Removed all the silk_ prefixes in source file names (not symbols)

1 files changed, 79 insertions, 0 deletions

diff --git a/silk/biquad_alt.c b/silk/biquad_alt.c
new file mode 100644
index 00000000..617b33ab
--- /dev/null
+++ b/silk/biquad_alt.c
@@ -0,0 +1,79 @@
+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, (subject to the limitations in the disclaimer below)
+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 Skype Limited, nor the names of specific
+contributors, may be used to endorse or promote products derived from
+this software without specific prior written permission.
+NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
+BY THIS LICENSE. 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.
+***********************************************************************/
+
+/*                                                                      *
+ * silk_biquad_alt.c                                              *
+ *                                                                      *
+ * Second order ARMA filter                                             *
+ * Can handle slowly varying filter coefficients                        *
+ *                                                                      */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "SigProc_FIX.h"
+
+
+/* Second order ARMA filter, alternative implementation */
+void silk_biquad_alt(
+    const opus_int16      *in,            /* I:    Input signal                   */
+    const opus_int32      *B_Q28,         /* I:    MA coefficients [3]            */
+    const opus_int32      *A_Q28,         /* I:    AR coefficients [2]            */
+    opus_int32            *S,             /* I/O:  State vector [2]               */
+    opus_int16            *out,           /* O:    Output signal                  */
+    const opus_int32      len,            /* I:    Signal length (must be even)   */
+    int stride
+)
+{
+    /* DIRECT FORM II TRANSPOSED (uses 2 element state vector) */
+    opus_int   k;
+    opus_int32 inval, A0_U_Q28, A0_L_Q28, A1_U_Q28, A1_L_Q28, out32_Q14;
+
+    /* Negate A_Q28 values and split in two parts */
+    A0_L_Q28 = ( -A_Q28[ 0 ] ) & 0x00003FFF;        /* lower part */
+    A0_U_Q28 = silk_RSHIFT( -A_Q28[ 0 ], 14 );       /* upper part */
+    A1_L_Q28 = ( -A_Q28[ 1 ] ) & 0x00003FFF;        /* lower part */
+    A1_U_Q28 = silk_RSHIFT( -A_Q28[ 1 ], 14 );       /* upper part */
+
+    for( k = 0; k < len; k++ ) {
+        /* S[ 0 ], S[ 1 ]: Q12 */
+        inval = in[ k*stride ];
+        out32_Q14 = silk_LSHIFT( silk_SMLAWB( S[ 0 ], B_Q28[ 0 ], inval ), 2 );
+
+        S[ 0 ] = S[1] + silk_RSHIFT_ROUND( silk_SMULWB( out32_Q14, A0_L_Q28 ), 14 );
+        S[ 0 ] = silk_SMLAWB( S[ 0 ], out32_Q14, A0_U_Q28 );
+        S[ 0 ] = silk_SMLAWB( S[ 0 ], B_Q28[ 1 ], inval);
+
+        S[ 1 ] = silk_RSHIFT_ROUND( silk_SMULWB( out32_Q14, A1_L_Q28 ), 14 );
+        S[ 1 ] = silk_SMLAWB( S[ 1 ], out32_Q14, A1_U_Q28 );
+        S[ 1 ] = silk_SMLAWB( S[ 1 ], B_Q28[ 2 ], inval );
+
+        /* Scale back to Q0 and saturate */
+        out[ k*stride ] = (opus_int16)silk_SAT16( silk_RSHIFT( out32_Q14 + (1<<14) - 1, 14 ) );
+    }
+}