silk: Add Arm NEON silk_VAD_GetSA_Q8

silk/VAD.c

@@ -33,7 +33,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "stack_alloc.h"
 
 /* Silk VAD noise level estimation */
-# if !defined(OPUS_X86_MAY_HAVE_SSE4_1)
+# if !defined(OPUS_X86_MAY_HAVE_SSE4_1) && !defined(OPUS_ARM_MAY_HAVE_NEON_INTR)
 static OPUS_INLINE void silk_VAD_GetNoiseLevels(
     const opus_int32             pX[ VAD_N_BANDS ], /* I    subband energies                            */
     silk_VAD_state              *psSilk_VAD         /* I/O  Pointer to Silk VAD state                   */
@@ -297,7 +297,7 @@ opus_int silk_VAD_GetSA_Q8_c(                                   /* O    Return v
 /**************************/
 /* Noise level estimation */
 /**************************/
-# if  !defined(OPUS_X86_MAY_HAVE_SSE4_1)
+# if  !defined(OPUS_X86_MAY_HAVE_SSE4_1) && !defined(OPUS_ARM_MAY_HAVE_NEON_INTR)
 static OPUS_INLINE
 #endif
 void silk_VAD_GetNoiseLevels(

silk/arm/VAD_arm.h

@@ -0,0 +1,69 @@
+/* Copyright (c) 2026 Xiph.Org Foundation */
+/*
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+
+   - Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+
+   - Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
+   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef SILK_VAD_ARM_H
+#define SILK_VAD_ARM_H
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#if defined(OPUS_ARM_MAY_HAVE_NEON_INTR)
+
+/* When NEON is enabled, silk_VAD_GetNoiseLevels is exported (rather than a
+   static inline in VAD.c) so the NEON silk_VAD_GetSA_Q8 can call it, mirroring
+   the x86 path. */
+void silk_VAD_GetNoiseLevels(
+    const opus_int32            pX[ VAD_N_BANDS ],
+    silk_VAD_state              *psSilk_VAD
+);
+
+opus_int silk_VAD_GetSA_Q8_neon(
+    silk_encoder_state          *psEncC,
+    const opus_int16            pIn[]
+);
+
+#if defined(OPUS_ARM_PRESUME_NEON_INTR)
+
+#define OVERRIDE_silk_VAD_GetSA_Q8
+#define silk_VAD_GetSA_Q8(psEnC, pIn, arch) \
+    ((void)(arch), silk_VAD_GetSA_Q8_neon(psEnC, pIn))
+
+#elif defined(OPUS_HAVE_RTCD)
+
+#define OVERRIDE_silk_VAD_GetSA_Q8
+extern opus_int (*const SILK_VAD_GETSA_Q8_IMPL[OPUS_ARCHMASK + 1])(
+    silk_encoder_state          *psEncC,
+    const opus_int16            pIn[]
+);
+#define silk_VAD_GetSA_Q8(psEnC, pIn, arch) \
+    ((*SILK_VAD_GETSA_Q8_IMPL[(arch) & OPUS_ARCHMASK])(psEnC, pIn))
+
+#endif
+
+#endif /* OPUS_ARM_MAY_HAVE_NEON_INTR */
+
+#endif /* SILK_VAD_ARM_H */

silk/arm/VAD_neon_intr.c

@@ -0,0 +1,288 @@
+/* Copyright (c) 2026 Xiph.Org Foundation
+   Arm NEON port of the SSE4.1 implementation by
+   XiangMingZhu WeiZhou MinPeng YanWang FrancisQuiers (Cisco Systems, INC)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+
+   - Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+
+   - Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <arm_neon.h>
+
+#include "main.h"
+#include "stack_alloc.h"
+
+/* Weighting factors for tilt measure */
+static const opus_int32 tiltWeights[ VAD_N_BANDS ] = { 30000, 6000, -12000, -12000 };
+
+/***************************************/
+/* Get the speech activity level in Q8 */
+/***************************************/
+opus_int silk_VAD_GetSA_Q8_neon(                    /* O    Return value, 0 if success                  */
+    silk_encoder_state          *psEncC,            /* I/O  Encoder state                               */
+    const opus_int16            pIn[]               /* I    PCM input                                   */
+)
+{
+    opus_int   SA_Q15, pSNR_dB_Q7, input_tilt;
+    opus_int   decimated_framelength1, decimated_framelength2;
+    opus_int   decimated_framelength;
+    opus_int   dec_subframe_length, dec_subframe_offset, SNR_Q7, i, b, s;
+    opus_int32 sumSquared, smooth_coef_Q16;
+    opus_int16 HPstateTmp;
+    VARDECL( opus_int16, X );
+    opus_int32 Xnrg[ VAD_N_BANDS ];
+    opus_int32 NrgToNoiseRatio_Q8[ VAD_N_BANDS ];
+    opus_int32 speech_nrg, x_tmp;
+    opus_int   X_offset[ VAD_N_BANDS ];
+    opus_int   ret = 0;
+    silk_VAD_state *psSilk_VAD = &psEncC->sVAD;
+
+    SAVE_STACK;
+
+#ifdef OPUS_CHECK_ASM
+    silk_encoder_state psEncC_c;
+    opus_int ret_c;
+
+    silk_memcpy( &psEncC_c, psEncC, sizeof( psEncC_c ) );
+    ret_c = silk_VAD_GetSA_Q8_c( &psEncC_c, pIn );
+#endif
+
+    /* Safety checks */
+    silk_assert( VAD_N_BANDS == 4 );
+    celt_assert( MAX_FRAME_LENGTH >= psEncC->frame_length );
+    celt_assert( psEncC->frame_length <= 512 );
+    celt_assert( psEncC->frame_length == 8 * silk_RSHIFT( psEncC->frame_length, 3 ) );
+
+    /***********************/
+    /* Filter and Decimate */
+    /***********************/
+    decimated_framelength1 = silk_RSHIFT( psEncC->frame_length, 1 );
+    decimated_framelength2 = silk_RSHIFT( psEncC->frame_length, 2 );
+    decimated_framelength = silk_RSHIFT( psEncC->frame_length, 3 );
+    /* Decimate into 4 bands:
+       0       L      3L       L              3L                             5L
+               -      --       -              --                             --
+               8       8       2               4                              4
+
+       [0-1 kHz| temp. |1-2 kHz|    2-4 kHz    |            4-8 kHz           |
+
+       They're arranged to allow the minimal ( frame_length / 4 ) extra
+       scratch space during the downsampling process */
+    X_offset[ 0 ] = 0;
+    X_offset[ 1 ] = decimated_framelength + decimated_framelength2;
+    X_offset[ 2 ] = X_offset[ 1 ] + decimated_framelength;
+    X_offset[ 3 ] = X_offset[ 2 ] + decimated_framelength2;
+    ALLOC( X, X_offset[ 3 ] + decimated_framelength1, opus_int16 );
+
+    /* 0-8 kHz to 0-4 kHz and 4-8 kHz */
+    silk_ana_filt_bank_1( pIn, &psSilk_VAD->AnaState[  0 ],
+        X, &X[ X_offset[ 3 ] ], psEncC->frame_length );
+
+    /* 0-4 kHz to 0-2 kHz and 2-4 kHz */
+    silk_ana_filt_bank_1( X, &psSilk_VAD->AnaState1[ 0 ],
+        X, &X[ X_offset[ 2 ] ], decimated_framelength1 );
+
+    /* 0-2 kHz to 0-1 kHz and 1-2 kHz */
+    silk_ana_filt_bank_1( X, &psSilk_VAD->AnaState2[ 0 ],
+        X, &X[ X_offset[ 1 ] ], decimated_framelength2 );
+
+    /*********************************************/
+    /* HP filter on lowest band (differentiator) */
+    /*********************************************/
+    X[ decimated_framelength - 1 ] = silk_RSHIFT( X[ decimated_framelength - 1 ], 1 );
+    HPstateTmp = X[ decimated_framelength - 1 ];
+    for( i = decimated_framelength - 1; i > 0; i-- ) {
+        X[ i - 1 ]  = silk_RSHIFT( X[ i - 1 ], 1 );
+        X[ i ]     -= X[ i - 1 ];
+    }
+    X[ 0 ] -= psSilk_VAD->HPstate;
+    psSilk_VAD->HPstate = HPstateTmp;
+
+    /*************************************/
+    /* Calculate the energy in each band */
+    /*************************************/
+    for( b = 0; b < VAD_N_BANDS; b++ ) {
+        /* Find the decimated framelength in the non-uniformly divided bands */
+        decimated_framelength = silk_RSHIFT( psEncC->frame_length, silk_min_int( VAD_N_BANDS - b, VAD_N_BANDS - 1 ) );
+
+        /* Split length into subframe lengths */
+        dec_subframe_length = silk_RSHIFT( decimated_framelength, VAD_INTERNAL_SUBFRAMES_LOG2 );
+        dec_subframe_offset = 0;
+
+        /* Compute energy per sub-frame */
+        /* initialize with summed energy of last subframe */
+        Xnrg[ b ] = psSilk_VAD->XnrgSubfr[ b ];
+        for( s = 0; s < VAD_INTERNAL_SUBFRAMES; s++ ) {
+            int32x4_t acc_s32x4;
+            sumSquared = 0;
+
+            acc_s32x4 = vdupq_n_s32( 0 );
+
+            /* Process 8 samples per iteration: ( X[i] >> 3 )^2, summed in int32
+               lanes. Bit-exact with the C reference (exact integer sum of
+               squares; no overflow for dec_subframe_length <= 128). */
+            for( i = 0; i < dec_subframe_length - 7; i += 8 )
+            {
+                int16x8_t x_s16x8 = vld1q_s16( &X[ X_offset[ b ] + i + dec_subframe_offset ] );
+                x_s16x8   = vshrq_n_s16( x_s16x8, 3 );
+                acc_s32x4 = vmlal_s16( acc_s32x4, vget_low_s16(  x_s16x8 ), vget_low_s16(  x_s16x8 ) );
+                acc_s32x4 = vmlal_s16( acc_s32x4, vget_high_s16( x_s16x8 ), vget_high_s16( x_s16x8 ) );
+            }
+
+            sumSquared += vaddvq_s32( acc_s32x4 );
+
+            for( ; i < dec_subframe_length; i++ ) {
+                /* The energy will be less than dec_subframe_length * ( silk_int16_MIN / 8 ) ^ 2.            */
+                /* Therefore we can accumulate with no risk of overflow (unless dec_subframe_length > 128)  */
+                x_tmp = silk_RSHIFT(
+                    X[ X_offset[ b ] + i + dec_subframe_offset ], 3 );
+                sumSquared = silk_SMLABB( sumSquared, x_tmp, x_tmp );
+
+                /* Safety check */
+                silk_assert( sumSquared >= 0 );
+            }
+
+            /* Add/saturate summed energy of current subframe */
+            if( s < VAD_INTERNAL_SUBFRAMES - 1 ) {
+                Xnrg[ b ] = silk_ADD_POS_SAT32( Xnrg[ b ], sumSquared );
+            } else {
+                /* Look-ahead subframe */
+                Xnrg[ b ] = silk_ADD_POS_SAT32( Xnrg[ b ], silk_RSHIFT( sumSquared, 1 ) );
+            }
+
+            dec_subframe_offset += dec_subframe_length;
+        }
+        psSilk_VAD->XnrgSubfr[ b ] = sumSquared;
+    }
+
+    /********************/
+    /* Noise estimation */
+    /********************/
+    silk_VAD_GetNoiseLevels( &Xnrg[ 0 ], psSilk_VAD );
+
+    /***********************************************/
+    /* Signal-plus-noise to noise ratio estimation */
+    /***********************************************/
+    sumSquared = 0;
+    input_tilt = 0;
+    for( b = 0; b < VAD_N_BANDS; b++ ) {
+        speech_nrg = Xnrg[ b ] - psSilk_VAD->NL[ b ];
+        if( speech_nrg > 0 ) {
+            /* Divide, with sufficient resolution */
+            if( ( Xnrg[ b ] & 0xFF800000 ) == 0 ) {
+                NrgToNoiseRatio_Q8[ b ] = silk_DIV32( silk_LSHIFT( Xnrg[ b ], 8 ), psSilk_VAD->NL[ b ] + 1 );
+            } else {
+                NrgToNoiseRatio_Q8[ b ] = silk_DIV32( Xnrg[ b ], silk_RSHIFT( psSilk_VAD->NL[ b ], 8 ) + 1 );
+            }
+
+            /* Convert to log domain */
+            SNR_Q7 = silk_lin2log( NrgToNoiseRatio_Q8[ b ] ) - 8 * 128;
+
+            /* Sum-of-squares */
+            sumSquared = silk_SMLABB( sumSquared, SNR_Q7, SNR_Q7 );          /* Q14 */
+
+            /* Tilt measure */
+            if( speech_nrg < ( (opus_int32)1 << 20 ) ) {
+                /* Scale down SNR value for small subband speech energies */
+                SNR_Q7 = silk_SMULWB( silk_LSHIFT( silk_SQRT_APPROX( speech_nrg ), 6 ), SNR_Q7 );
+            }
+            input_tilt = silk_SMLAWB( input_tilt, tiltWeights[ b ], SNR_Q7 );
+        } else {
+            NrgToNoiseRatio_Q8[ b ] = 256;
+        }
+    }
+
+    /* Mean-of-squares */
+    sumSquared = silk_DIV32_16( sumSquared, VAD_N_BANDS ); /* Q14 */
+
+    /* Root-mean-square approximation, scale to dBs, and write to output pointer */
+    pSNR_dB_Q7 = (opus_int16)( 3 * silk_SQRT_APPROX( sumSquared ) ); /* Q7 */
+
+    /*********************************/
+    /* Speech Probability Estimation */
+    /*********************************/
+    SA_Q15 = silk_sigm_Q15( silk_SMULWB( VAD_SNR_FACTOR_Q16, pSNR_dB_Q7 ) - VAD_NEGATIVE_OFFSET_Q5 );
+
+    /**************************/
+    /* Frequency Tilt Measure */
+    /**************************/
+    psEncC->input_tilt_Q15 = silk_LSHIFT( silk_sigm_Q15( input_tilt ) - 16384, 1 );
+
+    /**************************************************/
+    /* Scale the sigmoid output based on power levels */
+    /**************************************************/
+    speech_nrg = 0;
+    for( b = 0; b < VAD_N_BANDS; b++ ) {
+        /* Accumulate signal-without-noise energies, higher frequency bands have more weight */
+        speech_nrg += ( b + 1 ) * silk_RSHIFT( Xnrg[ b ] - psSilk_VAD->NL[ b ], 4 );
+    }
+
+    if( psEncC->frame_length == 20 * psEncC->fs_kHz ) {
+        speech_nrg = silk_RSHIFT32( speech_nrg, 1 );
+    }
+    /* Power scaling */
+    if( speech_nrg <= 0 ) {
+        SA_Q15 = silk_RSHIFT( SA_Q15, 1 );
+    } else if( speech_nrg < 16384 ) {
+        speech_nrg = silk_LSHIFT32( speech_nrg, 16 );
+
+        /* square-root */
+        speech_nrg = silk_SQRT_APPROX( speech_nrg );
+        SA_Q15 = silk_SMULWB( 32768 + speech_nrg, SA_Q15 );
+    }
+
+    /* Copy the resulting speech activity in Q8 */
+    psEncC->speech_activity_Q8 = silk_min_int( silk_RSHIFT( SA_Q15, 7 ), silk_uint8_MAX );
+
+    /***********************************/
+    /* Energy Level and SNR estimation */
+    /***********************************/
+    /* Smoothing coefficient */
+    smooth_coef_Q16 = silk_SMULWB( VAD_SNR_SMOOTH_COEF_Q18, silk_SMULWB( (opus_int32)SA_Q15, SA_Q15 ) );
+
+    if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {
+        smooth_coef_Q16 >>= 1;
+    }
+
+    for( b = 0; b < VAD_N_BANDS; b++ ) {
+        /* compute smoothed energy-to-noise ratio per band */
+        psSilk_VAD->NrgRatioSmth_Q8[ b ] = silk_SMLAWB( psSilk_VAD->NrgRatioSmth_Q8[ b ],
+            NrgToNoiseRatio_Q8[ b ] - psSilk_VAD->NrgRatioSmth_Q8[ b ], smooth_coef_Q16 );
+
+        /* signal to noise ratio in dB per band */
+        SNR_Q7 = 3 * ( silk_lin2log( psSilk_VAD->NrgRatioSmth_Q8[b] ) - 8 * 128 );
+        /* quality = sigmoid( 0.25 * ( SNR_dB - 16 ) ); */
+        psEncC->input_quality_bands_Q15[ b ] = silk_sigm_Q15( silk_RSHIFT( SNR_Q7 - 16 * 128, 4 ) );
+    }
+
+#ifdef OPUS_CHECK_ASM
+    silk_assert( ret == ret_c );
+    silk_assert( !memcmp( &psEncC_c, psEncC, sizeof( psEncC_c ) ) );
+#endif
+
+    RESTORE_STACK;
+    return( ret );
+}

silk/arm/arm_silk_map.c

@@ -37,6 +37,17 @@ POSSIBILITY OF SUCH DAMAGE.
 # if (defined(OPUS_ARM_MAY_HAVE_NEON_INTR) && \
  !defined(OPUS_ARM_PRESUME_NEON_INTR))
 
+opus_int (*const SILK_VAD_GETSA_Q8_IMPL[OPUS_ARCHMASK + 1])(
+        silk_encoder_state          *psEncC,            /* I/O  Encoder state                               */
+        const opus_int16            pIn[]               /* I    PCM input                                   */
+) = {
+      silk_VAD_GetSA_Q8_c,    /* ARMv4 */
+      silk_VAD_GetSA_Q8_c,    /* EDSP */
+      silk_VAD_GetSA_Q8_c,    /* Media */
+      silk_VAD_GetSA_Q8_neon, /* Neon */
+      silk_VAD_GetSA_Q8_neon, /* dotprod */
+};
+
 void (*const SILK_BIQUAD_ALT_STRIDE2_IMPL[OPUS_ARCHMASK + 1])(
         const opus_int16            *in,                /* I     input signal                                               */
         const opus_int32            *B_Q28,             /* I     MA coefficients [3]                                        */