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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Where ffmpeg arguments, it would be great to document why we are using them, rather than ending up with a recipe.
Presentation Links
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Overall workflow
For this paper, we are assuming that we are encoding from a file-sequence of frames into a movie (rather than re-encoding a movie), but we are also assuming almost all of the colorspace work would be done outside of ffmpeg, with tools using the OCIO library. Examples could include nuke and oiio. Once we get to ffmpeg, the goal being that the pixel data we get in, should be as close as possible to the data we get out of ffmpeg. However, there are still quite a few areas that a ffmpeg user could go wrong, which we break down below.
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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 |
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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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