73 lines
2.8 KiB
C
73 lines
2.8 KiB
C
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/**
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******************************************************************************
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* @file pdm_filter.h
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* @author MCD Application Team
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* @version V1.1.1
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* @date 14-May-2012
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* @brief Header file for PDM audio software decoding Library.
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* This Library is used to decode and reconstruct the audio signal
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* produced by MP45DT02 MEMS microphone from STMicroelectronics.
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* For more details about this Library, please refer to document
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* "PDM audio software decoding on STM32 microcontrollers (AN3998)".
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******************************************************************************
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* @attention
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*
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* <h2><center>© COPYRIGHT 2012 STMicroelectronics</center></h2>
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*
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* Licensed under MCD-ST Image SW License Agreement V2, (the "License");
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* You may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.st.com/software_license_agreement_image_v2
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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******************************************************************************
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*/
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/* Define to prevent recursive inclusion -------------------------------------*/
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#ifndef __PDM_FILTER_H
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#define __PDM_FILTER_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* Includes ------------------------------------------------------------------*/
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#include <stdint.h>
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/* Exported types ------------------------------------------------------------*/
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typedef struct {
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uint16_t Fs;
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float LP_HZ;
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float HP_HZ;
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uint16_t In_MicChannels;
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uint16_t Out_MicChannels;
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char InternalFilter[34];
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} PDMFilter_InitStruct;
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/* Exported constants --------------------------------------------------------*/
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/* Exported macros -----------------------------------------------------------*/
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#define HTONS(A) ((((u16)(A) & 0xff00) >> 8) | \
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(((u16)(A) & 0x00ff) << 8))
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/* Exported functions ------------------------------------------------------- */
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void PDM_Filter_Init(PDMFilter_InitStruct * Filter);
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int32_t PDM_Filter_64_MSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
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int32_t PDM_Filter_80_MSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
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int32_t PDM_Filter_64_LSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
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int32_t PDM_Filter_80_LSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
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#ifdef __cplusplus
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}
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#endif
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#endif /* __PDM_FILTER_H */
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/*******************(C)COPYRIGHT 2011 STMicroelectronics *****END OF FILE******/
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