public bool open(string file)
{
#if DEBUG
sout.println("WaveReader#open; file=" + file);
#endif
if (m_opened)
{
m_stream.Close();
}
m_stream = new FileStream(file, FileMode.Open, FileAccess.Read);
// RIFF
byte[] buf = new byte[4];
m_stream.Read(buf, 0, 4);
if (buf[0] != 'R' || buf[1] != 'I' || buf[2] != 'F' || buf[3] != 'F')
{
m_stream.Close();
#if DEBUG
serr.println("WaveReader#open; header error(RIFF)");
#endif
return(false);
}
// ファイルサイズ - 8最後に記入
m_stream.Read(buf, 0, 4);
// WAVE
m_stream.Read(buf, 0, 4);
if (buf[0] != 'W' || buf[1] != 'A' || buf[2] != 'V' || buf[3] != 'E')
{
m_stream.Close();
#if DEBUG
serr.println("WaveReader#open; header error(WAVE)");
#endif
return(false);
}
// fmt
m_stream.Read(buf, 0, 4);
if (buf[0] != 'f' || buf[1] != 'm' || buf[2] != 't' || buf[3] != ' ')
{
m_stream.Close();
#if DEBUG
serr.println("WaveReader#open; header error(fmt )");
#endif
return(false);
}
// fmt チャンクのサイズ
m_stream.Read(buf, 0, 4);
int chunksize = (int)PortUtil.make_uint32_le(buf);
long fmt_chunk_end_location = m_stream.Position + chunksize;
// format ID
m_stream.Read(buf, 0, 2);
// チャンネル数
m_stream.Read(buf, 0, 2);
m_channel = buf[1] << 8 | buf[0];
#if DEBUG
sout.println("WaveReader#open; m_channel=" + m_channel);
#endif
// サンプリングレート
m_stream.Read(buf, 0, 4);
m_sample_per_sec = (int)PortUtil.make_uint32_le(buf);
#if DEBUG
sout.println("WaveReader#open; m_sample_per_sec=" + m_sample_per_sec);
#endif
// データ速度
m_stream.Read(buf, 0, 4);
// ブロックサイズ
m_stream.Read(buf, 0, 2);
// サンプルあたりのビット数
m_stream.Read(buf, 0, 2);
int bit_per_sample = buf[1] << 8 | buf[0];
m_byte_per_sample = bit_per_sample / 8;
#if DEBUG
sout.println("WaveReader#open; m_byte_per_sample=" + m_byte_per_sample);
#endif
// 拡張部分
m_stream.Seek(fmt_chunk_end_location, SeekOrigin.Begin);
//m_stream.Read( buf, 0, 2 );
// data
m_stream.Read(buf, 0, 4);
if (buf[0] != 'd' || buf[1] != 'a' || buf[2] != 't' || buf[3] != 'a')
{
m_stream.Close();
#if DEBUG
serr.println("WaveReader#open; header error (data)");
#endif
return(false);
}
// size of data chunk
m_stream.Read(buf, 0, 4);
int size = (int)PortUtil.make_uint32_le(buf);
m_total_samples = size / (m_channel * m_byte_per_sample);
#if DEBUG
sout.println("WaveReader#open; m_total_samples=" + m_total_samples + "; total sec=" + (m_total_samples / (double)m_sample_per_sec));
#endif
m_opened = true;
m_header_offset = (int)m_stream.Position;
return(true);
}