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https://github.com/google/liblc3.git
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890 lines
30 KiB
C
890 lines
30 KiB
C
/******************************************************************************
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*
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* Copyright 2022 Google LLC
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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******************************************************************************/
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#include "sns.h"
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#include "tables.h"
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/* ----------------------------------------------------------------------------
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* DCT-16
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* -------------------------------------------------------------------------- */
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/**
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* Matrix of DCT-16 coefficients
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*
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* M[n][k] = 2f cos( Pi k (2n + 1) / 2N )
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*
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* k = [0..N-1], n = [0..N-1], N = 16
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* f = sqrt(1/4N) for k=0, sqrt(1/2N) otherwise
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*/
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static const float dct16_m[16][16] = {
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{ 2.50000000e-01, 3.51850934e-01, 3.46759961e-01, 3.38329500e-01,
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3.26640741e-01, 3.11806253e-01, 2.93968901e-01, 2.73300467e-01,
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2.50000000e-01, 2.24291897e-01, 1.96423740e-01, 1.66663915e-01,
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1.35299025e-01, 1.02631132e-01, 6.89748448e-02, 3.46542923e-02 },
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{ 2.50000000e-01, 3.38329500e-01, 2.93968901e-01, 2.24291897e-01,
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1.35299025e-01, 3.46542923e-02, -6.89748448e-02, -1.66663915e-01,
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-2.50000000e-01, -3.11806253e-01, -3.46759961e-01, -3.51850934e-01,
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-3.26640741e-01, -2.73300467e-01, -1.96423740e-01, -1.02631132e-01 },
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{ 2.50000000e-01, 3.11806253e-01, 1.96423740e-01, 3.46542923e-02,
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-1.35299025e-01, -2.73300467e-01, -3.46759961e-01, -3.38329500e-01,
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-2.50000000e-01, -1.02631132e-01, 6.89748448e-02, 2.24291897e-01,
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3.26640741e-01, 3.51850934e-01, 2.93968901e-01, 1.66663915e-01 },
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{ 2.50000000e-01, 2.73300467e-01, 6.89748448e-02, -1.66663915e-01,
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-3.26640741e-01, -3.38329500e-01, -1.96423740e-01, 3.46542923e-02,
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2.50000000e-01, 3.51850934e-01, 2.93968901e-01, 1.02631132e-01,
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-1.35299025e-01, -3.11806253e-01, -3.46759961e-01, -2.24291897e-01 },
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{ 2.50000000e-01, 2.24291897e-01, -6.89748448e-02, -3.11806253e-01,
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-3.26640741e-01, -1.02631132e-01, 1.96423740e-01, 3.51850934e-01,
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2.50000000e-01, -3.46542923e-02, -2.93968901e-01, -3.38329500e-01,
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-1.35299025e-01, 1.66663915e-01, 3.46759961e-01, 2.73300467e-01 },
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{ 2.50000000e-01, 1.66663915e-01, -1.96423740e-01, -3.51850934e-01,
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-1.35299025e-01, 2.24291897e-01, 3.46759961e-01, 1.02631132e-01,
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-2.50000000e-01, -3.38329500e-01, -6.89748448e-02, 2.73300467e-01,
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3.26640741e-01, 3.46542923e-02, -2.93968901e-01, -3.11806253e-01 },
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{ 2.50000000e-01, 1.02631132e-01, -2.93968901e-01, -2.73300467e-01,
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1.35299025e-01, 3.51850934e-01, 6.89748448e-02, -3.11806253e-01,
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-2.50000000e-01, 1.66663915e-01, 3.46759961e-01, 3.46542923e-02,
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-3.26640741e-01, -2.24291897e-01, 1.96423740e-01, 3.38329500e-01 },
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{ 2.50000000e-01, 3.46542923e-02, -3.46759961e-01, -1.02631132e-01,
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3.26640741e-01, 1.66663915e-01, -2.93968901e-01, -2.24291897e-01,
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2.50000000e-01, 2.73300467e-01, -1.96423740e-01, -3.11806253e-01,
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1.35299025e-01, 3.38329500e-01, -6.89748448e-02, -3.51850934e-01 },
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{ 2.50000000e-01, -3.46542923e-02, -3.46759961e-01, 1.02631132e-01,
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3.26640741e-01, -1.66663915e-01, -2.93968901e-01, 2.24291897e-01,
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2.50000000e-01, -2.73300467e-01, -1.96423740e-01, 3.11806253e-01,
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1.35299025e-01, -3.38329500e-01, -6.89748448e-02, 3.51850934e-01 },
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{ 2.50000000e-01, -1.02631132e-01, -2.93968901e-01, 2.73300467e-01,
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1.35299025e-01, -3.51850934e-01, 6.89748448e-02, 3.11806253e-01,
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-2.50000000e-01, -1.66663915e-01, 3.46759961e-01, -3.46542923e-02,
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-3.26640741e-01, 2.24291897e-01, 1.96423740e-01, -3.38329500e-01 },
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{ 2.50000000e-01, -1.66663915e-01, -1.96423740e-01, 3.51850934e-01,
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-1.35299025e-01, -2.24291897e-01, 3.46759961e-01, -1.02631132e-01,
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-2.50000000e-01, 3.38329500e-01, -6.89748448e-02, -2.73300467e-01,
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3.26640741e-01, -3.46542923e-02, -2.93968901e-01, 3.11806253e-01 },
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{ 2.50000000e-01, -2.24291897e-01, -6.89748448e-02, 3.11806253e-01,
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-3.26640741e-01, 1.02631132e-01, 1.96423740e-01, -3.51850934e-01,
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2.50000000e-01, 3.46542923e-02, -2.93968901e-01, 3.38329500e-01,
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-1.35299025e-01, -1.66663915e-01, 3.46759961e-01, -2.73300467e-01 },
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{ 2.50000000e-01, -2.73300467e-01, 6.89748448e-02, 1.66663915e-01,
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-3.26640741e-01, 3.38329500e-01, -1.96423740e-01, -3.46542923e-02,
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2.50000000e-01, -3.51850934e-01, 2.93968901e-01, -1.02631132e-01,
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-1.35299025e-01, 3.11806253e-01, -3.46759961e-01, 2.24291897e-01 },
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{ 2.50000000e-01, -3.11806253e-01, 1.96423740e-01, -3.46542923e-02,
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-1.35299025e-01, 2.73300467e-01, -3.46759961e-01, 3.38329500e-01,
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-2.50000000e-01, 1.02631132e-01, 6.89748448e-02, -2.24291897e-01,
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3.26640741e-01, -3.51850934e-01, 2.93968901e-01, -1.66663915e-01 },
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{ 2.50000000e-01, -3.38329500e-01, 2.93968901e-01, -2.24291897e-01,
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1.35299025e-01, -3.46542923e-02, -6.89748448e-02, 1.66663915e-01,
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-2.50000000e-01, 3.11806253e-01, -3.46759961e-01, 3.51850934e-01,
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-3.26640741e-01, 2.73300467e-01, -1.96423740e-01, 1.02631132e-01 },
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{ 2.50000000e-01, -3.51850934e-01, 3.46759961e-01, -3.38329500e-01,
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3.26640741e-01, -3.11806253e-01, 2.93968901e-01, -2.73300467e-01,
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2.50000000e-01, -2.24291897e-01, 1.96423740e-01, -1.66663915e-01,
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1.35299025e-01, -1.02631132e-01, 6.89748448e-02, -3.46542923e-02 },
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};
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/**
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* Forward DCT-16 transformation
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* x, y Input and output 16 values
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*/
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LC3_HOT static void dct16_forward(const float *x, float *y)
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{
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for (int i = 0, j; i < 16; i++)
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for (y[i] = 0, j = 0; j < 16; j++)
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y[i] += x[j] * dct16_m[j][i];
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}
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/**
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* Inverse DCT-16 transformation
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* x, y Input and output 16 values
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*/
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LC3_HOT static void dct16_inverse(const float *x, float *y)
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{
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for (int i = 0, j; i < 16; i++)
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for (y[i] = 0, j = 0; j < 16; j++)
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y[i] += x[j] * dct16_m[i][j];
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}
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/* ----------------------------------------------------------------------------
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* Scale factors
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* -------------------------------------------------------------------------- */
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/**
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* Scale factors
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* dt, sr Duration and samplerate of the frame
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* eb Energy estimation per bands
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* att 1: Attack detected 0: Otherwise
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* scf Output 16 scale factors
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*/
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LC3_HOT static void compute_scale_factors(
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enum lc3_dt dt, enum lc3_srate sr,
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const float *eb, bool att, float *scf)
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{
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/* Pre-emphasis gain table :
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* Ge[b] = 10 ^ (b * g_tilt) / 630 , b = [0..63] */
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static const float ge_table[LC3_NUM_SRATE][LC3_MAX_BANDS] = {
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[LC3_SRATE_8K] = { /* g_tilt = 14 */
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1.00000000e+00, 1.05250029e+00, 1.10775685e+00, 1.16591440e+00,
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1.22712524e+00, 1.29154967e+00, 1.35935639e+00, 1.43072299e+00,
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1.50583635e+00, 1.58489319e+00, 1.66810054e+00, 1.75567629e+00,
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1.84784980e+00, 1.94486244e+00, 2.04696827e+00, 2.15443469e+00,
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2.26754313e+00, 2.38658979e+00, 2.51188643e+00, 2.64376119e+00,
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2.78255940e+00, 2.92864456e+00, 3.08239924e+00, 3.24422608e+00,
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3.41454887e+00, 3.59381366e+00, 3.78248991e+00, 3.98107171e+00,
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4.19007911e+00, 4.41005945e+00, 4.64158883e+00, 4.88527357e+00,
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5.14175183e+00, 5.41169527e+00, 5.69581081e+00, 5.99484250e+00,
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6.30957344e+00, 6.64082785e+00, 6.98947321e+00, 7.35642254e+00,
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7.74263683e+00, 8.14912747e+00, 8.57695899e+00, 9.02725178e+00,
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9.50118507e+00, 1.00000000e+01, 1.05250029e+01, 1.10775685e+01,
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1.16591440e+01, 1.22712524e+01, 1.29154967e+01, 1.35935639e+01,
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1.43072299e+01, 1.50583635e+01, 1.58489319e+01, 1.66810054e+01,
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1.75567629e+01, 1.84784980e+01, 1.94486244e+01, 2.04696827e+01,
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2.15443469e+01, 2.26754313e+01, 2.38658979e+01, 2.51188643e+01 },
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[LC3_SRATE_16K] = { /* g_tilt = 18 */
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1.00000000e+00, 1.06800043e+00, 1.14062492e+00, 1.21818791e+00,
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1.30102522e+00, 1.38949549e+00, 1.48398179e+00, 1.58489319e+00,
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1.69266662e+00, 1.80776868e+00, 1.93069773e+00, 2.06198601e+00,
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2.20220195e+00, 2.35195264e+00, 2.51188643e+00, 2.68269580e+00,
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2.86512027e+00, 3.05994969e+00, 3.26802759e+00, 3.49025488e+00,
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3.72759372e+00, 3.98107171e+00, 4.25178630e+00, 4.54090961e+00,
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4.84969343e+00, 5.17947468e+00, 5.53168120e+00, 5.90783791e+00,
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6.30957344e+00, 6.73862717e+00, 7.19685673e+00, 7.68624610e+00,
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8.20891416e+00, 8.76712387e+00, 9.36329209e+00, 1.00000000e+01,
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1.06800043e+01, 1.14062492e+01, 1.21818791e+01, 1.30102522e+01,
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1.38949549e+01, 1.48398179e+01, 1.58489319e+01, 1.69266662e+01,
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1.80776868e+01, 1.93069773e+01, 2.06198601e+01, 2.20220195e+01,
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2.35195264e+01, 2.51188643e+01, 2.68269580e+01, 2.86512027e+01,
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3.05994969e+01, 3.26802759e+01, 3.49025488e+01, 3.72759372e+01,
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3.98107171e+01, 4.25178630e+01, 4.54090961e+01, 4.84969343e+01,
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5.17947468e+01, 5.53168120e+01, 5.90783791e+01, 6.30957344e+01 },
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[LC3_SRATE_24K] = { /* g_tilt = 22 */
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1.00000000e+00, 1.08372885e+00, 1.17446822e+00, 1.27280509e+00,
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1.37937560e+00, 1.49486913e+00, 1.62003281e+00, 1.75567629e+00,
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1.90267705e+00, 2.06198601e+00, 2.23463373e+00, 2.42173704e+00,
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2.62450630e+00, 2.84425319e+00, 3.08239924e+00, 3.34048498e+00,
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3.62017995e+00, 3.92329345e+00, 4.25178630e+00, 4.60778348e+00,
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4.99358789e+00, 5.41169527e+00, 5.86481029e+00, 6.35586411e+00,
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6.88803330e+00, 7.46476041e+00, 8.08977621e+00, 8.76712387e+00,
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9.50118507e+00, 1.02967084e+01, 1.11588399e+01, 1.20931568e+01,
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1.31057029e+01, 1.42030283e+01, 1.53922315e+01, 1.66810054e+01,
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1.80776868e+01, 1.95913107e+01, 2.12316686e+01, 2.30093718e+01,
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2.49359200e+01, 2.70237760e+01, 2.92864456e+01, 3.17385661e+01,
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3.43959997e+01, 3.72759372e+01, 4.03970086e+01, 4.37794036e+01,
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4.74450028e+01, 5.14175183e+01, 5.57226480e+01, 6.03882412e+01,
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6.54444792e+01, 7.09240702e+01, 7.68624610e+01, 8.32980665e+01,
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9.02725178e+01, 9.78309319e+01, 1.06022203e+02, 1.14899320e+02,
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1.24519708e+02, 1.34945600e+02, 1.46244440e+02, 1.58489319e+02 },
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[LC3_SRATE_32K] = { /* g_tilt = 26 */
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1.00000000e+00, 1.09968890e+00, 1.20931568e+00, 1.32987103e+00,
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1.46244440e+00, 1.60823388e+00, 1.76855694e+00, 1.94486244e+00,
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2.13874364e+00, 2.35195264e+00, 2.58641621e+00, 2.84425319e+00,
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3.12779366e+00, 3.43959997e+00, 3.78248991e+00, 4.15956216e+00,
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4.57422434e+00, 5.03022373e+00, 5.53168120e+00, 6.08312841e+00,
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6.68954879e+00, 7.35642254e+00, 8.08977621e+00, 8.89623710e+00,
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9.78309319e+00, 1.07583590e+01, 1.18308480e+01, 1.30102522e+01,
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1.43072299e+01, 1.57335019e+01, 1.73019574e+01, 1.90267705e+01,
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2.09235283e+01, 2.30093718e+01, 2.53031508e+01, 2.78255940e+01,
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3.05994969e+01, 3.36499270e+01, 3.70044512e+01, 4.06933843e+01,
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4.47500630e+01, 4.92111475e+01, 5.41169527e+01, 5.95118121e+01,
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6.54444792e+01, 7.19685673e+01, 7.91430346e+01, 8.70327166e+01,
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9.57089124e+01, 1.05250029e+02, 1.15742288e+02, 1.27280509e+02,
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1.39968963e+02, 1.53922315e+02, 1.69266662e+02, 1.86140669e+02,
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2.04696827e+02, 2.25102829e+02, 2.47543082e+02, 2.72220379e+02,
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2.99357729e+02, 3.29200372e+02, 3.62017995e+02, 3.98107171e+02 },
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[LC3_SRATE_48K] = { /* g_tilt = 30 */
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1.00000000e+00, 1.11588399e+00, 1.24519708e+00, 1.38949549e+00,
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1.55051578e+00, 1.73019574e+00, 1.93069773e+00, 2.15443469e+00,
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2.40409918e+00, 2.68269580e+00, 2.99357729e+00, 3.34048498e+00,
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3.72759372e+00, 4.15956216e+00, 4.64158883e+00, 5.17947468e+00,
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5.77969288e+00, 6.44946677e+00, 7.19685673e+00, 8.03085722e+00,
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8.96150502e+00, 1.00000000e+01, 1.11588399e+01, 1.24519708e+01,
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1.38949549e+01, 1.55051578e+01, 1.73019574e+01, 1.93069773e+01,
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2.15443469e+01, 2.40409918e+01, 2.68269580e+01, 2.99357729e+01,
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3.34048498e+01, 3.72759372e+01, 4.15956216e+01, 4.64158883e+01,
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5.17947468e+01, 5.77969288e+01, 6.44946677e+01, 7.19685673e+01,
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8.03085722e+01, 8.96150502e+01, 1.00000000e+02, 1.11588399e+02,
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1.24519708e+02, 1.38949549e+02, 1.55051578e+02, 1.73019574e+02,
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1.93069773e+02, 2.15443469e+02, 2.40409918e+02, 2.68269580e+02,
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2.99357729e+02, 3.34048498e+02, 3.72759372e+02, 4.15956216e+02,
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4.64158883e+02, 5.17947468e+02, 5.77969288e+02, 6.44946677e+02,
|
|
7.19685673e+02, 8.03085722e+02, 8.96150502e+02, 1.00000000e+03 },
|
|
};
|
|
|
|
float e[LC3_MAX_BANDS];
|
|
|
|
/* --- Copy and padding --- */
|
|
|
|
int nb = lc3_num_bands[dt][sr];
|
|
int n4 = nb < 32 ? 32 % nb : 0;
|
|
int n2 = nb < 32 ? nb - n4 : LC3_MAX_BANDS - nb;
|
|
|
|
for (int i4 = 0; i4 < n4; i4++)
|
|
e[4*i4 + 0] = e[4*i4 + 1] =
|
|
e[4*i4 + 2] = e[4*i4 + 3] = eb[i4];
|
|
|
|
for (int i2 = n4; i2 < n4+n2; i2++)
|
|
e[2*(n4+i2) + 0] = e[2*(n4+i2) + 1] = eb[i2];
|
|
|
|
memcpy(e + 4*n4 + 2*n2, eb + n4 + n2, (nb - n4 - n2) * sizeof(float));
|
|
|
|
/* --- Smoothing, pre-emphasis and logarithm --- */
|
|
|
|
const float *ge = ge_table[sr];
|
|
|
|
float e0 = e[0], e1 = e[0], e2;
|
|
float e_sum = 0;
|
|
|
|
for (int i = 0; i < LC3_MAX_BANDS-1; ) {
|
|
e[i] = (e0 * 0.25f + e1 * 0.5f + (e2 = e[i+1]) * 0.25f) * ge[i];
|
|
e_sum += e[i++];
|
|
|
|
e[i] = (e1 * 0.25f + e2 * 0.5f + (e0 = e[i+1]) * 0.25f) * ge[i];
|
|
e_sum += e[i++];
|
|
|
|
e[i] = (e2 * 0.25f + e0 * 0.5f + (e1 = e[i+1]) * 0.25f) * ge[i];
|
|
e_sum += e[i++];
|
|
}
|
|
|
|
e[LC3_MAX_BANDS-1] = (e0 * 0.25f + e1 * 0.75f) * ge[LC3_MAX_BANDS-1];
|
|
e_sum += e[LC3_MAX_BANDS-1];
|
|
|
|
float noise_floor = fmaxf(e_sum * (1e-4f / 64), 0x1p-32f);
|
|
|
|
for (int i = 0; i < LC3_MAX_BANDS; i++)
|
|
e[i] = fast_log2f(fmaxf(e[i], noise_floor)) * 0.5f;
|
|
|
|
/* --- Grouping & scaling --- */
|
|
|
|
float scf_sum;
|
|
|
|
scf[0] = (e[0] + e[4]) * 1.f/12 +
|
|
(e[0] + e[3]) * 2.f/12 +
|
|
(e[1] + e[2]) * 3.f/12 ;
|
|
scf_sum = scf[0];
|
|
|
|
for (int i = 1; i < 15; i++) {
|
|
scf[i] = (e[4*i-1] + e[4*i+4]) * 1.f/12 +
|
|
(e[4*i ] + e[4*i+3]) * 2.f/12 +
|
|
(e[4*i+1] + e[4*i+2]) * 3.f/12 ;
|
|
scf_sum += scf[i];
|
|
}
|
|
|
|
scf[15] = (e[59] + e[63]) * 1.f/12 +
|
|
(e[60] + e[63]) * 2.f/12 +
|
|
(e[61] + e[62]) * 3.f/12 ;
|
|
scf_sum += scf[15];
|
|
|
|
for (int i = 0; i < 16; i++)
|
|
scf[i] = 0.85f * (scf[i] - scf_sum * 1.f/16);
|
|
|
|
/* --- Attack handling --- */
|
|
|
|
if (!att)
|
|
return;
|
|
|
|
float s0, s1 = scf[0], s2 = scf[1], s3 = scf[2], s4 = scf[3];
|
|
float sn = s1 + s2;
|
|
|
|
scf[0] = (sn += s3) * 1.f/3;
|
|
scf[1] = (sn += s4) * 1.f/4;
|
|
scf_sum = scf[0] + scf[1];
|
|
|
|
for (int i = 2; i < 14; i++, sn -= s0) {
|
|
s0 = s1, s1 = s2, s2 = s3, s3 = s4, s4 = scf[i+2];
|
|
scf[i] = (sn += s4) * 1.f/5;
|
|
scf_sum += scf[i];
|
|
}
|
|
|
|
scf[14] = (sn ) * 1.f/4;
|
|
scf[15] = (sn -= s1) * 1.f/3;
|
|
scf_sum += scf[14] + scf[15];
|
|
|
|
for (int i = 0; i < 16; i++)
|
|
scf[i] = (dt == LC3_DT_7M5 ? 0.3f : 0.5f) *
|
|
(scf[i] - scf_sum * 1.f/16);
|
|
}
|
|
|
|
/**
|
|
* Codebooks
|
|
* scf Input 16 scale factors
|
|
* lf/hfcb_idx Output the low and high frequency codebooks index
|
|
*/
|
|
LC3_HOT static void resolve_codebooks(
|
|
const float *scf, int *lfcb_idx, int *hfcb_idx)
|
|
{
|
|
float dlfcb_max = 0, dhfcb_max = 0;
|
|
*lfcb_idx = *hfcb_idx = 0;
|
|
|
|
for (int icb = 0; icb < 32; icb++) {
|
|
const float *lfcb = lc3_sns_lfcb[icb];
|
|
const float *hfcb = lc3_sns_hfcb[icb];
|
|
float dlfcb = 0, dhfcb = 0;
|
|
|
|
for (int i = 0; i < 8; i++) {
|
|
dlfcb += (scf[ i] - lfcb[i]) * (scf[ i] - lfcb[i]);
|
|
dhfcb += (scf[8+i] - hfcb[i]) * (scf[8+i] - hfcb[i]);
|
|
}
|
|
|
|
if (icb == 0 || dlfcb < dlfcb_max)
|
|
*lfcb_idx = icb, dlfcb_max = dlfcb;
|
|
|
|
if (icb == 0 || dhfcb < dhfcb_max)
|
|
*hfcb_idx = icb, dhfcb_max = dhfcb;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Unit energy normalize pulse configuration
|
|
* c Pulse configuration
|
|
* cn Normalized pulse configuration
|
|
*/
|
|
LC3_HOT static void normalize(const int *c, float *cn)
|
|
{
|
|
int c2_sum = 0;
|
|
for (int i = 0; i < 16; i++)
|
|
c2_sum += c[i] * c[i];
|
|
|
|
float c_norm = 1.f / sqrtf(c2_sum);
|
|
|
|
for (int i = 0; i < 16; i++)
|
|
cn[i] = c[i] * c_norm;
|
|
}
|
|
|
|
/**
|
|
* Sub-procedure of `quantize()`, add unit pulse
|
|
* x, y, n Transformed residual, and vector of pulses with length
|
|
* start, end Current number of pulses, limit to reach
|
|
* corr, energy Correlation (x,y) and y energy, updated at output
|
|
*/
|
|
LC3_HOT static void add_pulse(const float *x, int *y, int n,
|
|
int start, int end, float *corr, float *energy)
|
|
{
|
|
for (int k = start; k < end; k++) {
|
|
float best_c2 = (*corr + x[0]) * (*corr + x[0]);
|
|
float best_e = *energy + 2*y[0] + 1;
|
|
int nbest = 0;
|
|
|
|
for (int i = 1; i < n; i++) {
|
|
float c2 = (*corr + x[i]) * (*corr + x[i]);
|
|
float e = *energy + 2*y[i] + 1;
|
|
|
|
if (c2 * best_e > e * best_c2)
|
|
best_c2 = c2, best_e = e, nbest = i;
|
|
}
|
|
|
|
*corr += x[nbest];
|
|
*energy += 2*y[nbest] + 1;
|
|
y[nbest]++;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Quantization of codebooks residual
|
|
* scf Input 16 scale factors, output quantized version
|
|
* lf/hfcb_idx Codebooks index
|
|
* c, cn Output 4 pulse configurations candidates, normalized
|
|
* shape/gain_idx Output selected shape/gain indexes
|
|
*/
|
|
LC3_HOT static void quantize(const float *scf, int lfcb_idx, int hfcb_idx,
|
|
int (*c)[16], float (*cn)[16], int *shape_idx, int *gain_idx)
|
|
{
|
|
/* --- Residual --- */
|
|
|
|
const float *lfcb = lc3_sns_lfcb[lfcb_idx];
|
|
const float *hfcb = lc3_sns_hfcb[hfcb_idx];
|
|
float r[16], x[16];
|
|
|
|
for (int i = 0; i < 8; i++) {
|
|
r[ i] = scf[ i] - lfcb[i];
|
|
r[8+i] = scf[8+i] - hfcb[i];
|
|
}
|
|
|
|
dct16_forward(r, x);
|
|
|
|
/* --- Shape 3 candidate ---
|
|
* Project to or below pyramid N = 16, K = 6,
|
|
* then add unit pulses until you reach K = 6, over N = 16 */
|
|
|
|
float xm[16];
|
|
float xm_sum = 0;
|
|
|
|
for (int i = 0; i < 16; i++) {
|
|
xm[i] = fabsf(x[i]);
|
|
xm_sum += xm[i];
|
|
}
|
|
|
|
float proj_factor = (6 - 1) / fmaxf(xm_sum, 1e-31f);
|
|
float corr = 0, energy = 0;
|
|
int npulses = 0;
|
|
|
|
for (int i = 0; i < 16; i++) {
|
|
c[3][i] = floorf(xm[i] * proj_factor);
|
|
npulses += c[3][i];
|
|
corr += c[3][i] * xm[i];
|
|
energy += c[3][i] * c[3][i];
|
|
}
|
|
|
|
add_pulse(xm, c[3], 16, npulses, 6, &corr, &energy);
|
|
npulses = 6;
|
|
|
|
/* --- Shape 2 candidate ---
|
|
* Add unit pulses until you reach K = 8 on shape 3 */
|
|
|
|
memcpy(c[2], c[3], sizeof(c[2]));
|
|
|
|
add_pulse(xm, c[2], 16, npulses, 8, &corr, &energy);
|
|
npulses = 8;
|
|
|
|
/* --- Shape 1 candidate ---
|
|
* Remove any unit pulses from shape 2 that are not part of 0 to 9
|
|
* Update energy and correlation terms accordingly
|
|
* Add unit pulses until you reach K = 10, over N = 10 */
|
|
|
|
memcpy(c[1], c[2], sizeof(c[1]));
|
|
|
|
for (int i = 10; i < 16; i++) {
|
|
c[1][i] = 0;
|
|
npulses -= c[2][i];
|
|
corr -= c[2][i] * xm[i];
|
|
energy -= c[2][i] * c[2][i];
|
|
}
|
|
|
|
add_pulse(xm, c[1], 10, npulses, 10, &corr, &energy);
|
|
npulses = 10;
|
|
|
|
/* --- Shape 0 candidate ---
|
|
* Add unit pulses until you reach K = 1, on shape 1 */
|
|
|
|
memcpy(c[0], c[1], sizeof(c[0]));
|
|
|
|
add_pulse(xm + 10, c[0] + 10, 6, 0, 1, &corr, &energy);
|
|
|
|
/* --- Add sign and unit energy normalize --- */
|
|
|
|
for (int j = 0; j < 16; j++)
|
|
for (int i = 0; i < 4; i++)
|
|
c[i][j] = x[j] < 0 ? -c[i][j] : c[i][j];
|
|
|
|
for (int i = 0; i < 4; i++)
|
|
normalize(c[i], cn[i]);
|
|
|
|
/* --- Determe shape & gain index ---
|
|
* Search the Mean Square Error, within (shape, gain) combinations */
|
|
|
|
float mse_min = INFINITY;
|
|
*shape_idx = *gain_idx = 0;
|
|
|
|
for (int ic = 0; ic < 4; ic++) {
|
|
const struct lc3_sns_vq_gains *cgains = lc3_sns_vq_gains + ic;
|
|
float cmse_min = INFINITY;
|
|
int cgain_idx = 0;
|
|
|
|
for (int ig = 0; ig < cgains->count; ig++) {
|
|
float g = cgains->v[ig];
|
|
|
|
float mse = 0;
|
|
for (int i = 0; i < 16; i++)
|
|
mse += (x[i] - g * cn[ic][i]) * (x[i] - g * cn[ic][i]);
|
|
|
|
if (mse < cmse_min) {
|
|
cgain_idx = ig,
|
|
cmse_min = mse;
|
|
}
|
|
}
|
|
|
|
if (cmse_min < mse_min) {
|
|
*shape_idx = ic, *gain_idx = cgain_idx;
|
|
mse_min = cmse_min;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Unquantization of codebooks residual
|
|
* lf/hfcb_idx Low and high frequency codebooks index
|
|
* c Table of normalized pulse configuration
|
|
* shape/gain Selected shape/gain indexes
|
|
* scf Return unquantized scale factors
|
|
*/
|
|
LC3_HOT static void unquantize(int lfcb_idx, int hfcb_idx,
|
|
const float *c, int shape, int gain, float *scf)
|
|
{
|
|
const float *lfcb = lc3_sns_lfcb[lfcb_idx];
|
|
const float *hfcb = lc3_sns_hfcb[hfcb_idx];
|
|
float g = lc3_sns_vq_gains[shape].v[gain];
|
|
|
|
dct16_inverse(c, scf);
|
|
|
|
for (int i = 0; i < 8; i++)
|
|
scf[i] = lfcb[i] + g * scf[i];
|
|
|
|
for (int i = 8; i < 16; i++)
|
|
scf[i] = hfcb[i-8] + g * scf[i];
|
|
}
|
|
|
|
/**
|
|
* Sub-procedure of `sns_enumerate()`, enumeration of a vector
|
|
* c, n Table of pulse configuration, and length
|
|
* idx, ls Return enumeration set
|
|
*/
|
|
static void enum_mvpq(const int *c, int n, int *idx, bool *ls)
|
|
{
|
|
int ci, i, j;
|
|
|
|
/* --- Scan for 1st significant coeff --- */
|
|
|
|
for (i = 0, c += n; (ci = *(--c)) == 0 ; i++);
|
|
|
|
*idx = 0;
|
|
*ls = ci < 0;
|
|
|
|
/* --- Scan remaining coefficients --- */
|
|
|
|
for (i++, j = LC3_ABS(ci); i < n; i++, j += LC3_ABS(ci)) {
|
|
|
|
if ((ci = *(--c)) != 0) {
|
|
*idx = (*idx << 1) | *ls;
|
|
*ls = ci < 0;
|
|
}
|
|
|
|
*idx += lc3_sns_mpvq_offsets[i][j];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Sub-procedure of `sns_deenumerate()`, deenumeration of a vector
|
|
* idx, ls Enumeration set
|
|
* npulses Number of pulses in the set
|
|
* c, n Table of pulses configuration, and length
|
|
*/
|
|
static void deenum_mvpq(int idx, bool ls, int npulses, int *c, int n)
|
|
{
|
|
int i;
|
|
|
|
/* --- Scan for coefficients --- */
|
|
|
|
for (i = n-1; i >= 0 && idx; i--) {
|
|
|
|
int ci = 0;
|
|
|
|
for (ci = 0; idx < lc3_sns_mpvq_offsets[i][npulses - ci]; ci++);
|
|
idx -= lc3_sns_mpvq_offsets[i][npulses - ci];
|
|
|
|
*(c++) = ls ? -ci : ci;
|
|
npulses -= ci;
|
|
if (ci > 0) {
|
|
ls = idx & 1;
|
|
idx >>= 1;
|
|
}
|
|
}
|
|
|
|
/* --- Set last significant --- */
|
|
|
|
int ci = npulses;
|
|
|
|
if (i-- >= 0)
|
|
*(c++) = ls ? -ci : ci;
|
|
|
|
while (i-- >= 0)
|
|
*(c++) = 0;
|
|
}
|
|
|
|
/**
|
|
* SNS Enumeration of PVQ configuration
|
|
* shape Selected shape index
|
|
* c Selected pulse configuration
|
|
* idx_a, ls_a Return enumeration set A
|
|
* idx_b, ls_b Return enumeration set B (shape = 0)
|
|
*/
|
|
static void enumerate(int shape, const int *c,
|
|
int *idx_a, bool *ls_a, int *idx_b, bool *ls_b)
|
|
{
|
|
enum_mvpq(c, shape < 2 ? 10 : 16, idx_a, ls_a);
|
|
|
|
if (shape == 0)
|
|
enum_mvpq(c + 10, 6, idx_b, ls_b);
|
|
}
|
|
|
|
/**
|
|
* SNS Deenumeration of PVQ configuration
|
|
* shape Selected shape index
|
|
* idx_a, ls_a enumeration set A
|
|
* idx_b, ls_b enumeration set B (shape = 0)
|
|
* c Return pulse configuration
|
|
*/
|
|
static void deenumerate(int shape,
|
|
int idx_a, bool ls_a, int idx_b, bool ls_b, int *c)
|
|
{
|
|
int npulses_a = (const int []){ 10, 10, 8, 6 }[shape];
|
|
|
|
deenum_mvpq(idx_a, ls_a, npulses_a, c, shape < 2 ? 10 : 16);
|
|
|
|
if (shape == 0)
|
|
deenum_mvpq(idx_b, ls_b, 1, c + 10, 6);
|
|
else if (shape == 1)
|
|
memset(c + 10, 0, 6 * sizeof(*c));
|
|
}
|
|
|
|
|
|
/* ----------------------------------------------------------------------------
|
|
* Filtering
|
|
* -------------------------------------------------------------------------- */
|
|
|
|
/**
|
|
* Spectral shaping
|
|
* dt, sr Duration and samplerate of the frame
|
|
* scf_q Quantized scale factors
|
|
* inv True on inverse shaping, False otherwise
|
|
* x Spectral coefficients
|
|
* y Return shapped coefficients
|
|
*
|
|
* `x` and `y` can be the same buffer
|
|
*/
|
|
LC3_HOT static void spectral_shaping(enum lc3_dt dt, enum lc3_srate sr,
|
|
const float *scf_q, bool inv, const float *x, float *y)
|
|
{
|
|
/* --- Interpolate scale factors --- */
|
|
|
|
float scf[LC3_MAX_BANDS];
|
|
float s0, s1 = inv ? -scf_q[0] : scf_q[0];
|
|
|
|
scf[0] = scf[1] = s1;
|
|
for (int i = 0; i < 15; i++) {
|
|
s0 = s1, s1 = inv ? -scf_q[i+1] : scf_q[i+1];
|
|
scf[4*i+2] = s0 + 0.125f * (s1 - s0);
|
|
scf[4*i+3] = s0 + 0.375f * (s1 - s0);
|
|
scf[4*i+4] = s0 + 0.625f * (s1 - s0);
|
|
scf[4*i+5] = s0 + 0.875f * (s1 - s0);
|
|
}
|
|
scf[62] = s1 + 0.125f * (s1 - s0);
|
|
scf[63] = s1 + 0.375f * (s1 - s0);
|
|
|
|
int nb = lc3_num_bands[dt][sr];
|
|
int n4 = nb < 32 ? 32 % nb : 0;
|
|
int n2 = nb < 32 ? nb - n4 : LC3_MAX_BANDS - nb;
|
|
|
|
for (int i4 = 0; i4 < n4; i4++)
|
|
scf[i4] = 0.25f * (scf[4*i4+0] + scf[4*i4+1] +
|
|
scf[4*i4+2] + scf[4*i4+3]);
|
|
|
|
for (int i2 = n4; i2 < n4+n2; i2++)
|
|
scf[i2] = 0.5f * (scf[2*(n4+i2)] + scf[2*(n4+i2)+1]);
|
|
|
|
memmove(scf + n4 + n2, scf + 4*n4 + 2*n2, (nb - n4 - n2) * sizeof(float));
|
|
|
|
/* --- Spectral shaping --- */
|
|
|
|
const uint16_t *lim = lc3_band_lim[dt][sr];
|
|
|
|
for (int i = 0, ib = 0; ib < nb; ib++) {
|
|
float g_sns = fast_exp2f(-scf[ib]);
|
|
|
|
for ( ; i < lim[ib+1]; i++)
|
|
y[i] = x[i] * g_sns;
|
|
}
|
|
}
|
|
|
|
|
|
/* ----------------------------------------------------------------------------
|
|
* Interface
|
|
* -------------------------------------------------------------------------- */
|
|
|
|
/**
|
|
* SNS analysis
|
|
*/
|
|
void lc3_sns_analyze(enum lc3_dt dt, enum lc3_srate sr,
|
|
const float *eb, bool att, struct lc3_sns_data *data,
|
|
const float *x, float *y)
|
|
{
|
|
/* Processing steps :
|
|
* - Determine 16 scale factors from bands energy estimation
|
|
* - Get codebooks indexes that match thoses scale factors
|
|
* - Quantize the residual with the selected codebook
|
|
* - The pulse configuration `c[]` is enumerated
|
|
* - Finally shape the spectrum coefficients accordingly */
|
|
|
|
float scf[16], cn[4][16];
|
|
int c[4][16];
|
|
|
|
compute_scale_factors(dt, sr, eb, att, scf);
|
|
|
|
resolve_codebooks(scf, &data->lfcb, &data->hfcb);
|
|
|
|
quantize(scf, data->lfcb, data->hfcb,
|
|
c, cn, &data->shape, &data->gain);
|
|
|
|
unquantize(data->lfcb, data->hfcb,
|
|
cn[data->shape], data->shape, data->gain, scf);
|
|
|
|
enumerate(data->shape, c[data->shape],
|
|
&data->idx_a, &data->ls_a, &data->idx_b, &data->ls_b);
|
|
|
|
spectral_shaping(dt, sr, scf, false, x, y);
|
|
}
|
|
|
|
/**
|
|
* SNS synthesis
|
|
*/
|
|
void lc3_sns_synthesize(enum lc3_dt dt, enum lc3_srate sr,
|
|
const lc3_sns_data_t *data, const float *x, float *y)
|
|
{
|
|
float scf[16], cn[16];
|
|
int c[16];
|
|
|
|
deenumerate(data->shape,
|
|
data->idx_a, data->ls_a, data->idx_b, data->ls_b, c);
|
|
|
|
normalize(c, cn);
|
|
|
|
unquantize(data->lfcb, data->hfcb, cn, data->shape, data->gain, scf);
|
|
|
|
spectral_shaping(dt, sr, scf, true, x, y);
|
|
}
|
|
|
|
/**
|
|
* Return number of bits coding the bitstream data
|
|
*/
|
|
int lc3_sns_get_nbits(void)
|
|
{
|
|
return 38;
|
|
}
|
|
|
|
/**
|
|
* Put bitstream data
|
|
*/
|
|
void lc3_sns_put_data(lc3_bits_t *bits, const struct lc3_sns_data *data)
|
|
{
|
|
/* --- Codebooks --- */
|
|
|
|
lc3_put_bits(bits, data->lfcb, 5);
|
|
lc3_put_bits(bits, data->hfcb, 5);
|
|
|
|
/* --- Shape, gain and vectors --- *
|
|
* Write MSB bit of shape index, next LSB bits of shape and gain,
|
|
* and MVPQ vectors indexes are muxed */
|
|
|
|
int shape_msb = data->shape >> 1;
|
|
lc3_put_bit(bits, shape_msb);
|
|
|
|
if (shape_msb == 0) {
|
|
const int size_a = 2390004;
|
|
int submode = data->shape & 1;
|
|
|
|
int mux_high = submode == 0 ?
|
|
2 * (data->idx_b + 1) + data->ls_b : data->gain & 1;
|
|
int mux_code = mux_high * size_a + data->idx_a;
|
|
|
|
lc3_put_bits(bits, data->gain >> submode, 1);
|
|
lc3_put_bits(bits, data->ls_a, 1);
|
|
lc3_put_bits(bits, mux_code, 25);
|
|
|
|
} else {
|
|
const int size_a = 15158272;
|
|
int submode = data->shape & 1;
|
|
|
|
int mux_code = submode == 0 ?
|
|
data->idx_a : size_a + 2 * data->idx_a + (data->gain & 1);
|
|
|
|
lc3_put_bits(bits, data->gain >> submode, 2);
|
|
lc3_put_bits(bits, data->ls_a, 1);
|
|
lc3_put_bits(bits, mux_code, 24);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Get bitstream data
|
|
*/
|
|
int lc3_sns_get_data(lc3_bits_t *bits, struct lc3_sns_data *data)
|
|
{
|
|
/* --- Codebooks --- */
|
|
|
|
*data = (struct lc3_sns_data){
|
|
.lfcb = lc3_get_bits(bits, 5),
|
|
.hfcb = lc3_get_bits(bits, 5)
|
|
};
|
|
|
|
/* --- Shape, gain and vectors --- */
|
|
|
|
int shape_msb = lc3_get_bit(bits);
|
|
data->gain = lc3_get_bits(bits, 1 + shape_msb);
|
|
data->ls_a = lc3_get_bit(bits);
|
|
|
|
int mux_code = lc3_get_bits(bits, 25 - shape_msb);
|
|
|
|
if (shape_msb == 0) {
|
|
const int size_a = 2390004;
|
|
|
|
if (mux_code >= size_a * 14)
|
|
return -1;
|
|
|
|
data->idx_a = mux_code % size_a;
|
|
mux_code = mux_code / size_a;
|
|
|
|
data->shape = (mux_code < 2);
|
|
|
|
if (data->shape == 0) {
|
|
data->idx_b = (mux_code - 2) / 2;
|
|
data->ls_b = (mux_code - 2) % 2;
|
|
} else {
|
|
data->gain = (data->gain << 1) + (mux_code % 2);
|
|
}
|
|
|
|
} else {
|
|
const int size_a = 15158272;
|
|
|
|
if (mux_code >= size_a + 1549824)
|
|
return -1;
|
|
|
|
data->shape = 2 + (mux_code >= size_a);
|
|
if (data->shape == 2) {
|
|
data->idx_a = mux_code;
|
|
} else {
|
|
mux_code -= size_a;
|
|
data->idx_a = mux_code / 2;
|
|
data->gain = (data->gain << 1) + (mux_code % 2);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|