91 lines
3.2 KiB
TypeScript
91 lines
3.2 KiB
TypeScript
import { promises as fs } from 'fs';
|
||
import os from 'os';
|
||
import path from 'path';
|
||
import { execFile } from 'child_process';
|
||
import { promisify } from 'util';
|
||
|
||
const execFileAsync = promisify(execFile);
|
||
|
||
export function pickBestPlayAddr(variants: PlayVariant[] | undefined | null) {
|
||
if (!variants?.length) return null;
|
||
|
||
const best = variants.reduce((best, cur) => {
|
||
const b1 = best?.bit_rate ?? -1;
|
||
const b2 = cur?.bit_rate ?? -1;
|
||
return b2 > b1 ? cur : best;
|
||
});
|
||
|
||
return best?.play_addr ?? null;
|
||
}
|
||
|
||
/**
|
||
* 使用 ffmpeg 从视频二进制中提取第一帧，返回 JPEG buffer
|
||
*/
|
||
export async function extractFirstFrame(videoBuffer: Buffer): Promise<{ buffer: Buffer; contentType: string; ext: string } | null> {
|
||
const ffmpegCmd = process.env.FFMPEG_PATH || 'ffmpeg';
|
||
const tmpDir = os.tmpdir();
|
||
const base = `dy_${Date.now()}_${Math.random().toString(36).slice(2, 8)}`;
|
||
const inPath = path.join(tmpDir, `${base}.mp4`);
|
||
const outPath = path.join(tmpDir, `${base}.jpg`);
|
||
|
||
try {
|
||
await fs.writeFile(inPath, videoBuffer);
|
||
const args = [
|
||
'-hide_banner',
|
||
'-loglevel', 'error',
|
||
'-ss', '0',
|
||
'-i', inPath,
|
||
'-frames:v', '1',
|
||
'-q:v', '2',
|
||
'-f', 'image2',
|
||
'-y',
|
||
outPath,
|
||
];
|
||
await execFileAsync(ffmpegCmd, args, { windowsHide: true });
|
||
const img = await fs.readFile(outPath);
|
||
return { buffer: img, contentType: 'image/jpeg', ext: 'jpg' };
|
||
} catch (e: any) {
|
||
if (e && (e.code === 'ENOENT' || /not found|is not recognized/i.test(String(e.message)))) {
|
||
console.warn('系统未检测到 ffmpeg，可安装并配置 PATH 或设置 FFMPEG_PATH 后启用封面提取。');
|
||
return null;
|
||
}
|
||
throw e;
|
||
} finally {
|
||
try { await fs.unlink(inPath); } catch { }
|
||
try { await fs.unlink(outPath); } catch { }
|
||
}
|
||
}
|
||
|
||
/**
|
||
* 使用 ffprobe 获取视频时长（毫秒）
|
||
*/
|
||
export async function getVideoDuration(videoBuffer: Buffer): Promise<number | null> {
|
||
const ffprobeCmd = process.env.FFPROBE_PATH || 'ffprobe';
|
||
const tmpDir = os.tmpdir();
|
||
const base = `dy_${Date.now()}_${Math.random().toString(36).slice(2, 8)}`;
|
||
const inPath = path.join(tmpDir, `${base}.mp4`);
|
||
|
||
try {
|
||
await fs.writeFile(inPath, videoBuffer);
|
||
const args = [
|
||
'-v', 'error',
|
||
'-show_entries', 'format=duration',
|
||
'-of', 'default=noprint_wrappers=1:nokey=1',
|
||
inPath,
|
||
];
|
||
const { stdout } = await execFileAsync(ffprobeCmd, args, { windowsHide: true });
|
||
const durationSeconds = parseFloat(stdout.trim());
|
||
if (isNaN(durationSeconds)) return null;
|
||
return Math.round(durationSeconds * 1000); // 转换为毫秒
|
||
} catch (e: any) {
|
||
if (e && (e.code === 'ENOENT' || /not found|is not recognized/i.test(String(e.message)))) {
|
||
console.warn('系统未检测到 ffprobe，可安装并配置 PATH 或设置 FFPROBE_PATH 后启用时长提取。');
|
||
return null;
|
||
}
|
||
console.warn(`获取视频时长失败: ${e?.message || e}`);
|
||
return null;
|
||
} finally {
|
||
try { await fs.unlink(inPath); } catch { }
|
||
}
|
||
}
|