include/wvaudioencoder.h

   1 /* -*- Mode: C++ -*-
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 1997-2003 Net Integration Technologies, Inc.
   4  *
   5  * Interface declaring additional methods required for a WvEncoder that
   6  * supports packetized audio formats.
   7  */
   8 #ifndef __WVAUDIOENCODER_H
   9 #define __WVAUDIOENCODER_H
  10
  11 #include "wvtypedencoder.h"
  12
  13 /**
  14  * Abstract base class for encoders for PCM audio.  This interface should be
  15  * added to a WvEncoder.
  16  */
  17 class WvAudioEncoder : public WvTypedEncoder<float, unsigned char>
  18 {
  19 public:
  20
  21     /**
  22      * Returns the number of channels.
  23      * Returns: the number of channels
  24      */
  25     virtual unsigned int channels() const = 0;
  26
  27     /**
  28      * Returns the number of samples per frame.
  29      * Returns: the frame size
  30      */
  31     virtual size_t samplesperframe() const = 0;
  32 };
  33
  34
  35 class WvAudioDecoder : public WvTypedEncoder<unsigned char, float>
  36 {
  37 public:
  38
  39     /**
  40      * Returns the number of channels.
  41      * Returns: the number of channels
  42      */
  43     virtual unsigned int channels() const = 0;
  44
  45     /**
  46      * Returns the number of samples per frame.
  47      * Returns: the frame size
  48      */
  49     virtual size_t samplesperframe() const = 0;
  50
  51     /**
  52      * Synthesizes one audio frame to compensate for a missing packet.
  53      * "outbuf" is the output buffer
  54      * Returns: true on success
  55      * @see encode
  56      */
  57     virtual bool missing(OBuffer &outbuf) = 0;
  58 };
  59
  60
  61 class WvSimpleAudioEncoder : public WvAudioEncoder
  62 {
  63 public:
  64
  65     WvSimpleAudioEncoder(unsigned int channels, unsigned int samplerate);
  66
  67     virtual unsigned int channels() const { return _channels; }
  68
  69     virtual size_t samplesperframe() const { return _samplesperframe; }
  70
  71 protected:
  72
  73     virtual bool _typedencode(IBuffer &inbuf, OBuffer &outbuf, bool flush);
  74
  75     virtual bool _typedfinish(OBuffer &outbuf);
  76
  77 private:
  78
  79     unsigned int _channels;
  80     size_t _samplesperframe;
  81 };
  82
  83
  84 class WvSimpleAudioDecoder : public WvAudioDecoder
  85 {
  86 public:
  87
  88     WvSimpleAudioDecoder(unsigned int channels, unsigned int samplerate);
  89
  90     virtual unsigned int channels() const { return _channels; }
  91
  92     virtual size_t samplesperframe() const { return _samplesperframe; }
  93
  94     virtual bool missing(OBuffer &outbuf) { return false; }
  95
  96 protected:
  97
  98     virtual bool _typedencode(IBuffer &inbuf, OBuffer &outbuf, bool flush);
  99
 100     virtual bool _typedfinish(OBuffer &outbuf);
 101
 102 private:
 103
 104     unsigned int _channels;
 105     size_t _samplesperframe;
 106 };
 107
 108
 109 #endif // __WVAUDIOENCODER_H