80 lines
1.7 KiB
TypeScript
80 lines
1.7 KiB
TypeScript
import { useEffect, useRef } from 'react';
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interface Props {
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position: number;
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duration: number;
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height: number;
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video: HTMLVideoElement;
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}
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export const VideoPreview: React.FC<Props> = ({
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position,
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duration,
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height,
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video,
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}: Props) => {
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const videoCanvasRef = useRef<HTMLCanvasElement>(null);
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// effects
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// render canvas
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useEffect(() => {
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// TODO: not sure if requestAnimationFrame is recommended here.
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requestAnimationFrame(() => {
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const canvas = videoCanvasRef.current;
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if (canvas == null) {
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console.error('no canvas ref available');
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return;
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}
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const ctx = canvas.getContext('2d');
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if (ctx == null) {
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console.error('no 2d context available');
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return;
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}
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// Set aspect ratio.
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canvas.width = canvas.height * (canvas.clientWidth / canvas.clientHeight);
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const durSecs = duration / 1000;
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const ratio = position / durSecs;
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const x = (canvas.width - 177) * ratio;
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ctx.clearRect(0, 0, x, canvas.height);
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ctx.clearRect(x + 177, 0, canvas.width - 177 - x, canvas.height);
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ctx.drawImage(video, x, 0, 177, 100);
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});
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}, [position]);
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// render component
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const containerStyles = {
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height: height + 'px',
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position: 'relative',
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flexGrow: 0,
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} as React.CSSProperties;
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const canvasStyles = {
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position: 'absolute',
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width: '100%',
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height: '100%',
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display: 'block',
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zIndex: 1,
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} as React.CSSProperties;
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return (
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<>
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<div style={containerStyles}>
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<canvas
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width="500"
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height="100"
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ref={videoCanvasRef}
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style={canvasStyles}
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></canvas>
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<canvas style={canvasStyles}></canvas>
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</div>
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</>
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);
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};
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