从HTML中提取Video信息
function extractVideosFromHTML(htmlString) {const dom = new DOMParser().parseFromString(htmlString, 'text/html');const videos = Array.from(dom.querySelectorAll('video'));return videos.map(videoElement => videoElement.getAttribute('src'));
}
获取视频的第一帧作为视频封面
function getFirstVideoFrame(videoUrl) {return new Promise((resolve, reject) => {const videoElement = document.createElement('video');videoElement.crossOrigin = 'anonymous';videoElement.muted = true; videoElement.style.display = 'none'; document.body.appendChild(videoElement); videoElement.addEventListener('loadedmetadata', () => {const canvas = document.createElement('canvas');canvas.width = videoElement.videoWidth;canvas.height = videoElement.videoHeight;const ctx = canvas.getContext('2d');videoElement.addEventListener('seeked', async () => {ctx.drawImage(videoElement, 0, 0, canvas.width, canvas.height);const imageData = canvas.toDataURL('image/jpeg'); document.body.removeChild(videoElement);resolve(imageData)});}, { once: true });videoElement.currentTime = 0;});videoElement.onerror = (error) => {reject(error); };videoElement.src = videoUrl;});
}
获取视频的播放时长
function getVideoDuration(file) {return new Promise((resolve, reject) => { const fileReader = new FileReader();fileReader.onload = (event) => {const blob = new Blob([event.target.result], {type: file.type});const video = document.createElement('video');video.src = URL.createObjectURL(blob);video.onloadedmetadata = () => {resolve(video.duration);URL.revokeObjectURL(video.src);video.remove();};video.onerror = (err) => {URL.revokeObjectURL(video.src);video.remove()reject(err)}};fileReader.readAsArrayBuffer(file);});
}
