--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/src/g722_decode.c	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,391 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * g722_decode.c - The ITU G.722 codec, decode part.
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2005 Steve Underwood
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Based in part on a single channel G.722 codec which is:
+ *
+ * Copyright (c) CMU 1993
+ * Computer Science, Speech Group
+ * Chengxiang Lu and Alex Hauptmann
+ *
+ * $Id: g722_decode.c,v 1.18 2006/11/19 14:07:24 steveu Exp $
+ */
+
+/*! \file */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <inttypes.h>
+#include <memory.h>
+#include <stdlib.h>
+#if defined(HAVE_TGMATH_H)
+#include <tgmath.h>
+#endif
+#if defined(HAVE_MATH_H)
+#include <math.h>
+#endif
+
+#include "spandsp/telephony.h"
+#include "spandsp/dc_restore.h"
+#include "spandsp/g722.h"
+
+static void block4(g722_decode_state_t *s, int band, int d);
+
+static void block4(g722_decode_state_t *s, int band, int d)
+{
+    int wd1;
+    int wd2;
+    int wd3;
+    int i;
+
+    /* Block 4, RECONS */
+    s->band[band].d[0] = d;
+    s->band[band].r[0] = saturate(s->band[band].s + d);
+
+    /* Block 4, PARREC */
+    s->band[band].p[0] = saturate(s->band[band].sz + d);
+
+    /* Block 4, UPPOL2 */
+    for (i = 0;  i < 3;  i++)
+        s->band[band].sg[i] = s->band[band].p[i] >> 15;
+    wd1 = saturate(s->band[band].a[1] << 2);
+
+    wd2 = (s->band[band].sg[0] == s->band[band].sg[1])  ?  -wd1  :  wd1;
+    if (wd2 > 32767)
+        wd2 = 32767;
+    wd3 = (s->band[band].sg[0] == s->band[band].sg[2])  ?  128  :  -128;
+    wd3 += (wd2 >> 7);
+    wd3 += (s->band[band].a[2]*32512) >> 15;
+    if (wd3 > 12288)
+        wd3 = 12288;
+    else if (wd3 < -12288)
+        wd3 = -12288;
+    s->band[band].ap[2] = wd3;
+
+    /* Block 4, UPPOL1 */
+    s->band[band].sg[0] = s->band[band].p[0] >> 15;
+    s->band[band].sg[1] = s->band[band].p[1] >> 15;
+    wd1 = (s->band[band].sg[0] == s->band[band].sg[1])  ?  192  :  -192;
+    wd2 = (s->band[band].a[1]*32640) >> 15;
+
+    s->band[band].ap[1] = saturate(wd1 + wd2);
+    wd3 = saturate(15360 - s->band[band].ap[2]);
+    if (s->band[band].ap[1] > wd3)
+        s->band[band].ap[1] = wd3;
+    else if (s->band[band].ap[1] < -wd3)
+        s->band[band].ap[1] = -wd3;
+
+    /* Block 4, UPZERO */
+    wd1 = (d == 0)  ?  0  :  128;
+    s->band[band].sg[0] = d >> 15;
+    for (i = 1;  i < 7;  i++)
+    {
+        s->band[band].sg[i] = s->band[band].d[i] >> 15;
+        wd2 = (s->band[band].sg[i] == s->band[band].sg[0])  ?  wd1  :  -wd1;
+        wd3 = (s->band[band].b[i]*32640) >> 15;
+        s->band[band].bp[i] = saturate(wd2 + wd3);
+    }
+
+    /* Block 4, DELAYA */
+    for (i = 6;  i > 0;  i--)
+    {
+        s->band[band].d[i] = s->band[band].d[i - 1];
+        s->band[band].b[i] = s->band[band].bp[i];
+    }
+    
+    for (i = 2;  i > 0;  i--)
+    {
+        s->band[band].r[i] = s->band[band].r[i - 1];
+        s->band[band].p[i] = s->band[band].p[i - 1];
+        s->band[band].a[i] = s->band[band].ap[i];
+    }
+
+    /* Block 4, FILTEP */
+    wd1 = saturate(s->band[band].r[1] + s->band[band].r[1]);
+    wd1 = (s->band[band].a[1]*wd1) >> 15;
+    wd2 = saturate(s->band[band].r[2] + s->band[band].r[2]);
+    wd2 = (s->band[band].a[2]*wd2) >> 15;
+    s->band[band].sp = saturate(wd1 + wd2);
+
+    /* Block 4, FILTEZ */
+    s->band[band].sz = 0;
+    for (i = 6;  i > 0;  i--)
+    {
+        wd1 = saturate(s->band[band].d[i] + s->band[band].d[i]);
+        s->band[band].sz += (s->band[band].b[i]*wd1) >> 15;
+    }
+    s->band[band].sz = saturate(s->band[band].sz);
+
+    /* Block 4, PREDIC */
+    s->band[band].s = saturate(s->band[band].sp + s->band[band].sz);
+}
+/*- End of function --------------------------------------------------------*/
+
+g722_decode_state_t *g722_decode_init(g722_decode_state_t *s, int rate, int options)
+{
+    if (s == NULL)
+    {
+        if ((s = (g722_decode_state_t *) malloc(sizeof(*s))) == NULL)
+            return NULL;
+    }
+    memset(s, 0, sizeof(*s));
+    if (rate == 48000)
+        s->bits_per_sample = 6;
+    else if (rate == 56000)
+        s->bits_per_sample = 7;
+    else
+        s->bits_per_sample = 8;
+    if ((options & G722_SAMPLE_RATE_8000))
+        s->eight_k = TRUE;
+    if ((options & G722_PACKED)  &&  s->bits_per_sample != 8)
+        s->packed = TRUE;
+    else
+        s->packed = FALSE;
+    s->band[0].det = 32;
+    s->band[1].det = 8;
+    return s;
+}
+/*- End of function --------------------------------------------------------*/
+
+int g722_decode_release(g722_decode_state_t *s)
+{
+    free(s);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+int g722_decode(g722_decode_state_t *s, int16_t amp[], const uint8_t g722_data[], int len)
+{
+    static const int wl[8] = {-60, -30, 58, 172, 334, 538, 1198, 3042 };
+    static const int rl42[16] = {0, 7, 6, 5, 4, 3, 2, 1, 7, 6, 5, 4, 3,  2, 1, 0 };
+    static const int ilb[32] =
+    {
+        2048, 2093, 2139, 2186, 2233, 2282, 2332,
+        2383, 2435, 2489, 2543, 2599, 2656, 2714,
+        2774, 2834, 2896, 2960, 3025, 3091, 3158,
+        3228, 3298, 3371, 3444, 3520, 3597, 3676,
+        3756, 3838, 3922, 4008
+    };
+    static const int wh[3] = {0, -214, 798};
+    static const int rh2[4] = {2, 1, 2, 1};
+    static const int qm2[4] = {-7408, -1616,  7408,   1616};
+    static const int qm4[16] = 
+    {
+              0, -20456, -12896,  -8968, 
+          -6288,  -4240,  -2584,  -1200,
+          20456,  12896,   8968,   6288,
+           4240,   2584,   1200,      0
+    };
+    static const int qm5[32] =
+    {
+           -280,   -280, -23352, -17560,
+         -14120, -11664,  -9752,  -8184,
+          -6864,  -5712,  -4696,  -3784,
+          -2960,  -2208,  -1520,   -880,
+          23352,  17560,  14120,  11664,
+           9752,   8184,   6864,   5712,
+           4696,   3784,   2960,   2208,
+           1520,    880,    280,   -280
+    };
+    static const int qm6[64] =
+    {
+           -136,   -136,   -136,   -136,
+         -24808, -21904, -19008, -16704,
+         -14984, -13512, -12280, -11192,
+         -10232,  -9360,  -8576,  -7856,
+          -7192,  -6576,  -6000,  -5456,
+          -4944,  -4464,  -4008,  -3576,
+          -3168,  -2776,  -2400,  -2032,
+          -1688,  -1360,  -1040,   -728,
+          24808,  21904,  19008,  16704,
+          14984,  13512,  12280,  11192,
+          10232,   9360,   8576,   7856,
+           7192,   6576,   6000,   5456,
+           4944,   4464,   4008,   3576,
+           3168,   2776,   2400,   2032,
+           1688,   1360,   1040,    728,
+            432,    136,   -432,   -136
+    };
+    static const int qmf_coeffs[12] =
+    {
+           3,  -11,   12,   32, -210,  951, 3876, -805,  362, -156,   53,  -11,
+    };
+
+    int dlowt;
+    int rlow;
+    int ihigh;
+    int dhigh;
+    int rhigh;
+    int xout1;
+    int xout2;
+    int wd1;
+    int wd2;
+    int wd3;
+    int code;
+    int outlen;
+    int i;
+    int j;
+
+    outlen = 0;
+    rhigh = 0;
+    for (j = 0;  j < len;  )
+    {
+        if (s->packed)
+        {
+            /* Unpack the code bits */
+            if (s->in_bits < s->bits_per_sample)
+            {
+                s->in_buffer |= (g722_data[j++] << s->in_bits);
+                s->in_bits += 8;
+            }
+            code = s->in_buffer & ((1 << s->bits_per_sample) - 1);
+            s->in_buffer >>= s->bits_per_sample;
+            s->in_bits -= s->bits_per_sample;
+        }
+        else
+        {
+            code = g722_data[j++];
+        }
+
+        switch (s->bits_per_sample)
+        {
+        default:
+        case 8:
+            wd1 = code & 0x3F;
+            ihigh = (code >> 6) & 0x03;
+            wd2 = qm6[wd1];
+            wd1 >>= 2;
+            break;
+        case 7:
+            wd1 = code & 0x1F;
+            ihigh = (code >> 5) & 0x03;
+            wd2 = qm5[wd1];
+            wd1 >>= 1;
+            break;
+        case 6:
+            wd1 = code & 0x0F;
+            ihigh = (code >> 4) & 0x03;
+            wd2 = qm4[wd1];
+            break;
+        }
+        /* Block 5L, LOW BAND INVQBL */
+        wd2 = (s->band[0].det*wd2) >> 15;
+        /* Block 5L, RECONS */
+        rlow = s->band[0].s + wd2;
+        /* Block 6L, LIMIT */
+        if (rlow > 16383)
+            rlow = 16383;
+        else if (rlow < -16384)
+            rlow = -16384;
+
+        /* Block 2L, INVQAL */
+        wd2 = qm4[wd1];
+        dlowt = (s->band[0].det*wd2) >> 15;
+
+        /* Block 3L, LOGSCL */
+        wd2 = rl42[wd1];
+        wd1 = (s->band[0].nb*127) >> 7;
+        wd1 += wl[wd2];
+        if (wd1 < 0)
+            wd1 = 0;
+        else if (wd1 > 18432)
+            wd1 = 18432;
+        s->band[0].nb = wd1;
+            
+        /* Block 3L, SCALEL */
+        wd1 = (s->band[0].nb >> 6) & 31;
+        wd2 = 8 - (s->band[0].nb >> 11);
+        wd3 = (wd2 < 0)  ?  (ilb[wd1] << -wd2)  :  (ilb[wd1] >> wd2);
+        s->band[0].det = wd3 << 2;
+
+        block4(s, 0, dlowt);
+        
+        if (!s->eight_k)
+        {
+            /* Block 2H, INVQAH */
+            wd2 = qm2[ihigh];
+            dhigh = (s->band[1].det*wd2) >> 15;
+            /* Block 5H, RECONS */
+            rhigh = dhigh + s->band[1].s;
+            /* Block 6H, LIMIT */
+            if (rhigh > 16383)
+                rhigh = 16383;
+            else if (rhigh < -16384)
+                rhigh = -16384;
+
+            /* Block 2H, INVQAH */
+            wd2 = rh2[ihigh];
+            wd1 = (s->band[1].nb*127) >> 7;
+            wd1 += wh[wd2];
+            if (wd1 < 0)
+                wd1 = 0;
+            else if (wd1 > 22528)
+                wd1 = 22528;
+            s->band[1].nb = wd1;
+            
+            /* Block 3H, SCALEH */
+            wd1 = (s->band[1].nb >> 6) & 31;
+            wd2 = 10 - (s->band[1].nb >> 11);
+            wd3 = (wd2 < 0)  ?  (ilb[wd1] << -wd2)  :  (ilb[wd1] >> wd2);
+            s->band[1].det = wd3 << 2;
+
+            block4(s, 1, dhigh);
+        }
+
+        if (s->itu_test_mode)
+        {
+            amp[outlen++] = (int16_t) (rlow << 1);
+            amp[outlen++] = (int16_t) (rhigh << 1);
+        }
+        else
+        {
+            if (s->eight_k)
+            {
+                amp[outlen++] = (int16_t) rlow;
+            }
+            else
+            {
+                /* Apply the receive QMF */
+                for (i = 0;  i < 22;  i++)
+                    s->x[i] = s->x[i + 2];
+                s->x[22] = rlow + rhigh;
+                s->x[23] = rlow - rhigh;
+
+                xout1 = 0;
+                xout2 = 0;
+                for (i = 0;  i < 12;  i++)
+                {
+                    xout2 += s->x[2*i]*qmf_coeffs[i];
+                    xout1 += s->x[2*i + 1]*qmf_coeffs[11 - i];
+                }
+                amp[outlen++] = (int16_t) (xout1 >> 12);
+                amp[outlen++] = (int16_t) (xout2 >> 12);
+            }
+        }
+    }
+    return outlen;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/