Pascal API for VAD (#1249)

pascal-api-examples/vad/remove_silence.pas

@@ -0,0 +1,115 @@
+{ Copyright (c)  2024  Xiaomi Corporation }
+{
+This file shows how to use the VAD API from sherpa-onnx
+to remove silences from a wave file.
+}
+program main;
+
+{$mode delphi}
+
+uses
+  sherpa_onnx,
+  SysUtils;
+
+var
+  Wave: TSherpaOnnxWave;
+
+  Config: TSherpaOnnxVadModelConfig;
+  Vad: TSherpaOnnxVoiceActivityDetector;
+  Offset: Integer;
+  WindowSize: Integer;
+  SpeechSegment: TSherpaOnnxSpeechSegment;
+
+  Start: Single;
+  Duration: Single;
+  SampleRate: Integer;
+
+  AllSpeechSegment: array of TSherpaOnnxSpeechSegment;
+  AllSamples: array of Single;
+  N: Integer;
+  I: Integer;
+begin
+  SampleRate := 16000; {Please don't change it unless you know the details}
+
+  Wave := SherpaOnnxReadWave('./lei-jun-test.wav');
+  if Wave.SampleRate <> SampleRate then
+    begin
+      WriteLn(Format('Expected sample rate: %d. Given: %d',
+        [SampleRate, Wave.SampleRate]));
+
+      Exit;
+    end;
+
+  WindowSize := 512; {Please don't change it unless you know the details}
+  Initialize(Config);
+
+  Config.SileroVad.Model := './silero_vad.onnx';
+  Config.SileroVad.MinSpeechDuration := 0.25;
+  Config.SileroVad.MinSilenceDuration := 0.5;
+  Config.SileroVad.Threshold := 0.5;
+  Config.SileroVad.WindowSize := WindowSize;
+  Config.NumThreads:= 1;
+  Config.Debug:= True;
+  Config.Provider:= 'cpu';
+  Config.SampleRate := SampleRate;
+
+  Vad := TSherpaOnnxVoiceActivityDetector.Create(Config, 20);
+
+  AllSpeechSegment := nil;
+  AllSamples := nil;
+  Offset := 0;
+  while Offset + WindowSize <= Length(Wave.Samples) do
+    begin
+      Vad.AcceptWaveform(Wave.Samples, Offset, WindowSize);
+      Inc(Offset, WindowSize);
+
+      while not Vad.IsEmpty do
+        begin
+          SetLength(AllSpeechSegment, Length(AllSpeechSegment) + 1);
+
+          SpeechSegment := Vad.Front();
+          Vad.Pop();
+          AllSpeechSegment[Length(AllSpeechSegment)-1] := SpeechSegment;
+
+          Start := SpeechSegment.Start / SampleRate;
+          Duration := Length(SpeechSegment.Samples) / SampleRate;
+          WriteLn(Format('%.3f -- %.3f', [Start, Start + Duration]));
+        end;
+    end;
+
+  Vad.Flush;
+
+  while not Vad.IsEmpty do
+    begin
+      SetLength(AllSpeechSegment, Length(AllSpeechSegment) + 1);
+
+      SpeechSegment := Vad.Front();
+      Vad.Pop();
+      AllSpeechSegment[Length(AllSpeechSegment)-1] := SpeechSegment;
+
+      Start := SpeechSegment.Start / SampleRate;
+      Duration := Length(SpeechSegment.Samples) / SampleRate;
+      WriteLn(Format('%.3f -- %.3f', [Start, Start + Duration]));
+    end;
+
+  N := 0;
+  for SpeechSegment in AllSpeechSegment do
+    Inc(N, Length(SpeechSegment.Samples));
+
+  SetLength(AllSamples, N);
+
+  N := 0;
+  for SpeechSegment in AllSpeechSegment do
+    begin
+      for I := Low(SpeechSegment.Samples) to High(SpeechSegment.Samples) do
+        begin
+          AllSamples[N] := SpeechSegment.Samples[I];
+          Inc(N);
+        end;
+    end;
+
+  SherpaOnnxWriteWave('./lei-jun-test-no-silence.wav', AllSamples, SampleRate);
+  WriteLn('Saved to ./lei-jun-test-no-silence.wav');
+
+  FreeAndNil(Vad);
+end.