vgaNAR6ta
13c91b464f
préparation du template intégration du fond animé fusion du style background et style pcp
118 lines
3.3 KiB
TypeScript
118 lines
3.3 KiB
TypeScript
import { Sample } from './muxer';
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let bytes = new Uint8Array(8);
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let view = new DataView(bytes.buffer);
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export const u8 = (value: number) => {
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return [(value % 0x100 + 0x100) % 0x100];
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};
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export const u16 = (value: number) => {
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view.setUint16(0, value, false);
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return [bytes[0], bytes[1]];
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};
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export const i16 = (value: number) => {
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view.setInt16(0, value, false);
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return [bytes[0], bytes[1]];
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};
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export const u24 = (value: number) => {
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view.setUint32(0, value, false);
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return [bytes[1], bytes[2], bytes[3]];
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};
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export const u32 = (value: number) => {
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view.setUint32(0, value, false);
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return [bytes[0], bytes[1], bytes[2], bytes[3]];
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};
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export const i32 = (value: number) => {
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view.setInt32(0, value, false);
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return [bytes[0], bytes[1], bytes[2], bytes[3]];
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};
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export const u64 = (value: number) => {
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view.setUint32(0, Math.floor(value / 2**32), false);
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view.setUint32(4, value, false);
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return [bytes[0], bytes[1], bytes[2], bytes[3], bytes[4], bytes[5], bytes[6], bytes[7]];
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};
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export const fixed_8_8 = (value: number) => {
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view.setInt16(0, 2**8 * value, false);
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return [bytes[0], bytes[1]];
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};
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export const fixed_16_16 = (value: number) => {
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view.setInt32(0, 2**16 * value, false);
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return [bytes[0], bytes[1], bytes[2], bytes[3]];
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};
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export const fixed_2_30 = (value: number) => {
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view.setInt32(0, 2**30 * value, false);
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return [bytes[0], bytes[1], bytes[2], bytes[3]];
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};
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export const ascii = (text: string, nullTerminated = false) => {
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let bytes = Array(text.length).fill(null).map((_, i) => text.charCodeAt(i));
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if (nullTerminated) bytes.push(0x00);
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return bytes;
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};
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export const last = <T>(arr: T[]) => {
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return arr && arr[arr.length - 1];
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};
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export const lastPresentedSample = (samples: Sample[]): Sample | undefined => {
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let result: Sample | undefined = undefined;
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for (let sample of samples) {
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if (!result || sample.presentationTimestamp > result.presentationTimestamp) {
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result = sample;
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}
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}
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return result;
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};
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export const intoTimescale = (timeInSeconds: number, timescale: number, round = true) => {
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let value = timeInSeconds * timescale;
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return round ? Math.round(value) : value;
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};
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export type TransformationMatrix = [number, number, number, number, number, number, number, number, number];
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export const rotationMatrix = (rotationInDegrees: number): TransformationMatrix => {
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let theta = rotationInDegrees * (Math.PI / 180);
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let cosTheta = Math.cos(theta);
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let sinTheta = Math.sin(theta);
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// Matrices are post-multiplied in MP4, meaning this is the transpose of your typical rotation matrix
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return [
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cosTheta, sinTheta, 0,
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-sinTheta, cosTheta, 0,
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0, 0, 1
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];
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};
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export const IDENTITY_MATRIX = rotationMatrix(0);
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export const matrixToBytes = (matrix: TransformationMatrix) => {
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return [
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fixed_16_16(matrix[0]), fixed_16_16(matrix[1]), fixed_2_30(matrix[2]),
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fixed_16_16(matrix[3]), fixed_16_16(matrix[4]), fixed_2_30(matrix[5]),
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fixed_16_16(matrix[6]), fixed_16_16(matrix[7]), fixed_2_30(matrix[8])
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];
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};
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export const deepClone = <T>(x: T): T => {
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if (!x) return x;
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if (typeof x !== 'object') return x;
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if (Array.isArray(x)) return x.map(deepClone) as T;
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return Object.fromEntries(Object.entries(x).map(([key, value]) => [key, deepClone(value)])) as T;
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};
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export const isU32 = (value: number) => {
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return value >= 0 && value < 2**32;
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};
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