/// <summary>
/// Decode the given input bits.
/// </summary>
/// <returns>1 if a terminator was found, 0 if not.</returns>
public virtual int Decode(Bits bits, float[] xout)
{
int i, sub, wideband, ret;
float[] low_pi_gain, low_exc, low_innov;
/* Decode the low-band */
ret = lowdec.Decode(bits, x0d);
if (ret != 0)
{
return(ret);
}
bool dtx = lowdec.Dtx;
if (bits == null)
{
DecodeLost(xout, dtx);
return(0);
}
/* Check "wideband bit" */
wideband = bits.Peek();
if (wideband != 0)
{
/* Regular wideband frame, read the submode */
wideband = bits.Unpack(1);
submodeID = bits.Unpack(3);
}
else
{
/* was a narrowband frame, set "null submode" */
submodeID = 0;
}
for (i = 0; i < frameSize; i++)
{
excBuf[i] = 0;
}
/* If null mode (no transmission), just set a couple things to zero */
if (submodes[submodeID] == null)
{
if (dtx)
{
DecodeLost(xout, true);
return(0);
}
for (i = 0; i < frameSize; i++)
{
excBuf[i] = NSpeex.NbCodec.VERY_SMALL;
}
first = 1;
/* Final signal synthesis from excitation */
NSpeex.Filters.Iir_mem2(excBuf, excIdx, interp_qlpc, high, 0,
frameSize, lpcSize, mem_sp);
filters.Fir_mem_up(x0d, NSpeex.Codebook_Constants.h0, y0,
fullFrameSize, NSpeex.SbCodec.QMF_ORDER, g0_mem);
filters.Fir_mem_up(high, NSpeex.Codebook_Constants.h1, y1,
fullFrameSize, NSpeex.SbCodec.QMF_ORDER, g1_mem);
for (i = 0; i < fullFrameSize; i++)
{
xout[i] = 2 * (y0[i] - y1[i]);
}
return(0);
}
low_pi_gain = lowdec.PiGain;
low_exc = lowdec.Exc;
low_innov = lowdec.Innov;
submodes[submodeID].LsqQuant.Unquant(qlsp, lpcSize, bits);
if (first != 0)
{
for (i = 0; i < lpcSize; i++)
{
old_qlsp[i] = qlsp[i];
}
}
for (sub = 0; sub < nbSubframes; sub++)
{
float tmp, filter_ratio, el = 0.0f, rl = 0.0f, rh = 0.0f;
int subIdx = subframeSize * sub;
/* LSP interpolation */
tmp = (1.0f + sub) / nbSubframes;
for (i = 0; i < lpcSize; i++)
{
interp_qlsp[i] = (1 - tmp) * old_qlsp[i] + tmp * qlsp[i];
}
NSpeex.Lsp.Enforce_margin(interp_qlsp, lpcSize, .05f);
/* LSPs to x-domain */
for (i = 0; i < lpcSize; i++)
{
interp_qlsp[i] = (float)System.Math.Cos(interp_qlsp[i]);
}
/* LSP to LPC */
m_lsp.Lsp2lpc(interp_qlsp, interp_qlpc, lpcSize);
if (enhanced)
{
float k1, k2, k3;
k1 = submodes[submodeID].LpcEnhK1;
k2 = submodes[submodeID].LpcEnhK2;
k3 = k1 - k2;
NSpeex.Filters.Bw_lpc(k1, interp_qlpc, awk1, lpcSize);
NSpeex.Filters.Bw_lpc(k2, interp_qlpc, awk2, lpcSize);
NSpeex.Filters.Bw_lpc(k3, interp_qlpc, awk3, lpcSize);
}
/*
* Calculate reponse ratio between low & high filter in band middle
* (4000 Hz)
*/
tmp = 1;
pi_gain[sub] = 0;
for (i = 0; i <= lpcSize; i++)
{
rh += tmp * interp_qlpc[i];
tmp = -tmp;
pi_gain[sub] += interp_qlpc[i];
}
rl = low_pi_gain[sub];
rl = 1 / (Math.Abs(rl) + .01f);
rh = 1 / (Math.Abs(rh) + .01f);
filter_ratio = Math.Abs(.01f + rh)
/ (.01f + Math.Abs(rl));
/* reset excitation buffer */
for (i = subIdx; i < subIdx + subframeSize; i++)
{
excBuf[i] = 0;
}
if (submodes[submodeID].Innovation == null)
{
float g;
int quant;
quant = bits.Unpack(5);
g = (float)Math.Exp(((double)quant - 10) / 8.0d);
g /= filter_ratio;
/* High-band excitation using the low-band excitation and a gain */
for (i = subIdx; i < subIdx + subframeSize; i++)
{
excBuf[i] = foldingGain * g * low_innov[i];
}
}
else
{
float gc, scale;
int qgc = bits.Unpack(4);
for (i = subIdx; i < subIdx + subframeSize; i++)
{
el += low_exc[i] * low_exc[i];
}
gc = (float)Math.Exp((1 / 3.7f) * qgc - 2);
scale = gc * (float)Math.Sqrt(1 + el) / filter_ratio;
submodes[submodeID].Innovation.Unquantify(excBuf, subIdx,
subframeSize, bits);
for (i = subIdx; i < subIdx + subframeSize; i++)
{
excBuf[i] *= scale;
}
if (submodes[submodeID].DoubleCodebook != 0)
{
for (i = 0; i < subframeSize; i++)
{
innov2[i] = 0;
}
submodes[submodeID].Innovation.Unquantify(innov2, 0,
subframeSize, bits);
for (i = 0; i < subframeSize; i++)
{
innov2[i] *= scale * (1 / 2.5f);
}
for (i = 0; i < subframeSize; i++)
{
excBuf[subIdx + i] += innov2[i];
}
}
}
for (i = subIdx; i < subIdx + subframeSize; i++)
{
high[i] = excBuf[i];
}
if (enhanced)
{
/* Use enhanced LPC filter */
NSpeex.Filters.Filter_mem2(high, subIdx, awk2, awk1,
subframeSize, lpcSize, mem_sp, lpcSize);
NSpeex.Filters.Filter_mem2(high, subIdx, awk3, interp_qlpc,
subframeSize, lpcSize, mem_sp, 0);
}
else
{
/* Use regular filter */
for (i = 0; i < lpcSize; i++)
{
mem_sp[lpcSize + i] = 0;
}
NSpeex.Filters.Iir_mem2(high, subIdx, interp_qlpc, high, subIdx,
subframeSize, lpcSize, mem_sp);
}
}
filters.Fir_mem_up(x0d, NSpeex.Codebook_Constants.h0, y0, fullFrameSize,
NSpeex.SbCodec.QMF_ORDER, g0_mem);
filters.Fir_mem_up(high, NSpeex.Codebook_Constants.h1, y1,
fullFrameSize, NSpeex.SbCodec.QMF_ORDER, g1_mem);
for (i = 0; i < fullFrameSize; i++)
{
xout[i] = 2 * (y0[i] - y1[i]);
}
for (i = 0; i < lpcSize; i++)
{
old_qlsp[i] = qlsp[i];
}
first = 0;
return(0);
}
public virtual int Decode(Bits bits, float[] xout)
{
int num = this.lowdec.Decode(bits, this.x0d);
if (num != 0)
{
return(num);
}
bool dtx = this.lowdec.Dtx;
if (bits == null)
{
this.DecodeLost(xout, dtx);
return(0);
}
int num2 = bits.Peek();
if (num2 != 0)
{
num2 = bits.Unpack(1);
this.submodeID = bits.Unpack(3);
}
else
{
this.submodeID = 0;
}
for (int i = 0; i < this.frameSize; i++)
{
this.excBuf[i] = 0f;
}
if (this.submodes[this.submodeID] != null)
{
float[] piGain = this.lowdec.PiGain;
float[] exc = this.lowdec.Exc;
float[] innov = this.lowdec.Innov;
this.submodes[this.submodeID].LsqQuant.Unquant(this.qlsp, this.lpcSize, bits);
if (this.first != 0)
{
for (int i = 0; i < this.lpcSize; i++)
{
this.old_qlsp[i] = this.qlsp[i];
}
}
for (int j = 0; j < this.nbSubframes; j++)
{
float num3 = 0f;
float num4 = 0f;
int num5 = this.subframeSize * j;
float num6 = (1f + (float)j) / (float)this.nbSubframes;
for (int i = 0; i < this.lpcSize; i++)
{
this.interp_qlsp[i] = (1f - num6) * this.old_qlsp[i] + num6 * this.qlsp[i];
}
Lsp.Enforce_margin(this.interp_qlsp, this.lpcSize, 0.05f);
for (int i = 0; i < this.lpcSize; i++)
{
this.interp_qlsp[i] = (float)Math.Cos((double)this.interp_qlsp[i]);
}
this.m_lsp.Lsp2lpc(this.interp_qlsp, this.interp_qlpc, this.lpcSize);
if (this.enhanced)
{
float lpcEnhK = this.submodes[this.submodeID].LpcEnhK1;
float lpcEnhK2 = this.submodes[this.submodeID].LpcEnhK2;
float gamma = lpcEnhK - lpcEnhK2;
Filters.Bw_lpc(lpcEnhK, this.interp_qlpc, this.awk1, this.lpcSize);
Filters.Bw_lpc(lpcEnhK2, this.interp_qlpc, this.awk2, this.lpcSize);
Filters.Bw_lpc(gamma, this.interp_qlpc, this.awk3, this.lpcSize);
}
num6 = 1f;
this.pi_gain[j] = 0f;
for (int i = 0; i <= this.lpcSize; i++)
{
num4 += num6 * this.interp_qlpc[i];
num6 = -num6;
this.pi_gain[j] += this.interp_qlpc[i];
}
float value = piGain[j];
value = 1f / (Math.Abs(value) + 0.01f);
num4 = 1f / (Math.Abs(num4) + 0.01f);
float num7 = Math.Abs(0.01f + num4) / (0.01f + Math.Abs(value));
for (int i = num5; i < num5 + this.subframeSize; i++)
{
this.excBuf[i] = 0f;
}
if (this.submodes[this.submodeID].Innovation == null)
{
int num8 = bits.Unpack(5);
float num9 = (float)Math.Exp(((double)num8 - 10.0) / 8.0);
num9 /= num7;
for (int i = num5; i < num5 + this.subframeSize; i++)
{
this.excBuf[i] = this.foldingGain * num9 * innov[i];
}
}
else
{
int num10 = bits.Unpack(4);
for (int i = num5; i < num5 + this.subframeSize; i++)
{
num3 += exc[i] * exc[i];
}
float num11 = (float)Math.Exp((double)(0.270270258f * (float)num10 - 2f));
float num12 = num11 * (float)Math.Sqrt((double)(1f + num3)) / num7;
this.submodes[this.submodeID].Innovation.Unquantify(this.excBuf, num5, this.subframeSize, bits);
for (int i = num5; i < num5 + this.subframeSize; i++)
{
this.excBuf[i] *= num12;
}
if (this.submodes[this.submodeID].DoubleCodebook != 0)
{
for (int i = 0; i < this.subframeSize; i++)
{
this.innov2[i] = 0f;
}
this.submodes[this.submodeID].Innovation.Unquantify(this.innov2, 0, this.subframeSize, bits);
for (int i = 0; i < this.subframeSize; i++)
{
this.innov2[i] *= num12 * 0.4f;
}
for (int i = 0; i < this.subframeSize; i++)
{
this.excBuf[num5 + i] += this.innov2[i];
}
}
}
for (int i = num5; i < num5 + this.subframeSize; i++)
{
this.high[i] = this.excBuf[i];
}
if (this.enhanced)
{
Filters.Filter_mem2(this.high, num5, this.awk2, this.awk1, this.subframeSize, this.lpcSize, this.mem_sp, this.lpcSize);
Filters.Filter_mem2(this.high, num5, this.awk3, this.interp_qlpc, this.subframeSize, this.lpcSize, this.mem_sp, 0);
}
else
{
for (int i = 0; i < this.lpcSize; i++)
{
this.mem_sp[this.lpcSize + i] = 0f;
}
Filters.Iir_mem2(this.high, num5, this.interp_qlpc, this.high, num5, this.subframeSize, this.lpcSize, this.mem_sp);
}
}
this.filters.Fir_mem_up(this.x0d, Codebook_Constants.h0, this.y0, this.fullFrameSize, 64, this.g0_mem);
this.filters.Fir_mem_up(this.high, Codebook_Constants.h1, this.y1, this.fullFrameSize, 64, this.g1_mem);
for (int i = 0; i < this.fullFrameSize; i++)
{
xout[i] = 2f * (this.y0[i] - this.y1[i]);
}
for (int i = 0; i < this.lpcSize; i++)
{
this.old_qlsp[i] = this.qlsp[i];
}
this.first = 0;
return(0);
}
if (dtx)
{
this.DecodeLost(xout, true);
return(0);
}
for (int i = 0; i < this.frameSize; i++)
{
this.excBuf[i] = 0f;
}
this.first = 1;
Filters.Iir_mem2(this.excBuf, this.excIdx, this.interp_qlpc, this.high, 0, this.frameSize, this.lpcSize, this.mem_sp);
this.filters.Fir_mem_up(this.x0d, Codebook_Constants.h0, this.y0, this.fullFrameSize, 64, this.g0_mem);
this.filters.Fir_mem_up(this.high, Codebook_Constants.h1, this.y1, this.fullFrameSize, 64, this.g1_mem);
for (int i = 0; i < this.fullFrameSize; i++)
{
xout[i] = 2f * (this.y0[i] - this.y1[i]);
}
return(0);
}