playa 0.1.142

Image sequence player (EXR, PNG, JPEG, TIFF, .MP4). Pure Rust with optional OpenEXR/FFmpeg support.
Documentation 
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

//! HSV (Hue, Saturation, Value) adjustment effect.
//!
//! Converts RGB to HSV color space, applies adjustments, converts back.
//! Useful for color grading and correction.
//!
//! # Parameters
//!
//! - `hue_shift`: -180 to 180 degrees rotation on color wheel
//! - `saturation`: 0.0 (grayscale) to 2.0 (oversaturated), 1.0 = no change
//! - `value`: 0.0 (black) to 2.0 (overbright), 1.0 = no change
//!
//! # Algorithm
//!
//! 1. Convert each pixel RGB -> HSV
//! 2. H += hue_shift (wrap around 0-360)
//! 3. S *= saturation (clamp 0-1)
//! 4. V *= value (no clamp for HDR)
//! 5. Convert HSV -> RGB

use half::f16 as F16;

use crate::entities::attrs::Attrs;
use crate::entities::frame::{Frame, PixelBuffer};

/// Apply HSV adjustment to a frame.
///
/// # Parameters
/// - `frame`: Source frame to adjust
/// - `attrs`: Effect attributes containing "hue_shift", "saturation", "value"
///
/// # Returns
/// New adjusted Frame, or None if processing fails
pub fn apply(frame: &Frame, attrs: &Attrs) -> Option<Frame> {
    let hue_shift = attrs.get_float("hue_shift").unwrap_or(0.0);
    let saturation = attrs.get_float("saturation").unwrap_or(1.0);
    let value = attrs.get_float("value").unwrap_or(1.0);

    // No adjustment needed
    if hue_shift.abs() < 0.01 && (saturation - 1.0).abs() < 0.001 && (value - 1.0).abs() < 0.001 {
        return Some(frame.clone());
    }

    let (width, height) = frame.resolution();
    let buffer = frame.buffer();

    let out_buffer = match buffer.as_ref() {
        PixelBuffer::U8(data) => {
            let mut result = Vec::with_capacity(data.len());

            for chunk in data.chunks_exact(4) {
                let r = chunk[0] as f32 / 255.0;
                let g = chunk[1] as f32 / 255.0;
                let b = chunk[2] as f32 / 255.0;
                let a = chunk[3];

                let (h, s, v) = rgb_to_hsv(r, g, b);

                // Apply adjustments
                let h_new = (h + hue_shift).rem_euclid(360.0);
                let s_new = (s * saturation).clamp(0.0, 1.0);
                let v_new = (v * value).clamp(0.0, 1.0); // Clamp for LDR

                let (r_out, g_out, b_out) = hsv_to_rgb(h_new, s_new, v_new);

                result.push((r_out * 255.0) as u8);
                result.push((g_out * 255.0) as u8);
                result.push((b_out * 255.0) as u8);
                result.push(a);
            }

            PixelBuffer::U8(result)
        }

        PixelBuffer::F16(data) => {
            let mut result = Vec::with_capacity(data.len());

            for chunk in data.chunks_exact(4) {
                let r = chunk[0].to_f32();
                let g = chunk[1].to_f32();
                let b = chunk[2].to_f32();
                let a = chunk[3];

                let (h, s, v) = rgb_to_hsv(r, g, b);

                // Apply adjustments (no value clamp for HDR)
                let h_new = (h + hue_shift).rem_euclid(360.0);
                let s_new = (s * saturation).clamp(0.0, 1.0);
                let v_new = v * value;

                let (r_out, g_out, b_out) = hsv_to_rgb(h_new, s_new, v_new);

                result.push(F16::from_f32(r_out));
                result.push(F16::from_f32(g_out));
                result.push(F16::from_f32(b_out));
                result.push(a);
            }

            PixelBuffer::F16(result)
        }

        PixelBuffer::F32(data) => {
            let mut result = Vec::with_capacity(data.len());

            for chunk in data.chunks_exact(4) {
                let r = chunk[0];
                let g = chunk[1];
                let b = chunk[2];
                let a = chunk[3];

                let (h, s, v) = rgb_to_hsv(r, g, b);

                // Apply adjustments (no value clamp for HDR)
                let h_new = (h + hue_shift).rem_euclid(360.0);
                let s_new = (s * saturation).clamp(0.0, 1.0);
                let v_new = v * value;

                let (r_out, g_out, b_out) = hsv_to_rgb(h_new, s_new, v_new);

                result.push(r_out);
                result.push(g_out);
                result.push(b_out);
                result.push(a);
            }

            PixelBuffer::F32(result)
        }
    };

    Some(Frame::from_buffer(out_buffer, frame.pixel_format(), width, height))
}

/// Convert RGB to HSV.
///
/// - R, G, B: 0.0 to 1.0 (or higher for HDR)
/// - H: 0 to 360 degrees
/// - S: 0 to 1
/// - V: 0 to max(R,G,B)
fn rgb_to_hsv(r: f32, g: f32, b: f32) -> (f32, f32, f32) {
    let max = r.max(g).max(b);
    let min = r.min(g).min(b);
    let delta = max - min;

    // Value = max component
    let v = max;

    // Saturation
    let s = if max > 0.0 { delta / max } else { 0.0 };

    // Hue
    let h = if delta.abs() < 0.0001 {
        0.0 // Achromatic (gray)
    } else if (max - r).abs() < 0.0001 {
        // Red is max
        60.0 * (((g - b) / delta) % 6.0)
    } else if (max - g).abs() < 0.0001 {
        // Green is max
        60.0 * ((b - r) / delta + 2.0)
    } else {
        // Blue is max
        60.0 * ((r - g) / delta + 4.0)
    };

    // Normalize hue to 0-360
    let h = if h < 0.0 { h + 360.0 } else { h };

    (h, s, v)
}

/// Convert HSV to RGB.
///
/// - H: 0 to 360 degrees
/// - S: 0 to 1
/// - V: any positive value (supports HDR)
fn hsv_to_rgb(h: f32, s: f32, v: f32) -> (f32, f32, f32) {
    if s <= 0.0 {
        // Achromatic (gray)
        return (v, v, v);
    }

    let h = h % 360.0;
    let h = if h < 0.0 { h + 360.0 } else { h };

    let c = v * s; // Chroma
    let h_prime = h / 60.0;
    let x = c * (1.0 - ((h_prime % 2.0) - 1.0).abs());
    let m = v - c;

    let (r1, g1, b1) = match h_prime as i32 {
        0 => (c, x, 0.0),
        1 => (x, c, 0.0),
        2 => (0.0, c, x),
        3 => (0.0, x, c),
        4 => (x, 0.0, c),
        _ => (c, 0.0, x), // 5 or edge cases
    };

    (r1 + m, g1 + m, b1 + m)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_rgb_hsv_roundtrip() {
        // Red
        let (h, s, v) = rgb_to_hsv(1.0, 0.0, 0.0);
        assert!((h - 0.0).abs() < 1.0); // Hue ~0
        assert!((s - 1.0).abs() < 0.01);
        assert!((v - 1.0).abs() < 0.01);

        let (r, g, b) = hsv_to_rgb(h, s, v);
        assert!((r - 1.0).abs() < 0.01);
        assert!(g.abs() < 0.01);
        assert!(b.abs() < 0.01);
    }

    #[test]
    fn test_hue_shift_red_to_green() {
        // Red shifted by 120 degrees should be green-ish
        let (h, s, v) = rgb_to_hsv(1.0, 0.0, 0.0);
        let (r, g, b) = hsv_to_rgb(h + 120.0, s, v);

        assert!(g > r); // Green should be dominant now
        assert!(g > b);
    }

    #[test]
    fn test_gray_unchanged() {
        // Gray has no hue, should be unaffected by hue shift
        let (h, s, v) = rgb_to_hsv(0.5, 0.5, 0.5);
        assert!(s < 0.01); // Saturation ~0 for gray

        let (r, g, b) = hsv_to_rgb(h + 180.0, s, v); // Shift hue by 180
        assert!((r - 0.5).abs() < 0.01); // Should still be gray
        assert!((g - 0.5).abs() < 0.01);
        assert!((b - 0.5).abs() < 0.01);
    }
}