Silk makes use of Opus VAD

Signed-off-by: Jean-Marc Valin <jmvalin@jmvalin.ca>

7 files changed, 33 insertions, 10 deletions

diff --git a/silk/API.h b/silk/API.h
index 0131acbb..4d90ff9a 100644
--- a/silk/API.h
+++ b/silk/API.h
@@ -80,7 +80,8 @@ opus_int silk_Encode(                                   /* O    Returns error co
     opus_int                        nSamplesIn,         /* I    Number of samples in input vector               */
     ec_enc                          *psRangeEnc,        /* I/O  Compressor data structure                       */
     opus_int32                      *nBytesOut,         /* I/O  Number of bytes in payload (input: Max bytes)   */
-    const opus_int                  prefillFlag         /* I    Flag to indicate prefilling buffers no coding   */
+    const opus_int                  prefillFlag,        /* I    Flag to indicate prefilling buffers no coding   */
+    int                             activity            /* I    Decision of Opus voice activity detector        */
 );
 
 /****************************************/
diff --git a/silk/define.h b/silk/define.h
index 1286048e..22fd720b 100644
--- a/silk/define.h
+++ b/silk/define.h
@@ -58,6 +58,11 @@ extern "C"
 #define MAX_CONSECUTIVE_DTX                     20      /* eq 400 ms */
 #define DTX_ACTIVITY_THRESHOLD                  0.1f
 
+/* VAD decision */
+#define VAD_NO_DECISION                         -1
+#define VAD_NO_ACTIVITY                         0
+#define VAD_ACTIVITY                            1
+
 /* Maximum sampling frequency */
 #define MAX_FS_KHZ                              16
 #define MAX_API_FS_KHZ                          48
diff --git a/silk/enc_API.c b/silk/enc_API.c
index 10adf2c3..7ae31a9e 100644
--- a/silk/enc_API.c
+++ b/silk/enc_API.c
@@ -144,7 +144,8 @@ opus_int silk_Encode(                                   /* O    Returns error co
     opus_int                        nSamplesIn,         /* I    Number of samples in input vector               */
     ec_enc                          *psRangeEnc,        /* I/O  Compressor data structure                       */
     opus_int32                      *nBytesOut,         /* I/O  Number of bytes in payload (input: Max bytes)   */
-    const opus_int                  prefillFlag         /* I    Flag to indicate prefilling buffers no coding   */
+    const opus_int                  prefillFlag,        /* I    Flag to indicate prefilling buffers no coding   */
+    opus_int                        activity            /* I    Decision of Opus voice activity detector        */
 )
 {
     opus_int   n, i, nBits, flags, tmp_payloadSize_ms = 0, tmp_complexity = 0, ret = 0;
@@ -425,7 +426,7 @@ opus_int silk_Encode(                                   /* O    Returns error co
                         psEnc->state_Fxx[ 1 ].sCmn.sNSQ.prev_gain_Q16      = 65536;
                         psEnc->state_Fxx[ 1 ].sCmn.first_frame_after_reset = 1;
                     }
-                    silk_encode_do_VAD_Fxx( &psEnc->state_Fxx[ 1 ] );
+                    silk_encode_do_VAD_Fxx( &psEnc->state_Fxx[ 1 ], activity );
                 } else {
                     psEnc->state_Fxx[ 1 ].sCmn.VAD_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] = 0;
                 }
@@ -440,7 +441,7 @@ opus_int silk_Encode(                                   /* O    Returns error co
                 silk_memcpy( psEnc->state_Fxx[ 0 ].sCmn.inputBuf, psEnc->sStereo.sMid, 2 * sizeof( opus_int16 ) );
                 silk_memcpy( psEnc->sStereo.sMid, &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.frame_length ], 2 * sizeof( opus_int16 ) );
             }
-            silk_encode_do_VAD_Fxx( &psEnc->state_Fxx[ 0 ] );
+            silk_encode_do_VAD_Fxx( &psEnc->state_Fxx[ 0 ], activity );
 
             /* Encode */
             for( n = 0; n < encControl->nChannelsInternal; n++ ) {
diff --git a/silk/fixed/encode_frame_FIX.c b/silk/fixed/encode_frame_FIX.c
index d49a0fe3..a02bf87d 100644
--- a/silk/fixed/encode_frame_FIX.c
+++ b/silk/fixed/encode_frame_FIX.c
@@ -43,18 +43,25 @@ static OPUS_INLINE void silk_LBRR_encode_FIX(
 );
 
 void silk_encode_do_VAD_FIX(
-    silk_encoder_state_FIX          *psEnc                                  /* I/O  Pointer to Silk FIX encoder state                                           */
+    silk_encoder_state_FIX          *psEnc,                                 /* I/O  Pointer to Silk FIX encoder state                                           */
+    opus_int                        activity                                /* I    Decision of Opus voice activity detector                                    */
 )
 {
+    const opus_int activity_threshold = SILK_FIX_CONST( SPEECH_ACTIVITY_DTX_THRES, 8 );
+
     /****************************/
     /* Voice Activity Detection */
     /****************************/
     silk_VAD_GetSA_Q8( &psEnc->sCmn, psEnc->sCmn.inputBuf + 1, psEnc->sCmn.arch );
+    /* If Opus VAD is inactive and Silk VAD is active: lower Silk VAD to just under the threshold */
+    if( activity == VAD_NO_ACTIVITY && psEnc->sCmn.speech_activity_Q8 >= activity_threshold ) {
+        psEnc->sCmn.speech_activity_Q8 = activity_threshold - 1;
+    }
 
     /**************************************************/
     /* Convert speech activity into VAD and DTX flags */
     /**************************************************/
-    if( psEnc->sCmn.speech_activity_Q8 < SILK_FIX_CONST( SPEECH_ACTIVITY_DTX_THRES, 8 ) ) {
+    if( psEnc->sCmn.speech_activity_Q8 < activity_threshold ) {
         psEnc->sCmn.indices.signalType = TYPE_NO_VOICE_ACTIVITY;
         psEnc->sCmn.noSpeechCounter++;
         if( psEnc->sCmn.noSpeechCounter <= NB_SPEECH_FRAMES_BEFORE_DTX ) {
diff --git a/silk/fixed/main_FIX.h b/silk/fixed/main_FIX.h
index 780afa39..6d2112e5 100644
--- a/silk/fixed/main_FIX.h
+++ b/silk/fixed/main_FIX.h
@@ -66,7 +66,8 @@ void silk_HP_variable_cutoff(
 
 /* Encoder main function */
 void silk_encode_do_VAD_FIX(
-    silk_encoder_state_FIX          *psEnc                                  /* I/O  Pointer to Silk FIX encoder state                                           */
+    silk_encoder_state_FIX          *psEnc,                                 /* I/O  Pointer to Silk FIX encoder state                                           */
+    opus_int                        activity                                /* I    Decision of Opus voice activity detector                                    */
 );
 
 /* Encoder main function */
diff --git a/silk/float/encode_frame_FLP.c b/silk/float/encode_frame_FLP.c
index 1d4d8a77..b029c3f5 100644
--- a/silk/float/encode_frame_FLP.c
+++ b/silk/float/encode_frame_FLP.c
@@ -42,18 +42,25 @@ static OPUS_INLINE void silk_LBRR_encode_FLP(
 );
 
 void silk_encode_do_VAD_FLP(
-    silk_encoder_state_FLP          *psEnc                              /* I/O  Encoder state FLP                           */
+    silk_encoder_state_FLP          *psEnc,                             /* I/O  Encoder state FLP                           */
+    opus_int                        activity                            /* I    Decision of Opus voice activity detector    */
 )
 {
+    const opus_int activity_threshold = SILK_FIX_CONST( SPEECH_ACTIVITY_DTX_THRES, 8 );
+
     /****************************/
     /* Voice Activity Detection */
     /****************************/
     silk_VAD_GetSA_Q8( &psEnc->sCmn, psEnc->sCmn.inputBuf + 1, psEnc->sCmn.arch );
+    /* If Opus VAD is inactive and Silk VAD is active: lower Silk VAD to just under the threshold */
+    if( activity == VAD_NO_ACTIVITY && psEnc->sCmn.speech_activity_Q8 >= activity_threshold ) {
+        psEnc->sCmn.speech_activity_Q8 = activity_threshold - 1;
+    }
 
     /**************************************************/
     /* Convert speech activity into VAD and DTX flags */
     /**************************************************/
-    if( psEnc->sCmn.speech_activity_Q8 < SILK_FIX_CONST( SPEECH_ACTIVITY_DTX_THRES, 8 ) ) {
+    if( psEnc->sCmn.speech_activity_Q8 < activity_threshold ) {
         psEnc->sCmn.indices.signalType = TYPE_NO_VOICE_ACTIVITY;
         psEnc->sCmn.noSpeechCounter++;
         if( psEnc->sCmn.noSpeechCounter <= NB_SPEECH_FRAMES_BEFORE_DTX ) {
diff --git a/silk/float/main_FLP.h b/silk/float/main_FLP.h
index f47fc93b..5dc0ccf4 100644
--- a/silk/float/main_FLP.h
+++ b/silk/float/main_FLP.h
@@ -56,7 +56,8 @@ void silk_HP_variable_cutoff(
 
 /* Encoder main function */
 void silk_encode_do_VAD_FLP(
-    silk_encoder_state_FLP          *psEnc                              /* I/O  Encoder state FLP                           */
+    silk_encoder_state_FLP          *psEnc,                             /* I/O  Encoder state FLP                           */
+    opus_int                        activity                            /* I    Decision of Opus voice activity detector    */
 );
 
 /* Encoder main function */