diff --git a/jni/libopus/silk/code_signs.c b/jni/libopus/silk/code_signs.c
new file mode 100644
index 0000000..9893cdd
--- /dev/null
+++ b/jni/libopus/silk/code_signs.c
@@ -0,0 +1,115 @@
+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+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.
+- Neither the name of Internet Society, IETF or IETF Trust, nor the 
+names of specific contributors, may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+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 "main.h"
+
+/*#define silk_enc_map(a)                ((a) > 0 ? 1 : 0)*/
+/*#define silk_dec_map(a)                ((a) > 0 ? 1 : -1)*/
+/* shifting avoids if-statement */
+#define silk_enc_map(a)                  ( silk_RSHIFT( (a), 15 ) + 1 )
+#define silk_dec_map(a)                  ( silk_LSHIFT( (a),  1 ) - 1 )
+
+/* Encodes signs of excitation */
+void silk_encode_signs(
+    ec_enc                      *psRangeEnc,                        /* I/O  Compressor data structure                   */
+    const opus_int8             pulses[],                           /* I    pulse signal                                */
+    opus_int                    length,                             /* I    length of input                             */
+    const opus_int              signalType,                         /* I    Signal type                                 */
+    const opus_int              quantOffsetType,                    /* I    Quantization offset type                    */
+    const opus_int              sum_pulses[ MAX_NB_SHELL_BLOCKS ]   /* I    Sum of absolute pulses per block            */
+)
+{
+    opus_int         i, j, p;
+    opus_uint8       icdf[ 2 ];
+    const opus_int8  *q_ptr;
+    const opus_uint8 *icdf_ptr;
+
+    icdf[ 1 ] = 0;
+    q_ptr = pulses;
+    i = silk_SMULBB( 7, silk_ADD_LSHIFT( quantOffsetType, signalType, 1 ) );
+    icdf_ptr = &silk_sign_iCDF[ i ];
+    length = silk_RSHIFT( length + SHELL_CODEC_FRAME_LENGTH/2, LOG2_SHELL_CODEC_FRAME_LENGTH );
+    for( i = 0; i < length; i++ ) {
+        p = sum_pulses[ i ];
+        if( p > 0 ) {
+            icdf[ 0 ] = icdf_ptr[ silk_min( p & 0x1F, 6 ) ];
+            for( j = 0; j < SHELL_CODEC_FRAME_LENGTH; j++ ) {
+                if( q_ptr[ j ] != 0 ) {
+                    ec_enc_icdf( psRangeEnc, silk_enc_map( q_ptr[ j ]), icdf, 8 );
+                }
+            }
+        }
+        q_ptr += SHELL_CODEC_FRAME_LENGTH;
+    }
+}
+
+/* Decodes signs of excitation */
+void silk_decode_signs(
+    ec_dec                      *psRangeDec,                        /* I/O  Compressor data structure                   */
+    opus_int                    pulses[],                           /* I/O  pulse signal                                */
+    opus_int                    length,                             /* I    length of input                             */
+    const opus_int              signalType,                         /* I    Signal type                                 */
+    const opus_int              quantOffsetType,                    /* I    Quantization offset type                    */
+    const opus_int              sum_pulses[ MAX_NB_SHELL_BLOCKS ]   /* I    Sum of absolute pulses per block            */
+)
+{
+    opus_int         i, j, p;
+    opus_uint8       icdf[ 2 ];
+    opus_int         *q_ptr;
+    const opus_uint8 *icdf_ptr;
+
+    icdf[ 1 ] = 0;
+    q_ptr = pulses;
+    i = silk_SMULBB( 7, silk_ADD_LSHIFT( quantOffsetType, signalType, 1 ) );
+    icdf_ptr = &silk_sign_iCDF[ i ];
+    length = silk_RSHIFT( length + SHELL_CODEC_FRAME_LENGTH/2, LOG2_SHELL_CODEC_FRAME_LENGTH );
+    for( i = 0; i < length; i++ ) {
+        p = sum_pulses[ i ];
+        if( p > 0 ) {
+            icdf[ 0 ] = icdf_ptr[ silk_min( p & 0x1F, 6 ) ];
+            for( j = 0; j < SHELL_CODEC_FRAME_LENGTH; j++ ) {
+                if( q_ptr[ j ] > 0 ) {
+                    /* attach sign */
+#if 0
+                    /* conditional implementation */
+                    if( ec_dec_icdf( psRangeDec, icdf, 8 ) == 0 ) {
+                        q_ptr[ j ] = -q_ptr[ j ];
+                    }
+#else
+                    /* implementation with shift, subtraction, multiplication */
+                    q_ptr[ j ] *= silk_dec_map( ec_dec_icdf( psRangeDec, icdf, 8 ) );
+#endif
+                }
+            }
+        }
+        q_ptr += SHELL_CODEC_FRAME_LENGTH;
+    }
+}