www.pudn.com > g729Decoder.rar > PIT_FR3.asm
;=====================================================
; File Name
; ----------
; PIT_FR3.ASM
;
; Brief Description of the Code:
; ------------------------------
; Find the pitch period with 1/3 subsample resolution.
;
; Ref
; ------
; PITCH_A.C
;======================================================
; Word16 Pitch_fr3_fast( /* (o) : pitch period. */
; Word16 exc[], /* (i) : excitation buffer */
; Word16 xn[], /* (i) : target vector */
; Word16 h[], /* (i)Q12 : impulse response of filters.*/
; Word16 L_subfr, /* (i) : Length of subframe */
; Word16 t0_min, /* (i) : minimum value in the searched range.*/
; Word16 t0_max, /* (i) : maximum value in the searched range.*/
; Word16 i_subfr, /* (i) : indicator for first subframe.*/
; Word16 *pit_frac /* (o) : chosen fraction. */
; )
;-------------------------------------------------------
; Constants : Addr_T0 -> T0 = output of Pitch_fr3
; Addr_T0_frac -> pit_frac
; Addr_T0_min -> t0_min
; Addr_T0_max -> t0_max
; Addr_i_subfr -> i_subfr
;
; Addr_xn1 -> xn
; Addr_h1 -> h1
;
; L_SUBFR = L_subfr
;
; Pointers : ptr_exc_subfrm -> exc
;----------------------------------------------------
; Local memory : Addr_pitch_fr3_buf
;----------------------------------------------------
; The following variables must be in same data page :
; Addr_T0 -> T0
; Addr_T0_frac -> pit_frac
; Addr_T0_min -> t0_min
; Addr_T0_max -> t0_max
; Addr_i_subfr -> i_subfr
;------------------------------------------------------
; T0=Pitch_fr3(&exc[i_subfr],xn,h1,L_SUBFR,T0_min,
; T0_max,i_subfr,&T0_frac);
;------------------------------------------------------
; Modified Registers : AR0, AR1, AR2, AR3, BRC
;------------------------------------------------------
.mmregs
.include ..\include\const.h
.include ..\include\struct.h
.include ..\include\ld8amem.h
.text
.def Pitch_fr3_fast
.ref Norm_Corr
.ref Corr_h_x
.ref Interpol_3
.ref Dot_product
.ref Pred_lt_3
param_norm_corr .tag Str_Norm_Corr
.asg "AR1", pCorr_norm
.asg "Addr_pitch_fr3_buf", corr_v
.asg "Addr_pitch_fr3_buf+40", max ;32bit
.asg "Addr_pitch_fr3_buf+42", lag
.asg "Addr_pitch_fr3_buf+43", corr
.asg "Addr_pitch_fr3_buf+44", frac
.asg "Addr_pitch_fr3_buf+45", index
.asg "Addr_pitch_fr3_buf+46", exc_tmp
Pitch_fr3_fast:
LD #param_norm_corr, DP
MVKD #ptr_exc, param_norm_corr.ptr_exc
ST #Addr_xn1, param_norm_corr.ptr_xn
ST #Addr_h1, param_norm_corr.ptr_h
MVKD #Addr_T0_min, param_norm_corr.t_min
MVKD #Addr_T0_max, param_norm_corr.t_max
;------------------------------------------------------------
; Compute correlation of target vector with impulse response
;------------------------------------------------------------
CALLD Corr_h_x
STM #Addr_xn1,AR5
;-----------------------------
; Find maximum integer delay.
;-----------------------------
LD #param_norm_corr, DP
LD param_norm_corr.t_max, B
SUB param_norm_corr.t_min, B
MVDM param_norm_corr.t_min, AR0 ; t = T0_min
STLM B, BRC
MVMM AR0,AR1 ; to = T0_min
RPTBD EndFindMax - 1
LD #0x8000, 16, B ; max = MIN_32
MVDM param_norm_corr.ptr_exc, AR4 ; AR4 -> exc[0]
STM #Addr_Dn, AR3
MAR *AR4-0 ; AR4 -> exc[-t]
CALLD Dot_product ; corr = Dot_Product()
STM #L_SUBFR-1,AR6
MAX B ; max(corr,max)
NOP
NOP
XC 1, NC
MVMM AR0, AR1 ; t -> t0
MAR *AR0+ ; t++
EndFindMax:
DST B, *(max)
LD #Addr_T0, DP
MVMD AR1, Addr_T0
;-----------------------
; Test fractions.
;-----------------------
LD #Addr_T0_frac, DP
ST #0, Addr_T0_frac ;frac = 0
LD #param_norm_corr, DP
LD param_norm_corr.ptr_exc, A
LD #ptr_exc_subfrm, DP
STL A, ptr_exc_subfrm
CALL Pred_lt_3
LD #param_norm_corr, DP
MVDM param_norm_corr.ptr_exc, AR4 ;AR4 -> exc[0]
STM #Addr_Dn, AR3 ;AR3 -> Dn
CALLD Dot_product ;corr = Dot_Product()
STM #L_SUBFR-1,AR6
DST A,*(max)
LD #Addr_pit_frac, DP
ST #0, Addr_pit_frac ; *pit_frac=0 *pit_frac = T0_frac
;-----------------------------------------------------------------
; If first subframe and lag>84 do not serch fractional pitch
;-----------------------------------------------------------------
LD #Addr_i_subfr, DP
LD Addr_i_subfr, A
BC NotFirstSubfrlag, ANEQ
LD #Addr_T0, DP
LD Addr_T0, A
SUB #84, A
BC NotFirstSubfrlag,ALEQ
RET ;return t0
NotFirstSubfrlag:
;-------------------------------------
; copy(exc, exc_tmp, L_subfr)
;-------------------------------------
LD #param_norm_corr, DP
MVDM param_norm_corr.ptr_exc, AR4 ;AR4 -> exc[0]
STM #exc_tmp, AR5
RPT #L_SUBFR - 1
MVDD *AR4+, *AR5+
;-------------------------------------
; Fraction -1/3
;-------------------------------------
LD #Addr_T0_frac, DP
ST #-1, Addr_T0_frac ;frac = -1
CALL Pred_lt_3
LD #param_norm_corr, DP
MVDM param_norm_corr.ptr_exc, AR4 ;AR4 -> exc[0]
STM #Addr_Dn, AR3 ;AR3 -> Dn
CALLD Dot_product ;corr = Dot_Product()
STM #L_SUBFR-1,AR6
DLD *(max), B
LD #Addr_pit_frac, DP
MAX B
NOP
NOP
BC EndFraction1, C
ST #-1, Addr_pit_frac ;*pit_frac=-1
DST B, *(max)
;-------------------------------------
; copy(exc, exc_tmp, L_subfr)
;-------------------------------------
LD #param_norm_corr, DP
MVDM param_norm_corr.ptr_exc, AR4 ;AR4 -> exc[0]
STM #exc_tmp, AR5
RPT #L_SUBFR - 1
MVDD *AR4+, *AR5+
EndFraction1:
;-------------------------------------
; Fraction +1/3
;-------------------------------------
LD #Addr_T0_frac, DP
ST #1, Addr_T0_frac ;frac = 1
CALL Pred_lt_3
LD #param_norm_corr, DP
MVDM param_norm_corr.ptr_exc, AR4 ;AR4 -> exc[0]
STM #Addr_Dn, AR3 ;AR3 -> Dn
CALLD Dot_product ;corr = Dot_Product()
STM #L_SUBFR-1,AR6
DLD *(max), B
LD #Addr_pit_frac, DP
MAX B
NOP
NOP
BC EndFraction2, C
ST #1, Addr_pit_frac ;*pit_frac=1
DST B, *(max)
EndFraction2:
BC EndPitchFr3, NC
;-------------------------------------
; copy(exc_tmp, exc, L_subfr)
;-------------------------------------
LD #param_norm_corr, DP
MVDM param_norm_corr.ptr_exc, AR5 ;AR5 -> exc[0]
STM #exc_tmp, AR4
RPT #L_SUBFR - 1
MVDD *AR4+, *AR5+
EndPitchFr3:
LD *(Addr_pit_frac), A
STL A, *(Addr_T0_frac)
RET ;return t0