diff spandsp-0.0.3/spandsp-0.0.3/src/g722_encode.c @ 5:f762bf195c4b

import spandsp-0.0.3
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Fri, 25 Jun 2010 16:00:21 +0200
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/src/g722_encode.c	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,391 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * g722_encode.c - The ITU G.722 codec, encode 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 on a single channel 64kbps only G.722 codec which is:
+ *
+ *****    Copyright (c) CMU    1993      *****
+ * Computer Science, Speech Group
+ * Chengxiang Lu and Alex Hauptmann
+ *
+ * $Id: g722_encode.c,v 1.16 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_encode_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 = (wd2 >> 7) + ((s->band[band].sg[0] == s->band[band].sg[2])  ?  128  :  -128);
+    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_encode_state_t *g722_encode_init(g722_encode_state_t *s, int rate, int options)
+{
+    if (s == NULL)
+    {
+        if ((s = (g722_encode_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_encode_release(g722_encode_state_t *s)
+{
+    free(s);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+int g722_encode(g722_encode_state_t *s, uint8_t g722_data[], const int16_t amp[], int len)
+{
+    static const int q6[32] =
+    {
+           0,   35,   72,  110,  150,  190,  233,  276,
+         323,  370,  422,  473,  530,  587,  650,  714,
+         786,  858,  940, 1023, 1121, 1219, 1339, 1458,
+        1612, 1765, 1980, 2195, 2557, 2919,    0,    0
+    };
+    static const int iln[32] =
+    {
+         0, 63, 62, 31, 30, 29, 28, 27,
+        26, 25, 24, 23, 22, 21, 20, 19,
+        18, 17, 16, 15, 14, 13, 12, 11,
+        10,  9,  8,  7,  6,  5,  4,  0
+    };
+    static const int ilp[32] =
+    {
+         0, 61, 60, 59, 58, 57, 56, 55,
+        54, 53, 52, 51, 50, 49, 48, 47,
+        46, 45, 44, 43, 42, 41, 40, 39,
+        38, 37, 36, 35, 34, 33, 32,  0
+    };
+    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 qm4[16] =
+    {
+             0, -20456, -12896, -8968,
+         -6288,  -4240,  -2584, -1200,
+         20456,  12896,   8968,  6288,
+          4240,   2584,   1200,     0
+    };
+    static const int qm2[4] =
+    {
+        -7408,  -1616,   7408,   1616
+    };
+    static const int qmf_coeffs[12] =
+    {
+           3,  -11,   12,   32, -210,  951, 3876, -805,  362, -156,   53,  -11,
+    };
+    static const int ihn[3] = {0, 1, 0};
+    static const int ihp[3] = {0, 3, 2};
+    static const int wh[3] = {0, -214, 798};
+    static const int rh2[4] = {2, 1, 2, 1};
+
+    int dlow;
+    int dhigh;
+    int el;
+    int wd;
+    int wd1;
+    int ril;
+    int wd2;
+    int il4;
+    int ih2;
+    int wd3;
+    int eh;
+    int mih;
+    int i;
+    int j;
+    /* Low and high band PCM from the QMF */
+    int xlow;
+    int xhigh;
+    int g722_bytes;
+    /* Even and odd tap accumulators */
+    int sumeven;
+    int sumodd;
+    int ihigh;
+    int ilow;
+    int code;
+
+    g722_bytes = 0;
+    xhigh = 0;
+    for (j = 0;  j < len;  )
+    {
+        if (s->itu_test_mode)
+        {
+            xlow =
+            xhigh = amp[j++] >> 1;
+        }
+        else
+        {
+            if (s->eight_k)
+            {
+                xlow = amp[j++];
+            }
+            else
+            {
+                /* Apply the transmit QMF */
+                /* Shuffle the buffer down */
+                for (i = 0;  i < 22;  i++)
+                    s->x[i] = s->x[i + 2];
+                s->x[22] = amp[j++];
+                s->x[23] = amp[j++];
+    
+                /* Discard every other QMF output */
+                sumeven = 0;
+                sumodd = 0;
+                for (i = 0;  i < 12;  i++)
+                {
+                    sumodd += s->x[2*i]*qmf_coeffs[i];
+                    sumeven += s->x[2*i + 1]*qmf_coeffs[11 - i];
+                }
+                xlow = (sumeven + sumodd) >> 13;
+                xhigh = (sumeven - sumodd) >> 13;
+            }
+        }
+        /* Block 1L, SUBTRA */
+        el = saturate(xlow - s->band[0].s);
+
+        /* Block 1L, QUANTL */
+        wd = (el >= 0)  ?  el  :  -(el + 1);
+
+        for (i = 1;  i < 30;  i++)
+        {
+            wd1 = (q6[i]*s->band[0].det) >> 12;
+            if (wd < wd1)
+                break;
+        }
+        ilow = (el < 0)  ?  iln[i]  :  ilp[i];
+
+        /* Block 2L, INVQAL */
+        ril = ilow >> 2;
+        wd2 = qm4[ril];
+        dlow = (s->band[0].det*wd2) >> 15;
+
+        /* Block 3L, LOGSCL */
+        il4 = rl42[ril];
+        wd = (s->band[0].nb*127) >> 7;
+        s->band[0].nb = wd + wl[il4];
+        if (s->band[0].nb < 0)
+            s->band[0].nb = 0;
+        else if (s->band[0].nb > 18432)
+            s->band[0].nb = 18432;
+
+        /* 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, dlow);
+        
+        if (s->eight_k)
+        {
+            /* Just leave the high bits as zero */
+            code = (0xC0 | ilow) >> (8 - s->bits_per_sample);
+        }
+        else
+        {
+            /* Block 1H, SUBTRA */
+            eh = saturate(xhigh - s->band[1].s);
+
+            /* Block 1H, QUANTH */
+            wd = (eh >= 0)  ?  eh  :  -(eh + 1);
+            wd1 = (564*s->band[1].det) >> 12;
+            mih = (wd >= wd1)  ?  2  :  1;
+            ihigh = (eh < 0)  ?  ihn[mih]  :  ihp[mih];
+
+            /* Block 2H, INVQAH */
+            wd2 = qm2[ihigh];
+            dhigh = (s->band[1].det*wd2) >> 15;
+
+            /* Block 3H, LOGSCH */
+            ih2 = rh2[ihigh];
+            wd = (s->band[1].nb*127) >> 7;
+            s->band[1].nb = wd + wh[ih2];
+            if (s->band[1].nb < 0)
+                s->band[1].nb = 0;
+            else if (s->band[1].nb > 22528)
+                s->band[1].nb = 22528;
+
+            /* 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);
+            code = ((ihigh << 6) | ilow) >> (8 - s->bits_per_sample);
+        }
+
+        if (s->packed)
+        {
+            /* Pack the code bits */
+            s->out_buffer |= (code << s->out_bits);
+            s->out_bits += s->bits_per_sample;
+            if (s->out_bits >= 8)
+            {
+                g722_data[g722_bytes++] = (uint8_t) (s->out_buffer & 0xFF);
+                s->out_bits -= 8;
+                s->out_buffer >>= 8;
+            }
+        }
+        else
+        {
+            g722_data[g722_bytes++] = (uint8_t) code;
+        }
+    }
+    return g722_bytes;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/

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