utils/wxMMedia/sndpcm.cpp

   1 #ifdef __GNUG__
   2 #pragma implementation "sndpcm.h"
   3 #endif
   4 #include "sndsnd.h"
   5 #include "sndpcm.h"
   6
   7 #define WX_BIG_ENDIAN 0
   8
   9 wxSoundPcmCodec::wxSoundPcmCodec()
  10   : wxSoundCodec()
  11 {
  12   m_orig_format.SetCodecCreate(FALSE);
  13   m_orig_format.SetCodecNo(WXSOUND_PCM);
  14 }
  15
  16 wxSoundPcmCodec::~wxSoundPcmCodec()
  17 {
  18 }
  19
  20 size_t wxSoundPcmCodec::GetByteRate() const
  21 {
  22   return (m_orig_format.GetBps()/8)*
  23           m_orig_format.GetSampleRate()*
  24           m_orig_format.GetChannels();
  25 }
  26
  27 wxSoundDataFormat wxSoundPcmCodec::GetPreferredFormat(int codec) const
  28 {
  29   wxSoundDataFormat prefFormat;
  30
  31   prefFormat = m_orig_format;
  32   return prefFormat;
  33 }
  34
  35 // ---------------------------------------------------------------------------
  36 // Main part of the decoder
  37 // ---------------------------------------------------------------------------
  38
  39 void wxSoundPcmCodec::Decode()
  40 {
  41   InitMode(DECODING);
  42   if (m_io_format == m_orig_format) {
  43     CopyToOutput();
  44     ExitMode();
  45     return;
  46   }
  47
  48   // Swap bytes
  49   switch (m_io_format.GetBps()) {
  50   case 8:
  51     InputSign8();
  52     break;
  53   case 16:
  54     InputSwapAndSign16();
  55     break;
  56   case 32:
  57   case 64:
  58   default:
  59     break;
  60   }
  61   ExitMode();
  62 }
  63
  64 // ---------------------------------------------------------------------------
  65 // Change the sign of a 8-bit sample.
  66
  67 #define GET() (m_in_sound->GetChar())
  68 #define PUT(c) (m_out_sound->PutChar(c))
  69
  70 void wxSoundPcmCodec::InputSign8()
  71 {
  72   unsigned char signer = 0;
  73
  74   if (m_io_format.GetSign() != m_orig_format.GetSign())
  75     signer = 128;
  76
  77   while (StreamOk())
  78     PUT(GET() + signer);
  79 }
  80
  81 // ---------------------------------------------------------------------------
  82 // Swap bytes and change the sign of a 16-bit sample.
  83
  84 void wxSoundPcmCodec::InputSwapAndSign16()
  85 {
  86   unsigned short signer1 = 0, signer2 = 0;
  87   bool swap = (m_io_format.GetByteOrder() != m_orig_format.GetByteOrder());
  88   register char temp, temp2;
  89
  90   if (m_io_format.GetSign() != m_orig_format.GetSign()) {
  91     if (m_io_format.GetByteOrder() == wxSND_SAMPLE_LE)
  92       signer2 = 0x80;
  93     else
  94       signer1 = 0x80;
  95   }
  96
  97   if (swap) {
  98     while (StreamOk()) {
  99       temp = GET();
 100       temp2 = GET();
 101       PUT(temp2 ^ signer2);
 102       if (!StreamOk()) {
 103         m_in_sound->WriteBack(temp);
 104         m_in_sound->WriteBack(temp2);
 105         break;
 106       }
 107       PUT(temp ^ signer1);
 108     }
 109   } else {
 110     while (StreamOk()) {
 111       temp = GET();
 112       PUT(temp ^ signer1);
 113       if (!StreamOk()) {
 114         m_in_sound->WriteBack(temp);
 115         break;
 116       }
 117       PUT(GET() ^ signer2);
 118     }
 119   }
 120 }
 121
 122 // ---------------------------------------------------------------------------
 123 // Encoder part.
 124 // ---------------------------------------------------------------------------
 125
 126 void wxSoundPcmCodec::OutputSign8()
 127 {
 128   unsigned char signer = 0;
 129
 130   if (m_io_format.GetSign() != m_orig_format.GetSign())
 131     signer = 128;
 132
 133   while (StreamOk())
 134     PUT((char)(GET() + signer));
 135 }
 136
 137 // ---------------------------------------------------------------------------
 138
 139 void wxSoundPcmCodec::OutputSwapAndSign16()
 140 {
 141   bool swap = (m_io_format.GetByteOrder() != m_orig_format.GetByteOrder());
 142   unsigned short signer1 = 0, signer2 = 0;
 143   register char temp, temp2;
 144
 145   if (m_io_format.GetSign() != m_orig_format.GetSign())
 146     if (m_io_format.GetByteOrder() == wxSND_SAMPLE_LE)
 147       signer1 = 0x80;
 148     else
 149       signer2 = 0x80;
 150
 151   if (swap) {
 152     while (StreamOk()) {
 153       temp = GET();
 154       temp2 = GET();
 155       PUT(temp2 ^ signer1);
 156       if (!StreamOk()) {
 157         m_in_sound->WriteBack(temp);
 158         m_in_sound->WriteBack(temp2);
 159         break;
 160       }
 161       PUT(temp ^ signer2);
 162     }
 163   } else {
 164     while (StreamOk()) {
 165       temp = GET();
 166       temp2 = GET();
 167       PUT(temp ^ signer1);
 168       if (!StreamOk()) {
 169         m_in_sound->WriteBack(temp);
 170         break;
 171       }
 172       PUT(temp2 ^ signer2);
 173     }
 174   }
 175
 176 }
 177
 178 // ---------------------------------------------------------------------------
 179
 180 void wxSoundPcmCodec::Encode()
 181 {
 182   InitMode(ENCODING);
 183   if (m_io_format == m_orig_format) {
 184     CopyToOutput();
 185     ExitMode();
 186     return;
 187   }
 188
 189   // Swap bytes
 190   switch (m_io_format.GetBps()) {
 191   case 8:
 192     OutputSign8();
 193     break;
 194   case 16:
 195     OutputSwapAndSign16();
 196     break;
 197   case 32:
 198   case 64:
 199   default:
 200     break;
 201   }
 202   ExitMode();
 203 }