utils/wxMMedia/sndpcm.cpp

   1 #ifdef __GNUG__
   2 #pragma implementation "sndpcm.h"
   3 #endif
   4 #include "sndsnd.h"
   5 #include "sndpcm.h"
   6 #include <dmalloc.h>
   7
   8 #define WX_BIG_ENDIAN 0
   9
  10 wxSoundPcmCodec::wxSoundPcmCodec()
  11   : wxSoundCodec()
  12 {
  13   m_orig_format.SetCodecCreate(FALSE);
  14   m_orig_format.SetCodecNo(1);
  15   m_char_bool = FALSE;
  16 }
  17
  18 wxSoundPcmCodec::~wxSoundPcmCodec()
  19 {
  20 }
  21
  22 size_t wxSoundPcmCodec::GetByteRate() const
  23 {
  24   return (m_orig_format.GetBps()/8)*
  25           m_orig_format.GetSampleRate()*
  26           m_orig_format.GetChannels();
  27 }
  28
  29 wxSoundDataFormat wxSoundPcmCodec::GetPreferredFormat(int codec) const
  30 {
  31   wxSoundDataFormat prefFormat;
  32
  33   prefFormat = m_orig_format;
  34   prefFormat.SetCodecNo(WXSOUND_PCM);
  35   return prefFormat;
  36 }
  37
  38 // ---------------------------------------------------------------------------
  39 // Main part of the decoder
  40 // ---------------------------------------------------------------------------
  41
  42 void wxSoundPcmCodec::Decode()
  43 {
  44   InitMode(DECODING);
  45   if (m_io_format == m_orig_format) {
  46     CopyToOutput();
  47     ExitMode();
  48     return;
  49   }
  50
  51   // Swap bytes
  52   switch (m_io_format.GetBps()) {
  53   case 8:
  54     InputSign8();
  55     break;
  56   case 16:
  57     InputSwapAndSign16();
  58     break;
  59   case 32:
  60   case 64:
  61   default:
  62     break;
  63   }
  64   ExitMode();
  65 }
  66
  67 // ---------------------------------------------------------------------------
  68 // Change the sign of a 8-bit sample.
  69
  70 #define GET() (m_in_sound->GetChar())
  71 #define PUT(c) (m_out_sound->PutChar(c))
  72 #define OUT_ERROR() (out->LastError() == wxStream_NOERROR)
  73 #define IN_ERROR() (in->LastError() == wxStream_NOERROR)
  74
  75 void wxSoundPcmCodec::InputSign8()
  76 {
  77   unsigned char signer = 0;
  78   wxStreamBase *in = m_out_sound->Stream(), *out = m_in_sound->Stream();
  79
  80   if (m_io_format.GetSign() != m_orig_format.GetSign())
  81     signer = 128;
  82
  83   while (IN_ERROR() && OUT_ERROR())
  84     PUT(GET() + signer);
  85
  86 }
  87
  88 // ---------------------------------------------------------------------------
  89 // Swap bytes and change the sign of a 16-bit sample.
  90
  91 void wxSoundPcmCodec::InputSwapAndSign16()
  92 {
  93   unsigned short signer1 = 0, signer2 = 0;
  94   wxStreamBase *in = m_out_sound->Stream(), *out = m_in_sound->Stream();
  95   bool swap = (m_io_format.GetByteOrder() != m_orig_format.GetByteOrder());
  96   char temp;
  97
  98   if (m_io_format.GetSign() != m_orig_format.GetSign()) {
  99     if (m_io_format.GetByteOrder() == wxSND_SAMPLE_LE)
 100       signer2 = 0x80;
 101     else
 102       signer1 = 0x80;
 103   }
 104
 105   if (swap) {
 106     while (IN_ERROR() && OUT_ERROR()) {
 107       temp = GET() ^ signer1;
 108       PUT(GET() ^ signer2);
 109       if (OUT_ERROR()) {
 110         m_char_bool = TRUE;
 111         m_char_stack = temp;
 112         break;
 113       }
 114       PUT(temp);
 115     }
 116   } else {
 117     while (IN_ERROR() && OUT_ERROR()) {
 118       PUT(GET() ^ signer1);
 119       if (OUT_ERROR()) {
 120         m_char_bool = TRUE;
 121         m_char_stack = temp;
 122         break;
 123       }
 124       PUT(GET() ^ signer2);
 125     }
 126   }
 127 }
 128
 129 // ---------------------------------------------------------------------------
 130 // Encoder part.
 131 // ---------------------------------------------------------------------------
 132
 133 void wxSoundPcmCodec::OutputSign8()
 134 {
 135   wxStreamBase *in = m_out_sound->Stream(), *out = m_in_sound->Stream();
 136   unsigned char signer = 0;
 137
 138   if (m_io_format.GetSign() != m_orig_format.GetSign())
 139     signer = 128;
 140
 141   while (IN_ERROR() && OUT_ERROR())
 142     PUT((char)(GET() + signer));
 143 }
 144
 145 // ---------------------------------------------------------------------------
 146
 147 void wxSoundPcmCodec::OutputSwapAndSign16()
 148 {
 149   bool swap = (m_io_format.GetByteOrder() != m_orig_format.GetByteOrder());
 150   unsigned short signer1 = 0, signer2 = 0;
 151   char temp;
 152   wxStreamBase *in = m_out_sound->Stream(), *out = m_in_sound->Stream();
 153
 154   if (m_char_bool) {
 155     PUT(GET());
 156     PUT(m_char_stack);
 157     m_char_bool = FALSE;
 158   }
 159
 160   if (m_io_format.GetSign() != m_orig_format.GetSign())
 161     if (m_io_format.GetByteOrder() == wxSND_SAMPLE_LE)
 162       signer1 = 0x80;
 163     else
 164       signer2 = 0x80;
 165
 166   if (swap) {
 167     while (IN_ERROR()) {
 168       temp = GET();
 169       PUT(GET() ^ signer1);
 170       if (OUT_ERROR()) {
 171         m_char_stack = temp ^ signer2;
 172         m_char_bool = TRUE;
 173         break;
 174       }
 175       PUT(temp ^ signer2);
 176     }
 177   } else {
 178     while (IN_ERROR()) {
 179       PUT(GET() ^ signer1);
 180       if (!OUT_ERROR()) {
 181         m_char_stack = GET() ^ signer2;
 182         m_char_bool = TRUE;
 183         break;
 184       }
 185       PUT(GET() ^ signer2);
 186     }
 187   }
 188
 189 }
 190
 191 // ---------------------------------------------------------------------------
 192
 193 void wxSoundPcmCodec::Encode()
 194 {
 195   InitMode(ENCODING);
 196   if (m_io_format == m_orig_format) {
 197     CopyToOutput();
 198     ExitMode();
 199     return;
 200   }
 201
 202   // Swap bytes
 203   switch (m_io_format.GetBps()) {
 204   case 8:
 205     OutputSign8();
 206     break;
 207   case 16:
 208     OutputSwapAndSign16();
 209     break;
 210   case 32:
 211   case 64:
 212   default:
 213     break;
 214   }
 215   ExitMode();
 216 }