Ejemplo n.º 1
0
 /// <summary>
 /// User in-band request (submode=13).
 /// </summary>
 /// <param name="bits"></param>
 public void userInbandRequest(Bits bits)
 {
     try
     {
         int req_size = bits.UnPack(4);
         bits.Advance(5 + 8 * req_size);
     }
     catch (Exception e)
     {
         throw new SpeexException(e.Message);
     }
 }
Ejemplo n.º 2
0
        public void UserInbandRequest(Bits bits)
        {
            int num = bits.Unpack(4);

            bits.Advance(5 + 8 * num);
        }
Ejemplo n.º 3
0
        public void SpeexInbandRequest(Bits bits)
        {
            switch (bits.Unpack(4))
            {
            case 0:
                bits.Advance(1);
                break;

            case 1:
                bits.Advance(1);
                break;

            case 2:
                bits.Advance(4);
                break;

            case 3:
                bits.Advance(4);
                break;

            case 4:
                bits.Advance(4);
                break;

            case 5:
                bits.Advance(4);
                break;

            case 6:
                bits.Advance(4);
                break;

            case 7:
                bits.Advance(4);
                break;

            case 8:
                bits.Advance(8);
                break;

            case 9:
                this.stereo.Init(bits);
                break;

            case 10:
                bits.Advance(16);
                break;

            case 11:
                bits.Advance(16);
                break;

            case 12:
                bits.Advance(32);
                break;

            case 13:
                bits.Advance(32);
                break;

            case 14:
                bits.Advance(64);
                break;

            case 15:
                bits.Advance(64);
                break;
            }
        }
Ejemplo n.º 4
0
        public virtual int Decode(Bits bits, float[] xout)
        {
            int num = 0;

            float[] array = new float[3];
            float   num2  = 0f;
            int     num3  = 40;
            float   num4  = 0f;
            float   num5  = 0f;

            if (bits == null && this.dtx_enabled != 0)
            {
                this.submodeID = 0;
            }
            else
            {
                if (bits == null)
                {
                    this.DecodeLost(xout);
                    return(0);
                }
                while (bits.BitsRemaining() >= 5)
                {
                    int num6;
                    if (bits.Unpack(1) != 0)
                    {
                        num6 = bits.Unpack(3);
                        int num7 = SbCodec.SB_FRAME_SIZE[num6];
                        if (num7 < 0)
                        {
                            throw new InvalidFormatException("Invalid sideband mode encountered (1st sideband): " + num6);
                        }
                        num7 -= 4;
                        bits.Advance(num7);
                        if (bits.Unpack(1) != 0)
                        {
                            num6 = bits.Unpack(3);
                            num7 = SbCodec.SB_FRAME_SIZE[num6];
                            if (num7 < 0)
                            {
                                throw new InvalidFormatException("Invalid sideband mode encountered. (2nd sideband): " + num6);
                            }
                            num7 -= 4;
                            bits.Advance(num7);
                            if (bits.Unpack(1) != 0)
                            {
                                throw new InvalidFormatException("More than two sideband layers found");
                            }
                        }
                    }
                    if (bits.BitsRemaining() < 4)
                    {
                        return(1);
                    }
                    num6 = bits.Unpack(4);
                    if (num6 == 15)
                    {
                        return(1);
                    }
                    if (num6 == 14)
                    {
                        this.inband.SpeexInbandRequest(bits);
                    }
                    else if (num6 == 13)
                    {
                        this.inband.UserInbandRequest(bits);
                    }
                    else if (num6 > 8)
                    {
                        throw new InvalidFormatException("Invalid mode encountered: " + num6);
                    }
                    if (num6 <= 8)
                    {
                        this.submodeID = num6;
                        goto IL_199;
                    }
                }
                return(-1);
            }
IL_199:
            Array.Copy(this.frmBuf, this.frameSize, this.frmBuf, 0, this.bufSize - this.frameSize);
            Array.Copy(this.excBuf, this.frameSize, this.excBuf, 0, this.bufSize - this.frameSize);
            if (this.submodes[this.submodeID] == null)
            {
                Filters.Bw_lpc(0.93f, this.interp_qlpc, this.lpc, 10);
                float num8 = 0f;
                for (int i = 0; i < this.frameSize; i++)
                {
                    num8 += this.innov[i] * this.innov[i];
                }
                num8 = (float)Math.Sqrt((double)(num8 / (float)this.frameSize));
                for (int i = this.excIdx; i < this.excIdx + this.frameSize; i++)
                {
                    this.excBuf[i] = (float)((double)(3f * num8) * (this.random.NextDouble() - 0.5));
                }
                this.first = 1;
                Filters.Iir_mem2(this.excBuf, this.excIdx, this.lpc, this.frmBuf, this.frmIdx, this.frameSize, this.lpcSize, this.mem_sp);
                xout[0] = this.frmBuf[this.frmIdx] + this.preemph * this.pre_mem;
                for (int i = 1; i < this.frameSize; i++)
                {
                    xout[i] = this.frmBuf[this.frmIdx + i] + this.preemph * xout[i - 1];
                }
                this.pre_mem    = xout[this.frameSize - 1];
                this.count_lost = 0;
                return(0);
            }
            this.submodes[this.submodeID].LsqQuant.Unquant(this.qlsp, this.lpcSize, bits);
            if (this.count_lost != 0)
            {
                float num9 = 0f;
                for (int i = 0; i < this.lpcSize; i++)
                {
                    num9 += Math.Abs(this.old_qlsp[i] - this.qlsp[i]);
                }
                float num10 = (float)(0.6 * Math.Exp(-0.2 * (double)num9));
                for (int i = 0; i < 2 * this.lpcSize; i++)
                {
                    this.mem_sp[i] *= num10;
                }
            }
            if (this.first != 0 || this.count_lost != 0)
            {
                for (int i = 0; i < this.lpcSize; i++)
                {
                    this.old_qlsp[i] = this.qlsp[i];
                }
            }
            if (this.submodes[this.submodeID].LbrPitch != -1)
            {
                num = this.min_pitch + bits.Unpack(7);
            }
            if (this.submodes[this.submodeID].ForcedPitchGain != 0)
            {
                int num11 = bits.Unpack(4);
                num2 = 0.066667f * (float)num11;
            }
            int   num12 = bits.Unpack(5);
            float num13 = (float)Math.Exp((double)num12 / 3.5);

            if (this.submodeID == 1)
            {
                int num14 = bits.Unpack(4);
                if (num14 == 15)
                {
                    this.dtx_enabled = 1;
                }
                else
                {
                    this.dtx_enabled = 0;
                }
            }
            if (this.submodeID > 1)
            {
                this.dtx_enabled = 0;
            }
            for (int j = 0; j < this.nbSubframes; j++)
            {
                int   num15 = this.subframeSize * j;
                int   num16 = this.frmIdx + num15;
                int   num17 = this.excIdx + num15;
                float num18 = (1f + (float)j) / (float)this.nbSubframes;
                for (int i = 0; i < this.lpcSize; i++)
                {
                    this.interp_qlsp[i] = (1f - num18) * this.old_qlsp[i] + num18 * this.qlsp[i];
                }
                Lsp.Enforce_margin(this.interp_qlsp, this.lpcSize, 0.002f);
                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 num19    = 0.9f;
                    float lpcEnhK  = this.submodes[this.submodeID].LpcEnhK1;
                    float lpcEnhK2 = this.submodes[this.submodeID].LpcEnhK2;
                    float gamma    = (1f - (1f - num19 * lpcEnhK) / (1f - num19 * lpcEnhK2)) / num19;
                    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);
                }
                num18           = 1f;
                this.pi_gain[j] = 0f;
                for (int i = 0; i <= this.lpcSize; i++)
                {
                    this.pi_gain[j] += num18 * this.interp_qlpc[i];
                    num18            = -num18;
                }
                for (int i = 0; i < this.subframeSize; i++)
                {
                    this.excBuf[num17 + i] = 0f;
                }
                int num20;
                if (this.submodes[this.submodeID].LbrPitch != -1)
                {
                    int lbrPitch = this.submodes[this.submodeID].LbrPitch;
                    if (lbrPitch != 0)
                    {
                        num20 = num - lbrPitch + 1;
                        if (num20 < this.min_pitch)
                        {
                            num20 = this.min_pitch;
                        }
                        int num21 = num + lbrPitch;
                        if (num21 > this.max_pitch)
                        {
                            num21 = this.max_pitch;
                        }
                    }
                    else
                    {
                        num20 = num;
                    }
                }
                else
                {
                    num20 = this.min_pitch;
                    int num21 = this.max_pitch;
                }
                int num22 = this.submodes[this.submodeID].Ltp.Unquant(this.excBuf, num17, num20, num2, this.subframeSize, array, bits, this.count_lost, num15, this.last_pitch_gain);
                if (this.count_lost != 0 && num13 < this.last_ol_gain)
                {
                    float num23 = num13 / (this.last_ol_gain + 1f);
                    for (int i = 0; i < this.subframeSize; i++)
                    {
                        this.excBuf[this.excIdx + i] *= num23;
                    }
                }
                num18 = Math.Abs(array[0] + array[1] + array[2]);
                num18 = Math.Abs(array[1]);
                if (array[0] > 0f)
                {
                    num18 += array[0];
                }
                else
                {
                    num18 -= 0.5f * array[0];
                }
                if (array[2] > 0f)
                {
                    num18 += array[2];
                }
                else
                {
                    num18 -= 0.5f * array[0];
                }
                num5 += num18;
                if (num18 > num4)
                {
                    num3 = num22;
                    num4 = num18;
                }
                int num24 = j * this.subframeSize;
                for (int i = num24; i < num24 + this.subframeSize; i++)
                {
                    this.innov[i] = 0f;
                }
                float num26;
                if (this.submodes[this.submodeID].HaveSubframeGain == 3)
                {
                    int num25 = bits.Unpack(3);
                    num26 = (float)((double)num13 * Math.Exp((double)NbCodec.exc_gain_quant_scal3[num25]));
                }
                else if (this.submodes[this.submodeID].HaveSubframeGain == 1)
                {
                    int num25 = bits.Unpack(1);
                    num26 = (float)((double)num13 * Math.Exp((double)NbCodec.exc_gain_quant_scal1[num25]));
                }
                else
                {
                    num26 = num13;
                }
                if (this.submodes[this.submodeID].Innovation != null)
                {
                    this.submodes[this.submodeID].Innovation.Unquantify(this.innov, num24, this.subframeSize, bits);
                }
                for (int i = num24; i < num24 + this.subframeSize; i++)
                {
                    this.innov[i] *= num26;
                }
                if (this.submodeID == 1)
                {
                    float num27 = num2;
                    for (int i = 0; i < this.subframeSize; i++)
                    {
                        this.excBuf[num17 + i] = 0f;
                    }
                    while (this.voc_offset < this.subframeSize)
                    {
                        if (this.voc_offset >= 0)
                        {
                            this.excBuf[num17 + this.voc_offset] = (float)Math.Sqrt((double)(1f * (float)num));
                        }
                        this.voc_offset += num;
                    }
                    this.voc_offset -= this.subframeSize;
                    num27            = 0.5f + 2f * (num27 - 0.6f);
                    if (num27 < 0f)
                    {
                        num27 = 0f;
                    }
                    if (num27 > 1f)
                    {
                        num27 = 1f;
                    }
                    for (int i = 0; i < this.subframeSize; i++)
                    {
                        float voc_m = this.excBuf[num17 + i];
                        this.excBuf[num17 + i]  = 0.8f * num27 * this.excBuf[num17 + i] * num13 + 0.6f * num27 * this.voc_m1 * num13 + 0.5f * num27 * this.innov[num24 + i] - 0.5f * num27 * this.voc_m2 + (1f - num27) * this.innov[num24 + i];
                        this.voc_m1             = voc_m;
                        this.voc_m2             = this.innov[num24 + i];
                        this.voc_mean           = 0.95f * this.voc_mean + 0.05f * this.excBuf[num17 + i];
                        this.excBuf[num17 + i] -= this.voc_mean;
                    }
                }
                else
                {
                    for (int i = 0; i < this.subframeSize; i++)
                    {
                        this.excBuf[num17 + i] += this.innov[num24 + i];
                    }
                }
                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] *= num26 * 0.454545438f;
                    }
                    for (int i = 0; i < this.subframeSize; i++)
                    {
                        this.excBuf[num17 + i] += this.innov2[i];
                    }
                }
                for (int i = 0; i < this.subframeSize; i++)
                {
                    this.frmBuf[num16 + i] = this.excBuf[num17 + i];
                }
                if (this.enhanced && this.submodes[this.submodeID].CombGain > 0f)
                {
                    this.filters.Comb_filter(this.excBuf, num17, this.frmBuf, num16, this.subframeSize, num22, array, this.submodes[this.submodeID].CombGain);
                }
                if (this.enhanced)
                {
                    Filters.Filter_mem2(this.frmBuf, num16, this.awk2, this.awk1, this.subframeSize, this.lpcSize, this.mem_sp, this.lpcSize);
                    Filters.Filter_mem2(this.frmBuf, num16, 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.frmBuf, num16, this.interp_qlpc, this.frmBuf, num16, this.subframeSize, this.lpcSize, this.mem_sp);
                }
            }
            xout[0] = this.frmBuf[this.frmIdx] + this.preemph * this.pre_mem;
            for (int i = 1; i < this.frameSize; i++)
            {
                xout[i] = this.frmBuf[this.frmIdx + i] + this.preemph * xout[i - 1];
            }
            this.pre_mem = xout[this.frameSize - 1];
            for (int i = 0; i < this.lpcSize; i++)
            {
                this.old_qlsp[i] = this.qlsp[i];
            }
            this.first           = 0;
            this.count_lost      = 0;
            this.last_pitch      = num3;
            this.last_pitch_gain = 0.25f * num5;
            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 = num13;
            return(0);
        }
Ejemplo n.º 5
0
        /// <summary>
        /// Decode the given input bits.
        /// </summary>
        /// <returns>1 if a terminator was found, 0 if not.</returns>
        /// <exception cref="InvalidFormatException">If there is an error detected in the data stream.</exception>
        public virtual int Decode(Bits bits, float[] xout)
        {
            int i, sub, pitch, ol_pitch = 0, m;

            float[] pitch_gain = new float[3];
            float   ol_gain = 0.0f, ol_pitch_coef = 0.0f;
            int     best_pitch      = 40;
            float   best_pitch_gain = 0;
            float   pitch_average   = 0;

            if (bits == null && dtx_enabled != 0)
            {
                submodeID = 0;
            }
            else
            {
                /*
                 * If bits is NULL, consider the packet to be lost (what could we do
                 * anyway)
                 */
                if (bits == null)
                {
                    DecodeLost(xout);
                    return(0);
                }

                /*
                 * Search for next narrowband block (handle requests, skip wideband
                 * blocks)
                 */
                do
                {
                    if (bits.BitsRemaining() < 5)
                    {
                        return(-1);
                    }

                    if (bits.Unpack(1) != 0)
                    {                     /*
                                           * Skip wideband block (for
                                           * compatibility)
                                           */
                        // Wideband
                        /* Get the sub-mode that was used */
                        m = bits.Unpack(NSpeex.SbCodec.SB_SUBMODE_BITS);
                        int advance = NSpeex.SbCodec.SB_FRAME_SIZE[m];
                        if (advance < 0)
                        {
                            throw new InvalidFormatException(
                                      "Invalid sideband mode encountered (1st sideband): "
                                      + m);
                            // return -2;
                        }
                        advance -= (NSpeex.SbCodec.SB_SUBMODE_BITS + 1);
                        bits.Advance(advance);
                        if (bits.Unpack(1) != 0)
                        {                         /*
                                                   * Skip ultra-wideband block
                                                   * (for compatibility)
                                                   */
                            /* Get the sub-mode that was used */
                            m       = bits.Unpack(NSpeex.SbCodec.SB_SUBMODE_BITS);
                            advance = NSpeex.SbCodec.SB_FRAME_SIZE[m];
                            if (advance < 0)
                            {
                                throw new InvalidFormatException(
                                          "Invalid sideband mode encountered. (2nd sideband): "
                                          + m);
                                // return -2;
                            }
                            advance -= (NSpeex.SbCodec.SB_SUBMODE_BITS + 1);
                            bits.Advance(advance);
                            if (bits.Unpack(1) != 0)
                            {                             /* Sanity check */
                                throw new InvalidFormatException(
                                          "More than two sideband layers found");
                                // return -2;
                            }
                        }
                        // */
                    }

                    if (bits.BitsRemaining() < 4)
                    {
                        return(1);
                    }

                    /* Get the sub-mode that was used */
                    m = bits.Unpack(NSpeex.NbCodec.NB_SUBMODE_BITS);
                    if (m == 15)
                    {                     /* We found a terminator */
                        return(1);
                    }
                    else if (m == 14)
                    {                     /* Speex in-band request */
                        inband.SpeexInbandRequest(bits);
                    }
                    else if (m == 13)
                    {                     /* User in-band request */
                        inband.UserInbandRequest(bits);
                    }
                    else if (m > 8)
                    {                     /* Invalid mode */
                        throw new InvalidFormatException(
                                  "Invalid mode encountered: " + m);
                        // return -2;
                    }
                } while (m > 8);
                submodeID = m;
            }

            /* Shift all buffers by one frame */
            System.Array.Copy(frmBuf, frameSize, frmBuf, 0, bufSize
                              - frameSize);
            System.Array.Copy(excBuf, frameSize, excBuf, 0, bufSize
                              - frameSize);

            /* If null mode (no transmission), just set a couple things to zero */
            if (submodes[submodeID] == null)
            {
                NSpeex.Filters.Bw_lpc(.93f, interp_qlpc, lpc, 10);

                float innov_gain = 0;
                for (i = 0; i < frameSize; i++)
                {
                    innov_gain += innov[i] * innov[i];
                }
                innov_gain = (float)Math.Sqrt(innov_gain / frameSize);
                for (i = excIdx; i < excIdx + frameSize; i++)
                {
                    excBuf[i] = (float)(3 * innov_gain * (random.NextDouble() - .5f));
                }
                first = 1;

                /* Final signal synthesis from excitation */
                NSpeex.Filters.Iir_mem2(excBuf, excIdx, lpc, frmBuf, frmIdx,
                                        frameSize, lpcSize, mem_sp);

                xout[0] = frmBuf[frmIdx] + preemph * pre_mem;
                for (i = 1; i < frameSize; i++)
                {
                    xout[i] = frmBuf[frmIdx + i] + preemph * xout[i - 1];
                }
                pre_mem    = xout[frameSize - 1];
                count_lost = 0;
                return(0);
            }

            /* Unquantize LSPs */
            submodes[submodeID].LsqQuant.Unquant(qlsp, lpcSize, bits);

            /* Damp memory if a frame was lost and the LSP changed too much */
            if (count_lost != 0)
            {
                float lsp_dist = 0, fact;
                for (i = 0; i < lpcSize; i++)
                {
                    lsp_dist += Math.Abs(old_qlsp[i] - qlsp[i]);
                }
                fact = (float)(.6d * Math.Exp(-.2d * lsp_dist));
                for (i = 0; i < 2 * lpcSize; i++)
                {
                    mem_sp[i] *= fact;
                }
            }

            /* Handle first frame and lost-packet case */
            if (first != 0 || count_lost != 0)
            {
                for (i = 0; i < lpcSize; i++)
                {
                    old_qlsp[i] = qlsp[i];
                }
            }

            /* Get open-loop pitch estimation for low bit-rate pitch coding */
            if (submodes[submodeID].LbrPitch != -1)
            {
                ol_pitch = min_pitch + bits.Unpack(7);
            }

            if (submodes[submodeID].ForcedPitchGain != 0)
            {
                int quant = bits.Unpack(4);
                ol_pitch_coef = 0.066667f * quant;
            }

            /* Get global excitation gain */
            int qe = bits.Unpack(5);

            ol_gain = (float)Math.Exp(qe / 3.5d);

            /* unpacks unused dtx bits */
            if (submodeID == 1)
            {
                int extra = bits.Unpack(4);
                if (extra == 15)
                {
                    dtx_enabled = 1;
                }
                else
                {
                    dtx_enabled = 0;
                }
            }
            if (submodeID > 1)
            {
                dtx_enabled = 0;
            }

            /* Loop on subframes */
            for (sub = 0; sub < nbSubframes; sub++)
            {
                int   offset, spIdx, extIdx;
                float tmp;
                /* Offset relative to start of frame */
                offset = subframeSize * sub;
                /* Original signal */
                spIdx = frmIdx + offset;
                /* Excitation */
                extIdx = excIdx + offset;

                /* LSP interpolation (quantized and unquantized) */
                tmp = (1.0f + sub) / nbSubframes;
                for (i = 0; i < lpcSize; i++)
                {
                    interp_qlsp[i] = (1 - tmp) * old_qlsp[i] + tmp * qlsp[i];
                }

                /* Make sure the LSP's are stable */
                NSpeex.Lsp.Enforce_margin(interp_qlsp, lpcSize, .002f);

                /* Compute interpolated LPCs (unquantized) */
                for (i = 0; i < lpcSize; i++)
                {
                    interp_qlsp[i] = (float)System.Math.Cos(interp_qlsp[i]);
                }
                m_lsp.Lsp2lpc(interp_qlsp, interp_qlpc, lpcSize);

                /* Compute enhanced synthesis filter */
                if (enhanced)
                {
                    float r = .9f;
                    float k1, k2, k3;

                    k1 = submodes[submodeID].LpcEnhK1;
                    k2 = submodes[submodeID].LpcEnhK2;
                    k3 = (1 - (1 - r * k1) / (1 - r * k2)) / r;
                    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);
                }

                /* Compute analysis filter at w=pi */
                tmp          = 1;
                pi_gain[sub] = 0;
                for (i = 0; i <= lpcSize; i++)
                {
                    pi_gain[sub] += tmp * interp_qlpc[i];
                    tmp           = -tmp;
                }

                /* Reset excitation */
                for (i = 0; i < subframeSize; i++)
                {
                    excBuf[extIdx + i] = 0;
                }

                /* Adaptive codebook contribution */
                int pit_min, pit_max;

                /* Handle pitch constraints if any */
                if (submodes[submodeID].LbrPitch != -1)
                {
                    int margin = submodes[submodeID].LbrPitch;
                    if (margin != 0)
                    {
                        pit_min = ol_pitch - margin + 1;
                        if (pit_min < min_pitch)
                        {
                            pit_min = min_pitch;
                        }
                        pit_max = ol_pitch + margin;
                        if (pit_max > max_pitch)
                        {
                            pit_max = max_pitch;
                        }
                    }
                    else
                    {
                        pit_min = pit_max = ol_pitch;
                    }
                }
                else
                {
                    pit_min = min_pitch;
                    pit_max = max_pitch;
                }

                /* Pitch synthesis */
                pitch = submodes[submodeID].Ltp.Unquant(excBuf, extIdx, pit_min,
                                                        ol_pitch_coef, subframeSize, pitch_gain, bits, count_lost,
                                                        offset, last_pitch_gain);

                /* If we had lost frames, check energy of last received frame */
                if (count_lost != 0 && ol_gain < last_ol_gain)
                {
                    float fact_0 = ol_gain / (last_ol_gain + 1);
                    for (i = 0; i < subframeSize; i++)
                    {
                        excBuf[excIdx + i] *= fact_0;
                    }
                }

                tmp = Math.Abs(pitch_gain[0] + pitch_gain[1]
                               + pitch_gain[2]);
                tmp = Math.Abs(pitch_gain[1]);
                if (pitch_gain[0] > 0)
                {
                    tmp += pitch_gain[0];
                }
                else
                {
                    tmp -= .5f * pitch_gain[0];
                }
                if (pitch_gain[2] > 0)
                {
                    tmp += pitch_gain[2];
                }
                else
                {
                    tmp -= .5f * pitch_gain[0];
                }

                pitch_average += tmp;
                if (tmp > best_pitch_gain)
                {
                    best_pitch      = pitch;
                    best_pitch_gain = tmp;
                }

                /* Unquantize the innovation */
                int   q_energy, ivi = sub * subframeSize;
                float ener;

                for (i = ivi; i < ivi + subframeSize; i++)
                {
                    innov[i] = 0.0f;
                }

                /* Decode sub-frame gain correction */
                if (submodes[submodeID].HaveSubframeGain == 3)
                {
                    q_energy = bits.Unpack(3);
                    ener     = (float)(ol_gain * Math.Exp(NSpeex.NbCodec.exc_gain_quant_scal3[q_energy]));
                }
                else if (submodes[submodeID].HaveSubframeGain == 1)
                {
                    q_energy = bits.Unpack(1);
                    ener     = (float)(ol_gain * Math.Exp(NSpeex.NbCodec.exc_gain_quant_scal1[q_energy]));
                }
                else
                {
                    ener = ol_gain;
                }

                if (submodes[submodeID].Innovation != null)
                {
                    /* Fixed codebook contribution */
                    submodes[submodeID].Innovation.Unquantify(innov, ivi,
                                                              subframeSize, bits);
                }

                /* De-normalize innovation and update excitation */
                for (i = ivi; i < ivi + subframeSize; i++)
                {
                    innov[i] *= ener;
                }

                /* Vocoder mode */
                if (submodeID == 1)
                {
                    float g = ol_pitch_coef;

                    for (i = 0; i < subframeSize; i++)
                    {
                        excBuf[extIdx + i] = 0;
                    }
                    while (voc_offset < subframeSize)
                    {
                        if (voc_offset >= 0)
                        {
                            excBuf[extIdx + voc_offset] = (float)Math.Sqrt(1.0f * ol_pitch);
                        }
                        voc_offset += ol_pitch;
                    }
                    voc_offset -= subframeSize;

                    g = .5f + 2 * (g - .6f);
                    if (g < 0)
                    {
                        g = 0;
                    }
                    if (g > 1)
                    {
                        g = 1;
                    }
                    for (i = 0; i < subframeSize; i++)
                    {
                        float itmp = excBuf[extIdx + i];
                        excBuf[extIdx + i] = .8f * g * excBuf[extIdx + i] * ol_gain
                                             + .6f * g * voc_m1 * ol_gain + .5f * g
                                             * innov[ivi + i] - .5f * g * voc_m2 + (1 - g)
                                             * innov[ivi + i];
                        voc_m1              = itmp;
                        voc_m2              = innov[ivi + i];
                        voc_mean            = .95f * voc_mean + .05f * excBuf[extIdx + i];
                        excBuf[extIdx + i] -= voc_mean;
                    }
                }
                else
                {
                    for (i = 0; i < subframeSize; i++)
                    {
                        excBuf[extIdx + i] += innov[ivi + i];
                    }
                }

                /* Decode second codebook (only for some modes) */
                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] *= ener * (1 / 2.2f);
                    }
                    for (i = 0; i < subframeSize; i++)
                    {
                        excBuf[extIdx + i] += innov2[i];
                    }
                }

                for (i = 0; i < subframeSize; i++)
                {
                    frmBuf[spIdx + i] = excBuf[extIdx + i];
                }

                /* Signal synthesis */
                if (enhanced && submodes[submodeID].CombGain > 0)
                {
                    filters.Comb_filter(excBuf, extIdx, frmBuf, spIdx,
                                        subframeSize, pitch, pitch_gain,
                                        submodes[submodeID].CombGain);
                }

                if (enhanced)
                {
                    /* Use enhanced LPC filter */
                    NSpeex.Filters.Filter_mem2(frmBuf, spIdx, awk2, awk1,
                                               subframeSize, lpcSize, mem_sp, lpcSize);
                    NSpeex.Filters.Filter_mem2(frmBuf, spIdx, 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(frmBuf, spIdx, interp_qlpc, frmBuf,
                                            spIdx, subframeSize, lpcSize, mem_sp);
                }
            }

            /* Copy output signal */
            xout[0] = frmBuf[frmIdx] + preemph * pre_mem;
            for (i = 1; i < frameSize; i++)
            {
                xout[i] = frmBuf[frmIdx + i] + preemph * xout[i - 1];
            }
            pre_mem = xout[frameSize - 1];

            /* Store the LSPs for interpolation in the next frame */
            for (i = 0; i < lpcSize; i++)
            {
                old_qlsp[i] = qlsp[i];
            }

            /* The next frame will not be the first (Duh!) */
            first           = 0;
            count_lost      = 0;
            last_pitch      = best_pitch;
            last_pitch_gain = .25f * pitch_average;
            pitch_gain_buf[pitch_gain_buf_idx++] = last_pitch_gain;
            if (pitch_gain_buf_idx > 2)             /* rollover */
            {
                pitch_gain_buf_idx = 0;
            }
            last_ol_gain = ol_gain;

            return(0);
        }
Ejemplo n.º 6
0
        /// <summary>
        /// Speex in-band request (submode=14).
        /// </summary>
        /// <param name="bits"></param>
        public void speexInbandRequest(Bits bits)
        {
            int code = bits.UnPack(4);

            switch (code)
            {
            case 0:     // asks the decoder to set perceptual enhancment off (0) or on (1)
                bits.Advance(1);
                break;

            case 1:     // asks (if 1) the encoder to be less "aggressive" due to high packet loss
                bits.Advance(1);
                break;

            case 2:     // asks the encoder to switch to mode N
                bits.Advance(4);
                break;

            case 3:     // asks the encoder to switch to mode N for low-band
                bits.Advance(4);
                break;

            case 4:     // asks the encoder to switch to mode N for high-band
                bits.Advance(4);
                break;

            case 5:     // asks the encoder to switch to quality N for VBR
                bits.Advance(4);
                break;

            case 6:     // request acknowledgement (0=no, 1=all, 2=only for inband data)
                bits.Advance(4);
                break;

            case 7:     // asks the encoder to set CBR(0), VAD(1), DTX(3), VBR(5), VBR+DTX(7)
                bits.Advance(4);
                break;

            case 8:     // transmit (8-bit) character to the other end
                bits.Advance(8);
                break;

            case 9:                 // intensity stereo information
                // setup the stereo decoder; to skip: tmp = bits.unpack(8); break;
                _stereo.init(bits); // read 8 bits
                break;

            case 10:     // announce maximum bit-rate acceptable (N in byets/second)
                bits.Advance(16);
                break;

            case 11:     // reserved
                bits.Advance(16);
                break;

            case 12:     // Acknowledge receiving packet N
                bits.Advance(32);
                break;

            case 13:     // reserved
                bits.Advance(32);
                break;

            case 14:     // reserved
                bits.Advance(64);
                break;

            case 15:     // reserved
                bits.Advance(64);
                break;

            default:
                break;
            }
        }