fix: drain FFmpeg stderr and sanitize playback diagnostics

src/audio/player.ts

@@ -7,6 +7,7 @@ import { join } from "node:path";
 import { createOpusEncoder, PCM_FRAME_BYTES, type Encoder } from "./encoder.js";
 import type { Readable } from "node:stream";
 import type { Logger } from "../logger.js";
+import { collectFfmpegDiagnostics, type FfmpegDiagnostics } from "./ffmpeg-diagnostics.js";
 
 const require = createRequire(import.meta.url);
 const ffmpegPath: string | null = require("ffmpeg-static");
@@ -52,6 +53,17 @@ export function getFfmpegCommand(): string {
   return resolvedFfmpeg;
 }
 
+function safeFfmpegSpawnError(err: Error): Error {
+  // Node spawn errors include spawnargs; Pino's Error serializer copies them,
+  // including the signed input URL. Preserve a known OS category only.
+  const allowedCodes = new Set(["ENOENT", "EACCES", "EPERM", "ENOEXEC", "EMFILE", "ENFILE", "ENOMEM", "EAGAIN", "EINVAL"]);
+  const code = (err as NodeJS.ErrnoException).code;
+  const safeCode = typeof code === "string" && allowedCodes.has(code) ? code : undefined;
+  const safeError = new Error(`FFmpeg failed to start${safeCode ? ` (${safeCode})` : ""}`);
+  if (safeCode) Object.assign(safeError, { code: safeCode });
+  return safeError;
+}
+
 const BROWSER_UA =
   "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36";
 
@@ -74,7 +86,7 @@ export function cleanupTempDir(dir: string): void {
 }
 
 export function buildFfmpegArgs(url: string, seekSeconds: number): string[] {
-  const args: string[] = [];
+  const args: string[] = ["-nostats"];
   const isHttp = /^https?:\/\//i.test(url);
   const isBilibili = isHttp && (url.includes("bilivideo") || url.includes("bilibili"));
 
@@ -167,6 +179,8 @@ const FRAME_DURATION_MS = 20;
 
 export class AudioPlayer extends EventEmitter {
   private ffmpeg: ChildProcess | null = null;
+  private ffmpegDiagnostics: FfmpegDiagnostics | null = null;
+  private readonly intentionalCleanup = new WeakSet<ChildProcess>();
   private encoder: Encoder;
   private state: PlayerState = "idle";
   private volume = 75;
@@ -258,6 +272,9 @@ export class AudioPlayer extends EventEmitter {
 
     const ffmpegBin = getFfmpegCommand();
     this.ffmpeg = spawn(ffmpegBin, args, { stdio: ["ignore", "pipe", "pipe"] });
+    const child = this.ffmpeg;
+    const diagnostics = collectFfmpegDiagnostics(child.stderr);
+    this.ffmpegDiagnostics = diagnostics;
     
     const currentPid = this.ffmpeg.pid;
     if (currentPid) {
@@ -280,7 +297,6 @@ export class AudioPlayer extends EventEmitter {
 
     this.ffmpeg.on("exit", (code, signal) => {
       if (currentPid) globalActivePids.delete(currentPid);
-      this.logger.info({ pid: currentPid, code, signal }, "FFmpeg exited");
       
       // 只有当前会话的进程结束才置空变量
       if (this.sessionId === currentSessionId) {
@@ -288,11 +304,21 @@ export class AudioPlayer extends EventEmitter {
       }
     });
 
+    // close follows stderr's end, so final unterminated diagnostics are ready.
+    this.ffmpeg.on("close", (code, signal) => {
+      const context = { pid: currentPid, sessionId: currentSessionId, code, signal };
+      if (!this.intentionalCleanup.has(child) && ((typeof code === "number" && code !== 0) || signal !== null)) {
+        this.logger.warn({ ...context, stderr: diagnostics.getTail() }, "FFmpeg exited");
+      } else {
+        this.logger.info(context, "FFmpeg exited");
+      }
+    });
+
     this.ffmpeg.on("error", (err) => {
       if (this.sessionId === currentSessionId) {
         this.spawnFailed = true;
         this.consecutiveFailures++;
-        this.emit("error", err);
+        this.emit("error", safeFfmpegSpawnError(err));
       }
     });
 
@@ -332,10 +358,7 @@ export class AudioPlayer extends EventEmitter {
     );
     this.downloader = ps;
 
-    let stderrTail = "";
-    ps.stderr!.on("data", (chunk: Buffer) => {
-      stderrTail = (stderrTail + chunk.toString()).slice(-500);
-    });
+    const diagnostics = collectFfmpegDiagnostics(ps.stderr);
 
     ps.on("exit", (code, signal) => {
       if (this.sessionId !== sessionId) {
@@ -344,7 +367,6 @@ export class AudioPlayer extends EventEmitter {
       }
       this.downloader = null;
       if (code !== 0) {
-        this.logger.warn({ code, signal, stderr: stderrTail }, "PowerShell download failed");
         this.spawnFailed = true;
         this.consecutiveFailures++;
         this.state = "idle";
@@ -356,6 +378,12 @@ export class AudioPlayer extends EventEmitter {
       this.spawnFfmpegFromFile(tempFile, seekSeconds, sessionId);
     });
 
+    ps.on("close", (code, signal) => {
+      if (!this.intentionalCleanup.has(ps) && ((typeof code === "number" && code !== 0) || signal !== null)) {
+        this.logger.warn({ pid: ps.pid, sessionId, code, signal, stderr: diagnostics.getTail() }, "PowerShell download failed");
+      }
+    });
+
     ps.on("error", (err) => {
       if (this.sessionId !== sessionId) return;
       this.downloader = null;
@@ -386,6 +414,9 @@ export class AudioPlayer extends EventEmitter {
     const args = buildFfmpegArgs(tempFile, seekSeconds);
     const ffmpegBin = getFfmpegCommand();
     this.ffmpeg = spawn(ffmpegBin, args, { stdio: ["ignore", "pipe", "pipe"] });
+    const child = this.ffmpeg;
+    const diagnostics = collectFfmpegDiagnostics(child.stderr);
+    this.ffmpegDiagnostics = diagnostics;
 
     const currentPid = this.ffmpeg.pid;
     if (currentPid) {
@@ -405,7 +436,6 @@ export class AudioPlayer extends EventEmitter {
 
     this.ffmpeg.on("exit", (code, signal) => {
       if (currentPid) globalActivePids.delete(currentPid);
-      this.logger.info({ pid: currentPid, code, signal }, "FFmpeg exited");
       if (this.sessionId === sessionId) {
         this.ffmpeg = null;
         if (this.currentTempDir === tempDirToCleanup) this.currentTempDir = null;
@@ -413,11 +443,20 @@ export class AudioPlayer extends EventEmitter {
       if (tempDirToCleanup) cleanupTempDir(tempDirToCleanup);
     });
 
+    this.ffmpeg.on("close", (code, signal) => {
+      const context = { pid: currentPid, sessionId, code, signal };
+      if (!this.intentionalCleanup.has(child) && ((typeof code === "number" && code !== 0) || signal !== null)) {
+        this.logger.warn({ ...context, stderr: diagnostics.getTail() }, "FFmpeg exited");
+      } else {
+        this.logger.info(context, "FFmpeg exited");
+      }
+    });
+
     this.ffmpeg.on("error", (err) => {
       if (this.sessionId === sessionId) {
         this.spawnFailed = true;
         this.consecutiveFailures++;
-        this.emit("error", err);
+        this.emit("error", safeFfmpegSpawnError(err));
       }
     });
 
@@ -543,6 +582,7 @@ export class AudioPlayer extends EventEmitter {
     
     // 立即清空缓冲区，确保切歌瞬间静音 （
     this.pcmBuffer = Buffer.alloc(0);
+    this.ffmpegDiagnostics = null;
 
     if (this.ffmpeg) {
       const procToKill = this.ffmpeg;
@@ -557,6 +597,7 @@ export class AudioPlayer extends EventEmitter {
     if (this.downloader) {
       const ps = this.downloader;
       this.downloader = null;
+      this.intentionalCleanup.add(ps);
       try { ps.kill("SIGTERM"); } catch { /* already gone */ }
     }
 
@@ -580,6 +621,7 @@ export class AudioPlayer extends EventEmitter {
   }
 
   private forceCleanup(proc: ChildProcess, pid: number): void {
+    this.intentionalCleanup.add(proc);
     if (!globalActivePids.has(pid)) return;
 
     try {
@@ -664,6 +706,7 @@ export class AudioPlayer extends EventEmitter {
             duration: this.currentSongDuration,
             remaining: Math.round(this.currentSongDuration - elapsed),
             nearEnd: isNearEnd,
+            stderr: this.ffmpegDiagnostics?.getTail() ?? "",
           }, "FFmpeg stopped outputting data, ending track");
           this.frameLoopRunning = false;
           // The outer gate guarantees state==="playing" here, so no !=="idle"