| /* |
| * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| /* |
| * filterbanks.c |
| * |
| * This file contains function |
| * WebRtcIsacfix_SplitAndFilter, and WebRtcIsacfix_FilterAndCombine |
| * which implement filterbanks that produce decimated lowpass and |
| * highpass versions of a signal, and performs reconstruction. |
| * |
| */ |
| |
| #include "codec.h" |
| #include "filterbank_internal.h" |
| #include "filterbank_tables.h" |
| #include "settings.h" |
| |
| |
| static void AllpassFilter2FixDec16(WebRtc_Word16 *InOut16, //Q0 |
| const WebRtc_Word16 *APSectionFactors, //Q15 |
| WebRtc_Word16 lengthInOut, |
| WebRtc_Word16 NumberOfSections, |
| WebRtc_Word32 *FilterState) //Q16 |
| { |
| int n, j; |
| WebRtc_Word32 a, b; |
| |
| for (j=0; j<NumberOfSections; j++) { |
| for (n=0;n<lengthInOut;n++) { |
| |
| |
| a = WEBRTC_SPL_MUL_16_16(APSectionFactors[j], InOut16[n]); //Q15*Q0=Q15 |
| a = WEBRTC_SPL_LSHIFT_W32(a, 1); // Q15 -> Q16 |
| b = WEBRTC_SPL_ADD_SAT_W32(a, FilterState[j]); //Q16+Q16=Q16 |
| a = WEBRTC_SPL_MUL_16_16_RSFT(-APSectionFactors[j], (WebRtc_Word16) WEBRTC_SPL_RSHIFT_W32(b, 16), 0); //Q15*Q0=Q15 |
| FilterState[j] = WEBRTC_SPL_ADD_SAT_W32(WEBRTC_SPL_LSHIFT_W32(a,1), WEBRTC_SPL_LSHIFT_W32((WebRtc_UWord32)InOut16[n],16)); // Q15<<1 + Q0<<16 = Q16 + Q16 = Q16 |
| InOut16[n] = (WebRtc_Word16) WEBRTC_SPL_RSHIFT_W32(b, 16); //Save as Q0 |
| |
| } |
| } |
| |
| } |
| |
| |
| void WebRtcIsacfix_HighpassFilterFixDec32(int16_t *io, |
| int16_t len, |
| const int16_t *coefficient, |
| int32_t *state) |
| { |
| int k; |
| WebRtc_Word32 a1 = 0, b1 = 0, c = 0, in = 0; |
| WebRtc_Word32 a2 = 0, b2 = 0; |
| WebRtc_Word32 state0 = state[0]; |
| WebRtc_Word32 state1 = state[1]; |
| |
| for (k=0; k<len; k++) { |
| in = (WebRtc_Word32)io[k]; |
| |
| #ifdef WEBRTC_ARCH_ARM_V7 |
| { |
| int tmp_coeff0 = 0; |
| int tmp_coeff1 = 0; |
| __asm __volatile( |
| "ldr %[tmp_coeff0], [%[coeff]]\n\t" |
| "ldr %[tmp_coeff1], [%[coeff], #4]\n\t" |
| "smmulr %[a2], %[tmp_coeff0], %[state0]\n\t" |
| "smmulr %[b2], %[tmp_coeff1], %[state1]\n\t" |
| "ldr %[tmp_coeff0], [%[coeff], #8]\n\t" |
| "ldr %[tmp_coeff1], [%[coeff], #12]\n\t" |
| "smmulr %[a1], %[tmp_coeff0], %[state0]\n\t" |
| "smmulr %[b1], %[tmp_coeff1], %[state1]\n\t" |
| :[a2]"+r"(a2), |
| [b2]"+r"(b2), |
| [a1]"+r"(a1), |
| [b1]"+r"(b1), |
| [tmp_coeff0]"+r"(tmp_coeff0), |
| [tmp_coeff1]"+r"(tmp_coeff1) |
| :[coeff]"r"(coefficient), |
| [state0]"r"(state0), |
| [state1]"r"(state1) |
| ); |
| } |
| #else |
| /* Q35 * Q4 = Q39 ; shift 32 bit => Q7 */ |
| a1 = WEBRTC_SPL_MUL_32_32_RSFT32(coefficient[5], coefficient[4], state0); |
| b1 = WEBRTC_SPL_MUL_32_32_RSFT32(coefficient[7], coefficient[6], state1); |
| |
| /* Q30 * Q4 = Q34 ; shift 32 bit => Q2 */ |
| a2 = WEBRTC_SPL_MUL_32_32_RSFT32(coefficient[1], coefficient[0], state0); |
| b2 = WEBRTC_SPL_MUL_32_32_RSFT32(coefficient[3], coefficient[2], state1); |
| #endif |
| |
| c = ((WebRtc_Word32)in) + WEBRTC_SPL_RSHIFT_W32(a1+b1, 7); // Q0 |
| io[k] = (WebRtc_Word16)WebRtcSpl_SatW32ToW16(c); // Write output as Q0. |
| |
| c = WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)in, 2) - a2 - b2; // In Q2. |
| c = (WebRtc_Word32)WEBRTC_SPL_SAT(536870911, c, -536870912); |
| |
| state1 = state0; |
| state0 = WEBRTC_SPL_LSHIFT_W32(c, 2); // Write state as Q4 |
| } |
| state[0] = state0; |
| state[1] = state1; |
| } |
| |
| |
| void WebRtcIsacfix_SplitAndFilter1(WebRtc_Word16 *pin, |
| WebRtc_Word16 *LP16, |
| WebRtc_Word16 *HP16, |
| PreFiltBankstr *prefiltdata) |
| { |
| /* Function WebRtcIsacfix_SplitAndFilter */ |
| /* This function creates low-pass and high-pass decimated versions of part of |
| the input signal, and part of the signal in the input 'lookahead buffer'. */ |
| |
| int k; |
| |
| WebRtc_Word16 tempin_ch1[FRAMESAMPLES/2 + QLOOKAHEAD]; |
| WebRtc_Word16 tempin_ch2[FRAMESAMPLES/2 + QLOOKAHEAD]; |
| WebRtc_Word32 tmpState[WEBRTC_SPL_MUL_16_16(2,(QORDER-1))]; /* 4 */ |
| |
| |
| /* High pass filter */ |
| WebRtcIsacfix_HighpassFilterFixDec32(pin, FRAMESAMPLES, WebRtcIsacfix_kHpStCoeffInQ30, prefiltdata->HPstates_fix); |
| |
| |
| /* First Channel */ |
| for (k=0;k<FRAMESAMPLES/2;k++) { |
| tempin_ch1[QLOOKAHEAD + k] = pin[1+WEBRTC_SPL_MUL_16_16(2, k)]; |
| } |
| for (k=0;k<QLOOKAHEAD;k++) { |
| tempin_ch1[k]=prefiltdata->INLABUF1_fix[k]; |
| prefiltdata->INLABUF1_fix[k]=pin[FRAMESAMPLES+1-WEBRTC_SPL_MUL_16_16(2, QLOOKAHEAD)+WEBRTC_SPL_MUL_16_16(2, k)]; |
| } |
| |
| /* Second Channel. This is exactly like the first channel, except that the |
| even samples are now filtered instead (lower channel). */ |
| for (k=0;k<FRAMESAMPLES/2;k++) { |
| tempin_ch2[QLOOKAHEAD+k] = pin[WEBRTC_SPL_MUL_16_16(2, k)]; |
| } |
| for (k=0;k<QLOOKAHEAD;k++) { |
| tempin_ch2[k]=prefiltdata->INLABUF2_fix[k]; |
| prefiltdata->INLABUF2_fix[k]=pin[FRAMESAMPLES-WEBRTC_SPL_MUL_16_16(2, QLOOKAHEAD)+WEBRTC_SPL_MUL_16_16(2, k)]; |
| } |
| |
| |
| /*obtain polyphase components by forward all-pass filtering through each channel */ |
| /* The all pass filtering automatically updates the filter states which are exported in the |
| prefiltdata structure */ |
| AllpassFilter2FixDec16(tempin_ch1,WebRtcIsacfix_kUpperApFactorsQ15, FRAMESAMPLES/2 , NUMBEROFCHANNELAPSECTIONS, prefiltdata->INSTAT1_fix); |
| AllpassFilter2FixDec16(tempin_ch2,WebRtcIsacfix_kLowerApFactorsQ15, FRAMESAMPLES/2 , NUMBEROFCHANNELAPSECTIONS, prefiltdata->INSTAT2_fix); |
| |
| for (k=0;k<WEBRTC_SPL_MUL_16_16(2, (QORDER-1));k++) |
| tmpState[k] = prefiltdata->INSTAT1_fix[k]; |
| AllpassFilter2FixDec16(tempin_ch1 + FRAMESAMPLES/2,WebRtcIsacfix_kUpperApFactorsQ15, QLOOKAHEAD , NUMBEROFCHANNELAPSECTIONS, tmpState); |
| for (k=0;k<WEBRTC_SPL_MUL_16_16(2, (QORDER-1));k++) |
| tmpState[k] = prefiltdata->INSTAT2_fix[k]; |
| AllpassFilter2FixDec16(tempin_ch2 + FRAMESAMPLES/2,WebRtcIsacfix_kLowerApFactorsQ15, QLOOKAHEAD , NUMBEROFCHANNELAPSECTIONS, tmpState); |
| |
| |
| /* Now Construct low-pass and high-pass signals as combinations of polyphase components */ |
| for (k=0; k<FRAMESAMPLES/2 + QLOOKAHEAD; k++) { |
| WebRtc_Word32 tmp1, tmp2, tmp3; |
| tmp1 = (WebRtc_Word32)tempin_ch1[k]; // Q0 -> Q0 |
| tmp2 = (WebRtc_Word32)tempin_ch2[k]; // Q0 -> Q0 |
| tmp3 = (WebRtc_Word32)WEBRTC_SPL_RSHIFT_W32((tmp1 + tmp2), 1);/* low pass signal*/ |
| LP16[k] = (WebRtc_Word16)WebRtcSpl_SatW32ToW16(tmp3); /*low pass */ |
| tmp3 = (WebRtc_Word32)WEBRTC_SPL_RSHIFT_W32((tmp1 - tmp2), 1);/* high pass signal*/ |
| HP16[k] = (WebRtc_Word16)WebRtcSpl_SatW32ToW16(tmp3); /*high pass */ |
| } |
| |
| }/*end of WebRtcIsacfix_SplitAndFilter */ |
| |
| |
| #ifdef WEBRTC_ISAC_FIX_NB_CALLS_ENABLED |
| |
| /* Without lookahead */ |
| void WebRtcIsacfix_SplitAndFilter2(WebRtc_Word16 *pin, |
| WebRtc_Word16 *LP16, |
| WebRtc_Word16 *HP16, |
| PreFiltBankstr *prefiltdata) |
| { |
| /* Function WebRtcIsacfix_SplitAndFilter2 */ |
| /* This function creates low-pass and high-pass decimated versions of part of |
| the input signal. */ |
| |
| int k; |
| |
| WebRtc_Word16 tempin_ch1[FRAMESAMPLES/2]; |
| WebRtc_Word16 tempin_ch2[FRAMESAMPLES/2]; |
| |
| |
| /* High pass filter */ |
| WebRtcIsacfix_HighpassFilterFixDec32(pin, FRAMESAMPLES, WebRtcIsacfix_kHpStCoeffInQ30, prefiltdata->HPstates_fix); |
| |
| |
| /* First Channel */ |
| for (k=0;k<FRAMESAMPLES/2;k++) { |
| tempin_ch1[k] = pin[1+WEBRTC_SPL_MUL_16_16(2, k)]; |
| } |
| |
| /* Second Channel. This is exactly like the first channel, except that the |
| even samples are now filtered instead (lower channel). */ |
| for (k=0;k<FRAMESAMPLES/2;k++) { |
| tempin_ch2[k] = pin[WEBRTC_SPL_MUL_16_16(2, k)]; |
| } |
| |
| |
| /*obtain polyphase components by forward all-pass filtering through each channel */ |
| /* The all pass filtering automatically updates the filter states which are exported in the |
| prefiltdata structure */ |
| AllpassFilter2FixDec16(tempin_ch1,WebRtcIsacfix_kUpperApFactorsQ15, FRAMESAMPLES/2 , NUMBEROFCHANNELAPSECTIONS, prefiltdata->INSTAT1_fix); |
| AllpassFilter2FixDec16(tempin_ch2,WebRtcIsacfix_kLowerApFactorsQ15, FRAMESAMPLES/2 , NUMBEROFCHANNELAPSECTIONS, prefiltdata->INSTAT2_fix); |
| |
| |
| /* Now Construct low-pass and high-pass signals as combinations of polyphase components */ |
| for (k=0; k<FRAMESAMPLES/2; k++) { |
| WebRtc_Word32 tmp1, tmp2, tmp3; |
| tmp1 = (WebRtc_Word32)tempin_ch1[k]; // Q0 -> Q0 |
| tmp2 = (WebRtc_Word32)tempin_ch2[k]; // Q0 -> Q0 |
| tmp3 = (WebRtc_Word32)WEBRTC_SPL_RSHIFT_W32((tmp1 + tmp2), 1);/* low pass signal*/ |
| LP16[k] = (WebRtc_Word16)WebRtcSpl_SatW32ToW16(tmp3); /*low pass */ |
| tmp3 = (WebRtc_Word32)WEBRTC_SPL_RSHIFT_W32((tmp1 - tmp2), 1);/* high pass signal*/ |
| HP16[k] = (WebRtc_Word16)WebRtcSpl_SatW32ToW16(tmp3); /*high pass */ |
| } |
| |
| }/*end of WebRtcIsacfix_SplitAndFilter */ |
| |
| #endif |
| |
| |
| |
| ////////////////////////////////////////////////////////// |
| ////////// Combining |
| /* Function WebRtcIsacfix_FilterAndCombine */ |
| /* This is a decoder function that takes the decimated |
| length FRAMESAMPLES/2 input low-pass and |
| high-pass signals and creates a reconstructed fullband |
| output signal of length FRAMESAMPLES. WebRtcIsacfix_FilterAndCombine |
| is the sibling function of WebRtcIsacfix_SplitAndFilter */ |
| /* INPUTS: |
| inLP: a length FRAMESAMPLES/2 array of input low-pass |
| samples. |
| inHP: a length FRAMESAMPLES/2 array of input high-pass |
| samples. |
| postfiltdata: input data structure containing the filterbank |
| states from the previous decoding iteration. |
| OUTPUTS: |
| Out: a length FRAMESAMPLES array of output reconstructed |
| samples (fullband) based on the input low-pass and |
| high-pass signals. |
| postfiltdata: the input data structure containing the filterbank |
| states is updated for the next decoding iteration */ |
| void WebRtcIsacfix_FilterAndCombine1(WebRtc_Word16 *tempin_ch1, |
| WebRtc_Word16 *tempin_ch2, |
| WebRtc_Word16 *out16, |
| PostFiltBankstr *postfiltdata) |
| { |
| int k; |
| WebRtc_Word16 in[FRAMESAMPLES]; |
| |
| /* all-pass filter the new upper channel signal. HOWEVER, use the all-pass filter factors |
| that were used as a lower channel at the encoding side. So at the decoder, the |
| corresponding all-pass filter factors for each channel are swapped.*/ |
| |
| AllpassFilter2FixDec16(tempin_ch1, WebRtcIsacfix_kLowerApFactorsQ15, FRAMESAMPLES/2, NUMBEROFCHANNELAPSECTIONS,postfiltdata->STATE_0_UPPER_fix); |
| |
| /* Now, all-pass filter the new lower channel signal. But since all-pass filter factors |
| at the decoder are swapped from the ones at the encoder, the 'upper' channel |
| all-pass filter factors (kUpperApFactors) are used to filter this new lower channel signal */ |
| |
| AllpassFilter2FixDec16(tempin_ch2, WebRtcIsacfix_kUpperApFactorsQ15, FRAMESAMPLES/2, NUMBEROFCHANNELAPSECTIONS,postfiltdata->STATE_0_LOWER_fix); |
| |
| /* Merge outputs to form the full length output signal.*/ |
| for (k=0;k<FRAMESAMPLES/2;k++) { |
| in[WEBRTC_SPL_MUL_16_16(2, k)]=tempin_ch2[k]; |
| in[WEBRTC_SPL_MUL_16_16(2, k)+1]=tempin_ch1[k]; |
| } |
| |
| /* High pass filter */ |
| WebRtcIsacfix_HighpassFilterFixDec32(in, FRAMESAMPLES, WebRtcIsacfix_kHPStCoeffOut1Q30, postfiltdata->HPstates1_fix); |
| WebRtcIsacfix_HighpassFilterFixDec32(in, FRAMESAMPLES, WebRtcIsacfix_kHPStCoeffOut2Q30, postfiltdata->HPstates2_fix); |
| |
| for (k=0;k<FRAMESAMPLES;k++) { |
| out16[k] = in[k]; |
| } |
| } |
| |
| |
| #ifdef WEBRTC_ISAC_FIX_NB_CALLS_ENABLED |
| /* Function WebRtcIsacfix_FilterAndCombine */ |
| /* This is a decoder function that takes the decimated |
| length len/2 input low-pass and |
| high-pass signals and creates a reconstructed fullband |
| output signal of length len. WebRtcIsacfix_FilterAndCombine |
| is the sibling function of WebRtcIsacfix_SplitAndFilter */ |
| /* INPUTS: |
| inLP: a length len/2 array of input low-pass |
| samples. |
| inHP: a length len/2 array of input high-pass |
| samples. |
| postfiltdata: input data structure containing the filterbank |
| states from the previous decoding iteration. |
| OUTPUTS: |
| Out: a length len array of output reconstructed |
| samples (fullband) based on the input low-pass and |
| high-pass signals. |
| postfiltdata: the input data structure containing the filterbank |
| states is updated for the next decoding iteration */ |
| void WebRtcIsacfix_FilterAndCombine2(WebRtc_Word16 *tempin_ch1, |
| WebRtc_Word16 *tempin_ch2, |
| WebRtc_Word16 *out16, |
| PostFiltBankstr *postfiltdata, |
| WebRtc_Word16 len) |
| { |
| int k; |
| WebRtc_Word16 in[FRAMESAMPLES]; |
| |
| /* all-pass filter the new upper channel signal. HOWEVER, use the all-pass filter factors |
| that were used as a lower channel at the encoding side. So at the decoder, the |
| corresponding all-pass filter factors for each channel are swapped.*/ |
| |
| AllpassFilter2FixDec16(tempin_ch1, WebRtcIsacfix_kLowerApFactorsQ15,(WebRtc_Word16) (len/2), NUMBEROFCHANNELAPSECTIONS,postfiltdata->STATE_0_UPPER_fix); |
| |
| /* Now, all-pass filter the new lower channel signal. But since all-pass filter factors |
| at the decoder are swapped from the ones at the encoder, the 'upper' channel |
| all-pass filter factors (kUpperApFactors) are used to filter this new lower channel signal */ |
| |
| AllpassFilter2FixDec16(tempin_ch2, WebRtcIsacfix_kUpperApFactorsQ15, (WebRtc_Word16) (len/2), NUMBEROFCHANNELAPSECTIONS,postfiltdata->STATE_0_LOWER_fix); |
| |
| /* Merge outputs to form the full length output signal.*/ |
| for (k=0;k<len/2;k++) { |
| in[WEBRTC_SPL_MUL_16_16(2, k)]=tempin_ch2[k]; |
| in[WEBRTC_SPL_MUL_16_16(2, k)+1]=tempin_ch1[k]; |
| } |
| |
| /* High pass filter */ |
| WebRtcIsacfix_HighpassFilterFixDec32(in, len, WebRtcIsacfix_kHPStCoeffOut1Q30, postfiltdata->HPstates1_fix); |
| WebRtcIsacfix_HighpassFilterFixDec32(in, len, WebRtcIsacfix_kHPStCoeffOut2Q30, postfiltdata->HPstates2_fix); |
| |
| for (k=0;k<len;k++) { |
| out16[k] = in[k]; |
| } |
| } |
| |
| #endif |
