sound.h

mgcp协议源代码。支持多种编码：g711

/*
 * sound.h
 *
 * Sound interface class.
 *
 * Portable Windows Library
 *
 * Copyright (c) 1993-1998 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Portable Windows Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions are Copyright (C) 1993 Free Software Foundation, Inc.
 * All Rights Reserved.
 *
 * Contributor(s): ______________________________________.
 *
 * $Log: sound.h,v $
 * Revision 1.16  2000/03/04 10:15:32  robertj
 * Added simple play functions for sound files.
 *
 * Revision 1.15  1999/05/28 14:04:10  robertj
 * Added function to get default audio device.
 *
 * Revision 1.14  1999/03/09 02:59:51  robertj
 * Changed comments to doc++ compatible documentation.
 *
 * Revision 1.13  1999/02/22 10:15:14  robertj
 * Sound driver interface implementation to Linux OSS specification.
 *
 * Revision 1.12  1999/02/16 06:02:27  robertj
 * Major implementation to Linux OSS model
 *
 * Revision 1.11  1998/09/23 06:21:27  robertj
 * Added open source copyright license.
 *
 * Revision 1.10  1995/06/17 11:13:26  robertj
 * Documentation update.
 *
 * Revision 1.9  1995/03/14 12:42:40  robertj
 * Updated documentation to use HTML codes.
 *
 * Revision 1.8  1995/01/16  09:42:05  robertj
 * Documentation.
 *
 * Revision 1.7  1994/08/23  11:32:52  robertj
 * Oops
 *
 * Revision 1.6  1994/08/22  00:46:48  robertj
 * Added pragma fro GNU C++ compiler.
 *
 * Revision 1.5  1994/06/25  11:55:15  robertj
 * Unix version synchronisation.
 *
 * Revision 1.4  1994/01/03  04:42:23  robertj
 * Mass changes to common container classes and interactors etc etc etc.
 *
 * Revision 1.3  1993/09/29  03:06:30  robertj
 * Added unix compatibility to Beep()
 *
 * Revision 1.2  1993/07/14  12:49:16  robertj
 * Fixed RCS keywords.
 *
 */


#define _PSOUND

#ifdef __GNUC__
#pragma interface
#endif


/** A class representing a sound. A sound is a highly platform dependent
   entity that is abstracted for use here. Very little manipulation of the
   sounds are possible.

   The most common sound to use is the static function #Beep()# which
   emits the system standard "warning" or "attention" sound.
 */
class PSound : public PBYTEArray
{
  PCLASSINFO(PSound, PBYTEArray);

  public:
  /**@name Construction */
  //@{
    /**Create a new sound, using the parameters provided.
       It is expected that the "lowest common denominator" encoding, linear PCM,
       is used.

       All other values for the encoding are platform dependent.
     */
    PSound(
      unsigned numChannels = 1,    /// Number of channels eg mono/stereo
      unsigned sampleRate = 8000,  /// Samples per second
      unsigned bitsPerSample = 16, /// Number of bits per sample
      PINDEX   bufferSize = 0,     /// Size of data
      const BYTE * data = NULL     /// Pointer to initial data
    );

    /**Create a new sound, reading from a platform dependent file.
     */
    PSound(
      const PFilePath & filename   /// Sound file to load.
    );

    /**Set new data bytes for the sound.
     */
    PSound & operator=(
      const PBYTEArray & data  // New data for sound
    );
  //@}

  /**@name File functions */
  //@{
    /**Load a platform dependent sound file (eg .WAV file for Win32) into the
       object. Note the whole file must able to be loaded into memory.

       Also note that not all possible files are playable by this library. No
       format conversions between file and driver are performed.

       @return
       TRUE if the sound is loaded successfully.
     */
    BOOL Load(
      const PFilePath & filename   /// Sound file to load.
    );

    /**Save a platform dependent sound file (eg .WAV file for Win32) from the
       object.

       @return
       TRUE if the sound is saved successfully.
     */
    BOOL Save(
      const PFilePath & filename   // Sound file to load.
    );
  //@}

  /**@name Access functions */
  //@{
    /// Play the sound on the default sound device.
    BOOL Play();

    /**Set the internal sound format to linear PCM at the specification in
       the parameters.
     */
    void SetFormat(
      unsigned numChannels,   // Number of channels eg mono/stereo
      unsigned sampleRate,    /// Samples per second
      unsigned bitsPerSample  /// Number of bits per sample
    );

    /**Get the current encoding. A value of 0 indicates linear PCM, any other
       value is platform dependent.
     */
    unsigned GetEncoding()   const { return encoding; }

    /// Get  the number of channels (mono/stereo) in the sound.
    unsigned GetChannels()   const { return numChannels; }

    /// Get the sample rate in samples per second.
    unsigned GetSampleRate() const { return sampleRate; }

    /// Get the sample size in bits per sample.
    unsigned GetSampleSize() const { return sampleSize; }

    /// Get the platform dependent error code from the last file load.
    DWORD    GetErrorCode()  const { return dwLastError; }

    /// Get the size of the platform dependent format info.
    PINDEX   GetFormatInfoSize()  const { return formatInfo.GetSize(); }

    /// Get pointer to the platform dependent format info.
    const void * GetFormatInfoData() const { return (const BYTE *)formatInfo; }
  //@}

  /**@name Miscellaneous functions */
  //@{
    /**Play a sound file to the default device. If the #wait#
       parameter is TRUE then the function does not return until the file has
       been played. If FALSE then the sound play is begun asynchronously and
       the function returns immediately.

       @return
       TRUE if the sound is playing or has played.
     */
    static BOOL PlayFile(
      const PFilePath & file, /// Sound file to play.
      BOOL wait = TRUE        /// Flag to play sound synchronously.
    );

    /// Play the "standard" warning beep for the platform.
    static void Beep();
  //@}

  protected:
    /// Format code
    unsigned   encoding;      
    /// Number of channels eg mono/stereo
    unsigned   numChannels;   
    /// Samples per second
    unsigned   sampleRate;    
    /// Number of bits per sample
    unsigned   sampleSize;    
    /// Last error code for Load()/Save() functions
    DWORD      dwLastError;   
    /// Full info on the format (platform dependent)
    PBYTEArray formatInfo;    
};


/**A class representing a sound channel. This class is provided mainly for
   the playback or recording of sounds on the system.

   A sound driver is either playing or recording. If simultaneous playing and
   recording is desired, two instances of PSoundChannel must be created.

   The sound is buffered and the size and number of buffers should be set
   before playing/recording. Each call to Write() will use one buffer, so care
   needs to be taken not to use a large number of small writes but tailor the
   buffers to the size of each write you make.

   Similarly for reading, an entire buffer must be read before any of it is
   available to a Read() call. Note that once a buffer is filled you can read
   it a byte at a time if desired, but as soon as all the data in the buffer
   is used returned, the next read will wait until the entire next buffer is
   read from the hardware. So again, tailor the number and size of buffers to
   the application. To avoid being blocked until the buffer fills, you can use
   the StartRecording() function to initiate the buffer filling, and the
   IsRecordingBufferFull() function to determine when the Read() function will
   no longer block.

   Note that this sound channel is implicitly a linear PCM channel. No data
   conversion is performed on data to/from the channel.
 */
class PSoundChannel : public PChannel
{
  PCLASSINFO(PSoundChannel, PChannel);

  public:
  /**@name Construction */
  //@{
    enum Directions {
      Recorder,
      Player
    };

    /// Create a sound channel.
    PSoundChannel();