--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/src/gsm0610_decode.c	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,227 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * gsm0610_decode.c - GSM 06.10 full rate speech codec.
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2006 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.
+ *
+ * This code is based on the widely used GSM 06.10 code available from
+ * http://kbs.cs.tu-berlin.de/~jutta/toast.html
+ *
+ * $Id: gsm0610_decode.c,v 1.12 2006/11/30 15:41:47 steveu Exp $
+ */
+
+/*! \file */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <assert.h>
+#include <inttypes.h>
+#if defined(HAVE_TGMATH_H)
+#include <tgmath.h>
+#endif
+#if defined(HAVE_MATH_H)
+#include <math.h>
+#endif
+#include <stdlib.h>
+#include <memory.h>
+
+#include "spandsp/telephony.h"
+#include "spandsp/dc_restore.h"
+#include "spandsp/bitstream.h"
+#include "spandsp/gsm0610.h"
+
+#include "gsm0610_local.h"
+
+/* 4.3 FIXED POINT IMPLEMENTATION OF THE RPE-LTP DECODER */
+
+static void postprocessing(gsm0610_state_t *s, int16_t amp[])
+{
+    int k;
+    int16_t msr;
+    int16_t tmp;
+
+    msr = s->msr;
+    for (k = 0;  k < GSM0610_FRAME_LEN;  k++)
+    {
+        tmp = gsm_mult_r(msr, 28180);
+        /* De-emphasis */
+        msr = gsm_add(amp[k], tmp);
+        /* Truncation & upscaling */
+        amp[k] = (int16_t) (gsm_add(msr, msr) & 0xFFF8);
+    }
+    /*endfor*/
+    s->msr = msr;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void decode_a_frame(gsm0610_state_t *s,
+                           int16_t amp[GSM0610_FRAME_LEN],
+                           gsm0610_frame_t *f)
+{
+    int j;
+    int k;
+    int16_t erp[40];
+    int16_t wt[GSM0610_FRAME_LEN];
+    int16_t *drp;
+
+    drp = s->dp0 + 120;
+    for (j = 0;  j < 4;  j++)
+    {
+        gsm0610_rpe_decoding(s, f->xmaxc[j], f->Mc[j], f->xMc[j], erp);
+        gsm0610_long_term_synthesis_filtering(s, f->Nc[j], f->bc[j], erp, drp);
+        for (k = 0;  k < 40;  k++)
+            wt[j*40 + k] = drp[k];
+        /*endfor*/
+    }
+    /*endfor*/
+
+    gsm0610_short_term_synthesis_filter(s, f->LARc, wt, amp);
+    postprocessing(s, amp);
+}
+/*- End of function --------------------------------------------------------*/
+
+int gsm0610_unpack_none(gsm0610_frame_t *s, const uint8_t c[])
+{
+    int i;
+    int j;
+    int k;
+    
+    i = 0;
+    for (j = 0;  j < 8;  j++)
+        s->LARc[j] = c[i++];
+    for (j = 0;  j < 4;  j++)
+    {
+        s->Nc[j] = c[i++];
+        s->bc[j] = c[i++];
+        s->Mc[j] = c[i++];
+        s->xmaxc[j] = c[i++];
+        for (k = 0;  k < 13;  k++)
+            s->xMc[j][k] = c[i++];
+    }
+    return 76;
+}
+/*- End of function --------------------------------------------------------*/
+
+int gsm0610_unpack_wav49(gsm0610_frame_t *s, const uint8_t code[], int half)
+{
+    int i;
+    int j;
+    static bitstream_state_t bs;
+    const uint8_t *c;
+
+    c = code;
+    if (half)
+        bitstream_init(&bs);
+    s->LARc[0] = (int16_t) bitstream_get(&bs, &c, 6);
+    s->LARc[1] = (int16_t) bitstream_get(&bs, &c, 6);
+    s->LARc[2] = (int16_t) bitstream_get(&bs, &c, 5);
+    s->LARc[3] = (int16_t) bitstream_get(&bs, &c, 5);
+    s->LARc[4] = (int16_t) bitstream_get(&bs, &c, 4);
+    s->LARc[5] = (int16_t) bitstream_get(&bs, &c, 4);
+    s->LARc[6] = (int16_t) bitstream_get(&bs, &c, 3);
+    s->LARc[7] = (int16_t) bitstream_get(&bs, &c, 3);
+    for (i = 0;  i < 4;  i++)
+    {
+        s->Nc[i] = (int16_t) bitstream_get(&bs, &c, 7);
+        s->bc[i] = (int16_t) bitstream_get(&bs, &c, 2);
+        s->Mc[i] = (int16_t) bitstream_get(&bs, &c, 2);
+        s->xmaxc[i] = (int16_t) bitstream_get(&bs, &c, 6);
+        for (j = 0;  j < 13;  j++)
+            s->xMc[i][j] = (int16_t) bitstream_get(&bs, &c, 3);
+    }
+    return (half)  ?  33  :  32;
+}
+/*- End of function --------------------------------------------------------*/
+
+int gsm0610_unpack_voip(gsm0610_frame_t *s, const uint8_t code[])
+{
+    int i;
+    int j;
+    const uint8_t *c;
+    unsigned int magic;
+    bitstream_state_t bs;
+
+    c = code;
+    bitstream_init(&bs);
+    magic = bitstream_get2(&bs, &c, 4);
+    if (magic != GSM0610_MAGIC)
+        return -1;
+    s->LARc[0] = (int16_t) bitstream_get2(&bs, &c, 6);
+    s->LARc[1] = (int16_t) bitstream_get2(&bs, &c, 6);
+    s->LARc[2] = (int16_t) bitstream_get2(&bs, &c, 5);
+    s->LARc[3] = (int16_t) bitstream_get2(&bs, &c, 5);
+    s->LARc[4] = (int16_t) bitstream_get2(&bs, &c, 4);
+    s->LARc[5] = (int16_t) bitstream_get2(&bs, &c, 4);
+    s->LARc[6] = (int16_t) bitstream_get2(&bs, &c, 3);
+    s->LARc[7] = (int16_t) bitstream_get2(&bs, &c, 3);
+    for (i = 0;  i < 4;  i++)
+    {
+        s->Nc[i] = (int16_t) bitstream_get2(&bs, &c, 7);
+        s->bc[i] = (int16_t) bitstream_get2(&bs, &c, 2);
+        s->Mc[i] = (int16_t) bitstream_get2(&bs, &c, 2);
+        s->xmaxc[i] = (int16_t) bitstream_get2(&bs, &c, 6);
+        for (j = 0;  j < 13;  j++)
+            s->xMc[i][j] = (int16_t) bitstream_get2(&bs, &c, 3);
+    }
+    return 33;
+}
+/*- End of function --------------------------------------------------------*/
+
+int gsm0610_decode(gsm0610_state_t *s, int16_t amp[], const uint8_t code[], int quant)
+{
+    gsm0610_frame_t frame;
+    const uint8_t *c;
+    int bytes;
+    int i;
+
+    if (s->packing == GSM0610_PACKING_WAV49)
+        quant <<= 1;
+    c = code;
+    for (i = 0;  i < quant;  i++)
+    {
+        switch (s->packing)
+        {
+        default:
+        case GSM0610_PACKING_NONE:
+            bytes = gsm0610_unpack_none(&frame, c);
+            break;
+        case GSM0610_PACKING_WAV49:
+            s->frame_index = !s->frame_index;
+            bytes = gsm0610_unpack_wav49(&frame, c, s->frame_index);
+            break;
+        case GSM0610_PACKING_VOIP:
+            bytes = gsm0610_unpack_voip(&frame, c);
+            break;
+        }
+        /*endswitch*/
+        if (bytes < 0)
+            return 0;
+        decode_a_frame(s, amp, &frame);
+        c += bytes;
+        amp += GSM0610_FRAME_LEN;
+    }
+    /*endwhile*/
+    return quant*GSM0610_FRAME_LEN;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/