Example of sending and receiving audio

This post is a simple example of capturing, compressing, and transmitting audio.

Executable demo

• sending and receiving audio.zip

Execute the test_AudioReceiver.exe file.

Execute the test_AudioSender.exe file.

Click the “off the air” button and say something.

Watch out for howling.
Keep the microphone away from the speaker.

Source codes

Delphi

• AudioSender
• AudioReceiver

C++

• RyuLib for C++
• AudioZip.dll

Main classes

TAudioZip (AudioZip.pas)

type
  TAudioZip = class
    {*
      Start capturing and compressing audio data.
      @param ADeviceID ID of the audio device to capture (-1 is the default device)
      @param AUseSystemAudio Decide whether to capture system audio.
    *}
    function Start(ADeviceID:integer; AUseSystemAudio:boolean=false):boolean;

    {*
      Stop capturing and compressing audio data.
    *}
    procedure Stop;

    property MicMuted : boolean read GetMicMuted write SetMicMuted;
    property SystemAudioMuted : boolean read GetSystemAudioMuted write SetSystemAudioMuted;
    property MicVolume : single read Get_MicVolume write Set_MicVolume;
    property SystemAudioVolume : single read GetSystemAudioVolume write SetSystemAudioVolume;
    property OnSouce : TDataEvent read FOnSouce write FOnSouce;
    property OnEncode : TDataEvent read FOnEncode write FOnEncode;
    property OnEror : TIntegerEvent read FOnEror write FOnEror;
  end;

TAudioUnZip (AudioZip.pas)

type
  TAudioUnZip = class
    {*
      Decompresse auido data and paly it.
      @parm AData Address of compressed audio data.
      @param ASize Size of the compressed audio data.
    *}
    procedure Play(AData:pointer; ASize:integer);

    {*
      Drop audio packets at the front of the buffer by a given number.
      This method will remove delays caused by voice transmission and reception.
      @param ACount Number of audio data to skip
    *}
    procedure Skip(ACount:integer);

    property DelayCount : integer read GetAudioUnZipDelayCount;
    property Muted : boolean read FMuted write FMuted;
    property Volume : single read GetVolume write SetVolume;
    property OnEror : TIntegerEvent read FOnEror write FOnEror;
  end;

TUDPSocket (UDPSocket.pas)

type
  TUDPSocket = class(TComponent)
    {*
      Start UDP socket.
      @param ANeedBinding If ANeedBinding is true, it becomes a server socket.
    *}
    procedure Start(ANeedBinding:boolean=true);

    {*
      Stop UDP socket.
    *}
    procedure Stop;

    {*
      Send binary data to the APort of an AHost.
    *}
    procedure SendTo(const AHost:string; APort:integer; AData:pointer; ASize:integer); overload;

    {*
      Send text data to the APort of an AHost.
    *}
    procedure SendTo(const AHost:string; APort:integer; AText:string); overload;

    property Active : boolean read FActive;
    property Port : integer read FPort write SetPort;
    property IsServer : boolean read FIsServer;
    property BufferSize : integer read FBufferSize write SetBufferSize;
    property TimeOutRead : integer read FTimeOutRead write FTimeOutRead;
    property TimeOutWrite : integer read FTimeOutWrite write FTimeOutWrite;
    property OnReceived : TUDPReceivedEvent read FOnReceived write FOnReceived;
  end;