phi_xits.h

MPEG-4编解码的实现(包括MPEG4视音频编解码)

long  num_of_pulses,    /* In:    Number of pulses in the sequence      */
long  pulse_spacing,    /* In:    Regular Spacing Between Pulses        */
long  num_fcbk_vecs,    /* In:    #Vectors in the fixed code book       */
long  nos,              /* In:    Number of samples to be processed     */
long  **cb,             /* Out:   Generated Local Fixed Codebook        */ 
long  p,                /* In:    Phase of the codebook vector          */
long  *amp,             /* In:    Pulse Amplitudes                      */ 
long  *pos               /* In:    Index to non-zero codevector          */
);

/*
----------------------------------------------------------------------------
  preselection of fixed codebook indices (Reduction from 16 to 5 WDBxx)
----------------------------------------------------------------------------
*/

void 
PHI_cbf_preselection
(
long  pulse_spacing,    /* In:   Regular Spacing Between Pulses         */
long  num_fcbk_cands,   /* In:   #Preselected candidates for fixed cbk  */
long  num_fcbk_vecs,    /* In:   #Vectors in the fixed code book        */
long  nos,              /* In:    Number of samples to be processed     */
long  **cb,             /* In:    Local fixed codebook,(Nf-1) by (nos-1)*/  
long  p,                /* In:    Phase  of the RPE codebook            */
float *tf,              /* In:    Backward-filtered target signal       */ 
float a,                /* In:    LPC coeffs of the preselection filter */
long  *pi               /* Out:   Result: Preselected Codebook Indices  */
);

/*
----------------------------------------------------------------------------
  fixed codebook search
----------------------------------------------------------------------------
*/

void 
PHI_cbf_search(
long  num_of_pulses,    /* In:  Number of pulses in the sequence        */
long  pulse_spacing,    /* In:  Regular Spacing Between Pulses          */
long  num_fcbk_cands,   /* In:  #Preselected candidates for fixed cbk   */
long  nos,              /* In:  Number of samples to be processed       */       
long  **cb,             /* In:  Local fixed codebook                    */ 
long  p,                /* In:  Phase of the fixed codebook, 0 to D-1   */     
long  *pi,              /* In:  Preselected codebook indices, p[0..Pf-1]*/ 
float *h,               /* In:  Synthesis filter impulse response,      */ 
float *e,               /* In:  Target residual signal, e[0..nos-1]     */
float *gain,            /* Out: Selected Fixed Codebook gain (Uncoded)  */ 
long  *gid,             /* Out: Selected Fixed Codebook gain index      */
long  *amp,             /* Out: S rpe pulse amplitudes, amp[0..Np-1]    */
long  n                 /* In:  Subframe index, 0 to n_subframes-1      */
);

/*
----------------------------------------------------------------------------
  encodes rpe pulse amplitudes and phase into one index  
----------------------------------------------------------------------------
*/

void 
PHI_code_cbf_amplitude_phase
(
long num_of_pulses,      /* In:     Number of pulses in the sequence     */
long pulse_spacing,      /* In:     Regular Spacing Between Pulses       */
long *amp,               /* In:   Array of Pulse Amplitudes, amp[0..Np-1]*/             
long phase,              /* In:   The Phase of the RPE sequence          */
long *index              /* Out:  Coded Index: Fixed Codebook index      */
);

/*
----------------------------------------------------------------------------
  Decodes the RPE amplitudes and phase from the cbk-index
----------------------------------------------------------------------------
*/
void
PHI_decode_cbf_amplitude_phase
(
const long    num_of_pulses,  /* In:     Number of pulses in the sequence     */
const long    pulse_spacing,  /* In:     Regular Spacing Between Pulses       */
long  * const amp,            /* Out:  The Array of pulse amplitudes          */
long  * const phase,          /* Out:  The phase of the RPE sequence          */ 
const  long    index           /* In:   Coded Fixed codebook index             */
);

/*
----------------------------------------------------------------------------
  Decodes the Adaptive-Codebook Gain
----------------------------------------------------------------------------
*/
void
PHI_DecodeAcbkGain
(
long  acbk_gain_index,
float *gain
);

/*
----------------------------------------------------------------------------
  Decodes the Fixed-Codebook Gain
----------------------------------------------------------------------------
*/
void
PHI_DecodeFcbkGain
(
long  fcbk_gain_index,
long  ctr,
float prev_gain, 
float *gain
);

/*
----------------------------------------------------------------------------
  computes excitation of the adaptive codebook
----------------------------------------------------------------------------
*/

void 
PHI_calc_cba_excitation
(
long   nos,             /* In:     Number of samples to be updated      */
long   max_lag,         /* In:     Maximum Permitted Adapt cbk Lag      */
long   min_lag,         /* In:     Minimum Permitted Adapt cbk Lag      */
float  *cb,             /* In:     The current Adaptive codebook content*/ 
long   idx,             /* In:     The chosen lag candidate             */
float  *v               /* Out:    The Adaptive Codebook contribution   */
);

/*
----------------------------------------------------------------------------
  computes excitation of the fixed codebook
----------------------------------------------------------------------------
*/

void 
PHI_calc_cbf_excitation
(
long   nos,             /* In:     Number of samples to be updated      */
long   num_of_pulses,   /* In:     Number of pulses in the sequence     */
long   pulse_spacing,   /* In:     Regular Spacing Between Pulses       */
long   *amp,            /* In:     Aray of RPE pulse amplitudes         */
long   p,               /* In:     Phase of the RPE sequence            */
float  *v               /* Out:    The fixed codebook contribution      */
);

/*
----------------------------------------------------------------------------
  compute the sum of the excitations
----------------------------------------------------------------------------
*/

void 
PHI_sum_excitations 
( 
long  nos,             /* In:     Number of samples to be updated      */
float again,           /* In:     Adaptive Codebook gain               */ 
float *asig,           /* In:     Adaptive Codebook Contribution       */ 
float fgain,           /* In:     Fixed Codebook gain                  */  
float *fsig,           /* In:     Fixed Codebook Contribution          */ 
float *sum_sig         /* Out:    The Excitation sequence              */
);

/*
----------------------------------------------------------------------------
  update adaptive codebook with the total excitation computed
----------------------------------------------------------------------------
*/

void 
PHI_update_cba_memory
(
long   nos,             /* In:     Number of samples to be updated      */
long   max_lag,         /* In:     Maximum Adaptive Codebook Lag        */
float *cb,              /* In/Out: Adaptive Codebook                    */ 
float *vi               /* In:     Sum of adaptive and fixed excitaion  */         
);

/*
---------------------------------------------------------------------------
  update synthesis filter states
----------------------------------------------------------------------------
*/

void 
PHI_update_filter_states
(
long   nos,             /* In:     Number of samples                    */
long   order,           /* In:     Order of the LPC                     */ 
float *vi,              /* In:     Total Codebook contribution          */
float *vp,              /* In/Out: Filter States, vp[0..order-1]        */ 
float *a                /* In:     Lpc Coefficients, a[0..order-1]      */
);


#ifdef __cplusplus
}
#endif

#endif  /* #ifndef _phi_xits_h_ */

/*======================================================================*/
/*      H I S T O R Y                                                   */
/*======================================================================*/
/* 17-04-96 R. Taori  Initial Version                                   */
/* 13-08-96 R. Taori  Added 2 subroutines CompAmpArray CompPosArray     */
/*                    Modified generate_cbf to reflect the above        */