audiomanager: fix crash and return error text if applicable

app/audio/audiomanager.cpp

@@ -189,7 +189,7 @@ void AudioManager::HardReset()
   Pa_Initialize();
 }
 
-bool AudioManager::StartRecording(const EncodingParams &params)
+bool AudioManager::StartRecording(const EncodingParams &params, QString *error_str)
 {
   if (input_device_ == paNoDevice) {
     return false;
@@ -203,12 +203,19 @@ bool AudioManager::StartRecording(const EncodingParams &params)
 
   PaStreamParameters p = GetPortAudioParams(params.audio_params(), input_device_);
 
-  if (Pa_OpenStream(&input_stream_, &p, nullptr, params.audio_params().sample_rate(), paFramesPerBufferUnspecified, paNoFlag, InputCallback, input_encoder_) == paNoError) {
-    if (Pa_StartStream(input_stream_) == paNoError) {
+  PaError r = Pa_OpenStream(&input_stream_, &p, nullptr, params.audio_params().sample_rate(), paFramesPerBufferUnspecified, paNoFlag, InputCallback, input_encoder_);
+  if (r == paNoError) {
+    //const PaStreamInfo* info = Pa_GetStreamInfo(input_stream_);
+    r = Pa_StartStream(input_stream_);
+    if (r == paNoError) {
       return true;
     }
   }
 
+  if (error_str) {
+    *error_str = Pa_GetErrorText(r);
+  }
+
   StopRecording();
   return false;
 }

app/audio/audiomanager.h

@@ -74,7 +74,7 @@ public:
 
   void HardReset();
 
-  bool StartRecording(const EncodingParams &params);
+  bool StartRecording(const EncodingParams &params, QString *error_str = nullptr);
 
   void StopRecording();
 

app/codec/ffmpeg/ffmpegencoder.cpp

@@ -285,7 +285,7 @@ bool FFmpegEncoder::WriteAudio(SampleBufferPtr audio)
     }
   }
 
-  result = WriteAudioData(audio->audio_params(), const_cast<const uint8_t**>(input_data), input_sample_count);
+  result = WriteAudioData(audio ? audio->audio_params() : params().audio_params(), const_cast<const uint8_t**>(input_data), input_sample_count);
 
   if (input_data) {
     av_freep(&input_data[0]);

app/widget/viewer/viewer.cpp

@@ -1190,12 +1190,13 @@ void ViewerWidget::Play(bool in_to_out_only)
     encode_param.SetFilename(recording_filename_);
     encode_param.set_audio_bit_rate(OLIVE_CONFIG("AudioRecordingBitRate").toInt() * 1000);
 
-    if (AudioManager::instance()->StartRecording(encode_param)) {
+    QString error;
+    if (AudioManager::instance()->StartRecording(encode_param, &error)) {
       recording_ = true;
       controls_->SetPauseButtonRecordingState(true);
       recording_callback_->EnableRecordingOverlay(TimelineCoordinate(recording_range_.in(), recording_track_));
     } else {
-      QMessageBox::critical(this, tr("Audio Recording"), tr("Failed to start audio recording"));
+      QMessageBox::critical(this, tr("Audio Recording"), tr("Failed to start audio recording: %1").arg(error));
       return;
     }
   }