285 lines
7.9 KiB
JavaScript
285 lines
7.9 KiB
JavaScript
import express from 'express';
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import ffmpeg from 'fluent-ffmpeg';
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import axios from 'axios';
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import { v4 as uuidv4 } from 'uuid';
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import { promises as fs } from 'fs';
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import path from 'path';
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import { fileURLToPath } from 'url';
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const __filename = fileURLToPath(import.meta.url);
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const __dirname = path.dirname(__filename);
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const router = express.Router();
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// 临时文件目录
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const TEMP_DIR = path.join(__dirname, '../temp');
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// 确保临时目录存在
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async function ensureTempDir() {
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try {
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await fs.mkdir(TEMP_DIR, { recursive: true });
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} catch (err) {
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console.error('创建临时目录失败:', err);
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}
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}
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ensureTempDir();
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/**
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* 下载资源到本地
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*/
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async function downloadResource(url, outputPath) {
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// 处理 base64 图片 (data:image/svg+xml,...)
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if (url.startsWith('data:')) {
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const matches = url.match(/^data:image\/(\w+);base64,(.+)$/);
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if (matches) {
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const buffer = Buffer.from(matches[2], 'base64');
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await fs.writeFile(outputPath, buffer);
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return outputPath;
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}
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// 处理 URL 编码的 SVG
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if (url.startsWith('data:image/svg+xml,')) {
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const svgContent = decodeURIComponent(url.replace('data:image/svg+xml,', ''));
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await fs.writeFile(outputPath, svgContent);
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return outputPath;
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}
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throw new Error('不支持的 base64 格式');
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}
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// 处理普通 HTTP URL
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const response = await axios({
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method: 'GET',
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url: url,
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responseType: 'arraybuffer',
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timeout: 60000,
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});
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await fs.writeFile(outputPath, response.data);
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return outputPath;
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}
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/**
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* 获取音频时长
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*/
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function getAudioDuration(audioPath) {
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return new Promise((resolve, reject) => {
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ffmpeg.ffprobe(audioPath, (err, metadata) => {
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if (err) {
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reject(err);
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return;
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}
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const duration = metadata.format.duration;
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resolve(duration);
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});
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});
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}
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/**
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* 合成单个视频片段
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*/
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async function composeSegment(imagePath, audioPath, outputPath, width, height) {
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const audioDuration = await getAudioDuration(audioPath);
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return new Promise((resolve, reject) => {
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ffmpeg()
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.input(imagePath)
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.loop(1)
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.input(audioPath)
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.outputOptions([
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'-tune stillimage',
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'-c:a aac',
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'-b:a 192k',
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'-pix_fmt yuv420p',
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'-shortest'
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])
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.videoFilter(`scale=${width}:${height}:force_original_aspect_ratio=decrease,pad=${width}:${height}:(ow-iw)/2:(oh-ih)/2`)
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.duration(audioDuration + 0.5)
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.output(outputPath)
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.on('start', (commandLine) => {
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console.log('FFmpeg 命令:', commandLine);
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})
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.on('end', () => resolve(outputPath))
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.on('error', (err, stdout, stderr) => {
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console.error('FFmpeg 错误输出:', stderr);
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reject(err);
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})
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.run();
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});
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}
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/**
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* 合并多个视频片段
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*/
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async function mergeSegments(segmentPaths, outputPath) {
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const listPath = path.join(TEMP_DIR, `concat_${uuidv4()}.txt`);
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// Windows 路径需要转义反斜杠或使用正斜杠
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const listContent = segmentPaths.map(p => {
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// 将反斜杠替换为正斜杠，FFmpeg 更兼容
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const normalizedPath = p.replace(/\\/g, '/');
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return `file '${normalizedPath}'`;
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}).join('\n');
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await fs.writeFile(listPath, listContent);
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console.log('合并列表内容:\n', listContent);
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return new Promise((resolve, reject) => {
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ffmpeg()
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.input(listPath)
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.inputOptions(['-f concat', '-safe 0'])
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.outputOptions(['-c copy'])
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.output(outputPath)
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.on('start', (commandLine) => {
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console.log('FFmpeg 合并命令:', commandLine);
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})
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.on('end', async () => {
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// 清理列表文件
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try {
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await fs.unlink(listPath);
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} catch (e) {
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console.error('清理列表文件失败:', e);
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}
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resolve(outputPath);
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})
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.on('error', (err, stdout, stderr) => {
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console.error('FFmpeg 合并错误:', stderr);
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reject(err);
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})
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.run();
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});
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}
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/**
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* POST /api/video/compose
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* 合成视频
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*
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* Body: {
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* slides: [{ imageUrl, audioUrl }],
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* width: 1920,
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* height: 1080
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* }
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*/
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router.post('/compose', async (req, res) => {
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const { slides, width = 1920, height = 1080 } = req.body;
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if (!slides || !Array.isArray(slides) || slides.length === 0) {
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return res.status(400).json({ error: '缺少 slides 参数或格式错误' });
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}
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const taskId = uuidv4();
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const taskDir = path.join(TEMP_DIR, taskId);
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console.log(`[${taskId}] 开始处理视频合成任务，共 ${slides.length} 个片段`);
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try {
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// 创建任务目录
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await fs.mkdir(taskDir, { recursive: true });
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const segmentPaths = [];
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// 逐个处理片段
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for (let i = 0; i < slides.length; i++) {
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const slide = slides[i];
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console.log(`[${taskId}] 处理第 ${i + 1}/${slides.length} 个片段`);
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if (!slide.imageUrl || !slide.audioUrl) {
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console.warn(`[${taskId}] 第 ${i + 1} 个片段缺少 imageUrl 或 audioUrl，跳过`);
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continue;
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}
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// 下载图片和音频
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const imagePath = path.join(taskDir, `image_${i}.png`);
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const audioPath = path.join(taskDir, `audio_${i}.mp3`);
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const segmentPath = path.join(taskDir, `segment_${i}.mp4`);
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console.log(`[${taskId}] 下载图片: ${slide.imageUrl.substring(0, 50)}...`);
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console.log(`[${taskId}] 下载音频: ${slide.audioUrl.substring(0, 50)}...`);
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await downloadResource(slide.imageUrl, imagePath);
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await downloadResource(slide.audioUrl, audioPath);
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// 检查文件是否成功创建
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try {
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const imageStats = await fs.stat(imagePath);
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const audioStats = await fs.stat(audioPath);
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console.log(`[${taskId}] 图片大小: ${imageStats.size} bytes, 音频大小: ${audioStats.size} bytes`);
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} catch (e) {
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console.error(`[${taskId}] 文件检查失败:`, e);
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}
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// 合成片段
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await composeSegment(imagePath, audioPath, segmentPath, width, height);
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segmentPaths.push(segmentPath);
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console.log(`[${taskId}] 第 ${i + 1} 个片段合成完成`);
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}
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if (segmentPaths.length === 0) {
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throw new Error('没有有效的片段可以合并');
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}
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// 合并所有片段
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console.log(`[${taskId}] 开始合并 ${segmentPaths.length} 个片段`);
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const finalPath = path.join(taskDir, 'output.mp4');
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await mergeSegments(segmentPaths, finalPath);
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console.log(`[${taskId}] 视频合成完成: ${finalPath}`);
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// 返回视频文件
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res.setHeader('Content-Type', 'video/mp4');
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res.setHeader('Content-Disposition', 'attachment; filename="question-explanation.mp4"');
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const videoBuffer = await fs.readFile(finalPath);
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res.send(videoBuffer);
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// 清理临时文件（延迟删除，确保响应已发送）
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setTimeout(async () => {
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try {
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await fs.rm(taskDir, { recursive: true, force: true });
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console.log(`[${taskId}] 临时文件已清理`);
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} catch (e) {
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console.error(`[${taskId}] 清理临时文件失败:`, e);
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}
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}, 1000);
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} catch (error) {
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console.error(`[${taskId}] 视频合成失败:`, error);
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// 清理临时文件
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try {
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await fs.rm(taskDir, { recursive: true, force: true });
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} catch (e) {
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// 忽略清理错误
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}
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res.status(500).json({
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error: '视频合成失败',
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message: error.message
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});
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}
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});
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/**
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* GET /api/video/health
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* 检查视频服务状态
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*/
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router.get('/health', (req, res) => {
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// 检查 ffmpeg 是否可用
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ffmpeg.getAvailableFormats((err, formats) => {
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if (err) {
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return res.status(500).json({
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status: 'error',
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message: 'FFmpeg 不可用',
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error: err.message
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});
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}
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res.json({
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status: 'ok',
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message: '视频合成服务正常运行',
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formats: formats ? Object.keys(formats).length : 'unknown'
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});
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});
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});
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export default router;
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