eden-emu/opus
17
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Addressing multiple LSF-related issues

Browse source 
- Merged the LPC stabilization from NLSF2A_stable.c into NLSF2A.c
- The bandwidth expansion in NLSF2A() now operates on int32 LPC coefficients in
Q17 domain (instead of int16 Q12 coefficients)
- The function bwexpander_32() has a more precise way of updating the chirp
variable (round to nearest, instead of round down)
- Changed a few variables in NLSF_stabilize() from int16 to int32 to avoid signed
wrap-around (no difference in results as the wrap-around would always be reversed
later)
- The LSF codebook for WB speech has a quantization stepsize of 0.15 (was 0.16).
This doesn't break the bitstream, although it slightly limits quality of signals
encoded with the old version and decoded with the new one (I can't really hear it
and PESQ gives high scores as well).  I does improve handling of tonal signals.
- As discussed: the Q-domain of the poly function is now in Q16 (was Q20)
- As discussed: limiting the LSFs in NLSF_decode() to 0...32767
- The silk_NLSF_DELTA_MIN values were lowered to deal with a possible future situation with less or no input HP filtering.
This commit is contained in:
Jean-Marc Valin 2011-06-11 08:14:35 -04:00
parent 8019e4e32e
commit f6e781ab8b
39 changed files with 204 additions and 666 deletions
Download patch file Download diff file Expand all files Collapse all files

18
silk/silk_NLSF_encode.c
View file

@ -32,11 +32,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
/***********************/
/* NLSF vector encoder */
/***********************/
SKP_int32 silk_NLSF_encode( /* O Returns RD value in Q25 */
SKP_int32 silk_NLSF_encode( /* O Returns RD value in Q25 */
SKP_int8 *NLSFIndices, /* I Codebook path vector [ LPC_ORDER + 1 ] */
SKP_int16 *pNLSF_Q15, /* I/O Quantized NLSF vector [ LPC_ORDER ] */
const silk_NLSF_CB_struct *psNLSF_CB, /* I Codebook object */
const SKP_int16 *pW_Q5, /* I NLSF weight vector [ LPC_ORDER ] */
const silk_NLSF_CB_struct *psNLSF_CB, /* I Codebook object */
const SKP_int16 *pW_QW, /* I NLSF weight vector [ LPC_ORDER ] */
const SKP_int NLSF_mu_Q20, /* I Rate weight for the RD optimization */
const SKP_int nSurvivors, /* I Max survivors after first stage */
const SKP_int signalType /* I Signal type: 0/1/2 */
@ -51,7 +51,7 @@ SKP_int32 silk_NLSF_encode( /* O Returns RD value
SKP_int16 res_Q15[ MAX_LPC_ORDER ];
SKP_int16 res_Q10[ MAX_LPC_ORDER ];
SKP_int16 NLSF_tmp_Q15[ MAX_LPC_ORDER ];
SKP_int16 W_tmp_Q5[ MAX_LPC_ORDER ];
SKP_int16 W_tmp_QW[ MAX_LPC_ORDER ];
SKP_int16 W_adj_Q5[ MAX_LPC_ORDER ];
SKP_uint8 pred_Q8[ MAX_LPC_ORDER ];
SKP_int16 ec_ix[ MAX_LPC_ORDER ];
@ -91,17 +91,17 @@ SKP_int32 silk_NLSF_encode( /* O Returns RD value
}
/* Weights from codebook vector */
silk_NLSF_VQ_weights_laroia( W_tmp_Q5, NLSF_tmp_Q15, psNLSF_CB->order );
silk_NLSF_VQ_weights_laroia( W_tmp_QW, NLSF_tmp_Q15, psNLSF_CB->order );
/* Apply square-rooted weights */
for( i = 0; i < psNLSF_CB->order; i++ ) {
W_tmp_Q9 = silk_SQRT_APPROX( SKP_LSHIFT( ( SKP_int32 )W_tmp_Q5[ i ], 13 ) );
W_tmp_Q9 = silk_SQRT_APPROX( SKP_LSHIFT( ( SKP_int32 )W_tmp_QW[ i ], 18 - NLSF_W_Q ) );
res_Q10[ i ] = ( SKP_int16 )SKP_RSHIFT( SKP_SMULBB( res_Q15[ i ], W_tmp_Q9 ), 14 );
}
/* Modify input weights accordingly */
for( i = 0; i < psNLSF_CB->order; i++ ) {
W_adj_Q5[ i ] = SKP_DIV32_16( SKP_LSHIFT( ( SKP_int32 )pW_Q5[ i ], 5 ), W_tmp_Q5[ i ] );
W_adj_Q5[ i ] = SKP_DIV32_16( SKP_LSHIFT( ( SKP_int32 )pW_QW[ i ], 5 ), W_tmp_QW[ i ] );
}
/* Unpack entropy table indices and predictor for current CB1 index */
@ -142,9 +142,9 @@ SKP_int32 silk_NLSF_encode( /* O Returns RD value
for( i = 0; i < psNLSF_CB->order; i++ ) {
NLSF_tmp_Q15[ i ] = SKP_LSHIFT16( ( SKP_int16 )pCB_element[ i ], 7 );
}
silk_NLSF_VQ_weights_laroia( W_tmp_Q5, NLSF_tmp_Q15, psNLSF_CB->order );
silk_NLSF_VQ_weights_laroia( W_tmp_QW, NLSF_tmp_Q15, psNLSF_CB->order );
for( i = 0; i < psNLSF_CB->order; i++ ) {
W_tmp_Q9 = silk_SQRT_APPROX( SKP_LSHIFT( ( SKP_int32 )W_tmp_Q5[ i ], 13 ) );
W_tmp_Q9 = silk_SQRT_APPROX( SKP_LSHIFT( ( SKP_int32 )W_tmp_QW[ i ], 18 - NLSF_W_Q ) );
res_Q15[ i ] = pNLSF_Q15_orig[ i ] - NLSF_tmp_Q15[ i ];
res_Q10[ i ] = (SKP_int16)SKP_RSHIFT( SKP_SMULBB( res_Q15[ i ], W_tmp_Q9 ), 14 );
DEBUG_STORE_DATA( NLSF_res_q10.dat, &res_Q10[ i ], sizeof( SKP_int16 ) );