/**
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* 视频处理工具函数
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*/
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/**
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* 从视频文件中提取第一帧作为封面图
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* @param {File} videoFile - 视频文件对象
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* @param {number} quality - 图片质量 (0-1)，默认0.8
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* @returns {Promise<Blob>} 返回图片Blob对象
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*/
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export const extractVideoFrame = (videoFile, quality = 0.8) => {
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return new Promise((resolve, reject) => {
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// 创建video元素
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const video = document.createElement('video')
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video.crossOrigin = 'anonymous'
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video.muted = true
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video.playsInline = true
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// 创建canvas元素
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const canvas = document.createElement('canvas')
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const ctx = canvas.getContext('2d')
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// 监听视频加载完成
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video.addEventListener('loadedmetadata', () => {
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// 设置canvas尺寸为视频尺寸
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canvas.width = video.videoWidth
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canvas.height = video.videoHeight
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// 跳转到第一帧（0.1秒处，避免黑屏）
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video.currentTime = 0.1
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})
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// 监听视频可以播放
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video.addEventListener('canplay', () => {
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// 绘制当前帧到canvas
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ctx.drawImage(video, 0, 0, canvas.width, canvas.height)
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// 将canvas转换为Blob
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canvas.toBlob((blob) => {
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if (blob) {
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resolve(blob)
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} else {
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reject(new Error('无法提取视频帧'))
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}
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}, 'image/jpeg', quality)
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// 清理资源
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video.src = ''
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URL.revokeObjectURL(video.src)
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})
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// 监听错误
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video.addEventListener('error', (e) => {
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reject(new Error('视频加载失败: ' + e.message))
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})
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// 设置视频源
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video.src = URL.createObjectURL(videoFile)
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})
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}
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/**
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* 检查文件是否为视频
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* @param {File} file - 文件对象
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* @returns {boolean} 是否为视频文件
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*/
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export const isVideoFile = (file) => {
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return file && file.type && file.type.startsWith('video/')
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}
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/**
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* 获取视频文件的基本信息
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* @param {File} videoFile - 视频文件对象
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* @returns {Promise<Object>} 返回视频信息对象
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*/
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export const getVideoInfo = (videoFile) => {
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return new Promise((resolve, reject) => {
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const video = document.createElement('video')
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video.crossOrigin = 'anonymous'
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video.muted = true
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video.playsInline = true
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video.addEventListener('loadedmetadata', () => {
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const info = {
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duration: video.duration,
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width: video.videoWidth,
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height: video.videoHeight,
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size: videoFile.size,
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type: videoFile.type,
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name: videoFile.name
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}
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resolve(info)
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// 清理资源
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video.src = ''
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URL.revokeObjectURL(video.src)
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})
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video.addEventListener('error', (e) => {
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reject(new Error('无法获取视频信息: ' + e.message))
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})
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video.src = URL.createObjectURL(videoFile)
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})
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}
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/**
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* 生成缩略图文件名
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* @param {string} originalFileName - 原始文件名
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* @returns {string} 缩略图文件名
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*/
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export const generateThumbnailFileName = (originalFileName) => {
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const nameWithoutExt = originalFileName.replace(/\.[^/.]+$/, '')
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const timestamp = Date.now()
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return `${nameWithoutExt}_thumb_${timestamp}.jpg`
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}
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