| /*********************************************************************** |
| 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" |
| #include "stack_alloc.h" |
| |
| /* Silk VAD noise level estimation */ |
| # if !defined(OPUS_X86_MAY_HAVE_SSE4_1) |
| static OPUS_INLINE void silk_VAD_GetNoiseLevels( |
| const opus_int32 pX[ VAD_N_BANDS ], /* I subband energies */ |
| silk_VAD_state *psSilk_VAD /* I/O Pointer to Silk VAD state */ |
| ); |
| #endif |
| |
| /**********************************/ |
| /* Initialization of the Silk VAD */ |
| /**********************************/ |
| opus_int silk_VAD_Init( /* O Return value, 0 if success */ |
| silk_VAD_state *psSilk_VAD /* I/O Pointer to Silk VAD state */ |
| ) |
| { |
| opus_int b, ret = 0; |
| |
| /* reset state memory */ |
| silk_memset( psSilk_VAD, 0, sizeof( silk_VAD_state ) ); |
| |
| /* init noise levels */ |
| /* Initialize array with approx pink noise levels (psd proportional to inverse of frequency) */ |
| for( b = 0; b < VAD_N_BANDS; b++ ) { |
| psSilk_VAD->NoiseLevelBias[ b ] = silk_max_32( silk_DIV32_16( VAD_NOISE_LEVELS_BIAS, b + 1 ), 1 ); |
| } |
| |
| /* Initialize state */ |
| for( b = 0; b < VAD_N_BANDS; b++ ) { |
| psSilk_VAD->NL[ b ] = silk_MUL( 100, psSilk_VAD->NoiseLevelBias[ b ] ); |
| psSilk_VAD->inv_NL[ b ] = silk_DIV32( silk_int32_MAX, psSilk_VAD->NL[ b ] ); |
| } |
| psSilk_VAD->counter = 15; |
| |
| /* init smoothed energy-to-noise ratio*/ |
| for( b = 0; b < VAD_N_BANDS; b++ ) { |
| psSilk_VAD->NrgRatioSmth_Q8[ b ] = 100 * 256; /* 100 * 256 --> 20 dB SNR */ |
| } |
| |
| return( ret ); |
| } |
| |
| /* Weighting factors for tilt measure */ |
| static const opus_int32 tiltWeights[ VAD_N_BANDS ] = { 30000, 6000, -12000, -12000 }; |
| |
| /***************************************/ |
| /* Get the speech activity level in Q8 */ |
| /***************************************/ |
| opus_int silk_VAD_GetSA_Q8_c( /* O Return value, 0 if success */ |
| silk_encoder_state *psEncC, /* I/O Encoder state */ |
| const opus_int16 pIn[] /* I PCM input */ |
| ) |
| { |
| opus_int SA_Q15, pSNR_dB_Q7, input_tilt; |
| opus_int decimated_framelength1, decimated_framelength2; |
| opus_int decimated_framelength; |
| opus_int dec_subframe_length, dec_subframe_offset, SNR_Q7, i, b, s; |
| opus_int32 sumSquared, smooth_coef_Q16; |
| opus_int16 HPstateTmp; |
| VARDECL( opus_int16, X ); |
| opus_int32 Xnrg[ VAD_N_BANDS ]; |
| opus_int32 NrgToNoiseRatio_Q8[ VAD_N_BANDS ]; |
| opus_int32 speech_nrg, x_tmp; |
| opus_int X_offset[ VAD_N_BANDS ]; |
| opus_int ret = 0; |
| silk_VAD_state *psSilk_VAD = &psEncC->sVAD; |
| SAVE_STACK; |
| |
| /* Safety checks */ |
| silk_assert( VAD_N_BANDS == 4 ); |
| celt_assert( MAX_FRAME_LENGTH >= psEncC->frame_length ); |
| celt_assert( psEncC->frame_length <= 512 ); |
| celt_assert( psEncC->frame_length == 8 * silk_RSHIFT( psEncC->frame_length, 3 ) ); |
| |
| /***********************/ |
| /* Filter and Decimate */ |
| /***********************/ |
| decimated_framelength1 = silk_RSHIFT( psEncC->frame_length, 1 ); |
| decimated_framelength2 = silk_RSHIFT( psEncC->frame_length, 2 ); |
| decimated_framelength = silk_RSHIFT( psEncC->frame_length, 3 ); |
| /* Decimate into 4 bands: |
| 0 L 3L L 3L 5L |
| - -- - -- -- |
| 8 8 2 4 4 |
| |
| [0-1 kHz| temp. |1-2 kHz| 2-4 kHz | 4-8 kHz | |
| |
| They're arranged to allow the minimal ( frame_length / 4 ) extra |
| scratch space during the downsampling process */ |
| X_offset[ 0 ] = 0; |
| X_offset[ 1 ] = decimated_framelength + decimated_framelength2; |
| X_offset[ 2 ] = X_offset[ 1 ] + decimated_framelength; |
| X_offset[ 3 ] = X_offset[ 2 ] + decimated_framelength2; |
| ALLOC( X, X_offset[ 3 ] + decimated_framelength1, opus_int16 ); |
| |
| /* 0-8 kHz to 0-4 kHz and 4-8 kHz */ |
| silk_ana_filt_bank_1( pIn, &psSilk_VAD->AnaState[ 0 ], |
| X, &X[ X_offset[ 3 ] ], psEncC->frame_length ); |
| |
| /* 0-4 kHz to 0-2 kHz and 2-4 kHz */ |
| silk_ana_filt_bank_1( X, &psSilk_VAD->AnaState1[ 0 ], |
| X, &X[ X_offset[ 2 ] ], decimated_framelength1 ); |
| |
| /* 0-2 kHz to 0-1 kHz and 1-2 kHz */ |
| silk_ana_filt_bank_1( X, &psSilk_VAD->AnaState2[ 0 ], |
| X, &X[ X_offset[ 1 ] ], decimated_framelength2 ); |
| |
| /*********************************************/ |
| /* HP filter on lowest band (differentiator) */ |
| /*********************************************/ |
| X[ decimated_framelength - 1 ] = silk_RSHIFT( X[ decimated_framelength - 1 ], 1 ); |
| HPstateTmp = X[ decimated_framelength - 1 ]; |
| for( i = decimated_framelength - 1; i > 0; i-- ) { |
| X[ i - 1 ] = silk_RSHIFT( X[ i - 1 ], 1 ); |
| X[ i ] -= X[ i - 1 ]; |
| } |
| X[ 0 ] -= psSilk_VAD->HPstate; |
| psSilk_VAD->HPstate = HPstateTmp; |
| |
| /*************************************/ |
| /* Calculate the energy in each band */ |
| /*************************************/ |
| for( b = 0; b < VAD_N_BANDS; b++ ) { |
| /* Find the decimated framelength in the non-uniformly divided bands */ |
| decimated_framelength = silk_RSHIFT( psEncC->frame_length, silk_min_int( VAD_N_BANDS - b, VAD_N_BANDS - 1 ) ); |
| |
| /* Split length into subframe lengths */ |
| dec_subframe_length = silk_RSHIFT( decimated_framelength, VAD_INTERNAL_SUBFRAMES_LOG2 ); |
| dec_subframe_offset = 0; |
| |
| /* Compute energy per sub-frame */ |
| /* initialize with summed energy of last subframe */ |
| Xnrg[ b ] = psSilk_VAD->XnrgSubfr[ b ]; |
| for( s = 0; s < VAD_INTERNAL_SUBFRAMES; s++ ) { |
| sumSquared = 0; |
| for( i = 0; i < dec_subframe_length; i++ ) { |
| /* The energy will be less than dec_subframe_length * ( silk_int16_MIN / 8 ) ^ 2. */ |
| /* Therefore we can accumulate with no risk of overflow (unless dec_subframe_length > 128) */ |
| x_tmp = silk_RSHIFT( |
| X[ X_offset[ b ] + i + dec_subframe_offset ], 3 ); |
| sumSquared = silk_SMLABB( sumSquared, x_tmp, x_tmp ); |
| |
| /* Safety check */ |
| silk_assert( sumSquared >= 0 ); |
| } |
| |
| /* Add/saturate summed energy of current subframe */ |
| if( s < VAD_INTERNAL_SUBFRAMES - 1 ) { |
| Xnrg[ b ] = silk_ADD_POS_SAT32( Xnrg[ b ], sumSquared ); |
| } else { |
| /* Look-ahead subframe */ |
| Xnrg[ b ] = silk_ADD_POS_SAT32( Xnrg[ b ], silk_RSHIFT( sumSquared, 1 ) ); |
| } |
| |
| dec_subframe_offset += dec_subframe_length; |
| } |
| psSilk_VAD->XnrgSubfr[ b ] = sumSquared; |
| } |
| |
| /********************/ |
| /* Noise estimation */ |
| /********************/ |
| silk_VAD_GetNoiseLevels( &Xnrg[ 0 ], psSilk_VAD ); |
| |
| /***********************************************/ |
| /* Signal-plus-noise to noise ratio estimation */ |
| /***********************************************/ |
| sumSquared = 0; |
| input_tilt = 0; |
| for( b = 0; b < VAD_N_BANDS; b++ ) { |
| speech_nrg = Xnrg[ b ] - psSilk_VAD->NL[ b ]; |
| if( speech_nrg > 0 ) { |
| /* Divide, with sufficient resolution */ |
| if( ( Xnrg[ b ] & 0xFF800000 ) == 0 ) { |
| NrgToNoiseRatio_Q8[ b ] = silk_DIV32( silk_LSHIFT( Xnrg[ b ], 8 ), psSilk_VAD->NL[ b ] + 1 ); |
| } else { |
| NrgToNoiseRatio_Q8[ b ] = silk_DIV32( Xnrg[ b ], silk_RSHIFT( psSilk_VAD->NL[ b ], 8 ) + 1 ); |
| } |
| |
| /* Convert to log domain */ |
| SNR_Q7 = silk_lin2log( NrgToNoiseRatio_Q8[ b ] ) - 8 * 128; |
| |
| /* Sum-of-squares */ |
| sumSquared = silk_SMLABB( sumSquared, SNR_Q7, SNR_Q7 ); /* Q14 */ |
| |
| /* Tilt measure */ |
| if( speech_nrg < ( (opus_int32)1 << 20 ) ) { |
| /* Scale down SNR value for small subband speech energies */ |
| SNR_Q7 = silk_SMULWB( silk_LSHIFT( silk_SQRT_APPROX( speech_nrg ), 6 ), SNR_Q7 ); |
| } |
| input_tilt = silk_SMLAWB( input_tilt, tiltWeights[ b ], SNR_Q7 ); |
| } else { |
| NrgToNoiseRatio_Q8[ b ] = 256; |
| } |
| } |
| |
| /* Mean-of-squares */ |
| sumSquared = silk_DIV32_16( sumSquared, VAD_N_BANDS ); /* Q14 */ |
| |
| /* Root-mean-square approximation, scale to dBs, and write to output pointer */ |
| pSNR_dB_Q7 = (opus_int16)( 3 * silk_SQRT_APPROX( sumSquared ) ); /* Q7 */ |
| |
| /*********************************/ |
| /* Speech Probability Estimation */ |
| /*********************************/ |
| SA_Q15 = silk_sigm_Q15( silk_SMULWB( VAD_SNR_FACTOR_Q16, pSNR_dB_Q7 ) - VAD_NEGATIVE_OFFSET_Q5 ); |
| |
| /**************************/ |
| /* Frequency Tilt Measure */ |
| /**************************/ |
| psEncC->input_tilt_Q15 = silk_LSHIFT( silk_sigm_Q15( input_tilt ) - 16384, 1 ); |
| |
| /**************************************************/ |
| /* Scale the sigmoid output based on power levels */ |
| /**************************************************/ |
| speech_nrg = 0; |
| for( b = 0; b < VAD_N_BANDS; b++ ) { |
| /* Accumulate signal-without-noise energies, higher frequency bands have more weight */ |
| speech_nrg += ( b + 1 ) * silk_RSHIFT( Xnrg[ b ] - psSilk_VAD->NL[ b ], 4 ); |
| } |
| |
| if( psEncC->frame_length == 20 * psEncC->fs_kHz ) { |
| speech_nrg = silk_RSHIFT32( speech_nrg, 1 ); |
| } |
| /* Power scaling */ |
| if( speech_nrg <= 0 ) { |
| SA_Q15 = silk_RSHIFT( SA_Q15, 1 ); |
| } else if( speech_nrg < 16384 ) { |
| speech_nrg = silk_LSHIFT32( speech_nrg, 16 ); |
| |
| /* square-root */ |
| speech_nrg = silk_SQRT_APPROX( speech_nrg ); |
| SA_Q15 = silk_SMULWB( 32768 + speech_nrg, SA_Q15 ); |
| } |
| |
| /* Copy the resulting speech activity in Q8 */ |
| psEncC->speech_activity_Q8 = silk_min_int( silk_RSHIFT( SA_Q15, 7 ), silk_uint8_MAX ); |
| |
| /***********************************/ |
| /* Energy Level and SNR estimation */ |
| /***********************************/ |
| /* Smoothing coefficient */ |
| smooth_coef_Q16 = silk_SMULWB( VAD_SNR_SMOOTH_COEF_Q18, silk_SMULWB( (opus_int32)SA_Q15, SA_Q15 ) ); |
| |
| if( psEncC->frame_length == 10 * psEncC->fs_kHz ) { |
| smooth_coef_Q16 >>= 1; |
| } |
| |
| for( b = 0; b < VAD_N_BANDS; b++ ) { |
| /* compute smoothed energy-to-noise ratio per band */ |
| psSilk_VAD->NrgRatioSmth_Q8[ b ] = silk_SMLAWB( psSilk_VAD->NrgRatioSmth_Q8[ b ], |
| NrgToNoiseRatio_Q8[ b ] - psSilk_VAD->NrgRatioSmth_Q8[ b ], smooth_coef_Q16 ); |
| |
| /* signal to noise ratio in dB per band */ |
| SNR_Q7 = 3 * ( silk_lin2log( psSilk_VAD->NrgRatioSmth_Q8[b] ) - 8 * 128 ); |
| /* quality = sigmoid( 0.25 * ( SNR_dB - 16 ) ); */ |
| psEncC->input_quality_bands_Q15[ b ] = silk_sigm_Q15( silk_RSHIFT( SNR_Q7 - 16 * 128, 4 ) ); |
| } |
| |
| RESTORE_STACK; |
| return( ret ); |
| } |
| |
| /**************************/ |
| /* Noise level estimation */ |
| /**************************/ |
| # if !defined(OPUS_X86_MAY_HAVE_SSE4_1) |
| static OPUS_INLINE |
| #endif |
| void silk_VAD_GetNoiseLevels( |
| const opus_int32 pX[ VAD_N_BANDS ], /* I subband energies */ |
| silk_VAD_state *psSilk_VAD /* I/O Pointer to Silk VAD state */ |
| ) |
| { |
| opus_int k; |
| opus_int32 nl, nrg, inv_nrg; |
| opus_int coef, min_coef; |
| |
| /* Initially faster smoothing */ |
| if( psSilk_VAD->counter < 1000 ) { /* 1000 = 20 sec */ |
| min_coef = silk_DIV32_16( silk_int16_MAX, silk_RSHIFT( psSilk_VAD->counter, 4 ) + 1 ); |
| } else { |
| min_coef = 0; |
| } |
| |
| for( k = 0; k < VAD_N_BANDS; k++ ) { |
| /* Get old noise level estimate for current band */ |
| nl = psSilk_VAD->NL[ k ]; |
| silk_assert( nl >= 0 ); |
| |
| /* Add bias */ |
| nrg = silk_ADD_POS_SAT32( pX[ k ], psSilk_VAD->NoiseLevelBias[ k ] ); |
| silk_assert( nrg > 0 ); |
| |
| /* Invert energies */ |
| inv_nrg = silk_DIV32( silk_int32_MAX, nrg ); |
| silk_assert( inv_nrg >= 0 ); |
| |
| /* Less update when subband energy is high */ |
| if( nrg > silk_LSHIFT( nl, 3 ) ) { |
| coef = VAD_NOISE_LEVEL_SMOOTH_COEF_Q16 >> 3; |
| } else if( nrg < nl ) { |
| coef = VAD_NOISE_LEVEL_SMOOTH_COEF_Q16; |
| } else { |
| coef = silk_SMULWB( silk_SMULWW( inv_nrg, nl ), VAD_NOISE_LEVEL_SMOOTH_COEF_Q16 << 1 ); |
| } |
| |
| /* Initially faster smoothing */ |
| coef = silk_max_int( coef, min_coef ); |
| |
| /* Smooth inverse energies */ |
| psSilk_VAD->inv_NL[ k ] = silk_SMLAWB( psSilk_VAD->inv_NL[ k ], inv_nrg - psSilk_VAD->inv_NL[ k ], coef ); |
| silk_assert( psSilk_VAD->inv_NL[ k ] >= 0 ); |
| |
| /* Compute noise level by inverting again */ |
| nl = silk_DIV32( silk_int32_MAX, psSilk_VAD->inv_NL[ k ] ); |
| silk_assert( nl >= 0 ); |
| |
| /* Limit noise levels (guarantee 7 bits of head room) */ |
| nl = silk_min( nl, 0x00FFFFFF ); |
| |
| /* Store as part of state */ |
| psSilk_VAD->NL[ k ] = nl; |
| } |
| |
| /* Increment frame counter */ |
| psSilk_VAD->counter++; |
| } |
