.gitmodules

+[submodule "lpcnet"]
+	path = lpcnet
+	url = https://github.com/xiph/LPCNet

Makefile.am

@@ -10,9 +10,11 @@ lib_LTLIBRARIES = libopus.la
 DIST_SUBDIRS = doc
 
 AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_srcdir)/celt -I$(top_srcdir)/silk \
-              -I$(top_srcdir)/silk/float -I$(top_srcdir)/silk/fixed $(NE10_CFLAGS)
+              -I$(top_srcdir)/silk/float -I$(top_srcdir)/silk/fixed $(NE10_CFLAGS) \
+              -I$(top_srcdir)/lpcnet/include
 
 include celt_sources.mk
+include lpcnet_sources.mk
 include silk_sources.mk
 include opus_sources.mk
 
@@ -75,7 +77,7 @@ include celt_headers.mk
 include silk_headers.mk
 include opus_headers.mk
 
-libopus_la_SOURCES = $(CELT_SOURCES) $(SILK_SOURCES) $(OPUS_SOURCES)
+libopus_la_SOURCES = $(CELT_SOURCES) $(SILK_SOURCES) $(LPCNET_SOURCES) $(OPUS_SOURCES)
 libopus_la_LDFLAGS = -no-undefined -version-info @OPUS_LT_CURRENT@:@OPUS_LT_REVISION@:@OPUS_LT_AGE@
 libopus_la_LIBADD = $(NE10_LIBS) $(LIBM)
 if OPUS_ARM_EXTERNAL_ASM
@@ -149,16 +151,17 @@ tests_test_opus_padding_LDADD = libopus.la $(NE10_LIBS) $(LIBM)
 
 CELT_OBJ = $(CELT_SOURCES:.c=.lo)
 SILK_OBJ = $(SILK_SOURCES:.c=.lo)
+LPCNET_OBJ = $(LPCNET_SOURCES:.c=.lo)
 OPUS_OBJ = $(OPUS_SOURCES:.c=.lo)
 
 tests_test_opus_projection_SOURCES = tests/test_opus_projection.c tests/test_opus_common.h
-tests_test_opus_projection_LDADD = $(OPUS_OBJ) $(SILK_OBJ) $(CELT_OBJ) $(NE10_LIBS) $(LIBM)
+tests_test_opus_projection_LDADD = $(OPUS_OBJ) $(SILK_OBJ) $(LPCNET_OBJ) $(CELT_OBJ) $(NE10_LIBS) $(LIBM)
 if OPUS_ARM_EXTERNAL_ASM
 tests_test_opus_projection_LDADD += libarmasm.la
 endif
 
 silk_tests_test_unit_LPC_inv_pred_gain_SOURCES = silk/tests/test_unit_LPC_inv_pred_gain.c
-silk_tests_test_unit_LPC_inv_pred_gain_LDADD = $(SILK_OBJ) $(CELT_OBJ) $(NE10_LIBS) $(LIBM)
+silk_tests_test_unit_LPC_inv_pred_gain_LDADD = $(SILK_OBJ) $(LPCNET_OBJ) $(CELT_OBJ) $(NE10_LIBS) $(LIBM)
 if OPUS_ARM_EXTERNAL_ASM
 silk_tests_test_unit_LPC_inv_pred_gain_LDADD += libarmasm.la
 endif

README

@@ -73,10 +73,13 @@ On Apple macOS, install Xcode and brew.sh, then in the Terminal enter:
 
 2) Compiling the source
 
+    % git submodule update --init
     % ./autogen.sh
     % ./configure
     % make
 
+On x86, it's a good idea to use a -march= option that allows the use of AVX2.
+
 3) Install the codec libraries (optional)
 
     % sudo make install

autogen.sh

@@ -9,6 +9,8 @@ set -e
 srcdir=`dirname $0`
 test -n "$srcdir" && cd "$srcdir"
 
+(cd lpcnet; ./download_model.sh plc_challenge_weights)
+
 echo "Updating build configuration files, please wait...."
 
 autoreconf -isf

configure.ac

@@ -153,7 +153,7 @@ AS_IF([test "$enable_float_api" = "no"],[
 
 AC_ARG_ENABLE([custom-modes],
     [AS_HELP_STRING([--enable-custom-modes], [enable non-Opus modes, e.g. 44.1 kHz & 2^n frames])],,
-    [enable_custom_modes=no])
+    [enable_custom_modes=yes])
 
 AS_IF([test "$enable_custom_modes" = "yes"],[
   AC_DEFINE([CUSTOM_MODES], [1], [Custom modes])
@@ -162,6 +162,14 @@ AS_IF([test "$enable_custom_modes" = "yes"],[
 
 AM_CONDITIONAL([CUSTOM_MODES], [test "$enable_custom_modes" = "yes"])
 
+AC_ARG_ENABLE([neural-plc],
+    [AS_HELP_STRING([--enable-neural-plc], [Use neural PLC for SILK])],,
+    [enable_neural_plc=yes])
+
+AS_IF([test "$enable_neural_plc" = "yes"],[
+  AC_DEFINE([NEURAL_PLC], [1], [Neural PLC])
+])
+
 has_float_approx=no
 #case "$host_cpu" in
 #i[[3456]]86 | x86_64 | powerpc64 | powerpc32 | ia64)

lpcnet @ e0acf521

+Subproject commit e0acf521b56094df4a3b88cc10f2c79c2db27cd0

lpcnet_sources.mk

+LPCNET_SOURCES = \
+lpcnet/src/burg.c \
+lpcnet/src/ceps_codebooks.c \
+lpcnet/src/common.c \
+lpcnet/src/freq.c \
+lpcnet/src/kiss99.c \
+lpcnet/src/lpcnet.c \
+lpcnet/src/lpcnet_dec.c \
+lpcnet/src/lpcnet_enc.c \
+lpcnet/src/lpcnet_plc.c \
+lpcnet/src/nnet.c \
+lpcnet/src/nnet_data.c \
+lpcnet/src/plc_data.c

silk/PLC.c

@@ -33,6 +33,10 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "stack_alloc.h"
 #include "PLC.h"
 
+#ifdef NEURAL_PLC
+#include "lpcnet.h"
+#endif
+
 #define NB_ATT 2
 static const opus_int16 HARM_ATT_Q15[NB_ATT]              = { 32440, 31130 }; /* 0.99, 0.95 */
 static const opus_int16 PLC_RAND_ATTENUATE_V_Q15[NB_ATT]  = { 31130, 26214 }; /* 0.95, 0.8 */
@@ -60,6 +64,14 @@ void silk_PLC_Reset(
     psDec->sPLC.prevGain_Q16[ 1 ] = SILK_FIX_CONST( 1, 16 );
     psDec->sPLC.subfr_length = 20;
     psDec->sPLC.nb_subfr = 2;
+#ifdef NEURAL_PLC
+    if( psDec->sPLC.lpcnet != NULL ) {
+        lpcnet_plc_init( psDec->sPLC.lpcnet, LPCNET_PLC_CODEC );
+    } else {
+        /* FIXME: This is leaking memory. The right fix is for the LPCNet state to be part of the PLC struct itself. */
+        psDec->sPLC.lpcnet = lpcnet_plc_create(LPCNET_PLC_CODEC);
+    }
+#endif
 }
 
 void silk_PLC(
@@ -88,6 +100,14 @@ void silk_PLC(
         /* Update state             */
         /****************************/
         silk_PLC_update( psDec, psDecCtrl );
+#ifdef NEURAL_PLC
+        if ( psDec->sPLC.fs_kHz == 16 ) {
+            int k;
+            for( k = 0; k < psDec->nb_subfr; k += 2 ) {
+                lpcnet_plc_update( psDec->sPLC.lpcnet, frame + k * psDec->subfr_length );
+            }
+        }
+#endif
     }
 }
 
@@ -371,6 +391,17 @@ static OPUS_INLINE void silk_PLC_conceal(
         /* Scale with Gain */
         frame[ i ] = (opus_int16)silk_SAT16( silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14_ptr[ MAX_LPC_ORDER + i ], prevGain_Q10[ 1 ] ), 8 ) ) );
     }
+#ifdef NEURAL_PLC
+    if ( psDec->sPLC.fs_kHz == 16 ) {
+        for( k = 0; k < psDec->nb_subfr; k += 2 ) {
+            lpcnet_plc_conceal(psDec->sPLC.lpcnet, frame + k * psDec->subfr_length );
+        }
+    }
+    /* We *should* be able to copy only from psDec->frame_length-MAX_LPC_ORDER, i.e. the last MAX_LPC_ORDER samples. */
+    for( i = 0; i < psDec->frame_length; i++ ) {
+        sLPC_Q14_ptr[ MAX_LPC_ORDER + i ] = (int)floor(.5 + frame[ i ] * (float)(1 << 24) / prevGain_Q10[ 1 ] );
+    }
+#endif
 
     /* Save LPC state */
     silk_memcpy( psDec->sLPC_Q14_buf, &sLPC_Q14_ptr[ psDec->frame_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
@@ -431,12 +462,16 @@ void silk_PLC_glue_frames(
                 slope_Q16 = silk_DIV32_16( ( (opus_int32)1 << 16 ) - gain_Q16, length );
                 /* Make slope 4x steeper to avoid missing onsets after DTX */
                 slope_Q16 = silk_LSHIFT( slope_Q16, 2 );
-
-                for( i = 0; i < length; i++ ) {
-                    frame[ i ] = silk_SMULWB( gain_Q16, frame[ i ] );
-                    gain_Q16 += slope_Q16;
-                    if( gain_Q16 > (opus_int32)1 << 16 ) {
-                        break;
+#ifdef NEURAL_PLC
+                if ( psDec->sPLC.fs_kHz != 16 )
+#endif
+                {
+                    for( i = 0; i < length; i++ ) {
+                        frame[ i ] = silk_SMULWB( gain_Q16, frame[ i ] );
+                        gain_Q16 += slope_Q16;
+                        if( gain_Q16 > (opus_int32)1 << 16 ) {
+                            break;
+                        }
                     }
                 }
             }

silk/structs.h

@@ -34,6 +34,10 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "entenc.h"
 #include "entdec.h"
 
+#ifdef NEURAL_PLC
+#include "lpcnet.h"
+#endif
+
 #ifdef __cplusplus
 extern "C"
 {
@@ -243,6 +247,10 @@ typedef struct {
     opus_int                    fs_kHz;
     opus_int                    nb_subfr;
     opus_int                    subfr_length;
+#ifdef NEURAL_PLC
+    /* FIXME: We should include the state struct directly to preserve the state shadow copy property. */
+    LPCNetPLCState              *lpcnet;
+#endif
 } silk_PLC_struct;
 
 /* Struct for CNG */