77 lines
3.9 KiB
C
77 lines
3.9 KiB
C
/***********************************************************************
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Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, (subject to the limitations in the disclaimer below)
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are permitted provided that the following conditions are met:
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- Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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- Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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- Neither the name of Skype Limited, nor the names of specific
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contributors, may be used to endorse or promote products derived from
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this software without specific prior written permission.
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NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
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BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
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BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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***********************************************************************/
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/*
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* Detect SWB input by measuring energy above 8 kHz.
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*/
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#include "SKP_Silk_main.h"
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void SKP_Silk_detect_SWB_input(
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SKP_Silk_detect_SWB_state *psSWBdetect, /* (I/O) encoder state */
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const SKP_int16 samplesIn[], /* (I) input to encoder */
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SKP_int nSamplesIn /* (I) length of input */
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)
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{
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SKP_int HP_8_kHz_len, i, shift;
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SKP_int16 in_HP_8_kHz[ MAX_FRAME_LENGTH ];
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SKP_int32 energy_32;
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/* High pass filter with cutoff at 8 khz */
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HP_8_kHz_len = SKP_min_int( nSamplesIn, MAX_FRAME_LENGTH );
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HP_8_kHz_len = SKP_max_int( HP_8_kHz_len, 0 );
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/* Cutoff around 9 khz */
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/* A = conv(conv([8192,14613, 6868], [8192,12883, 7337]), [8192,11586, 7911]); */
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/* B = conv(conv([575, -948, 575], [575, -221, 575]), [575, 104, 575]); */
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SKP_Silk_biquad( samplesIn, SKP_Silk_SWB_detect_B_HP_Q13[ 0 ], SKP_Silk_SWB_detect_A_HP_Q13[ 0 ],
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psSWBdetect->S_HP_8_kHz[ 0 ], in_HP_8_kHz, HP_8_kHz_len );
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for( i = 1; i < NB_SOS; i++ ) {
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SKP_Silk_biquad( in_HP_8_kHz, SKP_Silk_SWB_detect_B_HP_Q13[ i ], SKP_Silk_SWB_detect_A_HP_Q13[ i ],
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psSWBdetect->S_HP_8_kHz[ i ], in_HP_8_kHz, HP_8_kHz_len );
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}
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/* Calculate energy in HP signal */
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SKP_Silk_sum_sqr_shift( &energy_32, &shift, in_HP_8_kHz, HP_8_kHz_len );
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/* Count concecutive samples above threshold, after adjusting threshold for number of input samples and shift */
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if( energy_32 > SKP_RSHIFT( SKP_SMULBB( HP_8_KHZ_THRES, HP_8_kHz_len ), shift ) ) {
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psSWBdetect->ConsecSmplsAboveThres += nSamplesIn;
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if( psSWBdetect->ConsecSmplsAboveThres > CONCEC_SWB_SMPLS_THRES ) {
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psSWBdetect->SWB_detected = 1;
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}
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} else {
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psSWBdetect->ConsecSmplsAboveThres -= nSamplesIn;
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psSWBdetect->ConsecSmplsAboveThres = SKP_max( psSWBdetect->ConsecSmplsAboveThres, 0 );
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}
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/* If sufficient speech activity and no SWB detected, we detect the signal as being WB */
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if( ( psSWBdetect->ActiveSpeech_ms > WB_DETECT_ACTIVE_SPEECH_MS_THRES ) && ( psSWBdetect->SWB_detected == 0 ) ) {
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psSWBdetect->WB_detected = 1;
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}
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}
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