优化动图

app/api/fetcher/media.ts

@@ -55,3 +55,36 @@ export async function extractFirstFrame(videoBuffer: Buffer): Promise<{ buffer:
         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 { }
+    }
+}