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

sherpa-onnx/pascal-api/README.md

@@ -5,3 +5,7 @@ This directory contains APIs for [Object Pascal](https://en.wikipedia.org/wiki/O
 Please see
 https://github.com/k2-fsa/sherpa-onnx/tree/master/pascal-api-examples
 for usages.
+
+[portaudio.pas](./portaudio.pas)
+is copied from
+https://github.com/UltraStar-Deluxe/USDX/blob/master/src/lib/portaudio/portaudio.pas

sherpa-onnx/pascal-api/sherpa_onnx.pas

@@ -10,6 +10,8 @@ unit sherpa_onnx;
 (* {$LongStrings ON} *)
 
 interface
+uses
+  ctypes;
 
 type
   TSherpaOnnxWave = record
@@ -260,7 +262,8 @@ type
   public
     constructor Create(Capacity: Integer);
     destructor Destroy; override;
-    procedure Push(Samples: array of Single);
+    procedure Push(Samples: array of Single); overload;
+    procedure Push(Samples: pcfloat; N: Integer); overload;
     function Get(StartIndex: Integer; N: Integer): TSherpaOnnxSamplesArray;
     procedure Pop(N: Integer);
     procedure Reset;
@@ -305,7 +308,6 @@ type
 implementation
 
 uses
-  ctypes,
   fpjson,
     { See
       - https://wiki.freepascal.org/fcl-json
@@ -1323,6 +1325,11 @@ begin
   SherpaOnnxCircularBufferPush(Self.Handle, pcfloat(Samples), Length(Samples));
 end;
 
+procedure TSherpaOnnxCircularBuffer.Push(Samples: pcfloat; N: Integer);
+begin
+  SherpaOnnxCircularBufferPush(Self.Handle, Samples, N);
+end;
+
 function TSherpaOnnxCircularBuffer.Get(StartIndex: Integer; N: Integer): TSherpaOnnxSamplesArray;
 var
   P: pcfloat;