Object pascal examples for recording and playing audio with portaudio. (#1271)

The recording example can be used for speech recognition while the playing example can be used for text to speech. The portaudio wrapper for object pascal is copied from https://github.com/UltraStar-Deluxe/USDX/blob/master/src/lib/portaudio/portaudio.pas
2024-08-18 19:51:08 +08:00
parent f93f0ca94d
commit e34a1a2aa3
9 changed files with 1562 additions and 2 deletions
--- a/pascal-api-examples/portaudio-test/test-record.pas
+++ b/pascal-api-examples/portaudio-test/test-record.pas
@@ -0,0 +1,139 @@
+{ Copyright (c)  2024  Xiaomi Corporation }
+{
+This file shows how to use portaudio for recording.
+
+It records for 10 seconds and saves the audio samples to ./record.wav
+}
+program main;
+
+{$mode objfpc}
+
+uses
+  portaudio,
+  sherpa_onnx,
+  dos,
+  ctypes,
+  SysUtils;
+
+var
+  Version: String;
+  EnvStr: String;
+  Status: Integer;
+  NumDevices: Integer;
+  DeviceIndex: Integer;
+  DeviceInfo: PPaDeviceInfo;
+  I: Integer;
+  Param: TPaStreamParameters;
+  SampleRate: Double;
+  Stream: PPaStream;
+
+  Buffer: TSherpaOnnxCircularBuffer;
+  AllSamples: TSherpaOnnxSamplesArray;
+
+function RecordCallback(
+      input: Pointer; output: Pointer;
+      frameCount: culong;
+      timeInfo: PPaStreamCallbackTimeInfo;
+      statusFlags: TPaStreamCallbackFlags;
+      userData: Pointer ): cint; cdecl;
+begin
+  Buffer.Push(pcfloat(input), frameCount);
+  Result := paContinue;
+end;
+
+
+
+begin
+  Version := String(Pa_GetVersionText);
+  WriteLn('Version is ', Version);
+  Status := Pa_Initialize;
+  if Status <> paNoError then
+    begin
+      WriteLn('Failed to initialize portaudio, ', Pa_GetErrorText(Status));
+      Exit;
+    end;
+
+  NumDevices := Pa_GetDeviceCount;
+  WriteLn('Num devices: ', NumDevices);
+
+  DeviceIndex := Pa_GetDefaultInputDevice;
+
+  if DeviceIndex = paNoDevice then
+    begin
+      WriteLn('No default input device found');
+      Pa_Terminate;
+      Exit;
+    end;
+
+  EnvStr := GetEnv('SHERPA_ONNX_MIC_DEVICE');
+  if EnvStr <> '' then
+    begin
+      DeviceIndex := StrToIntDef(EnvStr, DeviceIndex);
+      WriteLn('Use device index from environment variable SHERPA_ONNX_MIC_DEVICE: ', EnvStr);
+    end;
+
+  for I := 0 to (NumDevices - 1) do
+    begin
+      DeviceInfo := Pa_GetDeviceInfo(I);
+      if I = DeviceIndex then
+        { WriteLn(Format(' * %d %s', [I, DeviceInfo^.Name])) }
+        WriteLn(Format(' * %d %s', [I, AnsiString(DeviceInfo^.Name)]))
+      else
+        WriteLn(Format('   %d %s', [I, AnsiString(DeviceInfo^.Name)]));
+    end;
+
+  WriteLn('Use device ', DeviceIndex);
+  WriteLn(' Name ', Pa_GetDeviceInfo(DeviceIndex)^.Name);
+  WriteLn(' Max input channels ', Pa_GetDeviceInfo(DeviceIndex)^.MaxInputChannels);
+
+  Initialize(Param);
+  Param.Device := DeviceIndex;
+  Param.ChannelCount := 1;
+  Param.SampleFormat := paFloat32;
+  param.SuggestedLatency := Pa_GetDeviceInfo(DeviceIndex)^.DefaultHighInputLatency;
+  param.HostApiSpecificStreamInfo := nil;
+
+  SampleRate := 48000;
+  Buffer := TSherpaOnnxCircularBuffer.Create(Round(SampleRate) * 20);
+
+  Status := Pa_OpenStream(stream, @Param, nil, SampleRate, paFramesPerBufferUnspecified, paNoFlag,
+    PPaStreamCallback(@RecordCallback), nil);
+
+  if Status <> paNoError then
+    begin
+      WriteLn('Failed to open stream, ', Pa_GetErrorText(Status));
+      Pa_Terminate;
+      Exit;
+    end;
+
+  Status := Pa_StartStream(stream);
+  if Status <> paNoError then
+    begin
+      WriteLn('Failed to start stream, ', Pa_GetErrorText(Status));
+      Pa_Terminate;
+      Exit;
+    end;
+
+  WriteLn('Please speak! It will exit after 10 seconds.');
+  Pa_Sleep(10000);  {sleep for 10 seconds }
+
+  Status := Pa_CloseStream(stream);
+  if Status <> paNoError then
+    begin
+      WriteLn('Failed to close stream, ', Pa_GetErrorText(Status));
+      Exit;
+    end;
+
+  AllSamples := Buffer.Get(0, Buffer.Size);
+
+  SherpaOnnxWriteWave('record.wav', AllSamples, Round(SampleRate));
+  WriteLn('Saved to record.wav');
+
+  Status := Pa_Terminate;
+  if Status <> paNoError then
+    begin
+      WriteLn('Failed to deinitialize portaudio, ', Pa_GetErrorText(Status));
+      Exit;
+    end;
+end.
+