utils/wxMMedia/sndadpcm.cpp

   1 #ifdef __GNUG__
   2 #pragma implementation "sndmulaw.h"
   3 #endif
   4
   5 #include "sndsnd.h"
   6 #include "sndfrmt.h"
   7 #include "sndadpcm.h"
   8 #include "adpcm/g72x.h"
   9
  10 wxSoundAdpcmCodec::wxSoundAdpcmCodec()
  11   : wxSoundCodec()
  12 {
  13   // TODO: For the moment, only 1 channel is supported.
  14   m_codec_state = new g72x_state;
  15   g72x_init_state(m_codec_state);
  16 }
  17
  18 wxSoundAdpcmCodec::~wxSoundAdpcmCodec()
  19 {
  20 }
  21
  22 void wxSoundAdpcmCodec::InitWith(const wxSoundDataFormat& format)
  23 {
  24   m_srate = format.GetSampleRate();
  25 }
  26
  27 int wxSoundAdpcmCodec::GetBits(int nbits)
  28 {
  29   unsigned int mask;
  30   int bits;
  31
  32   if (m_bits_waiting == 0)
  33     m_current_byte = m_in_sound->GetChar();
  34
  35   mask = (1 << nbits) - 1;
  36   bits = m_current_byte & mask;
  37   m_current_byte >>= nbits;
  38   m_bits_waiting -= nbits;
  39   return bits;
  40 }
  41
  42 void wxSoundAdpcmCodec::Decode()
  43 {
  44   int smp, bits;
  45   wxSoundDataFormat pref_frmt;
  46
  47   pref_frmt = GetPreferredFormat(0);
  48   if (!(m_io_format == pref_frmt))
  49     ChainCodecAfter(pref_frmt);
  50
  51   bits = GetBits(4);
  52   if (m_io_format.GetByteOrder() == wxSND_SAMPLE_LE) {
  53     while (!StreamOk()) {
  54       smp = g721_decoder(bits, AUDIO_ENCODING_LINEAR, m_codec_state);
  55       m_out_sound->PutChar(smp & 0x00ff);
  56       m_out_sound->PutChar((smp & 0xff00) >> 8);
  57       bits = GetBits(4);
  58     }
  59   } else {
  60     while (!StreamOk()) {
  61       smp = g721_decoder(bits, AUDIO_ENCODING_LINEAR, m_codec_state);
  62       m_out_sound->PutChar((smp & 0xff00) >> 8);
  63       m_out_sound->PutChar(smp & 0x00ff);
  64       bits = GetBits(4);
  65     }
  66   }
  67 }
  68
  69 void wxSoundAdpcmCodec::Encode()
  70 {
  71 /*
  72   int smp;
  73   wxSoundDataFormat pref_frmt;
  74
  75   pref_frmt = GetPreferredFormat(0);
  76   if (!(m_io_format == pref_frmt))
  77     ChainCodecAfter(pref_frmt);
  78
  79   bits = GetBits(4);
  80   if (m_io_format.GetByteOrder() == wxSND_SAMPLE_LE) {
  81     while (!StreamOk()) {
  82       smp = g721_decoder(bits, AUDIO_ENCODING_LINEAR, codec_state);
  83       m_out_sound->PutChar(smp & 0x00ff);
  84       m_out_sound->PutChar((smp & 0xff00) >> 8);
  85       bits = GetBits(4);
  86     }
  87   } else {
  88     while (!StreamOk()) {
  89       smp = g721_decoder(bits, AUDIO_ENCODING_LINEAR, codec_state);
  90       m_out_sound->PutChar((smp & 0xff00) >> 8);
  91       m_out_sound->PutChar(smp & 0x00ff);
  92       bits = GetBits(4);
  93     }
  94   }
  95 */
  96 }
  97
  98 size_t wxSoundAdpcmCodec::GetByteRate() const
  99 {
 100   return (m_io_format.GetSampleRate() * m_io_format.GetChannels()) / 2;
 101 }
 102
 103 wxSoundDataFormat wxSoundAdpcmCodec::GetPreferredFormat(int WXUNUSED(no)) const
 104 {
 105   wxSoundDataFormat format;
 106
 107   format.SetCodecNo(WXSOUND_PCM);
 108   format.SetSampleRate(m_srate);
 109   format.SetBps(16);
 110   format.SetChannels(1);
 111   format.SetSign(wxSND_SAMPLE_SIGNED);
 112 #ifdef USE_BE_MACH
 113   format.SetByteOrder(wxSND_SAMPLE_BE);
 114 #else
 115   format.SetByteOrder(wxSND_SAMPLE_LE);
 116 #endif
 117   return format;
 118 }