[Bug] Bluetooth A2DP: whole-track pitch shift/slowdown after toggling audio output mode (WASAPI shared/exclusive, Win11) #437

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1. github-actions commented on Nov 1, 2026

   

   github-actionsBot

   on Nov 1, 2026 – with GitHub Actions

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   👋 @himasadek09-hub

   感谢提交 Issue！我们已经收到您的反馈，会尽快确认您的问题。

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2. himasadek09-hub commented on Nov 1, 2026

   

   himasadek09-hub

   on Nov 1, 2026

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   Complete report (all details in one place)

   Environment

   • SPlayer-Next 1.2.1-nightly.1052 (also reproduced on 1.2.0-nightly.990), Windows 11 Pro 22631 x64
   • Output: Bluetooth A2DP headset "ROSE CAMBRIAN" (Intel Wireless Bluetooth 24.70.0.4); HFP/Hands-Free disabled
   • Reproduces in both shared and exclusive output modes; also after disabling "Allow applications to take exclusive control" for the endpoint
   • Controls: Realtek wired output OK; Windows built-in player OK; another BT headset with fixed 44.1k endpoint OK

   Symptom

   1. Playing a local file, the whole track sounds pitched down / slowed. Background loops audibly slow down and then catch up.
   2. Toggling Settings → Playback → Audio output mode (shared ↔ exclusive) reproduces it 100%.
   3. New: after disabling exclusive control, tracks sometimes start detuned and gradually return to correct pitch after a few seconds ("warm-up").
   4. Files are ruled out: downloaded file matches the online stream byte-for-byte (correlation 1.000); loopback capture of app output matched the source at scale 1.000 on Realtek; 440Hz tone stays 440.00Hz after 44.1→48k resampling on Realtek.

   Steps to reproduce

   1. Connect the BT headset in A2DP mode (HFP disabled)
   2. Play any local audio file
   3. Toggle audio output mode shared/exclusive
   4. Whole track is detuned; background loops drift and catch up

   Key log excerpts

   18:18:55 INFO  audio_engine::output::wasapi::format: 独占模式格式协商成功 rate=48000 channels=2 bits=16
   19:38:42 INFO  audio_engine::output::wasapi::format: 独占模式格式协商成功 rate=44100 channels=2 bits=16
   18:19:05 WARN  audio_engine::output::wasapi: 独占输出唤醒间隔超过两个设备周期 late_wakes=1 longest_gap_ms=21.5972 period_ms=10.0
   18:21:38 INFO  audio_engine::output::cpal_stream: 音频输出流因设备切换失效，准备重建
   18:25:36 WARN  audio_engine::bindings::player::device: 输出重建失败，播放器进入暂停态 error=audio error kind: Device
   19:56:18 INFO  audio_engine::player: 切换音频输出模式 enabled=true
   19:56:18 INFO  audio_engine::bindings::player::device: 重新初始化音频输出设备
   20:05:51 WARN  audio_engine::output::device: 独占模式协商失败，回退共享模式 reason="formatUnsupported" error=format unsupported
   20:08:25 DEBUG audio_engine::decoder::reader: 解码线程异常结束 error=FFmpeg error -1094995529: Invalid data found when processing input
   

   Engine strings found in audio-engine.node: 输出格式变化后重建重采样器失败, 构建 FFT 重采样器失败, 独占模式开流失败，尝试共享模式

   Hypothesis
   The BT endpoint's actual rate flips between 44.1k and 48k. After any output re-initialization (mode switch, device switch, output rebuild), the resampler ratio is not initialized from the actual stream format; it starts wrong and converges via adaptive clock correction, producing a detuned start and a "slow down, then catch up" effect.

   Expected

   • Initialize/rebuild the resampler from the actual output stream format;
   • On failure, keep a correct fallback (and avoid silently continuing with a wrong ratio);
   • Avoid hot format switching during playback / reload the stream after device or mode changes.

   Attachments
   Full filtered native audio-engine log and application log are attached in splayer-next-bt-audio-logs.zip.

   splayer-next-bt-audio-logs.zip