Keep adaptive requests above baseline and test backend fault events

tools/chatgui/src/audio_buffer_tuning.h

@@ -9,7 +9,7 @@
  * Состояние живёт до смены устройства/сессии; begin() сохраняет подобранный размер при reopen. */
 struct AudioBufferTuning {
     enum Result { Unchanged, Increase, Limit };
-    unsigned requestedMs = 0, actualMs = 0, periods = 1;
+    unsigned requestedMs = 0, baseMs = 0, actualMs = 0, periods = 1;
     int64_t settleUntil = 0, changeAfter = 0, firstFaultAt = -1;
     unsigned faultPolls = 0;
 
@@ -24,7 +24,7 @@ struct AudioBufferTuning {
         faultPolls = std::min(faultPolls + 1, 2u);
         if (faultPolls < 2 || now < changeAfter) return Unchanged;
         firstFaultAt = -1; faultPolls = 0; changeAfter = now + 5000;
-        unsigned current = std::max(actualMs, requestedMs), maximum = 100 / periods;
+        unsigned current = std::max({actualMs, requestedMs, baseMs}), maximum = 100 / periods;
         if (!current || current >= maximum) return Limit;
         requestedMs = std::min(current + 5, maximum);
         return Increase;

tools/chatgui/src/audio_device.cpp

@@ -48,6 +48,8 @@ bool AudioDevice::init(ma_context* context, ma_device_config config, const char*
     m_bufferKeyValid = true; m_bufferBackend = context->backend; m_bufferType = config.deviceType;
     m_bufferSession = session; m_bufferSelected = selected != nullptr;
     if (selected) m_bufferDeviceId = *selected;
+    m_bufferTuning.baseMs = config.periodSizeInFrames && config.sampleRate
+        ? unsigned((uint64_t(config.periodSizeInFrames) * 1000 + config.sampleRate - 1) / config.sampleRate) : config.periodSizeInMilliseconds;
     if (m_bufferTuning.requestedMs) {
         config.periodSizeInFrames = 0; config.periodSizeInMilliseconds = m_bufferTuning.requestedMs;
     }