public void append(double[] left, double[] right, int length)
{
while (RateConvertContext.convert(mContext, left, right, length))
{
mReceiver.append(mContext.bufferLeft, mContext.bufferRight, mContext.length);
}
}
/// <summary>
/// コンストラクタ．変換後のサンプリング周波数は，receiverのgetSampleRate()で自動的に取得される
/// </summary>
/// <param name="receiver">変換した波形を送る相手先</param>
/// <param name="sample_rate">変換前のサンプリング周波数</param>
public WaveRateConvertAdapter(IWaveReceiver receiver, int sample_rate)
{
mReceiver = receiver;
int rate_from = sample_rate;
int rate_to = receiver.getSampleRate();
try {
mContext = new RateConvertContext(rate_from, rate_to);
} catch (Exception ex) {
mContext = null; // m9(＠ｑ＠)
}
}
/// <summary>
/// 次にlengthサンプル分のデータを処理した時，結果として得られる変換データのサンプル数を計算します
/// </summary>
/// <param name="context"></param>
/// <param name="length"></param>
/// <returns></returns>
public static int estimateResultSamples(RateConvertContext context, int length)
{
if (context.aRate == context.bRate)
{
// 変換を行わなくてもいい場合
return(length);
}
else
{
// 変換しなくちゃならん
long astart = context.aEnd + 1;
long aend = calculateNextEnd(context, length);
return((int)(aend - astart + 1));
}
}
private static long calculateNextEnd(RateConvertContext context, int length)
{
double secStart = context.bCount * context.invBRate;
double secEnd = (context.bCount + length - 1) * context.invBRate;
// 送られてきたデータで、aStartからaEndまでのデータを作成できる
long next_astart = context.aEnd + 1;// (long)(context.secStart * context.aRate);
long next_aend = (long)(secEnd * context.aRate);
double tx = next_aend * context.invARate;
long btRequired = (long)(tx * context.bRate);
int tindx1 = (int)(btRequired - context.bCount) + 1;
if (tindx1 >= length)
{
next_aend--;
}
return(next_aend);
}
public static void run()
{
string dir = System.Windows.Forms.Application.StartupPath;
const int LEN = 100000;
const int BUFLEN = 1000;
// 元データのサンプルレート
int rate_from = 48000;
// 変換するサンプルレート
int rate_to = 44100;
// 何ヘルツの音のサイン波を作るか
const double hz = 440.0;
// 周期
double period = 1.0 / hz;
RateConvertContext c = new RateConvertContext(rate_from, rate_to);
double[] left = new double[BUFLEN];
double[] right = new double[BUFLEN];
int j = 0;
int total_s = 0;
int total_d = 0;
using (System.IO.StreamWriter sw_src = new System.IO.StreamWriter(System.IO.Path.Combine(dir, "TestRateConvertContext_src.txt")))
using (System.IO.StreamWriter sw_dst = new System.IO.StreamWriter(System.IO.Path.Combine(dir, "TestRateConvertContext_dst.txt"))) {
for (int i = 0; i < LEN; i++)
{
double x = i / (double)rate_from;
double y = Math.Sin(2.0 * Math.PI * x / period);
left[j] = y;
right[j] = y;
j++;
if (j >= BUFLEN)
{
// srcログに時系列データを書き込み
for (int k = 0; k < BUFLEN; k++)
{
double sx = total_s / (double)rate_from;
sw_src.WriteLine(sx + "\t" + left[k]);
total_s++;
}
while (RateConvertContext.convert(c, left, right, j))
{
for (int k = 0; k < c.length; k++)
{
double dx = total_d / (double)rate_to;
sw_dst.WriteLine(dx + "\t" + c.bufferRight[k]);
total_d++;
}
}
j = 0;
}
}
if (j > 0)
{
// srcログに時系列データを書き込み
for (int k = 0; k < BUFLEN; k++)
{
double sx = total_s / (double)rate_from;
sw_src.WriteLine(sx + "\t" + left[k]);
total_s++;
}
while (RateConvertContext.convert(c, left, right, j))
{
for (int k = 0; k < c.length; k++)
{
double dx = total_d / (double)rate_to;
sw_dst.WriteLine(dx + "\t" + c.bufferRight[k]);
total_d++;
}
}
}
}
}
/// <summary>
/// 変換を実行する．変換結果は，context.aBufSendLeft, aBufSendRightに格納される．
/// 変換後のデータの長さはaBufSendLengthに格納される．
/// 戻り値がfalseの場合，もう一度convertを呼ぶ必要はない．
/// 戻り値がtrueの場合，変換後のデータがaBufSendLeftなどに入りきらない場合なので，続けてもう一度convertを呼ばなくてはならない．
/// </summary>
/// <param name="context"></param>
/// <param name="left"></param>
/// <param name="right"></param>
/// <param name="length"></param>
public static bool convert(RateConvertContext context, double[] left, double[] right, int length)
{
if (context.mStatus == Status.COMPLETE)
{
context.length = 0;
context.mStatus = Status.NORMAL;
return(false);
}
// 変換前後で周波数が同じ，という指定の場合
if (context.aRate == context.bRate)
{
if (context.mStatus == Status.NORMAL)
{
context.a = context.aCount;
context.aStart = context.aCount;
context.aEnd = context.aCount + length;
}
int i = 0;
int offset = (int)(context.a - context.aStart);
for (; context.a < context.aEnd; context.a++)
{
context.bufferLeft[i] = left[i + offset];
context.bufferRight[i] = right[i + offset];
i++;
if (i >= BUFLEN)
{
context.length = BUFLEN;
context.mStatus = Status.CONTINUE;
return(true);
}
}
context.length = i;
context.aCount += length;
context.bCount += length;
context.mStatus = Status.COMPLETE;
return(true);
}
else
{
if (context.mStatus == Status.NORMAL)
{
// 送られてきたデータで、aStartからaEndまでのデータを作成できる
context.aStart = context.aEnd + 1;
context.aEnd = calculateNextEnd(context, length);//
context.a = context.aStart;
}
int i = 0;
for (; context.a <= context.aEnd; context.a++)
{
double x = context.a * context.invARate;
long bRequired = (long)(x * context.bRate);
double x0 = bRequired * context.invBRate;
double x1 = (bRequired + 1) * context.invBRate;
int indx0 = (int)(bRequired - context.bCount);
int indx1 = indx0 + 1;
// 左チャンネル
double y0 = 0.0;
if (0 <= indx0)
{
if (indx0 < length)
{
y0 = left[indx0];
}
}
else
{
int j = (int)(bRequired - context.bBufBase);
if (0 <= j && j < context.bBufLeft.Length)
{
y0 = context.bBufLeft[j];
}
}
double y1 = 0.0;
if (indx1 >= 0)
{
if (indx1 < length)
{
y1 = left[indx1];
}
}
else
{
int j = (int)(bRequired + 1 - context.bBufBase);
if (0 <= j && j < context.bBufLeft.Length)
{
y1 = context.bBufLeft[j];
}
}
double s = (y1 - y0) / (x1 - x0);
double y = y0 + s * (x - x0);
context.bufferLeft[i] = y;
// 右チャンネル
if (indx0 >= 0)
{
if (indx0 < length)
{
y0 = right[indx0];
}
}
else
{
int j = (int)(bRequired - context.bBufBase);
if (0 <= j && j < context.bBufRight.Length)
{
y0 = context.bBufRight[j];
}
}
if (indx1 >= 0)
{
if (indx1 < length)
{
y1 = right[indx1];
}
}
else
{
int j = (int)(bRequired + 1 - context.bBufBase);
if (0 <= j && j < context.bBufRight.Length)
{
y1 = context.bBufRight[j];
}
}
s = (y1 - y0) / (x1 - x0);
y = y0 + s * (x - x0);
context.bufferRight[i] = y;
// 事後処理
i++;
if (i >= BUFLEN)
{
// バッファがいっぱいだったら送信
context.length = BUFLEN;
context.mStatus = Status.CONTINUE;
context.a++;
return(true);
}
}
// 未送信のバッファがあれば送信
context.length = i;
// 次回に繰り越すデータを確保
// 次に送られてくるデータはbCount + length + 1から
long aNext = (long)((context.bCount + length + 1) * context.invBRate * context.aRate) + 1;
//long aNext = (long)((context.bCount + length + 1) * context.invBRate * context.aRate);
if (context.aEnd + 1 < aNext)
{
context.bBufBase = (long)((context.aEnd + 1) * context.invARate * context.bRate) - 2; // aEnd + 1番目のデータを作成するのに必要なデータ点のインデクス
int num = (int)(context.bCount + length - context.bBufBase);
if (num > 0)
{
if (context.bBufLeft == null)
{
context.bBufLeft = new double[num];
}
else if (context.bBufLeft.Length < num)
{
Array.Resize(ref context.bBufLeft, num);
}
if (context.bBufRight == null)
{
context.bBufRight = new double[num];
}
else if (context.bBufRight.Length < num)
{
Array.Resize(ref context.bBufRight, num);
}
for (int j = 0; j < num; j++)
{
int indx = (int)(context.bBufBase + j - context.bCount);
context.bBufLeft[j] = left[indx];
context.bBufRight[j] = right[indx];
}
}
}
context.bCount += length;
context.aCount = context.aEnd;
context.mStatus = Status.COMPLETE;
return(true);
}
}