MI APC API

1. OVERVIEW

1.1. Module Description

APC (short for Audio Process Chain) is a combination of algorithms including noise reduction, equalizer and automatic gain control.

The purpose of APC is to improve audio quality. The internal algorithm concatenation process is ANR → EQ/HPF → AGC. The SNR is improved through noise reduction and noise elimination. The EQ/HPF is adjusted according to the curve required by the customer, and the output is amplified or suppressed through AGC.

1.2. Keyword

  • AGC

    AGC(Automatic Gain Control), used to control the digital output gain.

  • EQ

    EQ(Equalizer), used to gain or attenuate specific frequency bands.

  • ANR

    ANR(Acoustic Noise Reduction), used to remove the continued and fixed frequency noise in the environment.

  • HPF

    HPF(High-Pass Filtering).

1.3. Note

In order to facilitate debugging and confirm the effect of the algorithm, the user application needs to implement replacement algorithm parameter and grab audio data.

2. API REFERENCE

2.1. API List

API name Features
IaaApc_GetBufferSize Get the memory size required for Apc algorithm running
IaaApc_Init Initialize the Apc algorithm
IaaApc_Config Configure the Apc algorithm
IaaApc_GetNrResult Get the Apc algorithm Anr processing result
IaaApc_GetNrEqResult Get the processing result of Anr and Eq in the Apc algorithm
IaaApc_Run Apc algorithm processing
IaaApc_Free Release Apc algorithm resources
IaaApc_Reset Reinitialize the Apc algorithm
IaaApc_GetConfig Get the Apc algorithm current configuration parameters
IaaAnr_GetBufferSize Get the memory size required for Anr algorithm running
IaaAnr_Init Initialize the Anr algorithm
IaaAnr_Config Configure the Anr algorithm
IaaAnr_Run Anr algorithm processing
IaaAnr_Free Release Anr algorithm resources
IaaAnr_Reset Reinitialize the Anr algorithm
IaaAnr_GetConfig Get the Anr algorithm current configuration parameters
IaaEq_GetBufferSize Get the memory size required for Eq algorithm running
IaaEq_Init Initialize the Eq algorithm
IaaEq_Config Configure the Eq algorithm
IaaEq_Run Eq algorithm processing
IaaEq_Free Release Eq algorithm resources
IaaEq_Reset Reinitialize the Eq algorithm
IaaEq_GetConfig Get the Eq algorithm current configuration parameters
IaaAgc_GetBufferSize Get the memory size required for Agc algorithm running
IaaAgc_Init Initialize the Agc algorithm
IaaAgc_Config Configure the Agc algorithm
IaaAgc_Run Agc algorithm processing
IaaAgc_Free Release Agc algorithm resources
IaaAgc_Reset Reinitialize the Eq algorithm
IaaAgc_GetConfig Get the Agc algorithm current configuration parameters

2.2. IaaApc_GetBufferSize

  • Features

    Get the memory size required for Apc algorithm running.

  • Syntax

    unsigned int IaaApc_GetBufferSize(AudioApcBufferConfig
*apc_switch);

  • Parameters

    Parameter name Description Input/output
    apc_switch Structure pointer for configure the Apc algorithm to enable Input

  • Return value

    Return value is the memory size required for Apc algorithm running.

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    The interface only returns the required memory size. The application and release of memory needs to be processed by the application.

  • Example

    Please refer to IaaApc_Run example.

2.3. IaaApc_Init

  • Features

    Initialize the Apc algorithm .

  • Syntax

    APC_HANDLE IaaApc_Init(char* const
working_buffer_address, AudioProcessInit
*audio_process_init, AudioApcBufferConfig
*apc_switch);

  • Parameters

    Parameter name Description Input/output
    working_buffer_address Apc algorithm memory address Input
    audio_process_init Apc algorithm initialization structure pointer Input
    apc_switch Apc algorithm enable structure pointer Input

  • Return value

    Return value Result
    Not NULL Successful
    NULL Failed

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • In the Apc algorithm, ANR/AGC/EQ supports 8K/16K/48K sampling rate, HPF only supports 8K/16K.

  • Example

    Please refer to IaaApc_Run example.

2.4. IaaApc_Config

  • Features

    Configure the Apc algorithm.

  • Syntax

    ALGO_APC_RET IaaApc_Config(APC_HANDLE handle,
                        AudioAnrConfig *anr_config,
                        AudioEqConfig *eq_config,
                        AudioHpfConfig *hpf_config,
                        AudioVadConfig *vad_config,
                        AudioDereverbConfig *dereverb_config,
                        AudioAgcConfig *agc_config);

  • Parameters

    Parameter name Description Input/output
    handle Apc algorithm handle Input
    anr_config Configure Anr algorithm structure pointer Input
    eq_config Configure Eq algorithm structure pointer Input
    hpf_config Configure Hpf algorithm structure pointer Input
    vad_config Configure Vad algorithm structure pointer(stop using) Input
    dereverb_config Configure Dereverb algorithm structure pointer (stop using) Input
    agc_config Configure Agc algorithm structure pointer Input

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaApc_Run example.

2.5. IaaApc_GetNrResult

  • Features

    Get the Apc algorithm Anr processing result.

  • Syntax

    ALGO_APC_RET IaaApc_GetNrResult(APC_HANDLE handle, short*
nr_audio_out);

  • Parameters

    Parameter name Description Input/output
    handle Apc algorithm handle Input
    nr_audio_out Anr handles Output data pointer Output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • Anr in the Apc algorithm must be enabled before calling the interface to obtain data.

  • Example

    Please refer to IaaApc_Run example.

2.6. IaaApc_GetNrEqResult

  • Features

    Get the processing result of Anr and Eq in the Apc algorithm

  • Syntax

    ALGO_APC_RET IaaApc_GetNrEqResult(APC_HANDLE handle,short*
nr_eq_audio_out);

  • Parameters

    Parameter name Description Input/output
    handle Aec algorithm handle Input
    nr_eq_audio_out Anr and Eq handle output data pointer Output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • Enable Anr and Eq in the Apc algorithm before calling this interface to obtain data.

  • Example

    Please refer to IaaApc_Run example.

2.7. IaaApc_Run

  • Features

    Apc algorithm processing.

  • Syntax

    ALGO_APC_RET IaaApc_Run(APC_HANDLE handle,short* pss_audio_in);

  • Parameters

    Parameter name Description Input/output
    handle Apc algorithm handle Input
    pss_audio_in Input data pointer Input/output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • The data must correspond to the point_number (sampling points required for one IaaApc_Run) set when calling IaaApc_Init. The processed data will be written back to the memory pointed to by pss_audio_in.

  • Example

    #include <stdio.h>  
#include <string.h>  
#include <stdlib.h>  
#include <sys/time.h>

#include "AudioProcess.h"

/*  0:Fixed input file  1:User input file   */  
#define IN_PARAMETER 1

float AVERAGE_RUN(int a)  
{  
    static unsigned int num = 0;  
    static float avg = 0;  
    if(0 == num)  
        avg = 0;  
    num++;  
    avg = avg + ((float)a - avg) / ((float)num);  
    return avg;  
}  
unsigned int _OsCounterGetMs(void)  
{  
    struct  timeval t1;  
    gettimeofday(&t1, NULL);  
    unsigned int T = ((1000000 * t1.tv_sec) + t1.tv_usec) / 1000;  
    return T;  
}

int main(int argc, char *argv[])  
{  
    short in_output[1024];  
    unsigned int T0, T1;  
    float avg = 0;  
    char src_file[128];  
    char dst_file[128];  
    int counter = 0;  
    unsigned int workingBufferSize;  
    char *workingBuffer = NULL;  
    AudioApcBufferConfig apc_switch;  
    FILE *fpIn, * fpOut;  
    ALGO_APC_RET ret;  
    AudioProcessInit apc_init;  
    AudioAnrConfig anr_config;  
    AudioEqConfig eq_config;  
    AudioHpfConfig hpf_config;  
    AudioAgcConfig agc_config;  
    APC_HANDLE handle;  
    /****************************User change section start**********************************/  
    int intensity_band[6] = {3,24,40,64,80,128};  
    int intensity[7] = {30,30,30,30,30,30,30};  
    short eq_table[129];  
    memset(eq_table, 0, sizeof(eq_table));  
    short compression_ratio_input[7] = {-65,-55,-48,-25,-18,-12,0};  
    short compression_ratio_output[7] = {-65,-50,-27,-12,-1,-1,-1};

    apc_switch.anr_enable = 1;  
    apc_switch.eq_enable = 1;  
    apc_switch.agc_enable = 1;

    apc_init.point_number = 128;  
    apc_init.channel = 1;  
    apc_init.sample_rate = IAA_APC_SAMPLE_RATE_16000;

    /******ANR Config*******/  
    anr_config.anr_enable = apc_switch.anr_enable;  
    anr_config.user_mode = 2;  
    memcpy(anr_config.anr_intensity_band, intensity_band, sizeof(intensity_band));  
    memcpy(anr_config.anr_intensity, intensity, sizeof(intensity));  
    anr_config.anr_smooth_level = 10;  
    anr_config.anr_converge_speed = 0;  
    /******EQ Config********/  
    eq_config.eq_enable = apc_switch.eq_enable;  
    eq_config.user_mode = 1;  
    memcpy(eq_config.eq_gain_db, eq_table, sizeof(eq_table));  
    /******HPF Config********/  
    hpf_config.hpf_enable = apc_switch.eq_enable;  
    hpf_config.user_mode = 1;  
    hpf_config.cutoff_frequency = AUDIO_HPF_FREQ_150;  
    /******AGC Config********/  
    agc_config.agc_enable = apc_switch.agc_enable;  
    agc_config.user_mode = 1;  
    agc_config.gain_info.gain_max  = 40;  
    agc_config.gain_info.gain_min  = -10;  
    agc_config.gain_info.gain_init = 12;  
    agc_config.drop_gain_max = 36;  
agc_config.gain_step = 1; 
    agc_config.attack_time = 1;  
    agc_config.release_time = 1;  
    agc_config.noise_gate_db = -80;  
    memcpy(agc_config.compression_ratio_input, compression_ratio_input, sizeof(compression_ratio_input));  
    memcpy(agc_config.compression_ratio_output, compression_ratio_output, sizeof(compression_ratio_output));  
    agc_config.noise_gate_attenuation_db = 0;  
    agc_config.drop_gain_threshold = -5;  
    /****************************User change section end***********************************/  
    //(1)IaaApc_GetBufferSize  
    workingBufferSize = IaaApc_GetBufferSize(&apc_switch);  
    workingBuffer = (char*)malloc(workingBufferSize);  
    if(NULL == workingBuffer)  
    {  
        printf("malloc workingBuffer failed !\n");  
        return -1;  
    }  
    printf("malloc workingBuffer succeed !\n");  
    //(2)IaaApc_Init  
    handle = IaaApc_Init(workingBuffer, &apc_init, &apc_switch);  
    if(NULL == handle)  
    {  
        printf("IaaApc_Init failed !\n");  
        return -1;  
    }  
    printf("IaaApc_Init succeed !\n");  
    //(3)IaaApc_Config  
    if(IaaApc_Config(handle, &anr_config, &eq_config, &hpf_config, NULL, NULL, &agc_config))  
    {  
        printf("IaaApc_Config failed !\n");  
        return -1;  
    }  
    printf("IaaApc_Config succeed !\n");

#if IN_PARAMETER  
    if(argc < 3)  
    {  
        printf("Please enter the correct parameters!\n");  
        return -1;  
    }  
    sscanf(argv[1], "%s", src_file);  
    sscanf(argv[2], "%s", dst_file);  
#else  
    sprintf(src_file, "%s", "./APC_AFE_16K.wav");  
    if(argc < 2)  
    {  
        printf("Please enter the correct parameters!\n");  
        return -1;  
    }  
    sscanf(argv[1], "%s", dst_file);  
#endif

    fpIn = fopen(src_file, "rb");  
    if(NULL == fpIn)  
    {  
        printf("src_file open failed !\n");  
        return -1;  
    }  
    printf("src_file open succeed !\n");  
    fpOut = fopen(dst_file, "wb");  
    if(NULL == fpOut)  
    {  
        printf("dst_file open failed !\n");  
        return -1;  
    }  
    printf("dst_file open succeed !\n");  
#if 1  
    fread(in_output, sizeof(char), 44, fpIn);  
    fwrite(in_output, sizeof(char), 44, fpOut);  
#endif  
    while(fread(in_output, sizeof(short), apc_init.point_number * apc_init.channel, fpIn))  
    {  
        counter++;  
        T0  = (long)_OsCounterGetMs();  
        ret = IaaApc_Run(handle, in_output);  
        T1  = (long)_OsCounterGetMs();  
        avg += (T1 - T0);

        if(counter%1000 == 999)  
        {  
            printf("counter = %d\n", counter);  
            printf("current time = %f\n", (float)counter * apc_init.point_number / apc_init.sample_rate);  
            printf("process time = %lu(ms)\t", (long)(T1 - T0));  
        }  
        if(ret)  
        {  
            printf("Error occured in NoiseReduct\n");  
            break;  
        }  
        fwrite(in_output, sizeof(short), apc_init.point_number * apc_init.channel, fpOut);  
    }  
    avg /= counter;  
    printf("AVG is %.2f ms\n", avg);  
    IaaApc_Free(handle);  
    free(workingBuffer);  
    fclose(fpIn);  
    fclose(fpOut);  
    printf("APC end !\n");

    return 0;  
}

2.8. IaaApc_Free

  • Features

    Release Apc algorithm resources

  • Syntax

    ALGO_APC_RET IaaApc_Free(APC_HANDLE handle);

  • Parameters

    Parameter name Description Input/output
    handle Apc algorithm handle Input

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaApc_Run example.

2.9. IaaApc_Reset

  • Features

    Reinitialize the Apc algorithm.

  • Syntax

    APC_HANDLE IaaApc_Reset(char* working_buffer_address,AudioProcessInit *audio_process_init, AudioApcBufferConfig *apc_switch);

  • Parameters

    Parameter name Description Input/output
    working_buffer_address Memory address used by Apc algorithm Input
    audio_process_init Apc algorithm initialization structure pointer Input
    apc_switch Structure pointer for configure the Apc algorithm to enable Input

  • Return value

    Return value Result
    Not NULL Successful
    NULL Failed

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    When the Apc algorithm is reinitialized and the function options are different from previous, we need to release the memory used by the original algorithm, call IaaApc_GetBufferSize again to get the memory size required by the current function options, and reapply for the corresponding size of memory for the Apc algorithm.

2.10. IaaApc_GetConfig

  • Features

    Get the Apc algorithm current configuration parameters.

  • Syntax

    ALGO_APC_RET IaaApc_GetConfig(APC_HANDLE handle,
                        AudioProcessInit *audio_process_init,
                        AudioAnrConfig *anr_config,
                        AudioEqConfig *eq_config,
                        AudioHpfConfig *hpf_config,
                        AudioVadConfig *vad_config,
                        AudioDereverbConfig *dereverb_config,
                        AudioAgcConfig *agc_config);

  • Parameters

    Parameter name Description Input/output
    handle Apc algorithm handle Input
    audio_process_init Apc algorithm initialization structure pointer Output
    anr_config The current Anr configuration parameters in the Apc algorithm Output
    eq_config The current Eq configuration parameters in the Apc algorithm Output
    hpf_config The current Hpf configuration parameters in the Apc algorithm Output
    vad_config The current Vad configuration parameters in the Apc algorithm(stop using) Output
    dereverb_config The current Dereverb configuration parameters in the Apc algorithm(stop using) Output
    agc_config The current Agc configuration parameters in the Apc algorithm Output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaApc_Run example.

2.11. IaaAnr_GetBufferSize

  • Features

    Get the memory size required for Anr algorithm running.

  • Syntax

    unsigned int IaaAnr_GetBufferSize(void);

  • Return value

    Return value is the memory size required for Anr algorithm running.

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    The interface only returns the required memory size. The application and release of memory needs to be processed by the application.。

  • Example

    Please refer to IaaAnr_Run example.

2.12. IaaAnr_Init

  • Features

    Initialize the Anr algorithm.

  • Syntax

    ANR_HANDLE IaaAnr_Init(char* working_buffer_address, AudioProcessInit *anr_init);

  • Parameters

    Parameter name Description Input/output
    working_buffer_address Anr algorithm memory address Input
    anr_init Anr algorithm initialization structure pointer Input

  • Return value

    Return value Result
    Not NULL Successful
    NULL Failed

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • ANR supports 8K/16K/48K sampling rate.

  • Example

    Please refer to IaaAnr_Run example.

2.13. IaaAnr_Config

  • Features

    Configure the Anr algorithm.

  • Syntax

    ALGO_APC_RET IaaAnr_Config(ANR_HANDLE handle,
AudioAnrConfig *anr_config);

  • Parameters

    Parameter name Description Input/output
    handle Anr algorithm handle Input
    anr_config Configure Anr algorithm structure pointer Input

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaAnr_Run example.

2.14. IaaAnr_Run

  • Features

    Anr algorithm processing.

  • Syntax

    ALGO_APC_RET IaaAnr_Run(ANR_HANDLE handle, short* pss_audio_in);

  • Parameters

    Parameter name Description Input/output
    handle Anr algorithm handle Input
    pss_audio_in Input data pointer Input/output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • The data must correspond to the point_number (sampling points required for one IaaAnr_Run) set when calling IaaAnr_Init. The processed data will be written back to the memory pointed to by pss_audio_in.

  • Example

    #include <stdio.h>  
#include <string.h>  
#include <stdlib.h>  
#include <sys/time.h>

#include "AudioProcess.h"

/*  0:Fixed input file  1:User input file   */  
#define IN_PARAMETER 1

int main(int argc, char *argv[])  
{  
    short in_output[1024];  
    unsigned int workingBufferSize;  
    char *workingBuffer = NULL;  
    ANR_HANDLE handle;  
    AudioProcessInit anr_init, anr_get_init;  
    AudioAnrConfig anr_config, anr_get_config;  
    ALGO_APC_RET ret;  
    int tempSize;  
    FILE* fpIn;  //input file  
    FILE* fpOut; //output file  
    char src_file[128] = {0};  
    char dst_file[128] = {0};  
    /*********************User change section start*******************/  
    int intensity_band[6] = {3,24,40,64,80,128};  
    int intensity[7] = {30,30,30,30,30,30,30};  
    anr_init.point_number = 128;  
    anr_init.channel = 1;  
    anr_init.sample_rate = IAA_APC_SAMPLE_RATE_16000;

    anr_config.anr_enable = 1;  
    anr_config.user_mode = 2;  
    anr_config.anr_smooth_level = 10;  
    anr_config.anr_converge_speed = 0;  
    /*********************User change section end*******************/  
    memcpy(anr_config.anr_intensity_band, intensity_band, sizeof(intensity_band));  
    memcpy(anr_config.anr_intensity, intensity, sizeof(intensity));  
    //(1)IaaAnr_GetBufferSize  
    workingBufferSize = IaaAnr_GetBufferSize();  
    workingBuffer = (char *)malloc(workingBufferSize);  
    if(NULL == workingBuffer)  
    {  
        printf("malloc workingBuffer failed !\n");  
        return -1;  
    }  
    printf("malloc workingBuffer succeed !\n");  
    //(2)IaaAnr_Init  
    handle = IaaAnr_Init(workingBuffer, &anr_init);  
    if(NULL == handle)  
    {  
        printf("IaaAnr_Init failed !\n");  
        return -1;  
    }  
    printf("IaaAnr_Init succeed !\n");  
    //(3)IaaAnr_Config  
    ret = IaaAnr_Config(handle, &anr_config);  
    if(ret)  
    {  
        printf("IaaAnr_Config failed !\n");  
        return -1;  
    }  
    printf("IaaAnr_Config succeed !\n");  
    //(4)IaaAnr_GetConfig  
    ret = IaaAnr_GetConfig(handle, &anr_get_init, &anr_get_config);  
    if(ret)  
    {  
        printf("IaaAnr_GetConfig failed !\n");  
        return -1;  
    }  
    printf("IaaAnr_GetConfig succeed !\n");  
    printf("anr_get_config.user_mode = %d, ...\n", anr_get_config.user_mode);

#if IN_PARAMETER  
    if(argc < 3)  
    {  
        printf("Please enter the correct parameters!\n");  
        return -1;  
    }  
    sscanf(argv[1], "%s", src_file);  
    sscanf(argv[2], "%s", dst_file);  
#else  
    sprintf(src_file, "%s", "./APC_AFE_16K.wav");  
    if(argc < 2)  
    {  
        printf("Please enter the correct parameters!\n");  
        return -1;  
    }  
    sscanf(argv[1], "%s", dst_file);  
#endif

    fpIn = fopen(src_file, "rb");  
    if(NULL == fpIn)  
    {  
        printf("fopen in_file failed !\n");  
        return -1;  
    }  
    printf("fopen in_file success !\n");  
    fpOut = fopen(dst_file, "wb");  
    if(NULL == fpOut)  
    {  
        printf("fopen out_file failed !\n");  
        return -1;  
    }  
    printf("fopen out_file success !\n");  
#if 1  
    fread(in_output, sizeof(char), 44, fpIn);  
    fwrite(in_output, sizeof(char), 44, fpOut);  
#endif  
    tempSize = anr_init.point_number * anr_init.channel;  
    while(tempSize == fread(in_output, sizeof(short), tempSize, fpIn))  
    {  
        //(5)IaaAnr_Run  
        ret = IaaAnr_Run(handle, in_output);  
        if(ret)  
        {  
            printf("IaaAnr_Run failed !\n");  
            return -1;  
        }  
        fwrite(in_output, sizeof(short), tempSize, fpOut);  
    }  
    printf("Break:needBytes =%d \t nBytesRead = %d\n", anr_init.point_number * anr_init.channel, tempSize);  
    //(6)IaaAnr_Free  
    IaaAnr_Free(handle);  
    free(workingBuffer);  
    fclose(fpIn);  
    fclose(fpOut);  
    printf("APC_ANR end !\n");

    return 0;  
}

2.15. IaaAnr_Free

  • Features

    Release Anr algorithm resources.

  • Syntax

    ALGO_APC_RET IaaAnr_Free(ANR_HANDLE handle);

  • Parameters

    Parameter name Description Input/output
    handle Anr algorithm handle Input

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaAnr_Run example.

2.16. IaaAnr_Reset

  • Features

    Reinitialize the Anr algorithm.

  • Syntax

    ANR_HANDLE IaaAnr_Reset(char* working_buffer_address,
AudioProcessInit *anr_init);

  • Parameters

    Parameter name Description Input/output
    working_buffer_address Memory address used by Anr algorithm Input
    anr_init Anr algorithm initialization structure pointer Input

  • Return value

    Return value Result
    Not NULL Successful
    NULL Failed

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

2.17. IaaAnr_GetConfig

  • Features

    Get the Anr algorithm current configuration parameters.

  • Syntax

    ALGO_APC_RET IaaAnr_GetConfig(ANR_HANDLE handle,
AudioProcessInit *anr_init,
AudioAnrConfig *anr_config);

  • Parameters

    Parameter name Description Input/output
    handle Anr algorithm handle Input
    anr_init Anr algorithm initialization structure pointer Output
    anr_config Anr algorithm in the current configuration parameters Output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaAnr_Run example.

2.18. IaaEq_GetBufferSize

  • Features

    Get the memory size required for Anr algorithm running.

  • Syntax

    unsigned int IaaEq_GetBufferSize(void);

  • Return value

    Return value is the memory size required for Eq algorithm running.

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    The interface only returns the required memory size. The application and release of memory needs to be processed by the application.。

  • Example

    Please refer to IaaEq_Run example.

2.19. IaaEq_Init

  • Features

    Initialize the Eq algorithm.

  • Syntax

    EQ_HANDLE IaaEq_Init(char* working_buffer_address,
AudioProcessInit *eq_init);

  • Parameters

    Parameter name Description Input/output
    working_buffer_address Eq algorithm memory address Input
    eq_init Eq algorithm initialization structure pointer Input

  • Return value

    Return value Result
    Not NULL Successful
    NULL Failed

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • Eq algorithm supports 8K/16K/48K sampling Rate，Hpf only supports 8K/16K.

  • Example

    Please refer to IaaEq_Run example.

2.20. IaaEq_Config

  • Features

    Configure the Eq algorithm.

  • Syntax

    ALGO_APC_RET IaaEq_Config(EQ_HANDLE handle,
AudioHpfConfig *hpf_config,
AudioEqConfig *eq_config);

  • Parameters

    Parameter name Description Input/output
    handle Eq algorithm handle Input
    hpf_config Configure Hpf algorithm structure pointer Input
    eq_config Configure Eq algorithm structure pointer Input

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaEq_Run example.

2.21. IaaEq_Run

  • Features

    Eq algorithm processing.

  • Syntax

    ALGO_APC_RET IaaEq_Run(EQ_HANDLE handle, short* pss_audio_in);

  • Parameters

    Parameter name Description Input/output
    handle Eq algorithm handle Input
    pss_audio_in Input data pointer Input/output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • he data must correspond to the point_number (sampling points required for one IaaEq_Run) set when calling IaaEq_Init. The processed data will be written back to the memory pointed to by pss_audio_in.

  • Example

    #include <stdio.h>  
#include <string.h>  
#include <stdlib.h>  
#include <sys/time.h>

#include "AudioProcess.h"

/*  0:Fixed input file  1:User input file   */  
#define IN_PARAMETER 1

int main(int argc, char *argv[])  
{  
    short in_output[1024];  
    unsigned int workingBufferSize;  
    char *workingBuffer = NULL;  
    EQ_HANDLE handle;  
    AudioProcessInit eq_init, eq_get_init;  
    AudioHpfConfig hpf_config, hpf_get_config;  
    AudioEqConfig  eq_config, eq_get_config;  
    ALGO_APC_RET ret;  
    int tempSize;

    FILE* fpIn;  //input file  
    FILE* fpOut; //output file  
    char src_file[128] = {0};  
    char dst_file[128] = {0};  
    /*********************User change section start*******************/  
    short eq_table[129];  
    memset(eq_table, 0, sizeof(eq_table));  
    eq_init.point_number = 128;  
    eq_init.channel = 1;  
    eq_init.sample_rate = IAA_APC_SAMPLE_RATE_16000;

    hpf_config.hpf_enable = 1;  
    hpf_config.user_mode = 1;  
    hpf_config.cutoff_frequency = AUDIO_HPF_FREQ_150;

    eq_config.eq_enable = 1;  
    eq_config.user_mode = 1;  
    /*********************User change section end*******************/  
    memcpy(eq_config.eq_gain_db, eq_table, sizeof(eq_table));  
    //(1)IaaEq_GetBufferSize  
    workingBufferSize = IaaEq_GetBufferSize();  
    workingBuffer = (char *)malloc(workingBufferSize);  
    if(NULL == workingBuffer)  
    {  
        printf("malloc workingBuffer failed !\n");  
        return -1;  
    }  
    printf("malloc workingBuffer succeed !\n");  
    //(2)IaaEq_Init  
    handle = IaaEq_Init(workingBuffer, &eq_init);  
    if(NULL == handle)  
    {  
        printf("IaaEq_Init failed !\n");  
        return -1;  
    }  
    printf("IaaEq_Init succeed !\n");  
    //(3)IaaEq_Config  
    ret = IaaEq_Config(handle, &hpf_config, &eq_config);  
    if(ret)  
    {  
        printf("IaaEq_Config failed !\n");  
        return -1;  
    }  
    printf("IaaEq_Config succeed !\n");  
    //(4)IaaEq_GetConfig  
    ret = IaaEq_GetConfig(handle, &eq_get_init, &hpf_get_config, &eq_get_config);  
    if(ret)  
    {  
        printf("IaaEq_GetConfig failed !\n");  
        return -1;  
    }  
    printf("IaaEq_GetConfig succeed !\n");  
    printf("eq_get_config.user_mode = %d, ...\n", eq_get_config.user_mode);

#if IN_PARAMETER  
    if(argc < 3)  
    {  
        printf("Please enter the correct parameters!\n");  
        return -1;  
    }  
    sscanf(argv[1], "%s", src_file);  
    sscanf(argv[2], "%s", dst_file);  
#else  
    sprintf(src_file, "%s", "./APC_AFE_16K.wav");  
    if(argc < 2)  
    {  
        printf("Please enter the correct parameters!\n");  
        return -1;  
    }  
    sscanf(argv[1], "%s", dst_file);  
#endif

    fpIn = fopen(src_file, "rb");  
    if(NULL == fpIn)  
    {  
        printf("fopen in_file failed !\n");  
        return -1;  
    }  
    printf("fopen in_file success !\n");  
    fpOut = fopen(dst_file, "wb");  
    if(NULL == fpOut)  
    {  
        printf("fopen out_file failed !\n");  
        return -1;  
    }  
    printf("fopen out_file success !\n");  
#if 1  
    fread(in_output, sizeof(char), 44, fpIn);  
    fwrite(in_output, sizeof(char), 44, fpOut);  
#endif  
    tempSize = eq_init.point_number * eq_init.channel;  
    while(tempSize == fread(in_output, sizeof(short), tempSize, fpIn))  
    {  
        //(5)IaaEq_Run  
        ret = IaaEq_Run(handle, in_output);  
        if(ret)  
        {  
            printf("IaaEq_Run failed !\n");  
            return -1;  
        }  
        fwrite(in_output, sizeof(short), tempSize, fpOut);  
    }  
    printf("Break:needBytes =%d \t nBytesRead = %d\n", eq_init.point_number * eq_init.channel, tempSize);  
    //(6)IaaEq_Free  
    IaaEq_Free(handle);  
    free(workingBuffer);  
    fclose(fpIn);  
    fclose(fpOut);  
    printf("APC_EQ end !\n");

    return 0;  
}

2.22. IaaEq_Free

  • Features

    Release Eq algorithm resources.

  • Syntax

    ALGO_APC_RET IaaEq_Free(EQ_HANDLE handle);

  • Parameters

    Parameter name Description Input/output
    handle Eq algorithm handle Input

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaEq_Run example.

2.23. IaaEq_Reset

  • Features

    Reinitialize the Eq algorithm.

  • Syntax

    EQ_HANDLE IaaEq_Reset(char* working_buffer_address,
AudioProcessInit *eq_init);

  • Parameters

    Parameter name Description Input/output
    working_buffer_address Memory address used by Eq algorithm Input
    eq_init Eq algorithm initialization structure pointer Input

  • Return value

    Return value Result
    Not NULL Successful
    NULL Failed

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

2.24. IaaEq_GetConfig

  • Features

    Get the Eq algorithm current configuration parameters.

  • Syntax

    ALGO_APC_RET IaaEq_GetConfig(EQ_HANDLE handle,
AudioProcessInit *eq_init,
AudioHpfConfig *hpf_config,
AudioEqConfig *eq_config);

  • Parameters

    Parameter name Description Input/output
    handle Eq algorithm handle Input
    eq_init Eq algorithm initialization structure pointer Output
    hpf_config Hpf algorithm in the current configuration parameters Output
    eq_config Eq algorithm in the current configuration parameters Output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaEq_Run example

2.25. IaaAgc_GetBufferSize

  • Features

    Get the memory size required for Agc algorithm running.

  • Syntax

    unsigned int IaaAgc_GetBufferSize(void);

  • Return value

    Return value is the memory size required for Agc algorithm running.

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    The interface only returns the required memory size. The application and release of memory needs to be processed by the application.。

  • Example

    Please refer to IaaAgc_Run example.

2.26. IaaAgc_Init

  • Features

    Initialize the Agc algorithm.

  • Syntax

    AGC_HANDLE IaaAgc_Init(char* working_buffer_address,
AudioProcessInit *agc_init);

  • Parameters

    Parameter name Description Input/output
    working_buffer_address Agc algorithm memory address Input
    agc_init Agc algorithm initialization structure pointer Input

  • Return value

    Return value Result
    Not NULL Successful
    NULL Failed

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • AGC supports 8K/16K/48K sampling rate.

  • Example

    Please refer to IaaAgc_Run example.

2.27. IaaAgc_Config

  • Features

    Configure the Agc algorithm.

  • Syntax

    ALGO_APC_RET IaaAgc_Config(AGC_HANDLE handle,
AudioAgcConfig *agc_config);

  • Parameters

    Parameter name Description Input/output
    handle Agc algorithm handle Input
    agc_config Configure Agc algorithm structure pointer Input

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaAgc_Run example.

2.28. IaaAgc_Run

  • Features

    Agc algorithm processing.

  • Syntax

    ALGO_APC_RET IaaAgc_Run(AGC_HANDLE handle, short* pss_audio_in);

  • Parameters

    Parameter name Description Input/output
    handle Agc algorithm handle Input
    pss_audio_in Input data pointer Input/output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Note

    • The data must correspond to the point_number (sampling points required for one IaaAgc_Run) set when calling IaaAgc_Init. The processed data will be written back to the memory pointed to by pss_audio_in.

  • Example

    #include <stdio.h>  
#include <string.h>  
#include <stdlib.h>  
#include <sys/time.h>

#include "AudioProcess.h"

/*  0:Fixed input file  1:User input file   */  
#define IN_PARAMETER 1

int main(int argc, char *argv[])  
{  
    short in_output[1024];  
    unsigned int workingBufferSize;  
    char *workingBuffer = NULL;  
    AGC_HANDLE handle;  
    AudioProcessInit agc_init, agc_get_init;  
    AudioAgcConfig agc_config, agc_get_config;  
    ALGO_APC_RET ret;  
    int tempSize;  
    FILE* fpIn;  //input file  
    FILE* fpOut; //output file  
    char src_file[128] = {0};  
    char dst_file[128] = {0};  
    /*********************User change section start*******************/  
    short compression_ratio_input[7] = {-65,-55,-48,-25,-18,-12,0};  
    short compression_ratio_output[7] = {-65,-50,-27,-12,-1,-1,-1};  
    agc_init.point_number = 128;  
    agc_init.channel = 1;  
    agc_init.sample_rate = IAA_APC_SAMPLE_RATE_16000;

    agc_config.agc_enable = 1;  
    agc_config.user_mode = 1;  
    agc_config.gain_info.gain_max  = 40;  
    agc_config.gain_info.gain_min  = -10;  
    agc_config.gain_info.gain_init = 12;  
    agc_config.drop_gain_max = 36;  
agc_config.gain_step = 1; 
    agc_config.attack_time = 1;  
    agc_config.release_time = 1;  
    agc_config.noise_gate_db = -80;  
    agc_config.noise_gate_attenuation_db = 0;  
    agc_config.drop_gain_threshold = -5;  
    /*********************User change section end*******************/  
    memcpy(agc_config.compression_ratio_input, compression_ratio_input, sizeof(compression_ratio_input));  
    memcpy(agc_config.compression_ratio_output, compression_ratio_output, sizeof(compression_ratio_output));  
    //(1)IaaAgc_GetBufferSize  
    workingBufferSize = IaaAgc_GetBufferSize();  
    workingBuffer = (char *)malloc(workingBufferSize);  
    if(NULL == workingBuffer)  
    {  
        printf("malloc workingBuffer failed !\n");  
        return -1;  
    }  
    printf("malloc workingBuffer succeed !\n");  
    //(2)IaaAgc_Init  
    handle = IaaAgc_Init(workingBuffer, &agc_init);  
    if(NULL == handle)  
    {  
        printf("IaaAgc_Init failed !\n");  
        return -1;  
    }  
    printf("IaaAgc_Init succeed !\n");  
    //(3)IaaAgc_Config  
    ret = IaaAgc_Config(handle, &agc_config);  
    if(ret)  
    {  
        printf("IaaAgc_Config failed !\n");  
        return -1;  
    }  
    printf("IaaAgc_Config succeed !\n");  
    //(4)IaaAgc_GetConfig  
    ret = IaaAgc_GetConfig(handle, &agc_get_init, &agc_get_config);  
    if(ret)  
    {  
        printf("IaaAgc_GetConfig failed !\n");  
        return -1;  
    }  
    printf("IaaAgc_GetConfig succeed !\n");  
    printf("agc_get_config.user_mode = %d, ...\n", agc_get_config.user_mode);

#if IN_PARAMETER  
    if(argc < 3)  
    {  
        printf("Please enter the correct parameters!\n");  
        return -1;  
    }  
    sscanf(argv[1], "%s", src_file);  
    sscanf(argv[2], "%s", dst_file);  
#else  
    sprintf(src_file, "%s", "./APC_AFE_16K.wav");  
    if(argc < 2)  
    {  
        printf("Please enter the correct parameters!\n");  
        return -1;  
    }  
    sscanf(argv[1], "%s", dst_file);  
#endif

    fpIn = fopen(src_file, "rb");  
    if(NULL == fpIn)  
    {  
        printf("fopen in_file failed !\n");  
        return -1;  
    }  
    printf("fopen in_file success !\n");  
    fpOut = fopen(dst_file, "wb");  
    if(NULL == fpOut)  
    {  
        printf("fopen out_file failed !\n");  
        return -1;  
    }  
    printf("fopen out_file success !\n");  
#if 1  
    fread(in_output, sizeof(char), 44, fpIn);  
    fwrite(in_output, sizeof(char), 44, fpOut);  
#endif  
    tempSize = agc_init.point_number * agc_init.channel;  
    while(tempSize == fread(in_output, sizeof(short), tempSize, fpIn))  
    {  
        //(5)IaaAgc_Run  
        ret = IaaAgc_Run(handle, in_output);  
        if(ret)  
        {  
            printf("IaaAnr_Run failed !\n");  
            return -1;  
        }  
        fwrite(in_output, sizeof(short), tempSize, fpOut);  
    }  
    printf("Break:needBytes =%d \t nBytesRead = %d\n", agc_init.point_number * agc_init.channel, tempSize);  
    //(6)IaaAgc_Free  
    IaaAgc_Free(handle);  
    free(workingBuffer);  
    fclose(fpIn);  
    fclose(fpOut);  
    printf("APC_AGC end !\n");

    return 0;  
}

2.29. IaaAgc_Free

  • Features

    Release Agc algorithm resources.

  • Syntax

    ALGO_APC_RET IaaAgc_Free(AGC_HANDLE handle);

  • Parameters

    Parameter name Description Input/output
    handle Agc algorithm handle Input

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaAgc_Run example.

2.30. IaaAgc_Reset

  • Features

    Reinitialize the Eq algorithm.

  • Syntax

    AGC_HANDLE IaaAgc_Reset(char* working_buffer_address,
AudioProcessInit *agc_init);

  • Parameters

    Parameter name Description Input/output
    working_buffer_address Memory address used by Agc algorithm Input
    agc_init Agc algorithm initialization structure pointer Input

  • Return value

    Return value Result
    Not NULL Successful
    NULL Failed

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

2.31. IaaAgc_GetConfig

  • Features

    Get the Agc algorithm current configuration parameters.

  • Syntax

    ALGO_APC_RET IaaAgc_GetConfig(AGC_HANDLE handle,
AudioProcessInit *agc_init,
AudioAgcConfig *agc_config);

  • Parameters

    Parameter name Description Input/output
    handle Agc algorithm handle Input
    agc_init Agc algorithm initialization structure pointer Output
    agc_config Agc algorithm in the current configuration parameters Output

  • Return value

    Return value Result
    0 Successful
    Non-zero Failed, refer to error code

  • Dependency

    • Header: AudioProcess.h

    • Library: libAPC_LINUX.so/ libAPC_LINUX.a

  • Example

    Please refer to IaaAgc_Run example.

3. APC DATA TYPE

3.1. APC data type list

Data type Definition
AudioApcBufferConfig The buffer configuration parameter structure type of the Apc algorithm
AudioProcessInit Apc algorithm initialization parameter structure type
APC_HANDLE Apc algorithm handle type
AudioAnrConfig The Anr configuration parameter structure type of the Apc algorithm
AudioEqConfig The Eq configuration parameter structure type of the Apc algorithm
AudioHpfConfig The Hpf configuration parameter structure type of the Apc algorithm
AudioAgcConfig The Agc configuration parameter structure type of the Apc algorithm
AgcGainInfo Agc gain parameter structure type in Apc algorithm
IAA_APC_SAMPLE_RATE Define the sampling rate type in the Apc algorithm
NR_CONVERGE_SPEED Anr algorithm convergence speed type
IAA_HPF_FREQ Hpf algorithm cut-off frequency type
ANR_HANDLE Anr algorithm handle type
EQ_HANDLE Eq algorithm handle type
AGC_HANDLE Agc algorithm handle type

3.2. AudioApcBufferConfig

  • Description

    Define the buffer configuration parameter structure type of the Apc algorithm.

  • Definition

    typedef struct{

    unsigned int anr_enable;

    unsigned int eq_enable;

    unsigned int dr_enable;

    unsigned int vad_enable;

    unsigned int agc_enable;

}AudioApcBufferConfig;

  • Member

    Member name Description
    anr_enable The Anr enable option in the Apc algorithm is used to assist in calculating the memory size required for Apc algorithm running.
    eq_enable The Eq enable option in the Apc algorithm is used to assist in calculating the memory size required for Apc algorithm running.
    dr_enable Algorithm is being developed
    vad_enable Vad algorithm has established a separate module, Vad is currently disabled in APC, it is recommended to close
    agc_enable The Agc enable option in the Apc algorithm is used to assist in calculating the memory size required for Apc algorithm running.

  • Related data types and interfaces

    IaaApc_GetBufferSize

    IaaApc_Init

    IaaApc_Reset

3.3. AudioProcessInit

  • Description

    Define Apc(Anr/Eq/Hpf/Agc) algorithm initialization parameter structure type.

  • Definition

    typedef struct {

    unsigned int point_number;

    unsigned int channel;

    IAA_APC_SAMPLE_RATE sample_rate;

}AudioProcessInit;

  • Member

    Member name Description
    point_number The amount of data processed by the algorithm once (that is, how many sampling points are in a frame), the value is 128 or 256, and how many short values need to be given to Apc is determined by chip. Value range: 128 or 256
    channel The channel numbers of data. If it is a dual channel, the data given to Apc in each frame is twice the point_number.
    sample_rate Data sampling frequency

  • Related data types and interfaces

    IaaApc_Init

    IaaApc_Reset

    IaaApc_GetConfig

    IaaAnr_Init

    IaaAnr_Reset

    IaaAnr_GetConfig

    IaaEq_Init

    IaaEq_Reset

    IaaEq_GetConfig

    IaaAgc_Init

    IaaAgc_Reset

    IaaAgc_GetConfig

3.4. APC_HANDLE

3.5. AudioAnrConfig

  • Description

    Define the Anr configuration parameter structure type of the Apc algorithm.

  • Definition

    typedef struct{

    unsigned int anr_enable;

    unsigned int user_mode;

    int anr_intensity_band[6];

    int anr_intensity[7];

    unsigned int anr_smooth_level;

    NR_CONVERGE_SPEED anr_converge_speed;

}AudioAnrConfig;

  • Member

    Member name Description
    anr_enable Whether to enable Anr algorithm
    user_mode Anr algorithm running mode
    anr_intensity_band ANR frequency range Range [1,127]; step size 1
    anr_intensity ANR intensity, the larger the value, the higher the ANR intensity, but at the same time it will also bring about the loss/damage of details. The recommended value is 10. Range [0,30]; step size 1
    anr_smooth_level Frequency domain smoothness Recommended value:10 Range [0,10]; step size 1
    anr_converge_speed Noise convergence speed Recommended value: mid Range [low; mid; high]

  • Note

    • When anr_enable is FALSE, other Anr parameters will not work;

    • user_mode specifies the running mode of Anr. 0, means that the Anr algorithm does not use other Anr parameters at all, but uses the internal settings of the Anr algorithm; 1 or 2 means that the Anr parameters under the application are completely used.

    • anr_intensity_band, ANR frequency range, the latter element must be greater than or equal to the first element.

      For example: u32NrIntensityBand[0]= 10, then: u32NrIntensityBand[1] must be greater than or equal to 10.

      The highest frequency corresponding to the current sampling rate is divided into 128 parts on average, and the frequency range corresponds to how many parts form a frequency band.

      For example: the current sampling rate is 16K, the corresponding maximum frequency is 8K, each one is 8000 / 128 ≈ 62.5Hz. Under the setting of {4,6,36, 49,50,51}, the ANR frequency range is {0~4 * 62.5Hz, 4~6 * 62.5Hz, 6~36 * 62.5Hz, 36~49 * 62.5Hz, 49~50 * 62.5Hz, 50~51 * 62.5Hz, 51-127 * 62.5Hz} = {0~250Hz, 250~375Hz, 375~2250Hz, 2250~3062.5Hz, 3062.5~3125Hz, 3125~3187.5Hz, 3187.5Hz~8000Hz}，anr_intensity is the ANR intensity, According to the frequency band division of anr_intensity_band, different parameters are set for the noise situation of each frequency band.

    • anr_smooth_level, the smoothness of Anr algorithm the frequency domain procession, avoid excessively large suppression gaps between adjacent frequencies during noise estimation, resulting in sound damage.

    • anr_converge_speed，Anr algorithm convergence speed, noise update speed, the faster the setting, the faster the ANR will converge, but the details will be lost/damaged.

  • Related data types and interfaces

    IaaApc_Config

    IaaApc_GetConfig

    IaaAnr_Config

    IaaAnr_GetConfig

3.6. AudioEqConfig

  • Description

    Define the Eq configuration parameter structure type of the Apc algorithm.

  • Definition

    typedef struct{

    unsigned int eq_enable;

    unsigned int user_mode;

    short eq_gain_db[129];

}AudioEqConfig;

  • Member

    Member name Description
    eq_enable Whether to enable Eq algorithm
    user_mode Eq algorithm running mode
    eq_gain_db Eq algorithm gain adjustment value, divide the frequency range of the current sampling rate into 129 frequency ranges for adjustment. Unit: 1dB Range [-50,20]; step size 1

  • Note

    • When eq_enable is FALSE, other Eq parameters will not work;

    • user_mode specifies the running mode of Eq. 0, means Eq uses the preset parameters which are all 0, without any gain or attenuation; 1 means that the Eq parameters under the application are completely used.

    • eq_gain_db is the table for gain adjustment, divide the frequency range of the current sampling rate into 129 frequency ranges for adjustment. For example: the current sampling rate is 16K, the corresponding highest frequency is 8K, 8000 / 129 ≈ 62Hz, the frequency range of a single adjustment is 62Hz, and 0-8K is divided into {0-1 * 62Hz，1-2 * 62Hz，2-3 * 62Hz，…，128-129 * 62Hz} = {0-62Hz，62-124Hz，124-186Hz，…，7938-8000Hz}, each segment corresponds to a gain value.

  • Related data types and interfaces

    IaaApc_Config

    IaaApc_GetConfig

    IaaEq_Config

    IaaEq_GetConfig

3.7. AudioHpfConfig

  • Description

    Define the Hpf configuration parameter structure type of the Apc algorithm.

  • Definition

    typedef struct{

    unsigned int hpf_enable;

    unsigned int user_mode;

    IAA_HPF_FREQ cutoff_frequency;

}AudioHpfConfig;

  • Member

    Member name Description
    hpf_enable Whether to enable Hpf algorithm
    user_mode Hpf algorithm running mode
    cutoff_frequency Hpf cutoff frequency Range: [80,120,150]

  • Note

    • When hpf_enable is FALSE, other Hpf parameters will not work;

    • user_mode specifies the running mode of Hpf. 0, means Eq uses the preset parameters, without any gain or attenuation; 1 means that the Hpf parameters under the application are completely used.

    • cutoff_frequency is the cutoff frequency of Hpf, signals below this frequency will be filtered out.

  • Related data types and interfaces

    IaaApc_Config

    IaaApc_GetConfig

    IaaEq_Config

    IaaEq_GetConfig

3.8. AudioAgcConfig

  • Description

    Define the Agc configuration parameter structure type of the Apc algorithm.

  • Definition

    typedef struct

{

    unsigned int agc_enable;

    unsigned int user_mode;

    //gain setting

    AgcGainInfo gain_info;

    unsigned int drop_gain_max;

    //attack time, release time

    unsigned int attack_time;

    unsigned int release_time;

    //target level

    short compression_ratio_input[7];

    short compression_ratio_output[7];

    int drop_gain_threshold;

    // noise gate

    int noise_gate_db;

    unsigned int noise_gate_attenuation_db;

    unsigned int gain_step;

}AudioAgcConfig;

  • Member

    Member name Description
    agc_enable Whether to enable Agc algorithm
    user_mode Agc algorithm running mode
    gain_info The Agc algorithm gain information, which defines the maximum, minimum and initial values of the AGC gain
    drop_gain_max The maximum value of instantaneous gain drop, prevent output saturation. If the output plus the current Gain exceeds the dB value set by drop_gain_threshold, Agc will instantly reduce the Gain to prevent the peak value of the current signal from exceeding drop_gain_threshold. Range: [0,60]; Step size: 1 Note：This value only represents the range that can be lowered, but the specific value that can be lowered depends on the minimum value of the AGC gain.
    attack_time Time step for gain reduction, take 4 milliseconds as 1 unit, if set to 2, it will judge whether to increase Gain every 8 milliseconds. Range: [1,20]; step size: 1
    release_time Time step for gain increase, take 4 milliseconds as 1 unit, if set to 2, it will judge whether to increase Gain every 8 milliseconds Range: [1,20]; step size: 1
    compression_ratio_input Use with compression_ratio_output, realize the curve with multiple slopes through multiple turning points to get the relationship between input power level and output power level. Range: [-80,0]dBFS; step size: 1
    compression_ratio_output Use with compression_ratio_input, realize the curve with multiple slopes through multiple turning points to get the relationship between input power level and output power level. Range: [-80,0]dBFS; step size: 1
    drop_gain_threshold Attenuation threshold, When the signal peak amplitude exceeds this value, it will attenuate instantly, and the attenuation amplitude is limited by drop_gain_max and gain_info. Range: [-80,0]dB; step size: 1
    noise_gate_db Noise threshold, when the signal is less than this value, treat it as noise. Case1: If you set noise_gate_db from -80 to 0, the current gain value will converge to 0 according to the release/attack time. Case2: If you set noise_gate_db from 1 to 80, when the signal is less than this value, the Gain value will not be changed, and keep the Gain value of the previous frame Range: [-80,80] ; step size: 1
    noise_gate_attenuation_db When the noise threshold is effective, it is input source attenuation percentage. Range: [0,100] ; step size: 1
    gain_step The speed of applying gain is 0.5dB as a unit. If it is set to 1, then ±0.5dB is applied per frame according to requirements. The higher the value, the faster the speed of increasing and decreasing the volume. Range: [1,10] ; step size: 1

  • Note

    • When agc_enable is FALSE, other Agc parameters will not work;

    • user_mode specifies the running mode of Agc. 0, means that the Agc algorithm does not use other Agc parameters at all, but uses the internal settings of the Agc algorithm; 1 means that the Agc parameters under the application are completely used.

    • Compression ratio Curve defines the relationship between InputOutput energy. By setting seven points, six different slope transitions can be obtained. For example, the parameters are set as follows:

      compression_ratio_input[7] = {-80, -60, -50,-40,-30,-12,0}

      compression_ratio_output[7] = {-80, -45, -36, -27, -18, -9, -6}

      The curve is shown in the figure below.

      If you don’t need so many different slopes, you can set the last compression ratio parameter to 0, as follows:

      compression_ratio_input[7] = {-70, -60, -30, 0,0,0,0};

      compression_ratio_output[7] = {-60, -50, -10, -3, 0,0,0};

    • There are two modes for the noise gate setting, which can converge Gain to 0 or keep it unchanged. Convergence to 0 can prevent signals smaller than the noise gate from being amplified, maintain noise stability, and maintain the Gain value unchanged to avoid the "breathing phenomenon" where the beginning and end of the voice disappear.

  • Related data types and interfaces

    IaaApc_Config

    IaaApc_GetConfig

    IaaAgc_Config

    IaaAgc_GetConfig

3.9. AgcGainInfo

  • Description

    Define Agc gain parameter structure type in Apc algorithm.

  • Definition

    typedef struct

{

    int gain_max; //gain maximum

    int gain_min; //gain minimum

    int gain_init; //default gain (initial gain)

}AgcGainInfo;

  • Member

    Member name Description
    gain_max Maximum gain Range: [0,60]; step size: 1
    gain_min Minimum gain Range: [-20,30] ; step size: 1
    gain_init Gain initial value Range: [-20,60] ; step size: 1

  • Related data types and interfaces

    AudioAgcConfig

3.10. IAA_APC_SAMPLE_RATE

  • Description

    Define the sampling rate type in the Apc algorithm.

  • Definition

    typedef enum {

    IAA_APC_SAMPLE_RATE_8000 = 8000 ,

    IAA_APC_SAMPLE_RATE_16000 = 16000 ,

    IAA_APC_SAMPLE_RATE_48000 = 48000 ,

}IAA_APC_SAMPLE_RATE;

  • Member

    Member name Description
    IAA_APC_SAMPLE_RATE_8000 8K sampling rate
    IAA_APC_SAMPLE_RATE_16000 16K sampling rate
    IAA_APC_SAMPLE_RATE_48000 48K sampling rate

  • Related data types and interfaces

    AudioProcessInit

3.11. NR_CONVERGE_SPEED

  • Description

    Define Anr algorithm convergence speed type.

  • Definition

    typedef enum {

    NR_SPEED_LOW,

    NR_SPEED_MID,

    NR_SPEED_HIGH

} NR_CONVERGE_SPEED;

  • Member

    Member name Description
    NR_SPEED_LOW Low speed
    NR_SPEED_MID Medium speed
    NR_SPEED_HIGH High speed

  • Note

    • Low/medium/high NR convergence speed represents 3/2/1 frame update once noise suppression

  • Related data types and interfaces

    AudioAnrConfig

3.12. IAA_HPF_FREQ

  • Description

    Define Hpf algorithm cut-off frequency type.

  • Definition

    typedef enum {

    AUDIO_HPF_FREQ_80 , /* 80Hz*/

    AUDIO_HPF_FREQ_120, /*120Hz*/

    AUDIO_HPF_FREQ_150, /*150Hz*/

    AUDIO_HPF_FREQ_BUTT,

}IAA_HPF_FREQ;

  • Member

    Member name Description
    AUDIO_HPF_FREQ_80 80Hz
    AUDIO_HPF_FREQ_120 120Hz
    AUDIO_HPF_FREQ_150 150Hz
    AUDIO_HPF_FREQ_BUTT

  • Related data types and interfaces

    AudioHpfConfig

3.13. ANR_HANDLE

3.14. EQ_HANDLE

3.15. AGC_HANDLE

4. Error code

APC API error codes are shown as follow:

Error code Definition Description
0x00000000 ALGO_APC_RET_SUCCESS APC run successful
0x10000501 ALGO_APC_RET_INIT_ERROR APC not initialized
0x10000502 ALGO_APC_RET_INVALID_HANDLE HANDLE invalid
0x10000503 ALGO_APC_RET_INVALID_SAMPLE_RATE Sampling frequency is not supported
0x10000504 ALGO_APC_RET_INVALID_POINT_NUMBER Points per frame not supported
0x10000505 ALGO_APC_RET_INVALID_CHANNEL Channel number doesn`t support
0x10000506 ALGO_APC_ANR_RET_INVALID_ENABLE ANR switch parameter setting is invalid
0x10000507 ALGO_APC_ANR_RET_INVALID_MODE ANR mode parameter setting is invalid
0x10000508 ALGO_APC_ANR_RET_INVALID_INTENSITY ANR intensive parameter setting is invalid
0x10000509 ALGO_APC_ANR_RET_INVALID_SMOOTH_LEVEL ANR smoothing parameter setting is invalid
0x10000510 ALGO_APC_ANR_RET_INVALID_COVERGE_SPEED ANR convergence rate parameter setting is invalid
0x10000511 ALGO_APC_EQ_RET_INVALID_ENABLE EQ switch parameter setting is invalid
0x10000512 ALGO_APC_EQ_RET_INVALID_MODE EQ mode parameter setting is invalid
0x10000513 ALGO_APC_EQ_RET_INVALID_TABLE EQ parameter setting is invalid
0x10000514 ALGO_APC_HPF_RET_INVALID_ENABLE HPF switch parameter setting is invalid
0x10000515 ALGO_APC_HPF_RET_INVALID_MODE HPF mode parameter setting is invalid
0x10000516 ALGO_APC_HPF_RET_INVALID_TABLE HPF parameter setting is invalid
0x10000517 ALGO_APC_AGC_RET_INVALID_ENABLE AGC switch parameter setting is invalid
0x10000518 ALGO_APC_AGC_RET_INVALID_MODE AGC mode parameter setting is invalid
0x10000519 ALGO_APC_AGC_RET_INVALID_COMPRESSION_RATIO AGC compression curve parameter setting is invalid
0x10000520 ALGO_APC_AGC_RET_INVALID_DROP_GAIN_MAX AGC anti-saturation parameter setting is invalid
0x10000521 ALGO_APC_AGC_RET_INVALID_GAIN_STEP AGC gain step parameter setting is invalid
0x10000522 ALGO_APC_AGC_RET_INVALID_RELEASE_TIME AGC recovery time parameter setting is invalid
0x10000523 ALGO_APC_AGC_RET_INVALID_ATTACK_TIME AGC subtracted time parameter setting is invalid
0x10000524 ALGO_APC_AGC_RET_INVALID_NOISE_GATE AGC noise threshold parameter setting is invalid
0x10000525 ALGO_APC_AGC_RET_INVALID_NOISE_ATTENU AGC noise attenuation setting is invalid
0x10000526 ALGO_APC_AGC_RET_INVALID_DROP_GAIN_LEVEL AGC anti-saturation threshold parameter setting is invalid
0x10000527 ALGO_APC_AGC_RET_INVALID_GAIN_INFO AGC gain control parameter setting is invalid
0x10000528 ALGO_APC_RET_API_CONFLICT Other APIs are running
0x10000529 ALGO_APC_RET_INVALID_CALLING Incorrect order of calling API
0x10000530 ALGO_APC_RET_FAILED Parameter setting error