Fixed an issue where the tail of the sound might be truncated in auto mode. (#1675)

main/application.cc

@@ -823,6 +823,12 @@ void Application::HandleStateChangedEvent() {
 
             // Make sure the audio processor is running
             if (!audio_service_.IsAudioProcessorRunning()) {
+                // For auto mode, wait for playback queue to be empty before enabling voice processing
+                // This prevents audio truncation when STOP arrives late due to network jitter
+                if (listening_mode_ == kListeningModeAutoStop) {
+                    audio_service_.WaitForPlaybackQueueEmpty();
+                }
+                
                 // Send the start listening command
                 protocol_->SendStartListening(listening_mode_);
                 audio_service_.EnableVoiceProcessing(true);

main/audio/audio_service.cc

@@ -740,6 +740,13 @@ bool AudioService::IsIdle() {
     return audio_encode_queue_.empty() && audio_decode_queue_.empty() && audio_playback_queue_.empty() && audio_testing_queue_.empty();
 }
 
+void AudioService::WaitForPlaybackQueueEmpty() {
+    std::unique_lock<std::mutex> lock(audio_queue_mutex_);
+    audio_queue_cv_.wait(lock, [this]() { 
+        return service_stopped_ || (audio_decode_queue_.empty() && audio_playback_queue_.empty()); 
+    });
+}
+
 void AudioService::ResetDecoder() {
     std::lock_guard<std::mutex> lock(audio_queue_mutex_);
     std::unique_lock<std::mutex> decoder_lock(decoder_mutex_);

main/audio/audio_service.h

@@ -115,6 +115,7 @@ public:
     const std::string& GetLastWakeWord() const;
     bool IsVoiceDetected() const { return voice_detected_; }
     bool IsIdle();
+    void WaitForPlaybackQueueEmpty();
     bool IsWakeWordRunning() const { return xEventGroupGetBits(event_group_) & AS_EVENT_WAKE_WORD_RUNNING; }
     bool IsAudioProcessorRunning() const { return xEventGroupGetBits(event_group_) & AS_EVENT_AUDIO_PROCESSOR_RUNNING; }
     bool IsAfeWakeWord();