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-rw-r--r--media/libopus/silk/fixed/apply_sine_window_FIX.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/media/libopus/silk/fixed/apply_sine_window_FIX.c b/media/libopus/silk/fixed/apply_sine_window_FIX.c
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+++ b/media/libopus/silk/fixed/apply_sine_window_FIX.c
@@ -0,0 +1,101 @@
+/***********************************************************************
+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 "SigProc_FIX.h"
+
+/* Apply sine window to signal vector. */
+/* Window types: */
+/* 1 -> sine window from 0 to pi/2 */
+/* 2 -> sine window from pi/2 to pi */
+/* Every other sample is linearly interpolated, for speed. */
+/* Window length must be between 16 and 120 (incl) and a multiple of 4. */
+
+/* Matlab code for table:
+ for k=16:9*4:16+2*9*4, fprintf(' %7.d,', -round(65536*pi ./ (k:4:k+8*4))); fprintf('\n'); end
+*/
+static const opus_int16 freq_table_Q16[ 27 ] = {
+ 12111, 9804, 8235, 7100, 6239, 5565, 5022, 4575, 4202,
+ 3885, 3612, 3375, 3167, 2984, 2820, 2674, 2542, 2422,
+ 2313, 2214, 2123, 2038, 1961, 1889, 1822, 1760, 1702,
+};
+
+void silk_apply_sine_window(
+ opus_int16 px_win[], /* O Pointer to windowed signal */
+ const opus_int16 px[], /* I Pointer to input signal */
+ const opus_int win_type, /* I Selects a window type */
+ const opus_int length /* I Window length, multiple of 4 */
+)
+{
+ opus_int k, f_Q16, c_Q16;
+ opus_int32 S0_Q16, S1_Q16;
+
+ celt_assert( win_type == 1 || win_type == 2 );
+
+ /* Length must be in a range from 16 to 120 and a multiple of 4 */
+ celt_assert( length >= 16 && length <= 120 );
+ celt_assert( ( length & 3 ) == 0 );
+
+ /* Frequency */
+ k = ( length >> 2 ) - 4;
+ celt_assert( k >= 0 && k <= 26 );
+ f_Q16 = (opus_int)freq_table_Q16[ k ];
+
+ /* Factor used for cosine approximation */
+ c_Q16 = silk_SMULWB( (opus_int32)f_Q16, -f_Q16 );
+ silk_assert( c_Q16 >= -32768 );
+
+ /* initialize state */
+ if( win_type == 1 ) {
+ /* start from 0 */
+ S0_Q16 = 0;
+ /* approximation of sin(f) */
+ S1_Q16 = f_Q16 + silk_RSHIFT( length, 3 );
+ } else {
+ /* start from 1 */
+ S0_Q16 = ( (opus_int32)1 << 16 );
+ /* approximation of cos(f) */
+ S1_Q16 = ( (opus_int32)1 << 16 ) + silk_RSHIFT( c_Q16, 1 ) + silk_RSHIFT( length, 4 );
+ }
+
+ /* Uses the recursive equation: sin(n*f) = 2 * cos(f) * sin((n-1)*f) - sin((n-2)*f) */
+ /* 4 samples at a time */
+ for( k = 0; k < length; k += 4 ) {
+ px_win[ k ] = (opus_int16)silk_SMULWB( silk_RSHIFT( S0_Q16 + S1_Q16, 1 ), px[ k ] );
+ px_win[ k + 1 ] = (opus_int16)silk_SMULWB( S1_Q16, px[ k + 1] );
+ S0_Q16 = silk_SMULWB( S1_Q16, c_Q16 ) + silk_LSHIFT( S1_Q16, 1 ) - S0_Q16 + 1;
+ S0_Q16 = silk_min( S0_Q16, ( (opus_int32)1 << 16 ) );
+
+ px_win[ k + 2 ] = (opus_int16)silk_SMULWB( silk_RSHIFT( S0_Q16 + S1_Q16, 1 ), px[ k + 2] );
+ px_win[ k + 3 ] = (opus_int16)silk_SMULWB( S0_Q16, px[ k + 3 ] );
+ S1_Q16 = silk_SMULWB( S0_Q16, c_Q16 ) + silk_LSHIFT( S0_Q16, 1 ) - S1_Q16;
+ S1_Q16 = silk_min( S1_Q16, ( (opus_int32)1 << 16 ) );
+ }
+}