unit ACMWaveIn;

interface

uses
  msacm, Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, mmsystem;

type
  TOnData = procedure(data: pointer; size: longint) of object;
  TACMWaveIn = class(TWinControl)
  private
    FOnData: TOnData;
    Fbuffersize: Integer;
    //FDeviceID: Integer;
    procedure WaveInCallback(var msg: TMessage); message MM_WIM_DATA;
    procedure Setbuffersize(Value: Integer);
    { Private declarations }
  protected
    procedure TWMPaint(var msg: TWMPaint); message WM_PAINT;

   { Protected declarations }
  public
    constructor Create(AOwner: TComponent); override;
    procedure Open(format: PWaveFormatEx; DeviceID: Integer = 0);
    procedure Close;
    function getsample: int64;
    { Public declarations }
  published
    property BufferSize: Integer read Fbuffersize write Setbuffersize default 160;
    property OnData: TOnData read FOnData write FOnData;
    { Published declarations }
  end;
var
  closed: boolean;
  sizebuf: integer;
  HWaveIn1: PHWaveIn;
procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('Milos', [TACMWaveIn]);
end;

procedure TACMWaveIn.TWMPaint(var msg: TWMPaint); //display icon
var
  icon: HIcon;
  dc: HDC;
begin
  if csDesigning in ComponentState then
  begin
    icon := LoadIcon(HInstance, MAKEINTRESOURCE('TACMWAVEIN'));
    dc := GetDC(Handle);
    DrawIcon(dc, 0, 0, icon);
    Width := 32;
    Height := 32;
    ReleaseDC(Handle, dc);
    FreeResource(icon);
  end;
  ValidateRect(Handle, nil);
end;


constructor TACMWaveIn.Create(AOwner: TComponent);
begin
  inherited create(AOwner);
  width := 32;
  height := 32;
  Fbuffersize := 160;
  Visible := false;
end;

procedure TACMWaveIn.WaveInCallback(var msg: TMessage); //this is called when is buffer full
var
  Header: PWaveHdr;
  i, bytesrecorded: integer;
  data: PChar;
begin

     {block has been recorded}
  Header := PWaveHdr(msg.lparam);
  if closed = false then
  begin
    i := waveInUnPrepareHeader(HWaveIn1^, Header, sizeof(TWavehdr));
    if i <> 0 then raise Exception.Create('In Un Prepare error');
    bytesrecorded := header.dwbytesrecorded;
    getmem(data, bytesrecorded); //allocate memory
    move(header.lpdata^, data^, bytesrecorded); //copy data
    if assigned(FOnData) then
    begin
      FOnData(data, bytesrecorded);
    end;

    Freemem(data); //free memory
          {reuse a old memory block}

    header.dwbufferlength := sizebuf;
    header.dwbytesrecorded := 0;
    header.dwUser := 0;
    header.dwflags := 0;
    header.dwloops := 0;

         {prepare the old block}
    i := waveInPrepareHeader(HWaveIn1^, Header, sizeof(TWavehdr));

    if i <> 0 then raise Exception.Create('In Prepare error');

          {add it to the buffer}
    i := waveInAddBuffer(HWaveIn1^, Header, sizeof(TWaveHdr));
    if i <> 0 then raise Exception.Create('Add buffer error');
  end
  else
  begin //free buffers if closed
    dispose(header.lpdata);
    dispose(header);
  end;
end;

procedure TACMWaveIn.Open(format: PWaveFormatEx; DeviceID: Integer = 0);
var
  WaveFormat: PWaveFormatEx;
  Header: PWaveHdr;
  memBlock: PChar;
  i, j, maxsizeformat: integer;
begin
  if (hwavein1 = nil) and (format <> nil) then
  begin
    acmMetrics(0, ACM_METRIC_MAX_SIZE_FORMAT, MaxSizeFormat);
    getmem(WaveFormat, MaxSizeFormat);
    move(format^, waveformat^, maxsizeformat);
    //sizebuf := format.nAvgBytesPerSec div 5;  //改变此处的大小,可以实现减少延时的作用
    sizebuf := 325; //GSM610
    //sizebuf := 160;  //G729
    HWaveIn1 := new(PHWaveIn);
     // create record handle with waveformatex structure
    i := WaveInOpen(HWaveIn1, DeviceID, waveformat, handle, 0, CALLBACK_WINDOW or WAVE_MAPPED);
    if i <> 0 then
    begin
      raise Exception.Create('Problem creating record handle' + inttostr(i));
      exit;
    end;
    closed := false;
     {need to add some buffers to the recording queue}
     {in case the messages that blocks have been recorded}
     {are delayed}
    for j := 1 to 3 do
    begin
          {make a new block}
      //Header := new(PWaveHdr);
      //memBlock := new(PChar);
      getmem(memblock, sizebuf); //allocate memory
      Header := new(PwaveHdr);
      header.lpdata := memBlock;
      header.dwbufferlength := sizebuf;
      header.dwbytesrecorded := 0;
      header.dwUser := 0;
      header.dwflags := 0;
      header.dwloops := 0;
          {prepare the new block}
      i := waveInPrepareHeader(HWaveIn1^, Header, sizeof(TWavehdr));
      if i <> 0 then raise Exception.Create('In Prepare error');

          {add it to the buffer}
      i := waveInAddBuffer(HWaveIn1^, Header, sizeof(TWaveHdr));

      if i <> 0 then raise Exception.Create('Add buffer error');


    end; {of loop}

     {finally start recording}
    i := waveInStart(HwaveIn1^);
    if i <> 0 then raise Exception.Create('Start error');
  end;
end;

procedure TACMWaveIn.Close;
begin
  if HWaveIn1 <> nil then
  begin
    closed := true;
    WaveInReset(HWaveIn1^);
    WaveInClose(HWaveIn1^);
    dispose(HWaveIn1);
    HWaveIn1 := nil;
  end;
end;

function TACMWaveIn.getsample: int64;
var
  mt: TMMTime;
begin
  mt.wType := TIME_SAMPLES;
  waveInGetPosition(HWaveIn1^, @mt, sizeof(mt));
  Result := mt.sample;
end;

procedure TACMWaveIn.Setbuffersize(Value: Integer);
begin
  if Value>0 then
    Fbuffersize := Value;
end;

end.