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¶

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¶

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¶

• Description

  Apc algorithm handle type.

• Definition

  typedef void* APC_HANDLE;
  

• Related data types and interfaces

  IaaApc_Init

  IaaApc_Config

  IaaApc_GetNrResult

  IaaApc_GetNrEqResult

  IaaApc_Run

  IaaApc_Free

  IaaApc_Reset

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¶

• Description

  Define Anr algorithm handle type.

• Definition

  typedef void* ANR_HANDLE;
  

• Related data types and interfaces

  IaaAnr_Init

  IaaAnr_Config

  IaaAnr_Run

  IaaAnr_Free

  IaaAnr_Reset

  IaaAnr_GetConfig

3.14. EQ_HANDLE¶

• Description

  Define Eq algorithm handle type.

• Definition

  typedef void* EQ_HANDLE;
  

• Related data types and interfaces

  IaaEq_Init

  IaaEq_Config

  IaaEq_Run

  IaaEq_Free

  IaaEq_Reset

  IaaEq_GetConfig

3.15. AGC_HANDLE¶

• Description

  Define Agc algorithm handle type.

• Definition

  typedef void* AGC_HANDLE;

• Related data types and interfaces

  IaaAgc_Init

  IaaAgc_Config

  IaaAgc_Run

  IaaAgc_Free

  IaaAgc_Reset

  IaaAgc_GetConfig

4. Error code¶

APC API error codes are shown as follow: