refactoring SettingsForm

AudioOutput.pas

@@ -15,6 +15,7 @@ unit AudioOutput;
 
 {$IFDEF FPC}
   {$MODE Delphi}
+  {$PACKRECORDS C}
 {$ENDIF}
 
 interface
@@ -166,9 +167,13 @@ const
     'libportaudio.so.0'
   );
 {$ELSE}
-  PA_LIBS: array[0..1] of AnsiString = (
+  PA_LIBS: array[0..5] of AnsiString = (
     'portaudio_x64.dll',
-    'portaudio.dll'
+    'portaudio_x86.dll',
+    'portaudio.dll',
+    'libportaudio-2.dll',
+    'libportaudio.dll',
+    'libportaudio64.dll'
   );
 {$ENDIF}
   PA_NO_ERROR  = 0;
@@ -282,7 +287,11 @@ begin
 
   if FLibHandle = NilHandle then
   begin
+{$IFDEF WINDOWS}
+    FLastError := 'PortAudio DLL not found. Put portaudio_x64.dll, portaudio.dll, or libportaudio-2.dll next to ewsdr.exe';
+{$ELSE}
     FLastError := 'libportaudio not found. sudo apt install libportaudio2';
+{$ENDIF}
     Exit;
   end;
 
@@ -297,7 +306,16 @@ begin
   FPa_CloseStream            := TPa_CloseStream(GetProcAddress(FLibHandle, 'Pa_CloseStream'));
   FPa_GetErrorText           := TPa_GetErrorText(GetProcAddress(FLibHandle, 'Pa_GetErrorText'));
 
-  if not Assigned(FPa_Initialize) or not Assigned(FPa_OpenStream) then
+  if not Assigned(FPa_Initialize) or
+     not Assigned(FPa_Terminate) or
+     not Assigned(FPa_GetDefaultOutputDevice) or
+     not Assigned(FPa_GetDeviceCount) or
+     not Assigned(FPa_GetDeviceInfo) or
+     not Assigned(FPa_OpenStream) or
+     not Assigned(FPa_StartStream) or
+     not Assigned(FPa_StopStream) or
+     not Assigned(FPa_CloseStream) or
+     not Assigned(FPa_GetErrorText) then
   begin
     FLastError := 'libportaudio: symbols not found';
     FreeLibrary(FLibHandle);
@@ -350,10 +368,27 @@ begin
   Count  := 0;
   Result := False;
   if not Initialize then Exit;
-  if not Assigned(FPa_GetDeviceCount) or not Assigned(FPa_GetDeviceInfo) then Exit;
+  if not Assigned(FPa_GetDeviceCount) or not Assigned(FPa_GetDeviceInfo) then
+  begin
+    FLastError := 'PortAudio device enumeration is not available';
+    Exit;
+  end;
 
   N := FPa_GetDeviceCount();
-  if N <= 0 then Exit;
+  if N < 0 then
+  begin
+    FLastError := 'Pa_GetDeviceCount: ';
+    if Assigned(FPa_GetErrorText) then
+      FLastError := FLastError + string(FPa_GetErrorText(N))
+    else
+      FLastError := FLastError + IntToStr(N);
+    Exit;
+  end;
+  if N = 0 then
+  begin
+    FLastError := 'No PortAudio devices found';
+    Exit;
+  end;
 
   for I := 0 to N - 1 do
   begin
@@ -416,6 +451,7 @@ var
   OutParam: TPaStreamParameters;
   Err:      TPaError;
   Dev:      TPaDeviceIndex;
+  Info:     PPaDeviceInfo;
 begin
   Result := False;
   if FOpen then begin Result := True; Exit; end;
@@ -441,8 +477,12 @@ begin
   OutParam.hostApiSpecificStreamInfo := nil;
   OutParam.sampleFormat              := PA_FLOAT32;
 {$IFDEF WINDOWS}
-  // На Windows latency=0 вызывает фризы — используем разумный минимум
-  OutParam.suggestedLatency := 0.050;  // 50ms — стабильно на Windows WASAPI/MME
+  // На Windows latency=0 часто ломает WASAPI/MME; берём значение от устройства.
+  Info := FPa_GetDeviceInfo(Dev);
+  if (Info <> nil) and (Info^.defaultLowOutputLatency > 0.0) then
+    OutParam.suggestedLatency := Info^.defaultLowOutputLatency
+  else
+    OutParam.suggestedLatency := 0.050;
 {$ELSE}
   OutParam.suggestedLatency := 0.0;    // на Linux ALSA справляется с минимумом
 {$ENDIF}