jassub
Version:
The Fastest JavaScript SSA/ASS Subtitle Renderer For Browsers
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JavaScript
// offset by 1, 0 = 1, to match CSS font-weight values, but dividing by 100 gives the correct index
export const WEIGHT_MAP = [
'thin',
'extralight',
'light',
'regular', // Normal isn't used
'medium',
'semibold',
'bold',
'extrabold',
'black',
'ultrablack'
];
export const IS_FIREFOX = navigator.userAgent.toLowerCase().includes('firefox');
const a = 'BT601';
const b = 'BT709';
const c = 'SMPTE240M';
const d = 'FCC';
export const LIBASS_YCBCR_MAP = [null, a, null, a, a, b, b, c, c, d, d];
export function _applyKeys(input, output) {
for (const v of Object.keys(input)) {
output[v] = input[v];
}
}
export const _fetch = globalThis.fetch;
export async function fetchtext(url) {
const res = await _fetch(url);
return await res.text();
}
export const THREAD_COUNT = !IS_FIREFOX && self.crossOriginIsolated ? Math.min(Math.max(1, navigator.hardwareConcurrency - 2), 8) : 1;
// @ts-expect-error new experimental API
export const SUPPORTS_GROWTH = !!WebAssembly.Memory.prototype.toResizableBuffer;
// HACK: 3 memory hacks to support here:
// 1. Chrome WASM Growable memory which can use a reference to the buffer to fix visual artifacts, which happen both with multithreading or without [fastest]
// 2. Chrome WASM non-growable, but mult-threaded only memory which needs to re-create the HEAPU8 on growth because of race conditions [medium]
// 3. Firefox non-growable memory which needs a copy of the data into a non-resizable buffer and can't use a reference [fastest single threaded, but only on Firefox, on Chrome this is slowest]
export const SHOULD_REFERENCE_MEMORY = !IS_FIREFOX && (SUPPORTS_GROWTH || THREAD_COUNT > 1);
export const IDENTITY_MATRIX = new Float32Array([
1, 0, 0,
0, 1, 0,
0, 0, 1
]);
// Color matrix conversion map - mat3x3 for WebGL2
// Each matrix converts FROM the key color space TO the nested key color space
export const colorMatrixConversionMap = {
BT601: {
BT709: new Float32Array([
1.0863, 0.0965, -0.01411,
-0.0723, 0.8451, -0.0277,
-0.0141, 0.0584, 1.0418
]),
BT601: IDENTITY_MATRIX
},
BT709: {
BT601: new Float32Array([
0.9137, 0.0784, 0.0079,
-0.1049, 1.1722, -0.0671,
0.0096, 0.0322, 0.9582
]),
BT709: IDENTITY_MATRIX
},
FCC: {
BT709: new Float32Array([
1.0873, -0.0736, -0.0137,
0.0974, 0.8494, 0.0531,
-0.0127, -0.0251, 1.0378
]),
BT601: new Float32Array([
1.001, -0.0008, -0.0002,
0.0009, 1.005, -0.006,
0.0013, 0.0027, 0.996
])
},
SMPTE240M: {
BT709: new Float32Array([
0.9993, 0.0006, 0.0001,
-0.0004, 0.9812, 0.0192,
-0.0034, -0.0114, 1.0148
]),
BT601: new Float32Array([
0.913, 0.0774, 0.0096,
-0.1051, 1.1508, -0.0456,
0.0063, 0.0207, 0.973
])
}
};
//# sourceMappingURL=util.js.map