www.pudn.com > layer1.rar > tonemod.h

/* 
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* 
*      COPYRIGHT (C) 2000 BY ERICSSON EUROLAB DEUTSCHLAND GmbH 
*      90411 NUERNBERG, GERMANY, Tel Int + 49 911 5217 100 
* 
*      The program(s) may be used and/or copied only with the 
*      written permission from Ericsson or in accordance 
*      with the terms and conditions stipulated in the agreement or 
*      contract under which the program(s) have been supplied. 
* 
*      Changes since October 13, 2000: 
*      - The type mod_state_t includes a new member txbits_fifo_state now. 
* 
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* 
*      File             : tonemod.h 
*      Purpose          : header file for tonemod.c 
* 
******************************************************************************* 
*/ 
 
#ifndef tonemod_h 
#define tonemod_h "$Id: $" 
 
/* 
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*                         INCLUDE FILES 
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*/ 
 
#include  
 
/* 
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*                         DECLARATION OF PROTOTYPES 
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*/ 
 
 
/* Define a type for the state variable of the function tonemod()     */ 
 
typedef struct { 
  WORD16      cntModulatedSamples; 
  WORD16      actualBits[2]; 
  fifo_state_t  txbits_fifo_state; 
} mod_state_t; 
 
 
/* ---------------------------------------------------------------------- */ 
/* Function init_tonemod()                                                */ 
/* ***********************                                                */ 
/* This function has to be executed before tonemod() can be used.         */ 
/* ---------------------------------------------------------------------- */ 
 
void init_tonemod(mod_state_t  *mod_state); 
 
 
/* ---------------------------------------------------------------------- */ 
/* Function tonemod()                                                     */ 
/* ******************                                                     */ 
/* Modulator of the Cellular Text Telephone Modem.                        */ 
/* The input vector bits_in must contain the bits that have to be         */ 
/* transmitted. The length of bits_in must be even because always two     */ 
/* bits are coded in parallel.                                            */ 
/* Bits are either unipolar (i.e. {0, 1}) or bipolar (i.e. {-1, +1)}.     */ 
/* The length of the output vector tones_out must be 20 times longer than */ 
/* the length of bits_in, since each pair of two bits is coded within a   */ 
/* frame of 40 audio samples.                                             */ 
/* ---------------------------------------------------------------------- */ 
 
void tonemod(WORD16    *tones_out, 
             WORD16    *bits_in, 
             WORD16     num_samples_tones_out, 
             WORD16     num_bits_in, 
             mod_state_t *mod_state); 
 
#endif