utils/wxMMedia/sndmulaw.cpp

   1 ////////////////////////////////////////////////////////////////////////////////
   2 // Name:       sndmulaw.cpp
   3 // Purpose:    wxMMedia
   4 // Author:     Guilhem Lavaux
   5 // Created:    1997
   6 // Updated:    December 1998
   7 // Copyright:  (C) 1997, 1998, Guilhem Lavaux
   8 // License:    wxWindows license
   9 ////////////////////////////////////////////////////////////////////////////////
  10 #ifdef __GNUG__
  11 #pragma implementation "sndmulaw.h"
  12 #endif
  13
  14 #include "sndsnd.h"
  15 #include "sndfrmt.h"
  16 #include "sndmulaw.h"
  17 #include "adpcm/g72x.h"
  18
  19 wxSoundMulawCodec::wxSoundMulawCodec()
  20   : wxSoundCodec()
  21 {
  22 }
  23
  24 wxSoundMulawCodec::~wxSoundMulawCodec()
  25 {
  26 }
  27
  28 void wxSoundMulawCodec::Decode()
  29 {
  30   int smp;
  31   wxSoundDataFormat pref_frmt;
  32
  33   pref_frmt = GetPreferredFormat(0);
  34   if (m_io_format != pref_frmt)
  35     ChainCodecAfter(pref_frmt);
  36
  37   InitMode(DECODING);
  38
  39   while (!StreamOk()) {
  40       smp = ulaw2linear(m_in_sound->GetChar());
  41 #ifdef USE_BE_MACH
  42       m_out_sound->PutChar((smp & 0xff00) >> 8);
  43       m_out_sound->PutChar(smp & 0xff);
  44 #else
  45       m_out_sound->PutChar(smp & 0xff);
  46       m_out_sound->PutChar((smp & 0xff00) >> 8);
  47 #endif
  48   }
  49 }
  50
  51 void wxSoundMulawCodec::Encode()
  52 {
  53   int smp;
  54   wxSoundDataFormat pref_frmt;
  55
  56   pref_frmt = GetPreferredFormat(0);
  57   if (m_io_format != pref_frmt)
  58     ChainCodecBefore(pref_frmt);
  59
  60   InitMode(ENCODING);
  61
  62   while (!StreamOk()) {
  63 #ifdef USE_BE_MACH
  64       smp = ((unsigned short)m_in_sound->GetChar()) << 8;
  65       smp |= m_in_sound->GetChar() & 0xff;
  66 #else
  67       smp = m_in_sound->GetChar() & 0xff;
  68       smp |= ((unsigned short)m_in_sound->GetChar()) << 8;
  69 #endif
  70       m_out_sound->PutChar(linear2ulaw(smp));
  71   }
  72 }
  73
  74 size_t wxSoundMulawCodec::GetByteRate() const
  75 {
  76   return m_srate;
  77 }
  78
  79 wxSoundDataFormat wxSoundMulawCodec::GetPreferredFormat(int WXUNUSED(no)) const
  80 {
  81   wxSoundDataFormat format;
  82
  83   format.SetCodecNo(WXSOUND_PCM);
  84   format.SetSampleRate(m_srate);
  85   format.SetBps(16);
  86   format.SetChannels(1);
  87   format.SetSign(wxSND_SAMPLE_SIGNED);
  88 #ifdef USE_BE_MACH
  89   format.SetByteOrder(wxSND_SAMPLE_BE);
  90 #else
  91   format.SetByteOrder(wxSND_SAMPLE_LE);
  92 #endif
  93   return format;
  94 }