| /*********************************************************************** |
| 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 |
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| POSSIBILITY OF SUCH DAMAGE. |
| ***********************************************************************/ |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| /* |
| * Matrix of resampling methods used: |
| * Fs_out (kHz) |
| * 8 12 16 24 48 |
| * |
| * 8 C UF U UF UF |
| * 12 AF C UF U UF |
| * Fs_in (kHz) 16 D AF C UF UF |
| * 24 AF D AF C U |
| * 48 AF AF AF D C |
| * |
| * C -> Copy (no resampling) |
| * D -> Allpass-based 2x downsampling |
| * U -> Allpass-based 2x upsampling |
| * UF -> Allpass-based 2x upsampling followed by FIR interpolation |
| * AF -> AR2 filter followed by FIR interpolation |
| */ |
| |
| #include "resampler_private.h" |
| |
| /* Tables with delay compensation values to equalize total delay for different modes */ |
| static const opus_int8 delay_matrix_enc[ 5 ][ 3 ] = { |
| /* in \ out 8 12 16 */ |
| /* 8 */ { 6, 0, 3 }, |
| /* 12 */ { 0, 7, 3 }, |
| /* 16 */ { 0, 1, 10 }, |
| /* 24 */ { 0, 2, 6 }, |
| /* 48 */ { 18, 10, 12 } |
| }; |
| |
| static const opus_int8 delay_matrix_dec[ 3 ][ 5 ] = { |
| /* in \ out 8 12 16 24 48 */ |
| /* 8 */ { 4, 0, 2, 0, 0 }, |
| /* 12 */ { 0, 9, 4, 7, 4 }, |
| /* 16 */ { 0, 3, 12, 7, 7 } |
| }; |
| |
| /* Simple way to make [8000, 12000, 16000, 24000, 48000] to [0, 1, 2, 3, 4] */ |
| #define rateID(R) ( ( ( ((R)>>12) - ((R)>16000) ) >> ((R)>24000) ) - 1 ) |
| |
| #define USE_silk_resampler_copy (0) |
| #define USE_silk_resampler_private_up2_HQ_wrapper (1) |
| #define USE_silk_resampler_private_IIR_FIR (2) |
| #define USE_silk_resampler_private_down_FIR (3) |
| |
| /* Initialize/reset the resampler state for a given pair of input/output sampling rates */ |
| opus_int silk_resampler_init( |
| silk_resampler_state_struct *S, /* I/O Resampler state */ |
| opus_int32 Fs_Hz_in, /* I Input sampling rate (Hz) */ |
| opus_int32 Fs_Hz_out, /* I Output sampling rate (Hz) */ |
| opus_int forEnc /* I If 1: encoder; if 0: decoder */ |
| ) |
| { |
| opus_int up2x; |
| |
| /* Clear state */ |
| silk_memset( S, 0, sizeof( silk_resampler_state_struct ) ); |
| |
| /* Input checking */ |
| if( forEnc ) { |
| if( ( Fs_Hz_in != 8000 && Fs_Hz_in != 12000 && Fs_Hz_in != 16000 && Fs_Hz_in != 24000 && Fs_Hz_in != 48000 ) || |
| ( Fs_Hz_out != 8000 && Fs_Hz_out != 12000 && Fs_Hz_out != 16000 ) ) { |
| silk_assert( 0 ); |
| return -1; |
| } |
| S->inputDelay = delay_matrix_enc[ rateID( Fs_Hz_in ) ][ rateID( Fs_Hz_out ) ]; |
| } else { |
| if( ( Fs_Hz_in != 8000 && Fs_Hz_in != 12000 && Fs_Hz_in != 16000 ) || |
| ( Fs_Hz_out != 8000 && Fs_Hz_out != 12000 && Fs_Hz_out != 16000 && Fs_Hz_out != 24000 && Fs_Hz_out != 48000 ) ) { |
| silk_assert( 0 ); |
| return -1; |
| } |
| S->inputDelay = delay_matrix_dec[ rateID( Fs_Hz_in ) ][ rateID( Fs_Hz_out ) ]; |
| } |
| |
| S->Fs_in_kHz = silk_DIV32_16( Fs_Hz_in, 1000 ); |
| S->Fs_out_kHz = silk_DIV32_16( Fs_Hz_out, 1000 ); |
| |
| /* Number of samples processed per batch */ |
| S->batchSize = S->Fs_in_kHz * RESAMPLER_MAX_BATCH_SIZE_MS; |
| |
| /* Find resampler with the right sampling ratio */ |
| up2x = 0; |
| if( Fs_Hz_out > Fs_Hz_in ) { |
| /* Upsample */ |
| if( Fs_Hz_out == silk_MUL( Fs_Hz_in, 2 ) ) { /* Fs_out : Fs_in = 2 : 1 */ |
| /* Special case: directly use 2x upsampler */ |
| S->resampler_function = USE_silk_resampler_private_up2_HQ_wrapper; |
| } else { |
| /* Default resampler */ |
| S->resampler_function = USE_silk_resampler_private_IIR_FIR; |
| up2x = 1; |
| } |
| } else if ( Fs_Hz_out < Fs_Hz_in ) { |
| /* Downsample */ |
| S->resampler_function = USE_silk_resampler_private_down_FIR; |
| if( silk_MUL( Fs_Hz_out, 4 ) == silk_MUL( Fs_Hz_in, 3 ) ) { /* Fs_out : Fs_in = 3 : 4 */ |
| S->FIR_Fracs = 3; |
| S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR0; |
| S->Coefs = silk_Resampler_3_4_COEFS; |
| } else if( silk_MUL( Fs_Hz_out, 3 ) == silk_MUL( Fs_Hz_in, 2 ) ) { /* Fs_out : Fs_in = 2 : 3 */ |
| S->FIR_Fracs = 2; |
| S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR0; |
| S->Coefs = silk_Resampler_2_3_COEFS; |
| } else if( silk_MUL( Fs_Hz_out, 2 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 2 */ |
| S->FIR_Fracs = 1; |
| S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR1; |
| S->Coefs = silk_Resampler_1_2_COEFS; |
| } else if( silk_MUL( Fs_Hz_out, 3 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 3 */ |
| S->FIR_Fracs = 1; |
| S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; |
| S->Coefs = silk_Resampler_1_3_COEFS; |
| } else if( silk_MUL( Fs_Hz_out, 4 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 4 */ |
| S->FIR_Fracs = 1; |
| S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; |
| S->Coefs = silk_Resampler_1_4_COEFS; |
| } else if( silk_MUL( Fs_Hz_out, 6 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 6 */ |
| S->FIR_Fracs = 1; |
| S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2; |
| S->Coefs = silk_Resampler_1_6_COEFS; |
| } else { |
| /* None available */ |
| silk_assert( 0 ); |
| return -1; |
| } |
| } else { |
| /* Input and output sampling rates are equal: copy */ |
| S->resampler_function = USE_silk_resampler_copy; |
| } |
| |
| /* Ratio of input/output samples */ |
| S->invRatio_Q16 = silk_LSHIFT32( silk_DIV32( silk_LSHIFT32( Fs_Hz_in, 14 + up2x ), Fs_Hz_out ), 2 ); |
| /* Make sure the ratio is rounded up */ |
| while( silk_SMULWW( S->invRatio_Q16, Fs_Hz_out ) < silk_LSHIFT32( Fs_Hz_in, up2x ) ) { |
| S->invRatio_Q16++; |
| } |
| |
| return 0; |
| } |
| |
| /* Resampler: convert from one sampling rate to another */ |
| /* Input and output sampling rate are at most 48000 Hz */ |
| opus_int silk_resampler( |
| silk_resampler_state_struct *S, /* I/O Resampler state */ |
| opus_int16 out[], /* O Output signal */ |
| const opus_int16 in[], /* I Input signal */ |
| opus_int32 inLen /* I Number of input samples */ |
| ) |
| { |
| opus_int nSamples; |
| |
| /* Need at least 1 ms of input data */ |
| silk_assert( inLen >= S->Fs_in_kHz ); |
| /* Delay can't exceed the 1 ms of buffering */ |
| silk_assert( S->inputDelay <= S->Fs_in_kHz ); |
| |
| nSamples = S->Fs_in_kHz - S->inputDelay; |
| |
| /* Copy to delay buffer */ |
| silk_memcpy( &S->delayBuf[ S->inputDelay ], in, nSamples * sizeof( opus_int16 ) ); |
| |
| switch( S->resampler_function ) { |
| case USE_silk_resampler_private_up2_HQ_wrapper: |
| silk_resampler_private_up2_HQ_wrapper( S, out, S->delayBuf, S->Fs_in_kHz ); |
| silk_resampler_private_up2_HQ_wrapper( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); |
| break; |
| case USE_silk_resampler_private_IIR_FIR: |
| silk_resampler_private_IIR_FIR( S, out, S->delayBuf, S->Fs_in_kHz ); |
| silk_resampler_private_IIR_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); |
| break; |
| case USE_silk_resampler_private_down_FIR: |
| silk_resampler_private_down_FIR( S, out, S->delayBuf, S->Fs_in_kHz ); |
| silk_resampler_private_down_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz ); |
| break; |
| default: |
| silk_memcpy( out, S->delayBuf, S->Fs_in_kHz * sizeof( opus_int16 ) ); |
| silk_memcpy( &out[ S->Fs_out_kHz ], &in[ nSamples ], ( inLen - S->Fs_in_kHz ) * sizeof( opus_int16 ) ); |
| } |
| |
| /* Copy to delay buffer */ |
| silk_memcpy( S->delayBuf, &in[ inLen - S->inputDelay ], S->inputDelay * sizeof( opus_int16 ) ); |
| |
| return 0; |
| } |
