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			401 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			401 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * SpanDSP - a series of DSP components for telephony
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|  *
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|  * g722_encode.c - The ITU G.722 codec, encode part.
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|  *
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|  * Written by Steve Underwood <steveu@coppice.org>
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|  *
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|  * Copyright (C) 2005 Steve Underwood
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|  *
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|  * All rights reserved.
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|  *
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|  *  Despite my general liking of the GPL, I place my own contributions
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|  *  to this code in the public domain for the benefit of all mankind -
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|  *  even the slimy ones who might try to proprietize my work and use it
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|  *  to my detriment.
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|  *
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|  * Based on a single channel 64kbps only G.722 codec which is:
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|  *
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|  *****    Copyright (c) CMU    1993      *****
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|  * Computer Science, Speech Group
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|  * Chengxiang Lu and Alex Hauptmann
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|  *
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|  * $Id$
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|  */
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| 
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| /*! \file */
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| 
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| #ifdef HAVE_CONFIG_H
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| #include <config.h>
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| #endif
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| 
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| #include <stdio.h>
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| #include <inttypes.h>
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| #include <memory.h>
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| #include <stdlib.h>
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| #if 0
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| #include <tgmath.h>
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| #endif
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| 
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| #include "g722.h"
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| 
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| #if !defined(FALSE)
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| #define FALSE 0
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| #endif
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| #if !defined(TRUE)
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| #define TRUE (!FALSE)
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| #endif
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| 
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| static __inline__ int16_t saturate(int32_t amp)
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| {
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|     int16_t amp16;
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| 
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|     /* Hopefully this is optimised for the common case - not clipping */
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|     amp16 = (int16_t) amp;
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|     if (amp == amp16)
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|         return amp16;
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|     if (amp > INT16_MAX)
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|         return  INT16_MAX;
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|     return  INT16_MIN;
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| }
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| /*- End of function --------------------------------------------------------*/
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| 
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| static void block4(g722_encode_state_t *s, int band, int d)
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| {
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|     int wd1;
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|     int wd2;
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|     int wd3;
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|     int i;
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| 
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|     /* Block 4, RECONS */
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|     s->band[band].d[0] = d;
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|     s->band[band].r[0] = saturate(s->band[band].s + d);
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| 
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|     /* Block 4, PARREC */
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|     s->band[band].p[0] = saturate(s->band[band].sz + d);
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| 
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|     /* Block 4, UPPOL2 */
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|     for (i = 0;  i < 3;  i++)
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|         s->band[band].sg[i] = s->band[band].p[i] >> 15;
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|     wd1 = saturate(s->band[band].a[1] << 2);
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| 
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|     wd2 = (s->band[band].sg[0] == s->band[band].sg[1])  ?  -wd1  :  wd1;
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|     if (wd2 > 32767)
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|         wd2 = 32767;
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|     wd3 = (wd2 >> 7) + ((s->band[band].sg[0] == s->band[band].sg[2])  ?  128  :  -128);
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|     wd3 += (s->band[band].a[2]*32512) >> 15;
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|     if (wd3 > 12288)
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|         wd3 = 12288;
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|     else if (wd3 < -12288)
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|         wd3 = -12288;
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|     s->band[band].ap[2] = wd3;
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| 
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|     /* Block 4, UPPOL1 */
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|     s->band[band].sg[0] = s->band[band].p[0] >> 15;
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|     s->band[band].sg[1] = s->band[band].p[1] >> 15;
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|     wd1 = (s->band[band].sg[0] == s->band[band].sg[1])  ?  192  :  -192;
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|     wd2 = (s->band[band].a[1]*32640) >> 15;
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| 
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|     s->band[band].ap[1] = saturate(wd1 + wd2);
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|     wd3 = saturate(15360 - s->band[band].ap[2]);
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|     if (s->band[band].ap[1] > wd3)
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|         s->band[band].ap[1] = wd3;
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|     else if (s->band[band].ap[1] < -wd3)
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|         s->band[band].ap[1] = -wd3;
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| 
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|     /* Block 4, UPZERO */
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|     wd1 = (d == 0)  ?  0  :  128;
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|     s->band[band].sg[0] = d >> 15;
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|     for (i = 1;  i < 7;  i++)
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|     {
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|         s->band[band].sg[i] = s->band[band].d[i] >> 15;
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|         wd2 = (s->band[band].sg[i] == s->band[band].sg[0])  ?  wd1  :  -wd1;
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|         wd3 = (s->band[band].b[i]*32640) >> 15;
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|         s->band[band].bp[i] = saturate(wd2 + wd3);
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|     }
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| 
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|     /* Block 4, DELAYA */
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|     for (i = 6;  i > 0;  i--)
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|     {
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|         s->band[band].d[i] = s->band[band].d[i - 1];
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|         s->band[band].b[i] = s->band[band].bp[i];
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|     }
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| 
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|     for (i = 2;  i > 0;  i--)
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|     {
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|         s->band[band].r[i] = s->band[band].r[i - 1];
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|         s->band[band].p[i] = s->band[band].p[i - 1];
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|         s->band[band].a[i] = s->band[band].ap[i];
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|     }
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| 
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|     /* Block 4, FILTEP */
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|     wd1 = saturate(s->band[band].r[1] + s->band[band].r[1]);
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|     wd1 = (s->band[band].a[1]*wd1) >> 15;
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|     wd2 = saturate(s->band[band].r[2] + s->band[band].r[2]);
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|     wd2 = (s->band[band].a[2]*wd2) >> 15;
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|     s->band[band].sp = saturate(wd1 + wd2);
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| 
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|     /* Block 4, FILTEZ */
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|     s->band[band].sz = 0;
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|     for (i = 6;  i > 0;  i--)
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|     {
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|         wd1 = saturate(s->band[band].d[i] + s->band[band].d[i]);
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|         s->band[band].sz += (s->band[band].b[i]*wd1) >> 15;
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|     }
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|     s->band[band].sz = saturate(s->band[band].sz);
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| 
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|     /* Block 4, PREDIC */
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|     s->band[band].s = saturate(s->band[band].sp + s->band[band].sz);
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| }
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| /*- End of function --------------------------------------------------------*/
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| 
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| g722_encode_state_t *g722_encode_init(g722_encode_state_t *s, int rate, int options)
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| {
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|     if (s == NULL)
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|     {
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|         if ((s = (g722_encode_state_t *) malloc(sizeof(*s))) == NULL)
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|             return NULL;
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|     }
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|     memset(s, 0, sizeof(*s));
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|     if (rate == 48000)
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|         s->bits_per_sample = 6;
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|     else if (rate == 56000)
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|         s->bits_per_sample = 7;
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|     else
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|         s->bits_per_sample = 8;
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|     if ((options & G722_SAMPLE_RATE_8000))
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|         s->eight_k = TRUE;
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|     if ((options & G722_PACKED)  &&  s->bits_per_sample != 8)
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|         s->packed = TRUE;
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|     else
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|         s->packed = FALSE;
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|     s->band[0].det = 32;
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|     s->band[1].det = 8;
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|     return s;
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| }
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| /*- End of function --------------------------------------------------------*/
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| 
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| int g722_encode_release(g722_encode_state_t *s)
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| {
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|     free(s);
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|     return 0;
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| }
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| /*- End of function --------------------------------------------------------*/
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| 
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| int g722_encode(g722_encode_state_t *s, uint8_t g722_data[], const int16_t amp[], int len)
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| {
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|     static const int q6[32] =
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|     {
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|            0,   35,   72,  110,  150,  190,  233,  276,
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|          323,  370,  422,  473,  530,  587,  650,  714,
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|          786,  858,  940, 1023, 1121, 1219, 1339, 1458,
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|         1612, 1765, 1980, 2195, 2557, 2919,    0,    0
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|     };
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|     static const int iln[32] =
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|     {
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|          0, 63, 62, 31, 30, 29, 28, 27,
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|         26, 25, 24, 23, 22, 21, 20, 19,
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|         18, 17, 16, 15, 14, 13, 12, 11,
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|         10,  9,  8,  7,  6,  5,  4,  0
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|     };
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|     static const int ilp[32] =
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|     {
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|          0, 61, 60, 59, 58, 57, 56, 55,
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|         54, 53, 52, 51, 50, 49, 48, 47,
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|         46, 45, 44, 43, 42, 41, 40, 39,
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|         38, 37, 36, 35, 34, 33, 32,  0
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|     };
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|     static const int wl[8] =
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|     {
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|         -60, -30, 58, 172, 334, 538, 1198, 3042
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|     };
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|     static const int rl42[16] =
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|     {
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|         0, 7, 6, 5, 4, 3, 2, 1, 7, 6, 5, 4, 3, 2, 1, 0
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|     };
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|     static const int ilb[32] =
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|     {
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|         2048, 2093, 2139, 2186, 2233, 2282, 2332,
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|         2383, 2435, 2489, 2543, 2599, 2656, 2714,
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|         2774, 2834, 2896, 2960, 3025, 3091, 3158,
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|         3228, 3298, 3371, 3444, 3520, 3597, 3676,
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|         3756, 3838, 3922, 4008
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|     };
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|     static const int qm4[16] =
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|     {
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|              0, -20456, -12896, -8968,
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|          -6288,  -4240,  -2584, -1200,
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|          20456,  12896,   8968,  6288,
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|           4240,   2584,   1200,     0
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|     };
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|     static const int qm2[4] =
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|     {
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|         -7408,  -1616,   7408,   1616
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|     };
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|     static const int qmf_coeffs[12] =
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|     {
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|            3,  -11,   12,   32, -210,  951, 3876, -805,  362, -156,   53,  -11,
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|     };
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|     static const int ihn[3] = {0, 1, 0};
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|     static const int ihp[3] = {0, 3, 2};
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|     static const int wh[3] = {0, -214, 798};
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|     static const int rh2[4] = {2, 1, 2, 1};
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| 
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|     int dlow;
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|     int dhigh;
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|     int el;
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|     int wd;
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|     int wd1;
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|     int ril;
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|     int wd2;
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|     int il4;
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|     int ih2;
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|     int wd3;
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|     int eh;
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|     int mih;
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|     int i;
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|     int j;
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|     /* Low and high band PCM from the QMF */
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|     int xlow;
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|     int xhigh;
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|     int g722_bytes;
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|     /* Even and odd tap accumulators */
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|     int sumeven;
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|     int sumodd;
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|     int ihigh;
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|     int ilow;
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|     int code;
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| 
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|     g722_bytes = 0;
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|     xhigh = 0;
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|     for (j = 0;  j < len;  )
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|     {
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|         if (s->itu_test_mode)
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|         {
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|             xlow =
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|             xhigh = amp[j++] >> 1;
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|         }
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|         else
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|         {
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|             if (s->eight_k)
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|             {
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|                 xlow = amp[j++] >> 1;
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|             }
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|             else
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|             {
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|                 /* Apply the transmit QMF */
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|                 /* Shuffle the buffer down */
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|                 for (i = 0;  i < 22;  i++)
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|                     s->x[i] = s->x[i + 2];
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|                 s->x[22] = amp[j++];
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|                 s->x[23] = amp[j++];
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| 
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|                 /* Discard every other QMF output */
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|                 sumeven = 0;
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|                 sumodd = 0;
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|                 for (i = 0;  i < 12;  i++)
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|                 {
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|                     sumodd += s->x[2*i]*qmf_coeffs[i];
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|                     sumeven += s->x[2*i + 1]*qmf_coeffs[11 - i];
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|                 }
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|                 xlow = (sumeven + sumodd) >> 14;
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|                 xhigh = (sumeven - sumodd) >> 14;
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|             }
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|         }
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|         /* Block 1L, SUBTRA */
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|         el = saturate(xlow - s->band[0].s);
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| 
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|         /* Block 1L, QUANTL */
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|         wd = (el >= 0)  ?  el  :  -(el + 1);
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| 
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|         for (i = 1;  i < 30;  i++)
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|         {
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|             wd1 = (q6[i]*s->band[0].det) >> 12;
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|             if (wd < wd1)
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|                 break;
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|         }
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|         ilow = (el < 0)  ?  iln[i]  :  ilp[i];
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| 
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|         /* Block 2L, INVQAL */
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|         ril = ilow >> 2;
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|         wd2 = qm4[ril];
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|         dlow = (s->band[0].det*wd2) >> 15;
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| 
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|         /* Block 3L, LOGSCL */
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|         il4 = rl42[ril];
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|         wd = (s->band[0].nb*127) >> 7;
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|         s->band[0].nb = wd + wl[il4];
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|         if (s->band[0].nb < 0)
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|             s->band[0].nb = 0;
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|         else if (s->band[0].nb > 18432)
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|             s->band[0].nb = 18432;
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| 
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|         /* Block 3L, SCALEL */
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|         wd1 = (s->band[0].nb >> 6) & 31;
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|         wd2 = 8 - (s->band[0].nb >> 11);
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|         wd3 = (wd2 < 0)  ?  (ilb[wd1] << -wd2)  :  (ilb[wd1] >> wd2);
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|         s->band[0].det = wd3 << 2;
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| 
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|         block4(s, 0, dlow);
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| 
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|         if (s->eight_k)
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|         {
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|             /* Just leave the high bits as zero */
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|             code = (0xC0 | ilow) >> (8 - s->bits_per_sample);
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|         }
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|         else
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|         {
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|             /* Block 1H, SUBTRA */
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|             eh = saturate(xhigh - s->band[1].s);
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| 
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|             /* Block 1H, QUANTH */
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|             wd = (eh >= 0)  ?  eh  :  -(eh + 1);
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|             wd1 = (564*s->band[1].det) >> 12;
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|             mih = (wd >= wd1)  ?  2  :  1;
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|             ihigh = (eh < 0)  ?  ihn[mih]  :  ihp[mih];
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| 
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|             /* Block 2H, INVQAH */
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|             wd2 = qm2[ihigh];
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|             dhigh = (s->band[1].det*wd2) >> 15;
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| 
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|             /* Block 3H, LOGSCH */
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|             ih2 = rh2[ihigh];
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|             wd = (s->band[1].nb*127) >> 7;
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|             s->band[1].nb = wd + wh[ih2];
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|             if (s->band[1].nb < 0)
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|                 s->band[1].nb = 0;
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|             else if (s->band[1].nb > 22528)
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|                 s->band[1].nb = 22528;
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| 
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|             /* Block 3H, SCALEH */
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|             wd1 = (s->band[1].nb >> 6) & 31;
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|             wd2 = 10 - (s->band[1].nb >> 11);
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|             wd3 = (wd2 < 0)  ?  (ilb[wd1] << -wd2)  :  (ilb[wd1] >> wd2);
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|             s->band[1].det = wd3 << 2;
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| 
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|             block4(s, 1, dhigh);
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|             code = ((ihigh << 6) | ilow) >> (8 - s->bits_per_sample);
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|         }
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| 
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|         if (s->packed)
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|         {
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|             /* Pack the code bits */
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|             s->out_buffer |= (code << s->out_bits);
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|             s->out_bits += s->bits_per_sample;
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|             if (s->out_bits >= 8)
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|             {
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|                 g722_data[g722_bytes++] = (uint8_t) (s->out_buffer & 0xFF);
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|                 s->out_bits -= 8;
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|                 s->out_buffer >>= 8;
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|             }
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|         }
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|         else
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|         {
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|             g722_data[g722_bytes++] = (uint8_t) code;
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|         }
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|     }
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|     return g722_bytes;
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| }
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| /*- End of function --------------------------------------------------------*/
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| /*- End of file ------------------------------------------------------------*/
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