public void pull(double[] l, double[] r, int length)
{
lock (mSyncRoot) {
if (mConverter == null)
{
int rate = mRoot.getSampleRate();
mConverter = new WaveRateConverter(mReader, rate);
}
try {
mConverter.read(mPosition, length, l, r);
mPosition += length;
} catch (Exception ex) {
serr.println("FileWaveSender#pull; ex=" + ex);
Logger.write(typeof(FileWaveSender) + ".pull; ex=" + ex + "\n");
}
}
}
/// <summary>
/// 指定したファイルの指定した区間を追加で読み込みます
/// </summary>
/// <param name="file"></param>
/// <param name="sec_from"></param>
/// <param name="sec_to"></param>
public void reloadPartial(string file, double sec_from, double sec_to)
{
if (!System.IO.File.Exists(file))
{
return;
}
WaveRateConverter wr = null;
try {
wr = new WaveRateConverter(new WaveReader(file), mSampleRate);
int saFrom = (int)(sec_from * mSampleRate);
int saTo = (int)(sec_to * mSampleRate);
// バッファを確保
int buflen = 1024;
double[] left = new double[buflen];
double[] right = new double[buflen];
// まず、読み込んだ区間の最大振幅を調べる
int remain = saTo - saFrom;
int pos = saFrom;
double max = 0.0;
while (remain > 0)
{
int delta = remain > buflen ? buflen : remain;
wr.read(pos, delta, left, right);
for (int i = 0; i < delta; i++)
{
double d = Math.Abs((left[i] + right[i]) * 0.5);
max = d > max ? d : max;
}
remain -= delta;
pos += delta;
}
// バッファが足りなければ確保
int oldLength = mWave.Length;
if (oldLength < saTo)
{
Array.Resize(ref mWave, saTo);
saFrom = oldLength;
}
if (mMaxAmplitude < max)
{
// 既存の波形の最大振幅より、読み込み部分の最大波形が大きいようなら、
// 既存波形の縮小を行う
double ampall = 1.0 / max;
for (int i = 0; i < mWave.Length; i++)
{
double vold = mWave[i] / 127.0 * mMaxAmplitude;
double vnew = vold * ampall;
mWave[i] = (sbyte)(vnew * 127);
}
}
// 最大振幅の値を更新
mMaxAmplitude = (max > mMaxAmplitude) ? (float)max : mMaxAmplitude;
// 今度は波形を取得するために読み込む
double amp = (mMaxAmplitude > 0.0f) ? (1.0 / mMaxAmplitude) : 0.0;
remain = saTo - saFrom;
pos = saFrom;
while (remain > 0)
{
int delta = remain > buflen ? buflen : remain;
wr.read(pos, delta, left, right);
for (int i = 0; i < delta; i++)
{
double d = (left[i] + right[i]) * 0.5 * amp;
sbyte b = (sbyte)(d * 127);
mWave[pos + i] = b;
}
pos += delta;
remain -= delta;
}
left = null;
right = null;
// mActualMaxAmplitudeの値を更新
mActualMaxAmplitude = 0.0f;
for (int i = 0; i < mWave.Length; i++)
{
double d = Math.Abs(mWave[i] / 127.0 * mMaxAmplitude);
mActualMaxAmplitude = (d > mActualMaxAmplitude) ? (float)d : mActualMaxAmplitude;
}
} catch (Exception ex) {
serr.println("WaveDrawContext#reloadPartial; ex=" + ex);
} finally {
if (wr != null)
{
try {
wr.close();
} catch (Exception ex2) {
serr.println("WaveDrawContext#reloadPartial; ex2=" + ex2);
}
}
}
}
