namespace NSpeex
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{
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using System;
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internal class NbDecoder : NbCodec, IDecoder
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{
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private int count_lost;
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protected internal bool enhanced;
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protected internal Inband inband;
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private float[] innov2;
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private float last_ol_gain;
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private int last_pitch;
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private float last_pitch_gain;
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private float[] pitch_gain_buf;
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private int pitch_gain_buf_idx;
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protected internal Random random = new Random();
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protected internal Stereo stereo = new Stereo();
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public NbDecoder()
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{
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this.inband = new Inband(this.stereo);
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this.enhanced = true;
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}
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public virtual int Decode(Bits bits, float[] xout)
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{
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int num;
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int num4 = 0;
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float[] numArray = new float[3];
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float num6 = 0f;
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float num7 = 0f;
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int num8 = 40;
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float num9 = 0f;
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float num10 = 0f;
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if ((bits == null) && (base.dtx_enabled != 0))
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{
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base.submodeID = 0;
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}
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else
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{
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int num5;
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if (bits == null)
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{
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this.DecodeLost(xout);
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return 0;
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}
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do
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{
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if (bits.BitsRemaining< 5)
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{
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return -1;
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}
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if (bits.Unpack(1) != 0)
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{
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num5 = bits.Unpack(3);
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int n = SbCodec.SB_FRAME_SIZE[num5];
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if (n < 0)
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{
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throw new InvalidFormatException("Invalid sideband mode encountered (1st sideband): " + num5);
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}
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n -= 4;
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bits.Advance(n);
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if (bits.Unpack(1) != 0)
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{
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num5 = bits.Unpack(3);
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n = SbCodec.SB_FRAME_SIZE[num5];
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if (n < 0)
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{
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throw new InvalidFormatException("Invalid sideband mode encountered. (2nd sideband): " + num5);
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}
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n -= 4;
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bits.Advance(n);
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if (bits.Unpack(1) != 0)
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{
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throw new InvalidFormatException("More than two sideband layers found");
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}
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}
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}
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if (bits.BitsRemaining < 4)
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{
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return 1;
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}
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num5 = bits.Unpack(4);
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switch (num5)
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{
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case 15:
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return 1;
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case 14:
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this.inband.SpeexInbandRequest(bits);
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break;
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case 13:
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this.inband.UserInbandRequest(bits);
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break;
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default:
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if (num5 > 8)
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{
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throw new InvalidFormatException("Invalid mode encountered: " + num5);
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}
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break;
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}
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}
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while (num5 > 8);
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base.submodeID = num5;
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}
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Array.Copy(base.frmBuf, base.frameSize, base.frmBuf, 0, base.bufSize - base.frameSize);
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Array.Copy(base.excBuf, base.frameSize, base.excBuf, 0, base.bufSize - base.frameSize);
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if (base.submodes[base.submodeID] == null)
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{
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Filters.Bw_lpc(0.93f, base.interp_qlpc, base.lpc, 10);
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float num12 = 0f;
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for (num = 0; num < base.frameSize; num++)
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{
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num12 += base.innov[num] * base.innov[num];
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}
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num12 = (float)Math.Sqrt((double)(num12 / ((float)base.frameSize)));
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for (num = base.excIdx; num < (base.excIdx + base.frameSize); num++)
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{
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base.excBuf[num] = (float)((3f * num12) * (this.random.NextDouble() - 0.5));
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}
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base.first = 1;
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Filters.Iir_mem2(base.excBuf, base.excIdx, base.lpc, base.frmBuf, base.frmIdx, base.frameSize, base.lpcSize, base.mem_sp);
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xout[0] = base.frmBuf[base.frmIdx] + (base.preemph * base.pre_mem);
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for (num = 1; num < base.frameSize; num++)
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{
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xout[num] = base.frmBuf[base.frmIdx + num] + (base.preemph * xout[num - 1]);
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}
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base.pre_mem = xout[base.frameSize - 1];
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this.count_lost = 0;
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return 0;
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}
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base.submodes[base.submodeID].LsqQuant.Unquant(base.qlsp, base.lpcSize, bits);
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if (this.count_lost != 0)
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{
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float num13 = 0f;
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for (num = 0; num < base.lpcSize; num++)
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{
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num13 += Math.Abs((float)(base.old_qlsp[num] - base.qlsp[num]));
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}
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float num14 = (float)(0.6 * Math.Exp(-0.2 * num13));
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for (num = 0; num < (2 * base.lpcSize); num++)
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{
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base.mem_sp[num] *= num14;
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}
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}
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if ((base.first != 0) || (this.count_lost != 0))
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{
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num = 0;
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while (num < base.lpcSize)
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{
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base.old_qlsp[num] = base.qlsp[num];
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num++;
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}
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}
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if (base.submodes[base.submodeID].LbrPitch != -1)
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{
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num4 = base.min_pitch + bits.Unpack(7);
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}
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if (base.submodes[base.submodeID].ForcedPitchGain != 0)
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{
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int num15 = bits.Unpack(4);
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num7 = 0.066667f * num15;
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}
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num6 = (float)Math.Exp(((double)bits.Unpack(5)) / 3.5);
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if (base.submodeID == 1)
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{
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if (bits.Unpack(4) == 15)
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{
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base.dtx_enabled = 1;
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}
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else
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{
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base.dtx_enabled = 0;
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}
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}
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if (base.submodeID > 1)
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{
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base.dtx_enabled = 0;
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}
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for (int i = 0; i < base.nbSubframes; i++)
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{
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int num26;
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int num27;
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int num30;
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float num32;
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int num18 = base.subframeSize * i;
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int nsi = base.frmIdx + num18;
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int es = base.excIdx + num18;
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float num21 = (1f + i) / ((float)base.nbSubframes);
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num = 0;
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while (num < base.lpcSize)
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{
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base.interp_qlsp[num] = ((1f - num21) * base.old_qlsp[num]) + (num21 * base.qlsp[num]);
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num++;
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}
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Lsp.Enforce_margin(base.interp_qlsp, base.lpcSize, 0.002f);
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num = 0;
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while (num < base.lpcSize)
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{
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base.interp_qlsp[num] = (float)Math.Cos((double)base.interp_qlsp[num]);
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num++;
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}
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base.m_lsp.Lsp2lpc(base.interp_qlsp, base.interp_qlpc, base.lpcSize);
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if (this.enhanced)
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{
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float num22 = 0.9f;
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float gamma = base.submodes[base.submodeID].LpcEnhK1;
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float num24 = base.submodes[base.submodeID].LpcEnhK2;
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float num25 = (1f - ((1f - (num22 * gamma)) / (1f - (num22 * num24)))) / num22;
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Filters.Bw_lpc(gamma, base.interp_qlpc, base.awk1, base.lpcSize);
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Filters.Bw_lpc(num24, base.interp_qlpc, base.awk2, base.lpcSize);
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Filters.Bw_lpc(num25, base.interp_qlpc, base.awk3, base.lpcSize);
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}
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num21 = 1f;
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base.pi_gain[i] = 0f;
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num = 0;
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while (num <= base.lpcSize)
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{
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base.pi_gain[i] += num21 * base.interp_qlpc[num];
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num21 = -num21;
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num++;
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}
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num = 0;
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while (num < base.subframeSize)
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{
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base.excBuf[es + num] = 0f;
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num++;
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}
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if (base.submodes[base.submodeID].LbrPitch != -1)
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{
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int lbrPitch = base.submodes[base.submodeID].LbrPitch;
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if (lbrPitch != 0)
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{
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num26 = (num4 - lbrPitch) + 1;
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if (num26 < base.min_pitch)
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{
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num26 = base.min_pitch;
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}
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num27 = num4 + lbrPitch;
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if (num27 > base.max_pitch)
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{
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num27 = base.max_pitch;
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}
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}
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else
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{
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num26 = num27 = num4;
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}
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}
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else
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{
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num26 = base.min_pitch;
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num27 = base.max_pitch;
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}
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int pitch = base.submodes[base.submodeID].Ltp.Unquant(base.excBuf, es, num26, num7, base.subframeSize, numArray, bits, this.count_lost, num18, this.last_pitch_gain);
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if ((this.count_lost != 0) && (num6 < this.last_ol_gain))
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{
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float num29 = num6 / (this.last_ol_gain + 1f);
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num = 0;
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while (num < base.subframeSize)
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{
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base.excBuf[base.excIdx + num] *= num29;
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num++;
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}
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}
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num21 = Math.Abs((float)((numArray[0] + numArray[1]) + numArray[2]));
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num21 = Math.Abs(numArray[1]);
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if (numArray[0] > 0f)
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{
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num21 += numArray[0];
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}
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else
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{
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num21 -= 0.5f * numArray[0];
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}
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if (numArray[2] > 0f)
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{
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num21 += numArray[2];
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}
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else
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{
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num21 -= 0.5f * numArray[0];
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}
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num10 += num21;
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if (num21 > num9)
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{
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num8 = pitch;
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num9 = num21;
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}
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int num31 = i * base.subframeSize;
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num = num31;
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while (num < (num31 + base.subframeSize))
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{
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base.innov[num] = 0f;
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num++;
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}
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if (base.submodes[base.submodeID].HaveSubframeGain == 3)
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{
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num30 = bits.Unpack(3);
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num32 = (float)(num6 * Math.Exp((double)NbCodec.exc_gain_quant_scal3[num30]));
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}
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else if (base.submodes[base.submodeID].HaveSubframeGain == 1)
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{
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num30 = bits.Unpack(1);
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num32 = (float)(num6 * Math.Exp((double)NbCodec.exc_gain_quant_scal1[num30]));
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}
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else
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{
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num32 = num6;
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}
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if (base.submodes[base.submodeID].Innovation != null)
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{
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base.submodes[base.submodeID].Innovation.Unquantify(base.innov, num31, base.subframeSize, bits);
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}
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num = num31;
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while (num < (num31 + base.subframeSize))
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{
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base.innov[num] *= num32;
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num++;
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}
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if (base.submodeID == 1)
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{
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float num33 = num7;
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num = 0;
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while (num < base.subframeSize)
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{
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base.excBuf[es + num] = 0f;
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num++;
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}
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while (base.voc_offset < base.subframeSize)
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{
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if (base.voc_offset >= 0)
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{
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base.excBuf[es + base.voc_offset] = (float)Math.Sqrt((double)(1f * num4));
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}
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base.voc_offset += num4;
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}
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base.voc_offset -= base.subframeSize;
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num33 = 0.5f + (2f * (num33 - 0.6f));
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if (num33 < 0f)
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{
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num33 = 0f;
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}
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if (num33 > 1f)
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{
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num33 = 1f;
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}
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num = 0;
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while (num < base.subframeSize)
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{
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float num34 = base.excBuf[es + num];
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base.excBuf[es + num] = ((((((0.8f * num33) * base.excBuf[es + num]) * num6) + (((0.6f * num33) * base.voc_m1) * num6)) + ((0.5f * num33) * base.innov[num31 + num])) - ((0.5f * num33) * base.voc_m2)) + ((1f - num33) * base.innov[num31 + num]);
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base.voc_m1 = num34;
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base.voc_m2 = base.innov[num31 + num];
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base.voc_mean = (0.95f * base.voc_mean) + (0.05f * base.excBuf[es + num]);
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base.excBuf[es + num] -= base.voc_mean;
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num++;
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}
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}
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else
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{
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num = 0;
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while (num < base.subframeSize)
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{
|
base.excBuf[es + num] += base.innov[num31 + num];
|
num++;
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}
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}
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if (base.submodes[base.submodeID].DoubleCodebook != 0)
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{
|
num = 0;
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while (num < base.subframeSize)
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{
|
this.innov2[num] = 0f;
|
num++;
|
}
|
base.submodes[base.submodeID].Innovation.Unquantify(this.innov2, 0, base.subframeSize, bits);
|
num = 0;
|
while (num < base.subframeSize)
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{
|
this.innov2[num] *= num32 * 0.4545454f;
|
num++;
|
}
|
num = 0;
|
while (num < base.subframeSize)
|
{
|
base.excBuf[es + num] += this.innov2[num];
|
num++;
|
}
|
}
|
num = 0;
|
while (num < base.subframeSize)
|
{
|
base.frmBuf[nsi + num] = base.excBuf[es + num];
|
num++;
|
}
|
if (this.enhanced && (base.submodes[base.submodeID].CombGain > 0f))
|
{
|
base.filters.Comb_filter(base.excBuf, es, base.frmBuf, nsi, base.subframeSize, pitch, numArray, base.submodes[base.submodeID].CombGain);
|
}
|
if (this.enhanced)
|
{
|
Filters.Filter_mem2(base.frmBuf, nsi, base.awk2, base.awk1, base.subframeSize, base.lpcSize, base.mem_sp, base.lpcSize);
|
Filters.Filter_mem2(base.frmBuf, nsi, base.awk3, base.interp_qlpc, base.subframeSize, base.lpcSize, base.mem_sp, 0);
|
}
|
else
|
{
|
num = 0;
|
while (num < base.lpcSize)
|
{
|
base.mem_sp[base.lpcSize + num] = 0f;
|
num++;
|
}
|
Filters.Iir_mem2(base.frmBuf, nsi, base.interp_qlpc, base.frmBuf, nsi, base.subframeSize, base.lpcSize, base.mem_sp);
|
}
|
}
|
xout[0] = base.frmBuf[base.frmIdx] + (base.preemph * base.pre_mem);
|
for (num = 1; num < base.frameSize; num++)
|
{
|
xout[num] = base.frmBuf[base.frmIdx + num] + (base.preemph * xout[num - 1]);
|
}
|
base.pre_mem = xout[base.frameSize - 1];
|
for (num = 0; num < base.lpcSize; num++)
|
{
|
base.old_qlsp[num] = base.qlsp[num];
|
}
|
base.first = 0;
|
this.count_lost = 0;
|
this.last_pitch = num8;
|
this.last_pitch_gain = 0.25f * num10;
|
this.pitch_gain_buf[this.pitch_gain_buf_idx++] = this.last_pitch_gain;
|
if (this.pitch_gain_buf_idx > 2)
|
{
|
this.pitch_gain_buf_idx = 0;
|
}
|
this.last_ol_gain = num6;
|
return 0;
|
}
|
|
public int DecodeLost(float[] xout)
|
{
|
int num;
|
float num3 = (float)Math.Exp((-0.04 * this.count_lost) * this.count_lost);
|
float num4 = (this.pitch_gain_buf[0] < this.pitch_gain_buf[1]) ? ((this.pitch_gain_buf[1] < this.pitch_gain_buf[2]) ? this.pitch_gain_buf[1] : ((this.pitch_gain_buf[0] < this.pitch_gain_buf[2]) ? this.pitch_gain_buf[2] : this.pitch_gain_buf[0])) : ((this.pitch_gain_buf[2] < this.pitch_gain_buf[1]) ? this.pitch_gain_buf[1] : ((this.pitch_gain_buf[2] < this.pitch_gain_buf[0]) ? this.pitch_gain_buf[2] : this.pitch_gain_buf[0]));
|
if (num4 < this.last_pitch_gain)
|
{
|
this.last_pitch_gain = num4;
|
}
|
float num2 = this.last_pitch_gain;
|
if (num2 > 0.95f)
|
{
|
num2 = 0.95f;
|
}
|
num2 *= num3;
|
Array.Copy(base.frmBuf, base.frameSize, base.frmBuf, 0, base.bufSize - base.frameSize);
|
Array.Copy(base.excBuf, base.frameSize, base.excBuf, 0, base.bufSize - base.frameSize);
|
for (int i = 0; i < base.nbSubframes; i++)
|
{
|
int num6 = base.subframeSize * i;
|
int xs = base.frmIdx + num6;
|
int num8 = base.excIdx + num6;
|
if (this.enhanced)
|
{
|
float num10;
|
float num11;
|
float num9 = 0.9f;
|
if (base.submodes[base.submodeID] != null)
|
{
|
num10 = base.submodes[base.submodeID].LpcEnhK1;
|
num11 = base.submodes[base.submodeID].LpcEnhK2;
|
}
|
else
|
{
|
num10 = num11 = 0.7f;
|
}
|
float gamma = (1f - ((1f - (num9 * num10)) / (1f - (num9 * num11)))) / num9;
|
Filters.Bw_lpc(num10, base.interp_qlpc, base.awk1, base.lpcSize);
|
Filters.Bw_lpc(num11, base.interp_qlpc, base.awk2, base.lpcSize);
|
Filters.Bw_lpc(gamma, base.interp_qlpc, base.awk3, base.lpcSize);
|
}
|
float num13 = 0f;
|
num = 0;
|
while (num < base.frameSize)
|
{
|
num13 += base.innov[num] * base.innov[num];
|
num++;
|
}
|
num13 = (float)Math.Sqrt((double)(num13 / ((float)base.frameSize)));
|
num = 0;
|
while (num < base.subframeSize)
|
{
|
base.excBuf[num8 + num] = (num2 * base.excBuf[(num8 + num) - this.last_pitch]) + ((((num3 * ((float)Math.Sqrt((double)(1f - num2)))) * 3f) * num13) * (((float)this.random.NextDouble()) - 0.5f));
|
num++;
|
}
|
num = 0;
|
while (num < base.subframeSize)
|
{
|
base.frmBuf[xs + num] = base.excBuf[num8 + num];
|
num++;
|
}
|
if (this.enhanced)
|
{
|
Filters.Filter_mem2(base.frmBuf, xs, base.awk2, base.awk1, base.subframeSize, base.lpcSize, base.mem_sp, base.lpcSize);
|
Filters.Filter_mem2(base.frmBuf, xs, base.awk3, base.interp_qlpc, base.subframeSize, base.lpcSize, base.mem_sp, 0);
|
}
|
else
|
{
|
num = 0;
|
while (num < base.lpcSize)
|
{
|
base.mem_sp[base.lpcSize + num] = 0f;
|
num++;
|
}
|
Filters.Iir_mem2(base.frmBuf, xs, base.interp_qlpc, base.frmBuf, xs, base.subframeSize, base.lpcSize, base.mem_sp);
|
}
|
}
|
xout[0] = base.frmBuf[0] + (base.preemph * base.pre_mem);
|
for (num = 1; num < base.frameSize; num++)
|
{
|
xout[num] = base.frmBuf[num] + (base.preemph * xout[num - 1]);
|
}
|
base.pre_mem = xout[base.frameSize - 1];
|
base.first = 0;
|
this.count_lost++;
|
this.pitch_gain_buf[this.pitch_gain_buf_idx++] = num2;
|
if (this.pitch_gain_buf_idx > 2)
|
{
|
this.pitch_gain_buf_idx = 0;
|
}
|
return 0;
|
}
|
|
public virtual void DecodeStereo(float[] data, int frameSize)
|
{
|
this.stereo.Decode(data, frameSize);
|
}
|
|
protected override void Init(int frameSize, int subframeSize, int lpcSize, int bufSize)
|
{
|
base.Init(frameSize, subframeSize, lpcSize, bufSize);
|
this.innov2 = new float[40];
|
this.count_lost = 0;
|
this.last_pitch = 40;
|
this.last_pitch_gain = 0f;
|
this.pitch_gain_buf = new float[3];
|
this.pitch_gain_buf_idx = 0;
|
this.last_ol_gain = 0f;
|
}
|
|
public bool Dtx {
|
get { return (base.dtx_enabled != 0); }
|
}
|
|
public virtual bool PerceptualEnhancement {
|
get {
|
return this.enhanced;
|
}
|
set {
|
this.enhanced = value;
|
}
|
}
|
}
|
}
|
