Cargo Features

[dependencies]
fferris-sys = { version = "0.0.0", default-features = false, features = ["avformat", "avcodec", "avdevice"] }
default = avcodec, avformat

These default features are set whenever fferris-sys is added without default-features = false somewhere in the dependency tree.

avformat default
avcodec default
avdevice

fferris-sys has 4 features without comments.