/*
* 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.
*
* Despite my general liking of the GPL, I place my own contributions
* to this code in the public domain for the benefit of all mankind -
* even the slimy ones who might try to proprietize my work and use it
* to my detriment.
*
* 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 1.14 2006/07/07 16:37:49 steveu Exp $
*/
/*! \file */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "g722_typedefs.h"
#include "g722_enc_dec.h"
#if !defined(FALSE)
#define FALSE 0
#endif
#if !defined(TRUE)
#define TRUE (!FALSE)
#endif
#define PACKED_OUTPUT (0)
#define BITS_PER_SAMPLE (8)
#ifndef BUILD_FEATURE_G722_USE_INTRINSIC_SAT
static __inline int16_t saturate(int32_t amp)
{
int16_t amp16;
/* Hopefully this is optimised for the common case - not clipping */
amp16 = (int16_t) amp;
if (amp == amp16)
return amp16;
if (amp > 0x7FFF)
return 0x7FFF;
return 0x8000;
}
#else
static __inline int16_t saturate(int32_t val)
{
register int32_t res;
__asm volatile (
"SSAT %0, #16, %1\n\t"
:"=r"(res)
:"r"(val)
:);
return (int16_t)res;
}
#endif
/*- End of function --------------------------------------------------------*/
static void block4(g722_band_t *band, int d)
{
int wd1;
int wd2;
int wd3;
int i;
int sg[7];
int ap1, ap2;
int sg0, sgi;
int sz;
/* Block 4, RECONS */
band->d[0] = d;
band->r[0] = saturate(band->s + d);
/* Block 4, PARREC */
band->p[0] = saturate(band->sz + d);
/* Block 4, UPPOL2 */
for (i = 0; i < 3; i++)
sg[i] = band->p[i] >> 15;
wd1 = saturate(band->a[1] << 2);
wd2 = (sg[0] == sg[1]) ? -wd1 : wd1;
if (wd2 > 32767)
wd2 = 32767;
ap2 = (wd2 >> 7) + ((sg[0] == sg[2]) ? 128 : -128);
ap2 += (band->a[2]*32512) >> 15;
if (ap2 > 12288)
ap2 = 12288;
else if (ap2 < -12288)
ap2 = -12288;
band->ap[2] = ap2;
/* Block 4, UPPOL1 */
sg[0] = band->p[0] >> 15;
sg[1] = band->p[1] >> 15;
wd1 = (sg[0] == sg[1]) ? 192 : -192;
wd2 = (band->a[1]*32640) >> 15;
ap1 = saturate(wd1 + wd2);
wd3 = saturate(15360 - band->ap[2]);
if (ap1 > wd3)
ap1 = wd3;
else if (ap1 < -wd3)
ap1 = -wd3;
band->ap[1] = ap1;
/* Block 4, UPZERO */
/* Block 4, FILTEZ */
wd1 = (d == 0) ? 0 : 128;
sg0 = sg[0] = d >> 15;
for (i = 1; i < 7; i++)
{
sgi = band->d[i] >> 15;
wd2 = (sgi == sg0) ? wd1 : -wd1;
wd3 = (band->b[i]*32640) >> 15;
band->bp[i] = saturate(wd2 + wd3);
}
/* Block 4, DELAYA */
sz = 0;
for (i = 6; i > 0; i--)
{
int bi;
band->d[i] = band->d[i - 1];
bi = band->b[i] = band->bp[i];
wd1 = saturate(band->d[i] + band->d[i]);
sz += (bi*wd1) >> 15;
}
band->sz = sz;
for (i = 2; i > 0; i--)
{
band->r[i] = band->r[i - 1];
band->p[i] = band->p[i - 1];
band->a[i] = band->ap[i];
}
/* Block 4, FILTEP */
wd1 = saturate(band->r[1] + band->r[1]);
wd1 = (band->a[1]*wd1) >> 15;
wd2 = saturate(band->r[2] + band->r[2]);
wd2 = (band->a[2]*wd2) >> 15;
band->sp = saturate(wd1 + wd2);
/* Block 4, PREDIC */
band->s = saturate(band->sp + band->sz);
}
/*- End of function --------------------------------------------------------*/
g722_encode_state_t *g722_encode_init(g722_encode_state_t *s,
unsigned int rate, int options)
{
if (s == NULL)
{
#ifdef G722_SUPPORT_MALLOC
if ((s = (g722_encode_state_t *) malloc(sizeof(*s))) == NULL)
#endif
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;
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 --------------------------------------------------------*/
/* WebRtc, tlegrand:
* Only define the following if bit-exactness with reference implementation
* is needed. Will only have any effect if input signal is saturated.
*/
//#define RUN_LIKE_REFERENCE_G722
#ifdef RUN_LIKE_REFERENCE_G722
int16_t limitValues (int16_t rl)
{
int16_t yl;
yl = (rl > 16383) ? 16383 : ((rl < -16384) ? -16384 : rl);
return (yl);
}
/*- End of function --------------------------------------------------------*/
#endif
static int16_t 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 int16_t 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 int16_t 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 int16_t wl[8] =
{
-60, -30, 58, 172, 334, 538, 1198, 3042
};
static int16_t rl42[16] =
{
0, 7, 6, 5, 4, 3, 2, 1, 7, 6, 5, 4, 3, 2, 1, 0
};
static int16_t 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 int16_t qm4[16] =
{
0, -20456, -12896, -8968,
-6288, -4240, -2584, -1200,
20456, 12896, 8968, 6288,
4240, 2584, 1200, 0
};
static int16_t qm2[4] =
{
-7408, -1616, 7408, 1616
};
static int16_t qmf_coeffs[12] =
{
3, -11, 12, 32, -210, 951, 3876, -805, 362, -156, 53, -11,
};
static int16_t ihn[3] = {0, 1, 0};
static int16_t ihp[3] = {0, 3, 2};
static int16_t wh[3] = {0, -214, 798};
static int16_t rh2[4] = {2, 1, 2, 1};
int g722_encode(g722_encode_state_t *s, uint8_t g722_data[],
const int16_t amp[], int len)
{
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
{
{
/* Apply the transmit QMF */
/* Shuffle the buffer down */
for (i = 0; i < 22; i++)
s->x[i] = s->x[i + 2];
//TODO: if len is odd, then this can be a buffer overrun
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];
}
/* We shift by 12 to allow for the QMF filters (DC gain = 4096), plus 1
to allow for us summing two filters, plus 1 to allow for the 15 bit
input to the G.722 algorithm. */
xlow = (sumeven + sumodd) >> 14;
xhigh = (sumeven - sumodd) >> 14;
#ifdef RUN_LIKE_REFERENCE_G722
/* The following lines are only used to verify bit-exactness
* with reference implementation of G.722. Higher precision
* is achieved without limiting the values.
*/
xlow = limitValues(xlow);
xhigh = limitValues(xhigh);
#endif
}
}
/* 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->band[0], dlow);
{
int nb;
/* 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;
nb = wd + wh[ih2];
if (nb < 0)
nb = 0;
else if (nb > 22528)
nb = 22528;
s->band[1].nb = nb;
/* 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->band[1], dhigh);
#if BITS_PER_SAMPLE == 8
code = ((ihigh << 6) | ilow);
#elif BITS_PER_SAMPLE == 7
code = ((ihigh << 6) | ilow) >> 1;
#elif BITS_PER_SAMPLE == 6
code = ((ihigh << 6) | ilow) >> 2;
#endif
}
#if PACKED_OUTPUT == 1
/* 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;
#endif
}
return g722_bytes;
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/