📄 util_lbc.c
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/*
**
** File: util_lbc.c
**
** Description: utility functions for the lbc codec
**
** Functions:
**
** I/O functions:
** Write_lbc()
**
** High-pass filtering:
**
** Rem_Dc()
**
** Miscellaneous signal processing functions:
**
** Vec_Norm()
** Mem_Shift()
** Comp_En()
** Scale()
**
** Bit stream packing/unpacking:
**
** Line_Pack()
** Line_Unpk()
**
** Mathematical functions:
**
** Sqrt_lbc()
** Rand_lbc()
*/
/*
ITU-T G.723 Speech Coder ANSI-C Source Code Version 5.00
copyright (c) 1995, AudioCodes, DSP Group, France Telecom,
Universite de Sherbrooke. All rights reserved.
*/
/*
**
** Function: Read_lbc()
**
** Description: Read in a file
**
** Links to text: Sections 2.2 & 4
**
** Arguments:
**
** Word16 *Dpnt
** int Len
** FILE *Fp
**
** Outputs:
**
** Word16 *Dpnt
**
** Return value: None
**
*/
void Read_lbc( Word16 *Dpnt, int Len, FILE *Fp )
{
int i ;
for ( i = 0 ; i < Len ; i ++ )
Dpnt[i] = (Word16) 0 ;
fread ( (char *)Dpnt, sizeof(Word16), Len, Fp ) ;
return;
}
void Line_Wr( char *Line, FILE *Fp )
{
Word16 Info ;
int Size ;
Info = Line[0] & (Word16)0x0003 ; //取其低两位
/* Check frame type and rate informations */
switch (Info) {
case 0x0002 : { /* SID frame （Silence Insertion descriptor） */
Size = 4;
break;
}
case 0x0003 : { /* untransmitted silence frame */
Size = 1;
break;
}
case 0x0001 : { /* active frame, low rate */
Size = 20;
break;
}
default : { /* active frame, high rate */
Size = 24;
}
}
fwrite( Line, Size , 1, Fp ) ;
}
/*
**
** Function: Rem_Dc()
**
** Description: High-pass filtering
**
** Links to text: Section 2.3
**
** Arguments:
**
** Word16 *Dpnt
**
** Inputs:
**
** CodStat.HpfZdl FIR filter memory from previous frame (1 word)
** CodStat.HpfPdl IIR filter memory from previous frame (1 word)
**
** Outputs:
**
** Word16 *Dpnt
**
** Return value: None
**
*/
void Rem_Dc( Word16 *Dpnt )
{
int i ;
Word32 Acc0,Acc1 ;
if ( UseHp ) {
for ( i = 0 ; i < Frame ; i ++ ) {
/* Do the Fir and scale by 2 */
Acc0 = L_mult( Dpnt[i], (Word16) 0x4000 ) ;
Acc0 = L_mac ( Acc0, CodStat.HpfZdl, (Word16) 0xc000 ) ;
CodStat.HpfZdl = Dpnt[i] ;
/* Do the Iir part */
Acc1 = L_mls( CodStat.HpfPdl, (Word16) 0x7f00 ) ;
Acc0 = L_add( Acc0, Acc1 ) ;
CodStat.HpfPdl = Acc0 ;
Dpnt[i] = round(Acc0) ;
}
}
else {
for ( i = 0 ; i < Frame ; i ++ )
Dpnt[i] = shr( Dpnt[i], (Word16) 1 ) ;
}
return;
}
/*
**
** Function: Vec_Norm()
**
** Description: Vector normalization
**
** Links to text:
**
** Arguments:
**
** Word16 *Vect
** Word16 Len
**
** Outputs:
**
** Word16 *Vect
**
** Return value: The power of 2 by which the data vector multiplyed.
**
*/
Word16 Vec_Norm( Word16 *Vect, Word16 Len )
{
int i ;
Word16 Acc0,Acc1 ;
Word16 Exp ;
Word16 Rez ;
Word32 Temp ;
static short ShiftTable[16] = {
0x0001 ,
0x0002 ,
0x0004 ,
0x0008 ,
0x0010 ,
0x0020 ,
0x0040 ,
0x0080 ,
0x0100 ,
0x0200 ,
0x0400 ,
0x0800 ,
0x1000 ,
0x2000 ,
0x4000 ,
0x7fff
} ;
/* Find absolute maximum */
Acc1 = (Word16) 0 ;
for ( i = 0 ; i < Len ; i ++ ) {
Acc0 = abs_s( Vect[i] ) ;
if ( Acc0 > Acc1 )
Acc1 = Acc0 ;
}
/* Get the shift count */
Rez = norm_s( Acc1 ) ;
Exp = ShiftTable[Rez] ;
/* Normalize all the vector */
for ( i = 0 ; i < Len ; i ++ ) {
Temp = L_mult( Exp, Vect[i] ) ;
Temp = L_shr( Temp, 4 ) ;
Vect[i] = extract_l( Temp ) ;
}
Rez = sub( Rez, (Word16) 3) ;
return Rez ;
}
/*
**
** Function: Mem_Shift()
**
** Description: Memory shift, update of the high-passed input speech signal
**
** Links to text:
**
** Arguments:
**
** Word16 *PrevDat
** Word16 *DataBuff
**
** Outputs:
**
** Word16 *PrevDat
** Word16 *DataBuff
**
** Return value: None
**
*/
void Mem_Shift( Word16 *PrevDat, Word16 *DataBuff )
{
int i ;
Word16 Dpnt[Frame+LpcFrame-SubFrLen] ;
/* Form Buffer */
for ( i = 0 ; i < LpcFrame-SubFrLen ; i ++ )
Dpnt[i] = PrevDat[i] ;
for ( i = 0 ; i < Frame ; i ++ )
Dpnt[i+LpcFrame-SubFrLen] = DataBuff[i] ;
/* Update PrevDat */
for ( i = 0 ; i < LpcFrame-SubFrLen ; i ++ )
PrevDat[i] = Dpnt[Frame+i] ;
/* Update DataBuff */
for ( i = 0 ; i < Frame ; i ++ )
DataBuff[i] = Dpnt[(LpcFrame-SubFrLen)/2+i] ;
return;
}
/*
**
** Function: Line_Pack()
**
** Description: Packing coded parameters in bitstream of 16-bit words
**
** Links to text: Section 4
**
** Arguments:
**
** LINEDEF *Line Coded parameters for a frame
** char *Vout bitstream chars
** Word16 VadBit Voice Activity Indicator
**
** Outputs:
**
** Word16 *Vout
**
** Return value: None
**
*/
void Line_Pack( LINEDEF *Line, char *Vout, Word16 Ftyp )
{
int i ;
int BitCount ;
Word16 BitStream[192] ;
Word16 *Bsp = BitStream ;
Word32 Temp ;
/* Clear the output vector */
for ( i = 0 ; i < 24 ; i ++ )
Vout[i] = 0 ;
/*
* Add the coder rate info and frame type info to the 2 msb
* of the first word of the frame.
* The signaling is as follows:
* Ftyp WrkRate => X1X0
* 1 Rate63 00 : High Rate
* 1 Rate53 01 : Low Rate
* 2 x 10 : Silence Insertion Descriptor frame
* 0 x 11 : Used only for simulation of
* untransmitted silence frames
*/
switch (Ftyp) {
case 0 : {
Temp = 0x00000003L;
break;
}
case 2 : {
Temp = 0x00000002L;
break;
}
default : {
if ( WrkRate == Rate63 )
Temp = 0x00000000L ;
else
Temp = 0x00000001L ;
break;
}
}
/* Serialize Control info */
Bsp = Par2Ser( Temp, Bsp, 2 ) ;
/* Check for Speech/NonSpeech case */
if ( Ftyp == 1 ) {
/* 24 bit LspId */
Temp = (*Line).LspId ;
Bsp = Par2Ser( Temp, Bsp, 24 ) ;
/*
* Do the part common to both rates
*/
/* Adaptive code book lags */
Temp = (Word32) (*Line).Olp[0] - (Word32) PitchMin ;
Bsp = Par2Ser( Temp, Bsp, 7 ) ;
Temp = (Word32) (*Line).Sfs[1].AcLg ;
Bsp = Par2Ser( Temp, Bsp, 2 ) ;
Temp = (Word32) (*Line).Olp[1] - (Word32) PitchMin ;
Bsp = Par2Ser( Temp, Bsp, 7 ) ;
Temp = (Word32) (*Line).Sfs[3].AcLg ;
Bsp = Par2Ser( Temp, Bsp, 2 ) ;
/* Write combined 12 bit index of all the gains */
for ( i = 0 ; i < SubFrames ; i ++ ) {
Temp = (*Line).Sfs[i].AcGn*NumOfGainLev + (*Line).Sfs[i].Mamp ;
if ( WrkRate == Rate63 )
Temp += (Word32) (*Line).Sfs[i].Tran << 11 ;
Bsp = Par2Ser( Temp, Bsp, 12 ) ;
}
/* Write all the Grid indices */
for ( i = 0 ; i < SubFrames ; i ++ )
*Bsp ++ = (*Line).Sfs[i].Grid ;
/* High rate only part */
if ( WrkRate == Rate63 ) {
/* Write the reserved bit as 0 */
*Bsp ++ = (Word16) 0 ;
/* Write 13 bit combined position index */
Temp = (*Line).Sfs[0].Ppos >> 16 ;
Temp = Temp * 9 + ( (*Line).Sfs[1].Ppos >> 14) ;
Temp *= 90 ;
Temp += ((*Line).Sfs[2].Ppos >> 16) * 9 + ( (*Line).Sfs[3].Ppos >> 14 ) ;
Bsp = Par2Ser( Temp, Bsp, 13 ) ;
/* Write all the pulse positions */
Temp = (*Line).Sfs[0].Ppos & 0x0000ffffL ;
Bsp = Par2Ser( Temp, Bsp, 16 ) ;
Temp = (*Line).Sfs[1].Ppos & 0x00003fffL ;
Bsp = Par2Ser( Temp, Bsp, 14 ) ;
Temp = (*Line).Sfs[2].Ppos & 0x0000ffffL ;
Bsp = Par2Ser( Temp, Bsp, 16 ) ;
Temp = (*Line).Sfs[3].Ppos & 0x00003fffL ;
Bsp = Par2Ser( Temp, Bsp, 14 ) ;
/* Write pulse amplitudes */
Temp = (Word32) (*Line).Sfs[0].Pamp ;
Bsp = Par2Ser( Temp, Bsp, 6 ) ;
Temp = (Word32) (*Line).Sfs[1].Pamp ;
Bsp = Par2Ser( Temp, Bsp, 5 ) ;
Temp = (Word32) (*Line).Sfs[2].Pamp ;
Bsp = Par2Ser( Temp, Bsp, 6 ) ;
Temp = (Word32) (*Line).Sfs[3].Pamp ;
Bsp = Par2Ser( Temp, Bsp, 5 ) ;
}
/* Low rate only part */
else {
/* Write 12 bits of positions */
for ( i = 0 ; i < SubFrames ; i ++ ) {
Temp = (*Line).Sfs[i].Ppos ;
Bsp = Par2Ser( Temp, Bsp, 12 ) ;
}
/* Write 4 bit Pamps */
for ( i = 0 ; i < SubFrames ; i ++ ) {
Temp = (*Line).Sfs[i].Pamp ;
Bsp = Par2Ser( Temp, Bsp, 4 ) ;
}
}
}
else if(Ftyp == 2) { /* SID frame */
/* 24 bit LspId */
Temp = (*Line).LspId ;
Bsp = Par2Ser( Temp, Bsp, 24 ) ;
/* Do Sid frame gain */
Temp = (Word32)(*Line).Sfs[0].Mamp ;
Bsp = Par2Ser( Temp, Bsp, 6 ) ;
}
/* Write out active frames */
if ( Ftyp == 1 ) {
if ( WrkRate == Rate63 )
BitCount = 192 ;
else
BitCount = 160 ;
}
/* Non active frames */
else if ( Ftyp == 2 )
BitCount = 32 ;
else
BitCount = 2;
for ( i = 0 ; i < BitCount ; i ++ )
Vout[i>>3] ^= BitStream[i] << (i & 0x0007) ;
return;
}
Word16* Par2Ser( Word32 Inp, Word16 *Pnt, int BitNum )
{
int i ;
Word16 Temp ;
for ( i = 0 ; i < BitNum ; i ++ ) {
Temp = (Word16) Inp & (Word16)0x0001 ;
Inp >>= 1 ;
*Pnt ++ = Temp ;
}
return Pnt ;
}
/*
**
** Function: Comp_En()
**
** Description: Compute energy of a subframe vector
**
** Links to text:
**
** Arguments:
**
** Word16 *Dpnt
**
** Outputs: None
**
** Return value:
**
** Word32 energy
**
*/
Word32 Comp_En( Word16 *Dpnt )
{
int i ;
Word32 Rez ;
Word16 Temp[SubFrLen] ;
for ( i = 0 ; i < SubFrLen ; i ++ )
Temp[i] = shr( Dpnt[i], (Word16) 2 ) ;
Rez = (Word32) 0 ;
for ( i = 0 ; i < SubFrLen ; i ++ )
Rez = L_mac( Rez, Temp[i], Temp[i] ) ;
return Rez ;
}
/*
**
** Function: Sqrt_lbc()
**
** Description: Square root computation
**
** Links to text:
**
** Arguments:
**
** Word32 Num
**
** Outputs: None
**
** Return value:
**
** Word16 square root of num
**
*/
Word16 Sqrt_lbc( Word32 Num )
{
int i ;
Word16 Rez = (Word16) 0 ;
Word16 Exp = (Word16) 0x4000 ;
Word32 Acc ;
for ( i = 0 ; i < 14 ; i ++ ) {
Acc = L_mult( add(Rez, Exp), add(Rez, Exp) ) ;
if ( Num >= Acc )
Rez = add( Rez, Exp ) ;
Exp = shr( Exp, (Word16) 1 ) ;
}
return Rez ;
}
/*
**
** Function: Rand_lbc()
**
** Description: Generator of random numbers
**
** Links to text: Section 3.10.2
**
** Arguments:
**
** Word16 *p
**
** Outputs:
**
** Word16 *p
**
** Return value:
**
** Word16 random number
**
*/
Word16 Rand_lbc( Word16 *p )
{
Word32 Temp ;
Temp = L_deposit_l( *p ) ;
Temp &= (Word32) 0x0000ffff ;
Temp = Temp*(Word32)521 + (Word32) 259 ;
*p = extract_l( Temp ) ;
return extract_l( Temp ) ;
}
/*
**
** Function: Scale()
**
** Description: Postfilter gain scaling
**
** Links to text: Section 3.9
**
** Arguments:
**
** Word16 *Tv
** Word32 Sen
**
** Inputs:
**
** Word16 DecStat.Gain
**
** Outputs:
**
** Word16 *Tv
**
** Return value: None
**
*/
void Scale( Word16 *Tv, Word32 Sen )
{
int i ;
Word32 Acc0,Acc1 ;
Word16 Exp,SfGain ;
Acc0 = Sen ;
Acc1 = Comp_En( Tv ) ;
/* Normalize both */
if ( (Acc1 != (Word32) 0) && (Acc0 != (Word32) 0 ) ) {
Exp = norm_l( Acc1 ) ;
Acc1 = L_shl( Acc1, Exp ) ;
SfGain = norm_l( Acc0 ) ;
Acc0 = L_shl( Acc0, SfGain ) ;
Acc0 = L_shr( Acc0, (Word16) 1 ) ;
Exp = sub( Exp, SfGain ) ;
Exp = add( Exp, (Word16) 1 ) ;
Exp = sub( (Word16) 6, Exp ) ;
if ( Exp < (Word16) 0 )
Exp = (Word16) 0 ;
SfGain = extract_h( Acc1 ) ;
SfGain = div_l( Acc0, SfGain ) ;
Acc0 = L_deposit_h( SfGain ) ;
Acc0 = L_shr( Acc0, Exp ) ;
SfGain = Sqrt_lbc( Acc0 ) ;
}
else
SfGain = 0x1000 ;
/* Filter the data */
for ( i = 0 ; i < SubFrLen ; i ++ ) {
/* Update gain */
Acc0 = L_deposit_h( DecStat.Gain ) ;
Acc0 = L_msu( Acc0, DecStat.Gain, (Word16) 0x0800 ) ;
Acc0 = L_mac( Acc0, SfGain, (Word16) 0x0800 ) ;
DecStat.Gain = round( Acc0 ) ;
Exp = add( DecStat.Gain, shr( DecStat.Gain, (Word16) 4) ) ;
Acc0 = L_mult( Tv[i], Exp ) ;
Acc0 = L_shl( Acc0, (Word16) 4 ) ;
Tv[i] = round( Acc0 ) ;
}
return;
}
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