- reference source code for EVS codec

src/libs/libevs/lib_com/lsf_msvq_ma.cpp

@@ -0,0 +1,159 @@
+/*====================================================================================
+    EVS Codec 3GPP TS26.442 Apr 03, 2018. Version 12.11.0 / 13.6.0 / 14.2.0
+  ====================================================================================*/
+
+#include <stdlib.h>
+#include <assert.h>
+#include "cnst_fx.h"
+#include "rom_com_fx.h"
+#include "prot_fx.h"
+#include "stl.h"
+#include "basop_util.h"
+#include "prot_fx.h"
+#include "options.h"
+
+#define swap(x,y,type) {type u__p; u__p=x; x=y; y=u__p;}
+
+extern const Word16 tbl_mid_gen_wb_5b_fx[];
+extern const Word16 tbl_mid_unv_wb_5b_fx[];
+
+
+
+
+void midlsf_dec(
+    const Word16 qlsf0[],  /* i: quantized lsf coefficients (3Q12) */
+    const Word16 qlsf1[],  /* i: quantized lsf coefficients (3Q12) */
+    Word16 idx,        /* i: codebook index          */
+    Word16 qlsf[],      /* o: decoded lsf coefficients   (3Q12) */
+    Word16 coder_type,
+    Word16 *mid_lsf_int,
+    Word16 prev_bfi,
+    Word16 safety_net)
+{
+    const Word16 *ratio=NULL;
+    Word16 j;
+    Word32 L_tmp;
+    Word16 bad_spacing = 0;
+
+    move16();
+    /* Select codebook */
+    IF ( sub(coder_type, UNVOICED) == 0 )
+    {
+        ratio = tbl_mid_unv_wb_5b_fx;
+    }
+    ELSE
+    {
+        ratio = tbl_mid_gen_wb_5b_fx;
+    }
+    FOR (j=0; j<M; j++)
+    {
+        L_tmp = L_mult(sub(0x2000, ratio[idx*M+j]), qlsf0[j]); /*Q(x2.56+13+1)->Q(x2.56+14)*/
+        L_tmp = L_mac(L_tmp, ratio[idx*M+j], qlsf1[j]); /*Q(x2.56+14)*/
+        qlsf[j] = round_fx(L_shl(L_tmp,2)); /*Q(x2.56)*/
+    }
+
+
+    IF(mid_lsf_int != NULL) /*at the decoder*/
+    {
+        /* check for incorrect LSF ordering */
+        IF ( sub(*mid_lsf_int, 1) == 0 )
+        {
+            FOR (j=1; j<M; j++)
+            {
+                IF ( sub(qlsf[j] , qlsf[j-1]) < 0 )
+                {
+                    bad_spacing = 1;
+                    move16();
+                    BREAK;
+                }
+            }
+        }
+        /* Redo mid-LSF interpolation with 0.4 in case of LSF instability */
+        test();
+        test();
+        IF( prev_bfi || ( sub(*mid_lsf_int, 1) == 0 && bad_spacing ) )
+        {
+            FOR (j=0; j<M; j++)
+            {
+                /* redo mid-LSF interpolation with 0.4 */
+                qlsf[j] = add(mult_r(13107, qlsf0[j]), mult_r(19661, qlsf1[j])); /* Q15 +x2.56 -Q15 13107 = 0.4(Q15), 19661 = 0.6 (Q15)*/ move16();
+
+                /* ensure correct ordering of LSF indices */
+                test();
+                test();
+                IF ( j > 0 && sub(j, M) <0 && sub(qlsf[j], add( qlsf[j-1], LSF_GAP_MID_FX))<0  )
+                {
+                    qlsf[j] = add(qlsf[j-1], LSF_GAP_MID_FX);
+                    move16();
+                }
+
+            }
+        }
+        ELSE
+        {
+            /* otherwise, use regular LSF spacing and ordering as in the encoder */
+            FOR (j=0; j<M; j++)
+            {
+                test();
+                test();
+                IF ( j > 0 && sub(j, M) < 0 && sub(qlsf[j], add( qlsf[j-1],LSF_GAP_MID_FX))<0 )
+                {
+                    qlsf[j] = add(qlsf[j-1], LSF_GAP_MID_FX);
+                    move16();
+                }
+            }
+        }
+        if ( prev_bfi )
+        {
+            /* continue redoing mid-LSF interpolation with 0.4 in order not to propagate the error */
+            *mid_lsf_int = 1;
+            move16();
+        }
+        if ( safety_net )
+        {
+            /* safety-net encountered -> stop redoing mid-LSF interpolation with 0.4 */
+            *mid_lsf_int = 0;
+            move16();
+        }
+    }
+    ELSE
+    {
+        /* use regular LSF spacing */
+        FOR (j=0; j<M; j++)
+        {
+            test();
+            test();
+            IF ( j > 0 && sub(j, M) <0 && sub(qlsf[j], add(qlsf[j-1], LSF_GAP_MID_FX))<0 )
+            {
+                qlsf[j] = add(qlsf[j-1], LSF_GAP_MID_FX);
+                move16();
+            }
+        }
+    }
+
+    return;
+}
+Word16 lsf_ind_is_active(
+    const Word16 lsf_q_ind[],
+    const Word16 means[],
+    Word16 narrowband,
+    Word16 cdk
+)
+{
+    Word16 lsf[2], min_distance;
+
+    lsf[0] = add(lsf_q_ind[0], means[0]);
+    move16();
+    lsf[1] = add(lsf_q_ind[1], means[1]);
+    move16();
+
+    min_distance = lsf[0];
+    move16();
+    min_distance = s_min(min_distance, sub(lsf[1], lsf[0]));
+
+    assert(narrowband == 0 || narrowband == 1);
+    assert(cdk == 0 || cdk == 1);
+
+    return sub(min_distance, min_distance_thr[narrowband][cdk]) < 0;
+}
+