708990?api=1&player_id=player_1&color=ffffff

    If you had to encode video like that on a ubuntu server, would you use ffmpeg or x264 or something else? And what kind of command line would you use (if you have examples)?

    I run with ffmpeg for years and even though I'm close of that result, I'm not there yet.

    Help would be very appreciated.
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  2. Member
    Join Date: Sep 2007
    Location: Canada
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    Yes, you could use ffmpeg libx264 or x264

    But the final quality has less to do with the encoding settings, than with the content itself (this example has very little motion , except for the end and has good lighting, shot well, little noise, shallow DoF) . All those factors make it easier to compress. If you had different content that had lots of motion , noise, it would "fall apart" at that bitrate . Long GOP video compression works by coding and storing the differences between frames - when there are few differences, the filesize required for a certain level of "quality" is much lower

    It's just the vimeo encoder. You can see the x264 settings used if you download the video. Most of it looks like the default "medium" settings , with 3 sec gop and vbv settings


    cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / 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=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / stitchable=1 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=72 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=5 / qpmax=69 / qpstep=4 / vbv_maxrate=6750 / vbv_bufsize=22500 / crf_max=0.0 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00


    Code:
    x264 --crf 20 --keyint 72 --min-keyint 24 --vbv-maxrate 6750 --vbv-bufsize 22500 --stitchable -o ouput.mp4 input.ext
    or

    Code:
    ffmpeg -i input.ext -vcodec libx264 -crf 20 -g 72 -x264opts vbv-bufsize=22500:vbv-maxrate=6750:min-keyint=24:stitchable -an output.mp4
    (I left audio out -an, in the ffmpeg example)
    Last edited by poisondeathray; 24th Jan 2014 at 12:42.
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  3. Hello poisondeathray

    Thank you very much for your reply.
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