1 /*********************************************************************** 2 Copyright (c) 2006-2011, Skype Limited. All rights reserved. 3 Redistribution and use in source and binary forms, with or without 4 modification, are permitted provided that the following conditions 5 are met: 6 - Redistributions of source code must retain the above copyright notice, 7 this list of conditions and the following disclaimer. 8 - Redistributions in binary form must reproduce the above copyright 9 notice, this list of conditions and the following disclaimer in the 10 documentation and/or other materials provided with the distribution. 11 - Neither the name of Internet Society, IETF or IETF Trust, nor the 12 names of specific contributors, may be used to endorse or promote 13 products derived from this software without specific prior written 14 permission. 15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 POSSIBILITY OF SUCH DAMAGE. 26 ***********************************************************************/ 27 28 #ifdef HAVE_CONFIG_H 29 #include "config.h" 30 #endif 31 32 /* 33 * Matrix of resampling methods used: 34 * Fs_out (kHz) 35 * 8 12 16 24 48 36 * 37 * 8 C UF U UF UF 38 * 12 AF C UF U UF 39 * Fs_in (kHz) 16 D AF C UF UF 40 * 24 AF D AF C U 41 * 48 AF AF AF D C 42 * 43 * C -> Copy (no resampling) 44 * D -> Allpass-based 2x downsampling 45 * U -> Allpass-based 2x upsampling 46 * UF -> Allpass-based 2x upsampling followed by FIR interpolation 47 * AF -> AR2 filter followed by FIR interpolation 48 */ 49 50 #include "resampler_private.h" 51 52 /* Tables with delay compensation values to equalize total delay for different modes */ 53 static const opus_int8 delay_matrix_enc[ 5 ][ 3 ] = { 54 /* in \ out 8 12 16 */ 55 /* 8 */ { 6, 0, 3 }, 56 /* 12 */ { 0, 7, 3 }, 57 /* 16 */ { 0, 1, 10 }, 58 /* 24 */ { 0, 2, 6 }, 59 /* 48 */ { 18, 10, 12 } 60 }; 61 62 static const opus_int8 delay_matrix_dec[ 3 ][ 5 ] = { 63 /* in \ out 8 12 16 24 48 */ 64 /* 8 */ { 4, 0, 2, 0, 0 }, 65 /* 12 */ { 0, 9, 4, 7, 4 }, 66 /* 16 */ { 0, 3, 12, 7, 7 } 67 }; 68 69 /* Simple way to make [8000, 12000, 16000, 24000, 48000] to [0, 1, 2, 3, 4] */ 70 #define rateID(R) ( ( ( ((R)>>12) - ((R)>16000) ) >> ((R)>24000) ) - 1 ) 71 72 #define USE_silk_resampler_copy (0) 73 #define USE_silk_resampler_private_up2_HQ_wrapper (1) 74 #define USE_silk_resampler_private_IIR_FIR (2) 75 #define USE_silk_resampler_private_down_FIR (3) 76 77 /* Initialize/reset the resampler state for a given pair of input/output sampling rates */ 78 opus_int silk_resampler_init( 79 silk_resampler_state_struct *S, /* I/O Resampler state */ 80 opus_int32 Fs_Hz_in, /* I Input sampling rate (Hz) */ 81 opus_int32 Fs_Hz_out, /* I Output sampling rate (Hz) */ 82 opus_int forEnc /* I If 1: encoder; if 0: decoder */ 83 ) 84 { 85 opus_int up2x; 86 87 /* Clear state */ 88 silk_memset( S, 0, sizeof( silk_resampler_state_struct ) ); 89 90 /* Input checking */ 91 if( forEnc ) { 92 if( ( Fs_Hz_in != 8000 && Fs_Hz_in != 12000 && Fs_Hz_in != 16000 && Fs_Hz_in != 24000 && Fs_Hz_in != 48000 ) || 93 ( Fs_Hz_out != 8000 && Fs_Hz_out != 12000 && Fs_Hz_out != 16000 ) ) { 94 silk_assert( 0 ); 95 return -1; 96 } 97 S->inputDelay = delay_matrix_enc[ rateID( Fs_Hz_in ) ][ rateID( Fs_Hz_out ) ]; 98 } else { 99 if( ( Fs_Hz_in != 8000 && Fs_Hz_in != 12000 && Fs_Hz_in != 16000 ) || 100 ( Fs_Hz_out != 8000 && Fs_Hz_out != 12000 && Fs_Hz_out != 16000 && Fs_Hz_out != 24000 && Fs_Hz_out != 48000 ) ) { 101 silk_assert( 0 ); 102 return -1; 103 } 104 S->inputDelay = delay_matrix_dec[ rateID( Fs_Hz_in ) ][ rateID( Fs_Hz_out ) ]; 105 } 106 107 S->Fs_in_kHz = silk_DIV32_16( Fs_Hz_in, 1000 ); 108 S->Fs_out_kHz = silk_DIV32_16( Fs_Hz_out, 1000 ); 109 110 /* Number of samples processed per batch */ 111 S->batchSize = S->Fs_in_kHz * RESAMPLER_MAX_BATCH_SIZE_MS; 112 113 /* Find resampler with the right sampling ratio */ 114 up2x = 0; 115 if( Fs_Hz_out > Fs_Hz_in ) { 116 /* Upsample */ 117 if( Fs_Hz_out == silk_MUL( Fs_Hz_in, 2 ) ) { /* Fs_out : Fs_in = 2 : 1 */ 118 /* Special case: directly use 2x upsampler */ 119 S->resampler_function = USE_silk_resampler_private_up2_HQ_wrapper; 120 } else { 121 /* Default resampler */ 122 S->resampler_function = USE_silk_resampler_private_IIR_FIR; 123 up2x = 1; 124 } 125 } else if ( Fs_Hz_out < Fs_Hz_in ) { 126 /* Downsample */ 127 S->resampler_function = USE_silk_resampler_private_down_FIR; 128 if( silk_MUL( Fs_Hz_out, 4 ) == silk_MUL( Fs_Hz_in, 3 ) ) { /* Fs_out : Fs_in = 3 : 4 */ 129 S->FIR_Fracs = 3; 130 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR0; 131 S->Coefs = silk_Resampler_3_4_COEFS; 132 } else if( silk_MUL( Fs_Hz_out, 3 ) == silk_MUL( Fs_Hz_in, 2 ) ) { /* Fs_out : Fs_in = 2 : 3 */ 133 S->FIR_Fracs = 2; 134 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR0; 135 S->Coefs = silk_Resampler_2_3_COEFS; 136 } else if( silk_MUL( Fs_Hz_out, 2 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 2 */ 137 S->FIR_Fracs = 1; 138 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR1; 139 S->Coefs = silk_Resampler_1_2_COEFS; 140 } else if( silk_MUL( Fs_Hz_out, 3 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 3 */ 141 S->FIR_Fracs = 1; 142 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; 143 S->Coefs = silk_Resampler_1_3_COEFS; 144 } else if( silk_MUL( Fs_Hz_out, 4 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 4 */ 145 S->FIR_Fracs = 1; 146 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; 147 S->Coefs = silk_Resampler_1_4_COEFS; 148 } else if( silk_MUL( Fs_Hz_out, 6 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 6 */ 149 S->FIR_Fracs = 1; 150 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; 151 S->Coefs = silk_Resampler_1_6_COEFS; 152 } else { 153 /* None available */ 154 silk_assert( 0 ); 155 return -1; 156 } 157 } else { 158 /* Input and output sampling rates are equal: copy */ 159 S->resampler_function = USE_silk_resampler_copy; 160 } 161 162 /* Ratio of input/output samples */ 163 S->invRatio_Q16 = silk_LSHIFT32( silk_DIV32( silk_LSHIFT32( Fs_Hz_in, 14 + up2x ), Fs_Hz_out ), 2 ); 164 /* Make sure the ratio is rounded up */ 165 while( silk_SMULWW( S->invRatio_Q16, Fs_Hz_out ) < silk_LSHIFT32( Fs_Hz_in, up2x ) ) { 166 S->invRatio_Q16++; 167 } 168 169 return 0; 170 } 171 172 /* Resampler: convert from one sampling rate to another */ 173 /* Input and output sampling rate are at most 48000 Hz */ 174 opus_int silk_resampler( 175 silk_resampler_state_struct *S, /* I/O Resampler state */ 176 opus_int16 out[], /* O Output signal */ 177 const opus_int16 in[], /* I Input signal */ 178 opus_int32 inLen /* I Number of input samples */ 179 ) 180 { 181 opus_int nSamples; 182 183 /* Need at least 1 ms of input data */ 184 silk_assert( inLen >= S->Fs_in_kHz ); 185 /* Delay can't exceed the 1 ms of buffering */ 186 silk_assert( S->inputDelay <= S->Fs_in_kHz ); 187 188 nSamples = S->Fs_in_kHz - S->inputDelay; 189 190 /* Copy to delay buffer */ 191 silk_memcpy( &S->delayBuf[ S->inputDelay ], in, nSamples * sizeof( opus_int16 ) ); 192 193 switch( S->resampler_function ) { 194 case USE_silk_resampler_private_up2_HQ_wrapper: 195 silk_resampler_private_up2_HQ_wrapper( S, out, S->delayBuf, S->Fs_in_kHz ); 196 silk_resampler_private_up2_HQ_wrapper( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); 197 break; 198 case USE_silk_resampler_private_IIR_FIR: 199 silk_resampler_private_IIR_FIR( S, out, S->delayBuf, S->Fs_in_kHz ); 200 silk_resampler_private_IIR_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); 201 break; 202 case USE_silk_resampler_private_down_FIR: 203 silk_resampler_private_down_FIR( S, out, S->delayBuf, S->Fs_in_kHz ); 204 silk_resampler_private_down_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); 205 break; 206 default: 207 silk_memcpy( out, S->delayBuf, S->Fs_in_kHz * sizeof( opus_int16 ) ); 208 silk_memcpy( &out[ S->Fs_out_kHz ], &in[ nSamples ], ( inLen - S->Fs_in_kHz ) * sizeof( opus_int16 ) ); 209 } 210 211 /* Copy to delay buffer */ 212 silk_memcpy( S->delayBuf, &in[ inLen - S->inputDelay ], S->inputDelay * sizeof( opus_int16 ) ); 213 214 return 0; 215 } 216
