From cff2bd2793e91ff1ce85975430683ba93f7babe6 Mon Sep 17 00:00:00 2001
From: yumoqing <yumoqing@gmail.com>
Date: Sun, 28 Jun 2026 10:24:04 +0800
Subject: [PATCH] fix: use kCMPersistentTrackID_Invalid for HLS audio tap
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Root cause found: HLS variant switching changes audio trackID mid-recording
(e.g. 2→10). Binding to a specific trackID causes tap to never fire.
Using kCMPersistentTrackID_Invalid (wildcard) matches all audio tracks
regardless of variant switches.
---
 Sources/PlayerRecorder.swift | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Sources/PlayerRecorder.swift b/Sources/PlayerRecorder.swift
index 5bf0dd7..e24f747 100644
--- a/Sources/PlayerRecorder.swift
+++ b/Sources/PlayerRecorder.swift
@@ -375,9 +375,10 @@ final class PlayerRecorder: NSObject {
             return
         }
         
-        // 创建 AudioMix
+        // 使用 kCMPersistentTrackID_Invalid 匹配所有音频轨道
+        // HLS variant 切换会导致 trackID 变化（如 2→10），绑死具体 ID 会失效
         let inputParams = AVMutableAudioMixInputParameters()
-        inputParams.trackID = audioTrackID
+        inputParams.trackID = kCMPersistentTrackID_Invalid
         inputParams.audioTapProcessor = tapRef
         
         let audioMix = AVMutableAudioMix()
@@ -393,7 +394,7 @@ final class PlayerRecorder: NSObject {
         }
         print("[Recorder:DIAG] === installAudioTap DONE ===")
         
-        ctx.mixTrackID = audioTrackID
+        ctx.mixTrackID = kCMPersistentTrackID_Invalid
         
         // 写诊断日志
         var diagLog = "=== installAudioTap Log ===\n"
@@ -403,7 +404,8 @@ final class PlayerRecorder: NSObject {
         for (i, t) in itemTracks.enumerated() {
             diagLog += "  itemTrack[\(i)]: trackID=\(t.assetTrack?.trackID ?? -1) mediaType=\(t.assetTrack?.mediaType.rawValue ?? "?") enabled=\(t.isEnabled)\n"
         }
-        diagLog += "Audio trackID used: \(audioTrackID)\n"
+        diagLog += "Audio trackID used: kCMPersistentTrackID_Invalid (wildcard, matches all)\n"
+        diagLog += "Discovered audio trackID: \(audioTrackID)\n"
         diagLog += "TapCreate status: \(tapStatus)\n"
         diagLog += "audioMix set: \(verifyMix != nil)\n"
         writeDiagLog(diagLog)