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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| Name | Target Usage | Source | ffmpeg flags | Description | Size |
|---|---|---|---|---|---|
| x264 -pix_fmt yuv420p | Proxy playback, for web review, and non-color critical workflows, e.g. animation, modeling, etc. | This should be a lightweight compression, capable of supporting HD with a reasonable bit-rate, hopefully supporting a wide range of web browsers. Final review, e.g. lighting | |||
| x264 -pix_fmt yuv444p10le | Final review, e.g. lighting | 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 | ||
| x264rgb | x264rgbFinal review, e.g. lighting | This is a variant of the above, its essentially using x264, but not converting to YCrCb. | |||
| Prores 4444 | For delivery to editorial | -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 | |||
DnxHD | For delivery to editorial | ||||
| Prores 422 HQ | For delivery to editorial | 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 | |||||
x264
Key flags (see https://trac.ffmpeg.org/wiki/Encode/H.264 )
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While it is possible to do the encoding outside of ffmpeg (see later).
For examples comparing these see: https://richardssam.github.io/ffmpeg-tests/tests/chip-chart-yuvconvert/compare.html
colormatrix filter
ffmpeg -y -i ../sourceimages/chip-chart-1080-noicc.png -sws_flags spline+accurate_rnd+full_chroma_int -vf "colormatrix=bt470bg:bt709" -c:v libx264 -preset placebo -qp 0 -x264-params "keyint=15:no-deblock=1" -pix_fmt yuv444p10le -qscale:v 1 -color_range 1 -colorspace 1 -color_primaries 1 -color_trc 1 ./chip-chart-yuvconvert/spline444colormatrix2.mp4
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ffmpeg -y -i ../sourceimages/chip-chart-1080-noicc.png -sws_flags spline+accurate_rnd+full_chroma_int+full_chroma_inp -vf "scale=in_range=full:in_color_matrix=bt709:out_range=tv:out_color_matrix=bt709" -c:v libx264 -preset placebo -qp 0 -x264-params "keyint=15:no-deblock=1" -pix_fmt yuv444p10le -qscale:v 1 -color_range 1 -colorspace 1 -color_primaries 1 -color_trc 1 ./chip-chart-yuvconvert/spline444out_color_matrix.mp4
Using the libavscale library. Seems similar to colorspace, but with image resizing, and levels built in. https://www.ffmpeg.org/ffmpeg-filters.html#scale-1
This is the recommended filter.
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| Browser | Platform | Interpret NCLC flags | Color Managed | Tested | Notes |
|---|---|---|---|---|---|
| Firefox | OSX | No | |||
| Firefox | Windows | No | |||
| Firefox | Windows | ||||
| Safari | OSX | Yes | Yes | ||
| Chrome | OSX | Yes | Yes | ||
| Safari | IOS | No | |||
| Chrome | Windows | Sometimes | Seems to occasionally stop working, it could be related to multiple screens. | ||
| Chrome | Linux | ||||
| Edge | Windows | Sometimes | Seems to occasionally stop working, it could be related to multiple screens. |
Gamma 2.4
There is not a color_trc flag for gamma 2.4, the only option that exists for OSX is a cheat
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ffmpeg -y -i chip-chart-1080.png -c:v libx264 -pix_fmt yuv444p -qscale:v 1 -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 2 -movflags write_colr+write_gama -mov_gamma 2.4 test2-h264-ffmpeg-yuv444p-gamma24.mp4
Full range vs. legal range
Typically x264 (and other codecs) are following the video standard that lumance is scaled to the range 16-235. This has a history from early signaling where 236-255 were used for signaling and 0-15 to avoid any noise in the low end (some of the logic was derived from analog video)
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