pwavfile.h

pwlib源码库

/*
 * pwavfile.h
 *
 * WAV file I/O channel class.
 *
 * Portable Windows Library
 *
 * Copyright (c) 2001 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
 * Roger Hardiman <[e-mail]>
 * and Shawn Pai-Hsiang Hsiao <[e-mail]>
 *
 * All Rights Reserved.
 *
 * Contributor(s): ______________________________________.
 *
 * $Log: pwavfile.h,v $
 * Revision 1.20  2005/06/09 00:33:12  csoutheren
 * Fixed crash problem caused by recent leak fix
 * Removed bogus error when reading all of file contents in a single read
 *
 * Revision 1.19  2005/05/12 05:25:04  csoutheren
 * PWAVFile format abstract factory must use a PCaseless as a key
 *
 * Revision 1.18  2005/03/19 02:52:53  csoutheren
 * Fix warnings from gcc 4.1-20050313 shapshot
 *
 * Revision 1.17  2005/01/04 07:44:02  csoutheren
 * More changes to implement the new configuration methodology, and also to
 * attack the global static problem
 *
 * Revision 1.16  2004/11/11 07:34:50  csoutheren
 * Added #include <ptlib.h>
 *
 * Revision 1.15  2004/11/08 04:07:40  csoutheren
 * Fixed crash opportunity under some conditions
 * Fixed incorrect WAV file type display
 *
 * Revision 1.14  2004/07/15 03:12:41  csoutheren
 * Migrated changes from crs_vxnml_devel branch into main trunk
 *
 * Revision 1.13.4.4  2004/07/13 08:13:04  csoutheren
 * Lots of implementation of factory-based PWAVFile
 *
 * Revision 1.13.4.3  2004/07/12 09:17:19  csoutheren
 * Fixed warnings and errors under Linux
 *
 * Revision 1.13.4.2  2004/07/12 08:30:16  csoutheren
 * More fixes for abstract factory implementation of PWAVFile
 *
 * Revision 1.13.4.1  2004/07/07 07:07:41  csoutheren
 * Changed PWAVFile to use abstract factories (extensively)
 * Removed redundant blocking/unblocking when using G.723.1
 * More support for call transfer
 *
 * Revision 1.13  2003/03/07 06:12:05  robertj
 * Added more WAV file "magic numbers".
 *
 * Revision 1.12  2002/09/16 01:08:59  robertj
 * Added #define so can select if #pragma interface/implementation is used on
 *   platform basis (eg MacOS) rather than compiler, thanks Robert Monaghan.
 *
 * Revision 1.11  2002/06/20 00:51:38  craigs
 * Added virtuals to allow overriding
 *
 * Revision 1.10  2002/05/21 01:56:53  robertj
 * Removed the enum which made yet another set of magic numbers for audio
 *   formats, now uses the WAV file format numbers.
 * Fixed failure to write header when destroying object without and explicit
 *   call to Close().
 * Fixed missing Open() function which does not have file name parameter.
 * Added ability to set the audio format after construction.
 *
 * Revision 1.9  2002/01/22 03:55:07  craigs
 * Added #define guards when file moved to PTCLib
 *
 * Revision 1.8  2002/01/13 21:00:41  rogerh
 * The type of new .WAV files must now be specified in the class constructor.
 * Take out Open() function from the last commit and create a new Open()
 * function which replaces the one in the PFile base class.
 *
 * Revision 1.7  2002/01/11 16:33:46  rogerh
 * Create a PWAVFile Open() function, which processes the WAV header
 *
 * Revision 1.6  2001/10/16 13:27:37  rogerh
 * Add support for writing G.723.1 WAV files.
 * MS Windows can play G.723.1 WAV Files in Media Player and Sound Recorder.
 * Sound Recorder can also convert them to normal PCM format WAV files.
 * Thanks go to M.Stoychev <[e-mail]> for sample WAV files.
 *
 * Revision 1.5  2001/10/15 11:48:15  rogerh
 * Add GetFormat to return the format of a WAV file
 *
 * Revision 1.4  2001/07/23 01:20:20  rogerh
 * Add updates from Shawn - ensure isvalidWAV is false for zero length files.
 * GetDataLength uses actual file size to support file updates as well as appends.
 * Add updates from Roger - Update Header() just writes to specific fields which
 * preserves any 'extra' data in an existing header between FORMAT and DATA chunks.
 *
 * Revision 1.3  2001/07/20 07:06:27  rogerh
 * Fix a typo
 *
 * Revision 1.2  2001/07/20 03:30:59  robertj
 * Minor cosmetic changes to new PWAVFile class.
 *
 * Revision 1.1  2001/07/19 09:55:48  rogerh
 * Add PWAVFile, a class to read and write .wav files, written by
 * Roger Hardiman and <[e-mail]> and
 * Shawn Pai-Hsiang Hsiao <[e-mail]>
 *
 *
 */

#ifndef _PWAVFILE
#define _PWAVFILE

//#ifdef P_USE_PRAGMA
//#pragma interface
//#endif

#include <ptlib.h>

class PWAVFile;

namespace PWAV {

#ifdef __GNUC__
#define P_PACKED    __attribute__ ((packed));
#else
#define P_PACKED
#pragma pack(1)
#endif

struct ChunkHeader
{
  char    tag[4] P_PACKED;
  PInt32l len    P_PACKED;
};

struct RIFFChunkHeader 
{
  ChunkHeader hdr    P_PACKED;
  char        tag[4] P_PACKED;
};

struct FMTChunk
{
  ChunkHeader hdr          P_PACKED;  // chunk header
  PUInt16l format          P_PACKED;  // Format 
  PUInt16l numChannels     P_PACKED;  // Channels 0x01 = mono, 0x02 = stereo
  PUInt32l sampleRate      P_PACKED;  // Sample Rate in Hz
  PUInt32l bytesPerSec     P_PACKED;  // Average bytes Per Second
  PUInt16l bytesPerSample  P_PACKED;  // Bytes Per Sample, eg 2
  PUInt16l bitsPerSample   P_PACKED;  // Bits Per Sample, eg 16
};

}; // namespace PWAV

#ifdef __GNUC__
#undef P_PACKED
#else
#pragma pack()
#endif

/**
  * abstract factory class for handling WAV files formats
  */
class PWAVFileFormat
{
  public:
    virtual ~PWAVFileFormat() { }

    /**
      * return a PWAVFile format code
      */
    virtual unsigned GetFormat() const = 0;

    /**
      * return a string that can be used as a media format
      */
    virtual PString GetFormatString() const = 0;

    /**
     *  return a string that can be used as a text description
     */
    virtual PString GetDescription() const = 0;

    /**
     *  populate the header with the correct values
     */
    virtual void CreateHeader(PWAV::FMTChunk & header, PBYTEArray & extendedHeader) = 0;

    /**
      * write any extra headers after the FORMAT chunk
      */
    virtual BOOL WriteExtraChunks(PWAVFile & /*file*/)
    { return TRUE; }

    /**
      * read any extra headers after the FORMAT chunk
      */
    virtual BOOL ReadExtraChunks(PWAVFile & /*file*/)
    { return TRUE; }

     /**
      * called before the reading/writing starts
      */
    virtual void OnStart()
    { }

     /**
      * called after the reading/writing stops
      */
    virtual void OnStop()
    { }

    /**
      * write data to the file
      */
    virtual BOOL Read(PWAVFile & file, void * buf, PINDEX & len);

    /**
      * read data from the file
      */
    virtual BOOL Write(PWAVFile & file, const void * buf, PINDEX & len);
};

typedef PFactory<PWAVFileFormat, PCaselessString> PWAVFileFormatByFormatFactory;
typedef PFactory<PWAVFileFormat, unsigned> PWAVFileFormatByIDFactory;

/**
  * abstract factory class for autoconversion of WAV files to/from PCM-16
  */
class PWAVFileConverter 
{
  public:
    virtual ~PWAVFileConverter() { }
    virtual unsigned GetFormat    (const PWAVFile & file) const = 0;
    virtual off_t GetPosition     (const PWAVFile & file) const = 0;
    virtual BOOL SetPosition      (PWAVFile & file, off_t pos, PFile::FilePositionOrigin origin) = 0;
    virtual unsigned GetSampleSize(const PWAVFile & file) const = 0;
    virtual off_t GetDataLength   (PWAVFile & file) = 0;
    virtual BOOL Read             (PWAVFile & file, void * buf, PINDEX len)  = 0;
    virtual BOOL Write            (PWAVFile & file, const void * buf, PINDEX len) = 0;
};

typedef PFactory<PWAVFileConverter, unsigned> PWAVFileConverterFactory;

/**A class representing a WAV audio file.
  */
class PWAVFile : public PFile
{
  PCLASSINFO(PWAVFile, PFile);

  public:
  /**@name Construction */
  //@{
    /**When a file is opened for writing, we can specify if this is a PCM
       wav file or a G.723.1 wav file.
     */
    enum {
      fmt_PCM         = 1,      /// PCM, 8kHz, 16 bit, mono
      fmt_ALaw        = 6,      /// A-Law 8kHz
      fmt_uLaw        = 7,      /// u-Law 8kHz
      fmt_GSM         = 0x31,   /// GSM
      fmt_G728        = 0x41,   /// RFC2361
      fmt_G723        = 0x42,   /// RFC2361