public WWFilterCpp CreateIIRFilterCpp(int osr, int decimation)
{
var fg = mIIRFilterDesign.CreateIIRFilterGraph();
var fgSerial = fg as IIRFilterSerial;
var fgParallel = fg as IIRFilterParallel;
var r = new WWFilterCpp();
if (fgSerial != null)
{
r.BuildIIRSerial(fg.BlockCount());
}
else
{
r.BuildIIRParallel(fg.BlockCount());
}
for (int i = 0; i < fg.BlockCount(); ++i)
{
var block = fg.GetNthBlock(i);
var a = block.A();
var b = block.B();
r.AddIIRBlock(a.Length, a, b.Length, b);
}
r.SetParam(osr, decimation);
return(r);
}
/// <summary>
/// mLoopFiltersを設計する。
/// </summary>
/// <param name="order">フィルターの次数(3,5,7)。</param>
/// <param name="numChannels">音声のチャンネル数。</param>
public void Design(int order, int numChannels)
{
mCh = numChannels;
var ntfHz = new NTFHzcoeffs(order);
// フィードバック係数g。Hzの分子の零(単位円上)のz=1からの角度 ω → g = 2 - 2cos(ω)
var g = new double[order / 2];
for (int i = 0; i < g.Length; ++i)
{
// Hzの分子の零の位置r。
var r = ntfHz.ZeroNth(i);
var cosω = r.real;
g[i] = 2.0 - 2.0 * cosω;
}
var d = new double[order + 1];
for (int i = 0; i < d.Length; ++i)
{
d[i] = ntfHz.D(i);
}
// CRFB構造のノイズシェイピングフィルターの係数a[]。
// R. Schreier and G. Temes, ΔΣ型アナログ/デジタル変換器入門,丸善,2007, pp.95,96
var a = new double[order];
switch (order)
{
case 2:
a[0] = d[0] + d[1] - g[0] + 1;
a[1] = 1 - d[0];
break;
case 3:
a[0] = 1 + d[0] + d[1] + d[2];
a[1] = 2 - d[0] + d[2] - g[0];
a[2] = 1 + d[0];
break;
case 4:
a[0] = 1 + d[0] + d[1] + d[2] + d[3] - 3 * g[0] - d[0] * g[0] - d[3] * g[0] + g[0] * g[0];
a[1] = 2 - 2 * d[0] - d[1] + d[3] - g[0] + d[0] * g[0];
a[2] = 3 + d[0] + d[3] - g[0] - g[1];
a[3] = 1 - d[0];
break;
case 5:
a[0] = 1 + d[0] + d[1] + d[2] + d[3] + d[4];
a[1] = 3 - 2 * d[0] - d[1] + d[3] + 2 * d[4] - 4 * g[0] + d[0] * g[0] - d[4] * g[0] + g[0] * g[0];
a[2] = 3 + 3 * d[0] + d[1] + d[4] - g[0] - d[0] * g[0];
a[3] = 4 - d[0] + d[4] - g[0] - g[1];
a[4] = 1 + d[0];
break;
case 6:
a[0] = 1 + d[0] + d[1] + d[2] + d[3] + d[4] + d[5] - 6 * g[0] - 3 * d[0] * g[0] - d[1] * g[0] - d[4] * g[0] - 3 * d[5] * g[0] + 5 * g[0] * g[0] + d[0] * g[0] * g[0] + d[5] * g[0] * g[0] - g[0] * g[0] * g[0];
a[1] = 3 - 3 * d[0] - 2 * d[1] - d[2] + d[4] + 2 * d[5] - 4 * g[0] + 4 * d[0] * g[0] + d[1] * g[0] - d[5] * g[0] + g[0] * g[0] - d[0] * g[0] * g[0];
a[2] = 6 + 3 * d[0] + d[1] + d[4] + 3 * d[5] - 5 * g[0] - d[0] * g[0] - d[5] * g[0] + g[0] * g[0] - 5 * g[1] - d[0] * g[1] - d[5] * g[1] + g[0] * g[1] + g[1] * g[1];
a[3] = 4 - 4 * d[0] - d[1] + d[5] - g[0] + d[0] * g[0] - g[1] + d[0] * g[1];
a[4] = 5 + d[0] + d[5] - g[0] - g[1] - g[2];
a[5] = 1 - d[0];
break;
case 7:
a[0] = 1 + d[0] + d[1] + d[2] + d[3] + d[4] + d[5] + d[6];
a[1] = 4 - 3 * d[0] - 2 * d[1] - d[2] + d[4] + 2 * d[5] + 3 * d[6] - 10 * g[0] + 4 * d[0] * g[0] + d[1] * g[0] - d[5] * g[0] - 4 * d[6] * g[0] + 6 * g[0] * g[0] - d[0] * g[0] * g[0] + d[6] * g[0] * g[0] - g[0] * g[0] * g[0];
a[2] = 6 + 6 * d[0] + 3 * d[1] + d[2] + d[5] + 3 * d[6] - 5 * g[0] - 5 * d[0] * g[0] - d[1] * g[0] - d[6] * g[0] + g[0] * g[0] + d[0] * g[0] * g[0];
a[3] = 10 - 4 * d[0] - d[1] + d[5] + 4 * d[6] - 6 * g[0] + d[0] * g[0] - d[6] * g[0] + g[0] * g[0] - 6 * g[1] + d[0] * g[1] - d[6] * g[1] + g[0] * g[1] + g[1] * g[1];
a[4] = 5 + 5 * d[0] + d[1] + d[6] - g[0] - d[0] * g[0] - g[1] - d[0] * g[1];
a[5] = 6 - d[0] + d[6] - g[0] - g[1] - g[2];
a[6] = 1 + d[0];
break;
default:
throw new NotImplementedException();
}
// CRFBでSTF==1になるようなb[]の係数。
var b = new double[order + 1];
for (int i = 0; i < order; ++i)
{
b[i] = a[i];
}
b[order] = 1.0;
/*
* Console.Write("double [] g = {");
* for (int i = 0; i < g.Length; ++i) {
* Console.Write("{0:R}, ", g[i]);
* }
* Console.WriteLine("};");
*
* Console.Write("double [] a = {");
* for (int i = 0; i < a.Length; ++i) {
* Console.Write("{0:R}, ", a[i]);
* }
* Console.WriteLine("};");
*
* Console.Write("double [] b = {");
* for (int i = 0; i < b.Length; ++i) {
* Console.Write("{0:R}, ", b[i]);
* }
* Console.WriteLine("};");
*
* Console.Write("double [] n = {");
* for (int i = 0; i < order+1; ++i) {
* Console.Write("{0:R}, ", ntfHz.N(i));
* }
* Console.WriteLine("};");
*
* Console.Write("double [] d = {");
* for (int i = 0; i < d.Length; ++i) {
* Console.Write("{0:R}, ", d[i]);
* }
* Console.WriteLine("};");
*/
#if USE_CPP
mLoopFiltersCpp = new WWFilterCpp[numChannels];
for (int ch = 0; ch < numChannels; ++ch)
{
var p = new WWFilterCpp();
p.BuildCrfb(order, a, b, g, 0.5);
mLoopFiltersCpp[ch] = p;
}
#else
mLoopFilters = new LoopFilterCRFB[numChannels];
for (int ch = 0; ch < numChannels; ++ch)
{
mLoopFilters[ch] = new LoopFilterCRFB(a, b, g);
}
#endif
}
public BWCompletedParam DoWork(BWStartParams param, ProgressReportDelegate ReportProgress)
{
int rv = 0;
var flacR = new WWFlacRWCS.FlacRW();
do
{
// FLACファイルからメタデータ、画像、音声を取り出す。
WWFlacRWCS.Metadata metaR;
rv = flacR.DecodeAll(param.inputFile);
if (rv < 0)
{
// do-whileを抜けたところでflacR.DecodeEndする。
break;
}
flacR.GetDecodedMetadata(out metaR);
byte[] picture = null;
if (0 < metaR.pictureBytes)
{
rv = flacR.GetDecodedPicture(out picture, metaR.pictureBytes);
if (rv < 0)
{
// do-whileを抜けたところでflacR.DecodeEndする。
break;
}
}
// flacRはまだ使用するのでここではDecodeEndしない。
long lcm = WWMath.Functions.LCM(metaR.sampleRate, param.targetSampleRate);
int upsampleScale = (int)(lcm / metaR.sampleRate);
int downsampleScale = (int)(lcm / param.targetSampleRate);
// IIRフィルターを設計。
// ストップバンド最小周波数fs。
double fs = metaR.sampleRate / 2 * STOPBAND_FREQ_RATIO;
if (param.targetSampleRate / 2 * STOPBAND_FREQ_RATIO < fs)
{
fs = param.targetSampleRate / 2 * STOPBAND_FREQ_RATIO;
}
// カットオフ周波数fc。
double fc = CUTOFF_STOPBAND_RATIO * fs;
mIIRFilterDesign = new IIRFilterDesign();
mIIRFilterDesign.Design(fc, fs, lcm, param.method);
ReportProgress(CONVERT_START_PERCENT, new BWProgressParam(State.FilterDesigned,
string.Format("Read FLAC completed.\nSource sample rate = {0}kHz.\nTarget sample rate = {1}kHz. ratio={2}/{3}\n",
metaR.sampleRate / 1000.0, param.targetSampleRate / 1000.0,
lcm / metaR.sampleRate, lcm / param.targetSampleRate)));
double RESAMPLE_RATIO = param.targetSampleRate / metaR.sampleRate;
mSw.Restart();
// 書き込み準備。
WWFlacRWCS.Metadata metaW = new WWFlacRWCS.Metadata(metaR);
metaW.sampleRate = param.targetSampleRate;
metaW.pictureBytes = metaR.pictureBytes;
metaW.bitsPerSample = 24;
metaW.totalSamples = metaR.totalSamples * upsampleScale / downsampleScale;
if (param.isTargetPcm)
{
mFlacWrite = new FlacWrite();
mFlacWrite.Setup(metaW, picture);
}
else
{
mDsfWrite = new DsfWrite();
mDsfWrite.Setup(metaW, picture);
}
var stat = new SampleValueStatistics();
long totalSamplesOfAllChannels = metaR.totalSamples * metaR.channels;
long processedSamples = 0;
// Mathematica用の設定。
WWComplex.imaginaryUnit = "I";
// 変換する
for (int ch = 0; ch < metaR.channels; ++ch)
{
//Parallel.For(0, metaR.channels, (int ch) => {
var pcmW = new WWUtil.LargeArray <byte>(metaW.totalSamples * metaW.BytesPerSample);
#if USE_ZOH_UPSAMPLE
// 零次ホールドのハイ落ち補償フィルター。
# if USE_CPP
var zohCompensation = new WWFilterCpp();
zohCompensation.BuildZohCompensation();
# else
var zohCompensation = new WWIIRFilterDesign.ZohNosdacCompensation(33);
# endif