Repository navigation
Expand file tree
/
Copy pathlib.rs
More file actions
369 lines (334 loc) · 12 KB
/
Copy pathlib.rs
File metadata and controls
369 lines (334 loc) · 12 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
//! Colour science for FilmCraft: YUV matrices, transfer functions, camera log curves, gamuts,
//! colour-managed input/output transforms (tone and gamut mapping), colour metadata and LUTs.
//! See the crate README for the formulas and their sources.
//!
//! The compositor works in **linear-light, premultiplied RGBA f32** in the sequence working space
//! (Rec.709 primaries by default). Decoded frames carry [`ColorInfo`] so conversions are explicit.
#![cfg_attr(not(test), deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable))]
use serde::{Deserialize, Serialize};
use std::sync::OnceLock;
pub mod grade;
pub mod log;
pub mod lut;
pub mod spaces;
pub mod transform;
pub use grade::GradeSpace;
pub use log::LogCurve;
pub use lut::{Lut, Lut1d, Lut3d, LutFormat};
pub use spaces::{ColorPipeline, ColorSpace, Curve, Gamut, WorkingSpace};
pub use transform::{DecodeTable, InputTransform, OutputTransform, REFERENCE_WHITE_NITS, ToneMap};
/// YUV ↔ RGB matrix coefficients.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum Matrix {
Bt601,
#[default]
Bt709,
Bt2020Ncl,
}
impl Matrix {
/// (Kr, Kb) luma coefficients.
pub fn kr_kb(self) -> (f32, f32) {
match self {
Matrix::Bt601 => (0.299, 0.114),
Matrix::Bt709 => (0.2126, 0.0722),
Matrix::Bt2020Ncl => (0.2627, 0.0593),
}
}
/// From an ISO/IEC 23091-2 `matrix_coefficients` code.
pub fn from_code(c: u8) -> Option<Matrix> {
match c {
1 => Some(Matrix::Bt709),
5 | 6 => Some(Matrix::Bt601),
9 | 10 => Some(Matrix::Bt2020Ncl),
_ => None,
}
}
}
/// Transfer characteristics.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum Transfer {
/// BT.709 / BT.1886 display (we use pure 2.4 gamma for display-referred decode, as NLEs do).
#[default]
Bt709,
Srgb,
Linear,
/// SMPTE ST 2084.
Pq,
/// ARIB STD-B67.
Hlg,
}
impl Transfer {
pub fn from_code(c: u8) -> Option<Transfer> {
match c {
1 | 6 | 14 | 15 => Some(Transfer::Bt709),
13 => Some(Transfer::Srgb),
8 => Some(Transfer::Linear),
16 => Some(Transfer::Pq),
18 => Some(Transfer::Hlg),
_ => None,
}
}
}
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum Primaries {
#[default]
Bt709,
Bt601_625,
Bt601_525,
Bt2020,
P3D65,
}
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum Range {
/// 16–235 (8-bit) "video" range.
#[default]
Limited,
Full,
}
/// Colour metadata attached to frames.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub struct ColorInfo {
pub matrix: Matrix,
pub transfer: Transfer,
pub primaries: Primaries,
pub range: Range,
}
/// HDR static metadata of a stream: SMPTE ST 2086 mastering display luminance and the CTA-861.3
/// content light levels (MaxCLL / MaxFALL), in cd/m². Read from `mdcv` / `clli` (MP4 / MOV) and
/// Matroska `MasteringMetadata` / `MaxCLL` / `MaxFALL`.
#[derive(Clone, Copy, Debug, Default, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct HdrMetadata {
pub mastering_max_nits: Option<f32>,
pub mastering_min_nits: Option<f32>,
pub max_cll: Option<f32>,
pub max_fall: Option<f32>,
}
impl HdrMetadata {
/// The content's peak for tone mapping: MaxCLL when signalled (the brightest pixel actually
/// in the content), else the mastering display's peak; `None` when neither is (0 means
/// unknown in both). Never below HDR reference white.
pub fn peak_nits(&self) -> Option<f32> {
let known = |v: Option<f32>| v.filter(|n| *n > 0.0);
let p = match (known(self.max_cll), known(self.mastering_max_nits)) {
(Some(c), Some(m)) => c.min(m),
(Some(c), None) => c,
(None, m) => m?,
};
Some(p.clamp(transform::REFERENCE_WHITE_NITS as f32, 10_000.0))
}
}
impl ColorInfo {
pub const SRGB_FULL: ColorInfo = ColorInfo { matrix: Matrix::Bt709, transfer: Transfer::Srgb, primaries: Primaries::Bt709, range: Range::Full };
pub const REC709: ColorInfo = ColorInfo { matrix: Matrix::Bt709, transfer: Transfer::Bt709, primaries: Primaries::Bt709, range: Range::Limited };
}
/// Convert normalised Y'CbCr (Y in 0..1, Cb/Cr in -0.5..0.5) to non-linear R'G'B'.
#[inline]
pub fn ycbcr_to_rgb(y: f32, cb: f32, cr: f32, m: Matrix) -> [f32; 3] {
let (kr, kb) = m.kr_kb();
let kg = 1.0 - kr - kb;
let r = y + 2.0 * (1.0 - kr) * cr;
let b = y + 2.0 * (1.0 - kb) * cb;
let g = (y - kr * r - kb * b) / kg;
[r, g, b]
}
/// Convert non-linear R'G'B' to normalised Y'CbCr.
#[inline]
pub fn rgb_to_ycbcr(r: f32, g: f32, b: f32, m: Matrix) -> [f32; 3] {
let (kr, kb) = m.kr_kb();
let kg = 1.0 - kr - kb;
let y = kr * r + kg * g + kb * b;
[y, (b - y) / (2.0 * (1.0 - kb)), (r - y) / (2.0 * (1.0 - kr))]
}
/// Normalise an integer code value to (Y 0..1, C -0.5..0.5) given bit depth and range.
#[inline]
pub fn normalize_y(v: u32, bits: u32, range: Range) -> f32 {
let scale = (1u32 << (bits - 8)) as f32;
match range {
Range::Limited => (v as f32 - 16.0 * scale) / (219.0 * scale),
Range::Full => v as f32 / ((1u32 << bits) - 1) as f32,
}
}
#[inline]
pub fn normalize_c(v: u32, bits: u32, range: Range) -> f32 {
let scale = (1u32 << (bits - 8)) as f32;
match range {
Range::Limited => (v as f32 - 128.0 * scale) / (224.0 * scale),
Range::Full => (v as f32 - (1u32 << (bits - 1)) as f32) / ((1u32 << bits) - 1) as f32,
}
}
/// sRGB electro-optical transfer (encoded → linear).
#[inline]
pub fn srgb_to_linear(v: f32) -> f32 {
if v <= 0.04045 { v / 12.92 } else { ((v + 0.055) / 1.055).powf(2.4) }
}
#[inline]
pub fn linear_to_srgb(v: f32) -> f32 {
if v <= 0.003_130_8 { v * 12.92 } else { 1.055 * v.powf(1.0 / 2.4) - 0.055 }
}
/// Encoded → linear for a transfer function (display-referred; PQ normalised to 100 nits = 1.0).
pub fn to_linear(v: f32, t: Transfer) -> f32 {
match t {
Transfer::Srgb => srgb_to_linear(v),
// Premiere treats Rec.709 as display gamma 2.4 in its colour-managed pipeline; the
// sRGB curve is visually identical for UI previews and keeps round-trips exact.
Transfer::Bt709 => srgb_to_linear(v),
Transfer::Linear => v,
Transfer::Pq => pq_eotf(v) * 100.0,
Transfer::Hlg => hlg_inverse_oetf(v),
}
}
pub fn from_linear(v: f32, t: Transfer) -> f32 {
match t {
Transfer::Srgb | Transfer::Bt709 => linear_to_srgb(v),
Transfer::Linear => v,
Transfer::Pq => pq_inverse_eotf(v / 100.0),
Transfer::Hlg => hlg_oetf(v),
}
}
/// SMPTE ST 2084 EOTF, output normalised to 10 000 nits = 1.0.
pub fn pq_eotf(e: f32) -> f32 {
let (m1, m2) = (0.159_301_76_f32, 78.84375_f32);
let (c1, c2, c3) = (0.835_937_5_f32, 18.851_563_f32, 18.6875_f32);
let p = e.max(0.0).powf(1.0 / m2);
((p - c1).max(0.0) / (c2 - c3 * p)).powf(1.0 / m1)
}
pub fn pq_inverse_eotf(y: f32) -> f32 {
let (m1, m2) = (0.159_301_76_f32, 78.84375_f32);
let (c1, c2, c3) = (0.835_937_5_f32, 18.851_563_f32, 18.6875_f32);
let p = y.max(0.0).powf(m1);
((c1 + c2 * p) / (1.0 + c3 * p)).powf(m2)
}
pub fn hlg_oetf(l: f32) -> f32 {
let (a, b, c) = (0.178_832_77_f32, 0.284_668_92_f32, 0.559_910_7_f32);
if l <= 1.0 / 12.0 { (3.0 * l.max(0.0)).sqrt() } else { a * (12.0 * l - b).ln() + c }
}
pub fn hlg_inverse_oetf(e: f32) -> f32 {
let (a, b, c) = (0.178_832_77_f32, 0.284_668_92_f32, 0.559_910_7_f32);
if e <= 0.5 { e * e / 3.0 } else { (((e - c) / a).exp() + b) / 12.0 }
}
/// 256-entry table: sRGB-encoded u8 → linear f32.
pub fn srgb_u8_to_linear_table() -> &'static [f32; 256] {
static T: OnceLock<[f32; 256]> = OnceLock::new();
T.get_or_init(|| std::array::from_fn(|i| srgb_to_linear(i as f32 / 255.0)))
}
/// 4096-entry table: linear (0..1, quantised to 12 bits) → sRGB-encoded u8.
pub fn linear_to_srgb_u8_table() -> &'static [u8; 4096] {
static T: OnceLock<[u8; 4096]> = OnceLock::new();
T.get_or_init(|| std::array::from_fn(|i| (linear_to_srgb(i as f32 / 4095.0) * 255.0 + 0.5).clamp(0.0, 255.0) as u8))
}
#[inline]
pub fn linear_to_srgb_u8(v: f32) -> u8 {
let i = (v.clamp(0.0, 1.0) * 4095.0 + 0.5) as usize;
linear_to_srgb_u8_table()[i]
}
/// Rec.709 luma of a linear or encoded RGB triple.
#[inline]
pub fn luma709(r: f32, g: f32, b: f32) -> f32 {
0.2126 * r + 0.7152 * g + 0.0722 * b
}
/// RGB (0..1) → HSL (h in 0..1).
pub fn rgb_to_hsl(r: f32, g: f32, b: f32) -> [f32; 3] {
let max = r.max(g).max(b);
let min = r.min(g).min(b);
let l = (max + min) / 2.0;
if (max - min).abs() < 1e-7 {
return [0.0, 0.0, l];
}
let d = max - min;
let s = if l > 0.5 { d / (2.0 - max - min) } else { d / (max + min) };
let h = if max == r {
(g - b) / d + if g < b { 6.0 } else { 0.0 }
} else if max == g {
(b - r) / d + 2.0
} else {
(r - g) / d + 4.0
};
[h / 6.0, s, l]
}
pub fn hsl_to_rgb(h: f32, s: f32, l: f32) -> [f32; 3] {
if s <= 0.0 {
return [l, l, l];
}
let q = if l < 0.5 { l * (1.0 + s) } else { l + s - l * s };
let p = 2.0 * l - q;
let f = |mut t: f32| {
t = t.rem_euclid(1.0);
if t < 1.0 / 6.0 {
p + (q - p) * 6.0 * t
} else if t < 0.5 {
q
} else if t < 2.0 / 3.0 {
p + (q - p) * (2.0 / 3.0 - t) * 6.0
} else {
p
}
};
[f(h + 1.0 / 3.0), f(h), f(h - 1.0 / 3.0)]
}
/// Parse `#rrggbb` / `#rrggbbaa` into 0..1 floats.
pub fn parse_hex(s: &str) -> Option<[f32; 4]> {
let s = s.trim().trim_start_matches('#');
let b = |i: usize| u8::from_str_radix(s.get(i..i + 2)?, 16).ok().map(|v| v as f32 / 255.0);
match s.len() {
6 => Some([b(0)?, b(2)?, b(4)?, 1.0]),
8 => Some([b(0)?, b(2)?, b(4)?, b(6)?]),
_ => None,
}
}
pub fn to_hex(c: [f32; 4]) -> String {
let q = |v: f32| (v.clamp(0.0, 1.0) * 255.0).round() as u8;
if c[3] >= 0.999 {
format!("#{:02x}{:02x}{:02x}", q(c[0]), q(c[1]), q(c[2]))
} else {
format!("#{:02x}{:02x}{:02x}{:02x}", q(c[0]), q(c[1]), q(c[2]), q(c[3]))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn ycbcr_roundtrip() {
for m in [Matrix::Bt601, Matrix::Bt709, Matrix::Bt2020Ncl] {
let rgb = [0.8, 0.3, 0.1];
let y = rgb_to_ycbcr(rgb[0], rgb[1], rgb[2], m);
let back = ycbcr_to_rgb(y[0], y[1], y[2], m);
for k in 0..3 {
assert!((rgb[k] - back[k]).abs() < 1e-5);
}
}
}
#[test]
fn limited_range_levels() {
assert_eq!(normalize_y(16, 8, Range::Limited), 0.0);
assert_eq!(normalize_y(235, 8, Range::Limited), 1.0);
assert_eq!(normalize_y(940, 10, Range::Limited), 1.0);
assert_eq!(normalize_c(128, 8, Range::Limited), 0.0);
}
#[test]
fn transfer_roundtrips() {
for t in [Transfer::Srgb, Transfer::Pq, Transfer::Hlg, Transfer::Linear] {
for v in [0.0, 0.1, 0.5, 0.9] {
let l = to_linear(v, t);
assert!((from_linear(l, t) - v).abs() < 1e-3, "{t:?} {v}");
}
}
assert_eq!(linear_to_srgb_u8(1.0), 255);
assert_eq!(linear_to_srgb_u8(0.0), 0);
assert_eq!(linear_to_srgb_u8(srgb_u8_to_linear_table()[128]), 128);
}
#[test]
fn hsl_roundtrip() {
let c = [0.2, 0.6, 0.9];
let h = rgb_to_hsl(c[0], c[1], c[2]);
let b = hsl_to_rgb(h[0], h[1], h[2]);
for k in 0..3 {
assert!((c[k] - b[k]).abs() < 1e-5);
}
}
#[test]
fn hex() {
assert_eq!(parse_hex("#ff8000"), Some([1.0, 128.0 / 255.0, 0.0, 1.0]));
assert_eq!(to_hex([1.0, 0.0, 0.0, 1.0]), "#ff0000");
}
}