diff --git a/Sources/PlayerRecorder.swift b/Sources/PlayerRecorder.swift
index 7ae1b93..33e90b9 100644
--- a/Sources/PlayerRecorder.swift
+++ b/Sources/PlayerRecorder.swift
@@ -36,6 +36,7 @@ class AudioTapContext {
     nonisolated(unsafe) var notReadyCount: Int = 0            // writerInput not ready 次数
     nonisolated(unsafe) var lastActiveTimestamp: Double = 0   // 最后一次有声音的时间(秒)
     nonisolated(unsafe) var recordStartTime: Date?            // 录制开始时间
+    nonisolated(unsafe) var mixTrackID: Int32 = -1            // audioMix 绑定的 trackID
     
     let audioQueue = DispatchQueue(label: "miniplayer.audioTap")
 }
@@ -274,6 +275,7 @@ struct AudioDiagStats {
     let lastActiveTimestamp: Double
     let sampleRate: Double
     let channelsPerFrame: UInt32
+    let mixTrackID: Int32
 }
 
 // MARK: - PlayerRecorder
@@ -316,58 +318,109 @@ final class PlayerRecorder: NSObject {
     
     // MARK: - Audio Tap Setup
     
-    /// 在录制开始时安装音频 Tap 到 playerItem
+    /// 异步安装音频 Tap（HLS 流需要异步加载 tracks）
     private func installAudioTap(on playerItem: AVPlayerItem) {
         // 确保全局上下文存在
         if gTapContext == nil {
             gTapContext = AudioTapContext()
         }
-        guard let ctx = gTapContext else { return }
         
-        // 同步获取音频 track（录制时 asset 已经加载完毕）
-        let audioTracks = playerItem.asset.tracks(withMediaType: .audio)
-        guard let audioTrack = audioTracks.first else {
-            NSLog("[Recorder] ⚠️ No audio track found (tried %d tracks)", audioTracks.count)
-            return
+        Task { @MainActor in
+            guard let ctx = gTapContext else { return }
+            
+            print("[Recorder:DIAG] === installAudioTap START (async) ===")
+            print("[Recorder:DIAG] asset class: \(type(of: playerItem.asset))")
+            
+            // HLS 流的 tracks 是异步加载的，必须用 loadTracks
+            let audioTracks: [AVAssetTrack]
+            do {
+                audioTracks = try await playerItem.asset.loadTracks(withMediaType: .audio)
+            } catch {
+                print("[Recorder:DIAG] ⚠️ loadTracks failed: \(error)")
+                // 写诊断日志
+                writeDiagLog("loadTracks error: \(error)")
+                return
+            }
+            
+            guard let audioTrack = audioTracks.first else {
+                print("[Recorder:DIAG] ⚠️ No audio track found after async load!")
+                writeDiagLog("No audio tracks found")
+                return
+            }
+            
+            print("[Recorder:DIAG] Using audio trackID=\(audioTrack.trackID)")
+            
+            // 列出所有 tracks 用于诊断
+            let allTracks = try? await playerItem.asset.load(.tracks)
+            if let tracks = allTracks {
+                for (i, t) in tracks.enumerated() {
+                    print("[Recorder:DIAG]   track[\(i)]: ID=\(t.trackID) mediaType=\(t.mediaType.rawValue)")
+                }
+            }
+            
+            // 创建 MTAudioProcessingTap
+            var callbacks = MTAudioProcessingTapCallbacks(
+                version: kMTAudioProcessingTapCallbacksVersion_0,
+                clientInfo: Unmanaged.passUnretained(ctx).toOpaque(),
+                init: tapInit,
+                finalize: tapFinalize,
+                prepare: tapPrepare,
+                unprepare: tapUnprepare,
+                process: tapProcess
+            )
+            
+            var tap: MTAudioProcessingTap?
+            let tapStatus = MTAudioProcessingTapCreate(
+                kCFAllocatorDefault, &callbacks,
+                kMTAudioProcessingTapCreationFlag_PreEffects,
+                &tap
+            )
+            print("[Recorder:DIAG] MTAudioProcessingTapCreate status=\(tapStatus) (noErr=\(noErr))")
+            guard tapStatus == noErr, let tapRef = tap else {
+                print("[Recorder:DIAG] ⚠️ Tap creation failed!")
+                return
+            }
+            
+            // 创建 AudioMix
+            let inputParams = AVMutableAudioMixInputParameters()
+            inputParams.trackID = audioTrack.trackID
+            inputParams.audioTapProcessor = tapRef
+            
+            let audioMix = AVMutableAudioMix()
+            audioMix.inputParameters = [inputParams]
+            
+            playerItem.audioMix = audioMix
+            
+            // 验证
+            let verifyMix = playerItem.audioMix
+            print("[Recorder:DIAG] playerItem.audioMix set=\(verifyMix != nil)")
+            if let vMix = verifyMix, let params = vMix.inputParameters.first {
+                print("[Recorder:DIAG] verified trackID=\(params.trackID)")
+            }
+            print("[Recorder:DIAG] === installAudioTap DONE ===")
+            
+            ctx.mixTrackID = audioTrack.trackID
+            
+            // 写诊断日志
+            var diagLog = "=== installAudioTap Log ===\n"
+            diagLog += "Time: \(Date())\n"
+            diagLog += "Asset class: \(type(of: playerItem.asset))\n"
+            diagLog += "Audio trackID used: \(audioTrack.trackID)\n"
+            diagLog += "TapCreate status: \(tapStatus)\n"
+            diagLog += "audioMix set: \(verifyMix != nil)\n"
+            if let vMix = verifyMix, let params = vMix.inputParameters.first {
+                diagLog += "Verified trackID: \(params.trackID)\n"
+            }
+            writeDiagLog(diagLog)
         }
-        
-        NSLog("[Recorder] Found audio track: ID=%d, formatDescriptions=%d",
-              audioTrack.trackID, audioTrack.formatDescriptions.count)
-        
-        // 创建 MTAudioProcessingTap
-        var callbacks = MTAudioProcessingTapCallbacks(
-            version: kMTAudioProcessingTapCallbacksVersion_0,
-            clientInfo: Unmanaged.passUnretained(ctx).toOpaque(),
-            init: tapInit,
-            finalize: tapFinalize,
-            prepare: tapPrepare,
-            unprepare: tapUnprepare,
-            process: tapProcess
-        )
-        
-        var tap: MTAudioProcessingTap?
-        let status = MTAudioProcessingTapCreate(
-            kCFAllocatorDefault, &callbacks,
-            kMTAudioProcessingTapCreationFlag_PreEffects,
-            &tap
-        )
-        guard status == noErr, let tapRef = tap else {
-            NSLog("[Recorder] ⚠️ MTAudioProcessingTapCreate failed: %d", status)
-            return
+    }
+    
+    private func writeDiagLog(_ content: String) {
+        if let moviesDir = FileManager.default.urls(for: .moviesDirectory, in: .userDomainMask).first {
+            let logPath = moviesDir.appendingPathComponent("MiniPlayer/tap_install_log.txt")
+            try? content.write(to: logPath, atomically: true, encoding: .utf8)
+            print("[Recorder:DIAG] Log written to: \(logPath.path)")
         }
-        
-        // 创建 AudioMix — 必须用实际 trackID
-        // kCMPersistentTrackID_Invalid (=0) 实测不会触发 tap
-        let inputParams = AVMutableAudioMixInputParameters()
-        inputParams.trackID = audioTrack.trackID
-        inputParams.audioTapProcessor = tapRef
-        
-        let audioMix = AVMutableAudioMix()
-        audioMix.inputParameters = [inputParams]
-        
-        playerItem.audioMix = audioMix
-        NSLog("[Recorder] ✓ Audio tap installed: trackID=%d, asset tracks=%d, playerItem.audioMix set",
-              audioTrack.trackID, playerItem.asset.tracks.count)
     }
     
     // MARK: - 开始录制
@@ -527,7 +580,8 @@ final class PlayerRecorder: NSObject {
             notReadyCount: tapContext?.notReadyCount ?? 0,
             lastActiveTimestamp: tapContext?.lastActiveTimestamp ?? 0,
             sampleRate: tapContext?.sampleRate ?? 0,
-            channelsPerFrame: tapContext?.channelsPerFrame ?? 0
+            channelsPerFrame: tapContext?.channelsPerFrame ?? 0,
+            mixTrackID: tapContext?.mixTrackID ?? -1
         )
         
         NSLog("[Recorder] Stopping: videoFrames=%d, audioProcessCalls=%d, audioAppended=%d, peak=%.4f, active=%d, silent=%d",
@@ -718,6 +772,7 @@ final class PlayerRecorder: NSObject {
             "--- Audio Format ---",
             "sampleRate:       \(String(format: "%.0f", stats.sampleRate)) Hz",
             "channelsPerFrame: \(stats.channelsPerFrame)",
+            "mixTrackID:       \(stats.mixTrackID) (bound in audioMix, -1=not set)",
             "peakAmplitude:    \(String(format: "%.6f", stats.peakAmplitude)) (\(String(format: "%.1f", peakDB)) dB)",
             "",
             "--- Skip/Error Counts ---",