ff-format

Shared data types for the ff-* crate family. No FFmpeg dependency — these types exist so crates can exchange frames and stream metadata without coupling to FFmpeg's internal structs.

Key Types

These are the types ff-decode hands back when you decode a frame, and the types ff-encode expects when you push a frame.

Color Science Types

HDR and colour-space metadata is represented as pure-Rust enums — no FFmpeg dependency required:

use ff_format::{ColorTransfer, ColorSpace, ColorPrimaries, ColorRange};

// Tag a stream as HLG broadcast HDR.
let transfer  = ColorTransfer::Hlg;
let space     = ColorSpace::Bt2020;
let primaries = ColorPrimaries::Bt2020;
let range     = ColorRange::Limited;

// Tag a stream as HDR10 (PQ transfer + BT.2020 primaries).
let transfer  = ColorTransfer::Pq;

Hdr10Metadata and MasteringDisplay carry HDR10 static metadata that is embedded as side data on key-frame packets:

use ff_format::{Hdr10Metadata, MasteringDisplay};

// BT.2020 D65 primaries, coordinates × 50000; luminance × 10000 nits.
let meta = Hdr10Metadata {
    max_cll: 1000,    // MaxCLL in nits
    max_fall: 400,    // MaxFALL in nits
    mastering_display: MasteringDisplay {
        red_x: 17000, red_y: 8500,
        green_x: 13250, green_y: 34500,
        blue_x: 7500, blue_y: 3000,
        white_x: 15635, white_y: 16450,
        min_luminance: 50,           // 0.005 nit deep black
        max_luminance: 10_000_000,   // 1000 nit peak
    },
};

Example

use ff_format::{Timestamp, Rational};

// Create a timestamp at 2.5 seconds (5/2).
let ts = Timestamp::new(5, 2);

// Arithmetic on rational timestamps stays exact.
let one_second = Timestamp::new(1, 1);
let three_seconds = ts + one_second * Rational::new(1, 1);

assert_eq!(ts.as_secs_f64(), 2.5);

MSRV

Rust 1.93.0 (edition 2024).

License

MIT OR Apache-2.0