/*
**
** Function: Dec_Cng()
**
** Description: Receives Ftyp
** 0 : for untransmitted frames
** 2 : for SID frames
** Decodes SID frames
** Computes current frame excitation
** Computes current frame LSPs
**
** Links to text:
**
** Arguments:
**
** int16_t Ftyp Type of silence frame
** LINEDEF *Line Coded parameters
** int16_t *DataExc Current frame excitation
** int16_t *QntLpc Interpolated frame LPC coefficients
**
** Outputs:
**
** int16_t *DataExc
** int16_t *QntLpc
**
** Return value: None
**
*/
void Dec_Cng(int16_t Ftyp, LINEDEF * Line, int16_t * DataExc,
int16_t * QntLpc)
{
int16_t temp;
int i;
if (Ftyp == 2) {
/*
* SID Frame decoding
*/
DecCng.SidGain = Dec_SidGain(Line->Sfs[0].Mamp);
/* Inverse quantization of the LSP */
Lsp_Inq(DecCng.LspSid, DecStat.PrevLsp, Line->LspId, 0);
}
else {
/*
* non SID Frame
*/
if (DecCng.PastFtyp == 1) {
/*
* Case of 1st SID frame erased : quantize-decode
* energy estimate stored in DecCng.SidGain
* scaling factor in DecCng.CurGain
*/
temp = Qua_SidGain(&DecCng.SidGain, &DecCng.CurGain, 0);
DecCng.SidGain = Dec_SidGain(temp);
}
}
if (DecCng.PastFtyp == 1) {
DecCng.CurGain = DecCng.SidGain;
} else {
DecCng.CurGain =
g723_extract_h(L_g723_add
(L_g723_mult(DecCng.CurGain, 0x7000),
L_g723_mult(DecCng.SidGain, 0x1000)));
}
Calc_Exc_Rand(DecCng.CurGain, DecStat.PrevExc, DataExc,
&DecCng.RandSeed, Line);
/* Interpolate the Lsp vectors */
Lsp_Int(QntLpc, DecCng.LspSid, DecStat.PrevLsp);
/* Copy the LSP vector for the next frame */
for (i = 0; i < LpcOrder; i++)
DecStat.PrevLsp[i] = DecCng.LspSid[i];
return;
}
void Dec_Cng(Word16 Ftyp, LINEDEF *Line, Word16 *DataExc, Word16 *QntLpc,DEC_HANDLE *handle)
{
Word16 temp;
int i;
if(Ftyp == 2) {
/*
* SID Frame decoding
*/
handle->DecCng.SidGain = Dec_SidGain(Line->Sfs[0].Mamp);
/* Inverse quantization of the LSP */
Lsp_Inq( handle->DecCng.LspSid, handle->DecStat.PrevLsp, Line->LspId, 0) ;
}
else {
/*
* non SID Frame
*/
if(handle->DecCng.PastFtyp == 1) {
/*
* Case of 1st SID frame erased : quantize-decode
* energy estimate stored in DecCng.SidGain
* scaling factor in DecCng.CurGain
*/
temp = Qua_SidGain(&handle->DecCng.SidGain, &handle->DecCng.CurGain, 0);
handle->DecCng.SidGain = Dec_SidGain(temp);
}
}
if(handle->DecCng.PastFtyp == 1) {
handle->DecCng.CurGain = handle->DecCng.SidGain;
}
else {
handle->DecCng.CurGain = extract_h(L_add( L_mult(handle->DecCng.CurGain,0x7000),
L_mult(handle->DecCng.SidGain,0x1000) ) ) ;
}
Calc_Exc_Rand(handle->DecCng.CurGain, handle->DecStat.PrevExc, DataExc,
&handle->DecCng.RandSeed, Line,handle->mode);
/* Interpolate the Lsp vectors */
Lsp_Int( QntLpc, handle->DecCng.LspSid, handle->DecStat.PrevLsp ) ;
/* Copy the LSP vector for the next frame */
for ( i = 0 ; i < LpcOrder ; i ++ )
handle->DecStat.PrevLsp[i] = handle->DecCng.LspSid[i] ;
return;
}
