FFmpeg is frequently used by different studios for encoding their media, however the documentation for ffmpeg is often poor, or cryptic so its often harder than it should be to come up with a good starting point. We are aiming to come up with recommendations for different scenarios as well as document what the different flags are doing with the aim to make this easier to get to a good baseline.
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- Best color preservation for output to:
- Web, OSX, IOS and Windows.
- Common applications: e.g. RV, Nuke.
- Rec709, P3, rec2020 and HDR.
- Web browser - Firefox reviewing mp4. - use firefox plugin.
- RV
- Codec recommendations for:
- Proxy H264 playback (e.g. web streaming), should be setup for web streaming.
- Animation/Modelling/Layout movie playback. - somewhat lower quality playback, but should always provide smooth motion.
- Lookdev/lighting/compositing movie playback - should have excellent color fidelity and minimal encoding artifacts
- Should any filmlook be baked in, or should we assume that is always applied during viewing.
- How much should we be able to adjust color and have the image hold up? (Or rely on exr's for that?).
- Export to editorial.
- High-resolution or frame rate - e.g. 4k, 8k, 60fps, 120fps.
- Stereo or VR.
- Q: Which container should we be considering: mov, mp4, mxf.
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| Name | Source | ffmpeg flags | Description | Size |
|---|---|---|---|---|
| colorspace_yuv444p10le | https://trac.ffmpeg.org/wiki/colorspace | -c:v libx264 -preset placebo -qp 0 -x264-params "keyint=15:no-deblock=1" -pix_fmt yuv444p10le -sws_flags spline+accurate_rnd+full_chroma_int -vf "colorspace=bt709:iall=bt601-6-625:fast=1" -color_range 1 -colorspace 1 -color_primaries 1 -color_trc 1 | ||
| Prores 4444 | -c:v prores_ks -profile:v 4444 -qscale:v 1 -pix_fmt yuv444p10le -sws_flags spline+accurate_rnd+full_chroma_int -vf "colorspace=bt709:iall=bt601-6-625:fast=1" -color_range 1 -colorspace 1 -color_primaries 1 -color_trc 1 | |||
| -profile:v 4444 is equivalent to -profile:v 4 | ||||
| shotgun_diy_encode | https://support.shotgunsoftware.com/hc/en-us/articles/219030418-Do-it-yourself-DIY-transcoding', | -vcodec libx264 -pix_fmt yuv420p -g 30 -vprofile high -bf 0 -crf 2 | ||
| Prores 422 HQ | Some FFMpeg commands I need to remember for converting footage for video editing. http://bit.ly/vidsnippets · GitHub |
| ||
Note the -profile:v 3 is equivalent to -profile:v hq | ||||
VMAF
I did explore using VMAF - Video Multi-Method Assessment Fusion as a way to quantify the compression, the notes for setting this up are below, however I think we are going with a fairly high compression factor , so I think this is probably not really going to help us much.
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- https://vimeo.com/349868875
- https://developer.apple.com/documentation/avfoundation/media_assets_and_metadata/sample-level_reading_and_writing/tagging_media_with_video_color_information
TODO:
- See if we can get ISO spechttps://www.iso.org/standard/73412.html - Note this has a link to the download of the earlier version of the doc, the latest and paywalled version is here: https://www.iso.org/standard/57794.html
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