File ns_audio_mfcc.h

File List > includes-api > ns_audio_mfcc.h
/*
 * Copyright (C) 2018 Arm Limited or its affiliates. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __AM_MFCC_H__
    #define __AM_MFCC_H__
    #include "arm_math.h"

    #ifdef __cplusplus
extern "C" {
    #endif

    #include "ns_audio_features_common.h"
    #include "ns_core.h"
    #include "string.h"

    #define NS_MFCC_V0_0_1                                                                         \
        { .major = 0, .minor = 0, .revision = 1 }
    #define NS_MFCC_V1_0_0                                                                         \
        { .major = 1, .minor = 0, .revision = 0 }

    #define NS_MFCC_OLDEST_SUPPORTED_VERSION NS_MFCC_V0_0_1
    #define NS_MFCC_CURRENT_VERSION NS_MFCC_V1_0_0
    #define NS_MFCC_API_ID 0xCA0005

extern const ns_core_api_t ns_mfcc_V0_0_1;
extern const ns_core_api_t ns_mfcc_V1_0_0;
extern const ns_core_api_t ns_mfcc_oldest_supported_version;
extern const ns_core_api_t ns_mfcc_current_version;

typedef struct {
    const ns_core_api_t *api;  
    uint8_t *arena;            
    uint32_t sample_frequency; 
    uint32_t num_fbank_bins;   
    uint32_t low_freq;         
    uint32_t high_freq;        
    uint32_t num_frames;       
    uint32_t num_coeffs;       
    uint32_t num_dec_bits;     
    uint32_t frame_shift_ms;   
    uint32_t frame_len_ms;     
    uint32_t frame_len;        
    uint32_t frame_len_pow2;   
    float *mfccFrame;          
    float *mfccBuffer;         
    float *mfccEnergies;       
    float *mfccWindowFunction; 
    float *mfccDCTMatrix;      
    ns_fbanks_cfg_t fbc;       
} ns_mfcc_cfg_t;

    #define NS_MFCC_SIZEBINS 53

// Arena should be enough to accomodate the various buffers
// e.g. MFCC_ARENA_SIZE  32*(MY_MFCC_FRAME_LEN_POW2*2 +
// MY_MFCC_NUM_FBANK_BINS*(NS_MFCC_SIZEBINS+MY_MFCC_NUM_MFCC_COEFFS)) where '32' is size of float
// and int32_t

    #define M_2PI 6.283185307179586476925286766559005
    #ifndef M_PI
        #define M_PI 3.14159265358979323846264338328
    #endif

    #ifdef MFCC_DEBUG
extern float g_audioMax;
extern float g_audioMin;
extern float g_audioSum;
extern float g_audioMaxInt;
extern float g_audioMinInt;
extern float g_audioSumInt;
    #endif

extern uint32_t ns_mfcc_init(ns_mfcc_cfg_t *c);

extern uint32_t ns_mfcc_compute(ns_mfcc_cfg_t *c, const int16_t *audio_data, float *mfcc_out);

    #ifdef __cplusplus
}
    #endif
#endif // End Doxygen Group