Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 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. |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 12 | names of specific contributors, may be used to endorse or promote |
| 13 | products derived from this software without specific prior written |
| 14 | permission. |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 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 | } |