resampler.c (10146B)
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[ 6 ][ 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 /* 96 */ { 0, 0, 44 } 61 }; 62 63 static const opus_int8 delay_matrix_dec[ 3 ][ 6 ] = { 64 /* in \ out 8 12 16 24 48 96*/ 65 /* 8 */ { 4, 0, 2, 0, 0, 0 }, 66 /* 12 */ { 0, 9, 4, 7, 4, 4 }, 67 /* 16 */ { 0, 3, 12, 7, 7, 7 } 68 }; 69 70 /* Simple way to make [8000, 12000, 16000, 24000, 48000] to [0, 1, 2, 3, 4] */ 71 #define rateID(R) IMIN(5, ( ( ( ((R)>>12) - ((R)>16000) ) >> ((R)>24000) ) - 1 )) 72 73 #define USE_silk_resampler_copy (0) 74 #define USE_silk_resampler_private_up2_HQ_wrapper (1) 75 #define USE_silk_resampler_private_IIR_FIR (2) 76 #define USE_silk_resampler_private_down_FIR (3) 77 78 /* Initialize/reset the resampler state for a given pair of input/output sampling rates */ 79 opus_int silk_resampler_init( 80 silk_resampler_state_struct *S, /* I/O Resampler state */ 81 opus_int32 Fs_Hz_in, /* I Input sampling rate (Hz) */ 82 opus_int32 Fs_Hz_out, /* I Output sampling rate (Hz) */ 83 opus_int forEnc /* I If 1: encoder; if 0: decoder */ 84 ) 85 { 86 opus_int up2x; 87 88 /* Clear state */ 89 silk_memset( S, 0, sizeof( silk_resampler_state_struct ) ); 90 91 /* Input checking */ 92 if( forEnc ) { 93 if( ( Fs_Hz_in != 8000 && Fs_Hz_in != 12000 && Fs_Hz_in != 16000 && Fs_Hz_in != 24000 && Fs_Hz_in != 48000 94 #ifdef ENABLE_QEXT 95 && Fs_Hz_in != 96000 96 #endif 97 ) || 98 ( Fs_Hz_out != 8000 && Fs_Hz_out != 12000 && Fs_Hz_out != 16000 ) ) { 99 celt_assert( 0 ); 100 return -1; 101 } 102 S->inputDelay = delay_matrix_enc[ rateID( Fs_Hz_in ) ][ rateID( Fs_Hz_out ) ]; 103 } else { 104 if( ( Fs_Hz_in != 8000 && Fs_Hz_in != 12000 && Fs_Hz_in != 16000 ) || 105 ( Fs_Hz_out != 8000 && Fs_Hz_out != 12000 && Fs_Hz_out != 16000 && Fs_Hz_out != 24000 && Fs_Hz_out != 48000 106 #ifdef ENABLE_QEXT 107 && Fs_Hz_out != 96000 108 #endif 109 ) ) { 110 celt_assert( 0 ); 111 return -1; 112 } 113 S->inputDelay = delay_matrix_dec[ rateID( Fs_Hz_in ) ][ rateID( Fs_Hz_out ) ]; 114 } 115 116 S->Fs_in_kHz = silk_DIV32_16( Fs_Hz_in, 1000 ); 117 S->Fs_out_kHz = silk_DIV32_16( Fs_Hz_out, 1000 ); 118 119 /* Number of samples processed per batch */ 120 S->batchSize = S->Fs_in_kHz * RESAMPLER_MAX_BATCH_SIZE_MS; 121 122 /* Find resampler with the right sampling ratio */ 123 up2x = 0; 124 if( Fs_Hz_out > Fs_Hz_in ) { 125 /* Upsample */ 126 if( Fs_Hz_out == silk_MUL( Fs_Hz_in, 2 ) ) { /* Fs_out : Fs_in = 2 : 1 */ 127 /* Special case: directly use 2x upsampler */ 128 S->resampler_function = USE_silk_resampler_private_up2_HQ_wrapper; 129 } else { 130 /* Default resampler */ 131 S->resampler_function = USE_silk_resampler_private_IIR_FIR; 132 up2x = 1; 133 } 134 } else if ( Fs_Hz_out < Fs_Hz_in ) { 135 /* Downsample */ 136 S->resampler_function = USE_silk_resampler_private_down_FIR; 137 if( silk_MUL( Fs_Hz_out, 4 ) == silk_MUL( Fs_Hz_in, 3 ) ) { /* Fs_out : Fs_in = 3 : 4 */ 138 S->FIR_Fracs = 3; 139 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR0; 140 S->Coefs = silk_Resampler_3_4_COEFS; 141 } else if( silk_MUL( Fs_Hz_out, 3 ) == silk_MUL( Fs_Hz_in, 2 ) ) { /* Fs_out : Fs_in = 2 : 3 */ 142 S->FIR_Fracs = 2; 143 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR0; 144 S->Coefs = silk_Resampler_2_3_COEFS; 145 } else if( silk_MUL( Fs_Hz_out, 2 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 2 */ 146 S->FIR_Fracs = 1; 147 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR1; 148 S->Coefs = silk_Resampler_1_2_COEFS; 149 } else if( silk_MUL( Fs_Hz_out, 3 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 3 */ 150 S->FIR_Fracs = 1; 151 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; 152 S->Coefs = silk_Resampler_1_3_COEFS; 153 } else if( silk_MUL( Fs_Hz_out, 4 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 4 */ 154 S->FIR_Fracs = 1; 155 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; 156 S->Coefs = silk_Resampler_1_4_COEFS; 157 } else if( silk_MUL( Fs_Hz_out, 6 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 6 */ 158 S->FIR_Fracs = 1; 159 S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; 160 S->Coefs = silk_Resampler_1_6_COEFS; 161 } else { 162 /* None available */ 163 celt_assert( 0 ); 164 return -1; 165 } 166 } else { 167 /* Input and output sampling rates are equal: copy */ 168 S->resampler_function = USE_silk_resampler_copy; 169 } 170 171 /* Ratio of input/output samples */ 172 S->invRatio_Q16 = silk_LSHIFT32( silk_DIV32( silk_LSHIFT32( Fs_Hz_in, 14 + up2x ), Fs_Hz_out ), 2 ); 173 /* Make sure the ratio is rounded up */ 174 while( silk_SMULWW( S->invRatio_Q16, Fs_Hz_out ) < silk_LSHIFT32( Fs_Hz_in, up2x ) ) { 175 S->invRatio_Q16++; 176 } 177 178 return 0; 179 } 180 181 /* Resampler: convert from one sampling rate to another */ 182 /* Input and output sampling rate are at most 48000 Hz */ 183 opus_int silk_resampler( 184 silk_resampler_state_struct *S, /* I/O Resampler state */ 185 opus_int16 out[], /* O Output signal */ 186 const opus_int16 in[], /* I Input signal */ 187 opus_int32 inLen /* I Number of input samples */ 188 ) 189 { 190 opus_int nSamples; 191 192 /* Need at least 1 ms of input data */ 193 celt_assert( inLen >= S->Fs_in_kHz ); 194 /* Delay can't exceed the 1 ms of buffering */ 195 celt_assert( S->inputDelay <= S->Fs_in_kHz ); 196 197 nSamples = S->Fs_in_kHz - S->inputDelay; 198 199 /* Copy to delay buffer */ 200 silk_memcpy( &S->delayBuf[ S->inputDelay ], in, nSamples * sizeof( opus_int16 ) ); 201 202 switch( S->resampler_function ) { 203 case USE_silk_resampler_private_up2_HQ_wrapper: 204 silk_resampler_private_up2_HQ_wrapper( S, out, S->delayBuf, S->Fs_in_kHz ); 205 silk_resampler_private_up2_HQ_wrapper( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); 206 break; 207 case USE_silk_resampler_private_IIR_FIR: 208 silk_resampler_private_IIR_FIR( S, out, S->delayBuf, S->Fs_in_kHz ); 209 silk_resampler_private_IIR_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); 210 break; 211 case USE_silk_resampler_private_down_FIR: 212 silk_resampler_private_down_FIR( S, out, S->delayBuf, S->Fs_in_kHz ); 213 silk_resampler_private_down_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); 214 break; 215 default: 216 silk_memcpy( out, S->delayBuf, S->Fs_in_kHz * sizeof( opus_int16 ) ); 217 silk_memcpy( &out[ S->Fs_out_kHz ], &in[ nSamples ], ( inLen - S->Fs_in_kHz ) * sizeof( opus_int16 ) ); 218 } 219 220 /* Copy to delay buffer */ 221 silk_memcpy( S->delayBuf, &in[ inLen - S->inputDelay ], S->inputDelay * sizeof( opus_int16 ) ); 222 223 return 0; 224 }