c2_11pf.h

arm音频编解码库

/*
********************************************************************************
*
*      GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001
*                                R99   Version 3.3.0                
*                                REL-4 Version 4.1.0                
*
********************************************************************************
*
*      File             : c2_11pf.h
*      Purpose          : Searches a 11 bit algebraic codebook containing 2 pulses
*                         in a frame of 40 samples.
*
********************************************************************************
*/
#ifndef c2_11pf_h
#define c2_11pf_h "$Id $"
 
/*
********************************************************************************
*                         INCLUDE FILES
********************************************************************************
*/
#include "typedef.h"

/*
********************************************************************************
*                         LOCAL VARIABLES AND TABLES
********************************************************************************
*/

/*
********************************************************************************
*                         DEFINITION OF DATA TYPES
********************************************************************************
*/

/*
********************************************************************************
*                         DECLARATION OF PROTOTYPES
********************************************************************************
*/
/*************************************************************************
 *
 *  FUNCTION:  code_2i40_11bits()
 *
 *  PURPOSE:  Searches a 11 bit algebraic codebook containing 2 pulses
 *            in a frame of 40 samples.
 *
 *  DESCRIPTION:
 *    The code length is 40, containing 2 nonzero pulses: i0...i1.
 *    All pulses can have two possible amplitudes: +1 or -1.
 *    Pulse i0 can have 2x8=16 possible positions, pulse i1 can have
 *    4x8=32 positions.
 *
 *       i0 :  1, 6, 11, 16, 21, 26, 31, 36.
 *             3, 8, 13, 18, 23, 28, 33, 38.
 *       i1 :  0, 5, 10, 15, 20, 25, 30, 35.
 *             1, 6, 11, 16, 21, 26, 31, 36. 
 *             2, 7, 12, 17, 22, 27, 32, 37.
 *             4, 9, 14, 19, 24, 29, 34, 39.
 * 
 *************************************************************************/

Word16 code_2i40_11bits(
    Word16 x[], /* i : target vector                                 */
    Word16 h[], /* i : impulse response of weighted synthesis filter */
                /*     h[-L_subfr..-1] must be set to zero.          */
    Word16 T0,  /* i : Pitch lag                                     */
    Word16 pitch_sharp, /* i : Last quantized pitch gain             */
    Word16 code[],      /* o : Innovative codebook                   */
    Word16 y[],         /* o : filtered fixed codebook excitation    */
    Word16 * sign       /* o : Signs of 2 pulses                     */
);

#endif