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/**
******************************************************************************
* @file Audio_playback_and_record/Src/waverecorder.c
* @author MCD Application Team
* @brief I2S Audio recorder program.
******************************************************************************
* @attention
*
* Copyright (c) 2017 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "waverecorder.h"
#include "string.h"
/** @addtogroup STM32F4-Discovery_Audio_Player_Recorder
* @{
*/
/* Private typedef -----------------------------------------------------------*/
typedef struct {
int32_t offset;
uint32_t fptr;
}Audio_BufferTypeDef;
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Wave recorded counter.*/
__IO uint32_t WaveCounter = 0;
extern __IO uint32_t CmdIndex, LEDsState, TimeRecBase;
FIL WavFile;
/* USB variable to check if USB connected or not*/
extern MSC_ApplicationTypeDef AppliState;
/* Variable used to switch play from audio sample available on USB to recorded file*/
uint32_t WaveRecStatus = 0;
uint8_t pHeaderBuff[44];
uint16_t WrBuffer[WR_BUFFER_SIZE];
static uint16_t RecBuf[PCM_OUT_SIZE*2];/* PCM stereo samples are saved in RecBuf */
static uint16_t InternalBuffer[INTERNAL_BUFF_SIZE];
__IO uint32_t ITCounter = 0;
Audio_BufferTypeDef BufferCtl;
/* Temporary data sample */
__IO uint32_t AUDIODataReady = 0, AUDIOBuffOffset = 0;
WAVE_FormatTypeDef WaveFormat;
__IO FRESULT res;
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
static uint32_t WavProcess_EncInit(uint32_t Freq, uint8_t* pHeader);
static uint32_t WavProcess_HeaderInit(uint8_t* pHeader, WAVE_FormatTypeDef* pWaveFormatStruct);
static uint32_t WavProcess_HeaderUpdate(uint8_t* pHeader, WAVE_FormatTypeDef* pWaveFormatStruct);
/*
A single MEMS microphone MP45DT02 mounted on STM32F4-Discovery is connected
to the Inter-IC Sound (I2S) peripheral. The I2S is configured in master
receiver mode. In this mode, the I2S peripheral provides the clock to the MEMS
microphone through CLK_IN and acquires the data (Audio samples) from the MEMS
microphone through PDM_OUT.
Data acquisition is performed in 16-bit PDM format and using I2S IT mode.
In order to avoid data-loss, two buffers are used:
- When there are enough data to be transmitted to USB, there is a buffer reception
switch.
To avoid data-loss:
- IT ISR priority must be set at a higher priority than USB, this priority
order must be respected when managing other interrupts;
Note that a PDM Audio software decoding library provided in binary is used in
this application. For IAR EWARM toolchain, the library is labeled
"libPDMFilter_CM4_IAR.a".
*/
/**
* @brief Start Audio recording.
* @param pbuf: pointer to a buffer
* size: Buffer size
* @retval None
*/
uint8_t WaveRecorderStart(uint16_t* pBuf, uint32_t wSize)
{
return (BSP_AUDIO_IN_Record(pBuf, wSize));
}
/**
* @brief Stop Audio recording.
* @param None
* @retval None
*/
uint32_t WaveRecorderStop(void)
{
return BSP_AUDIO_IN_Stop();
}
/**
* @brief Update the recorded data.
* @param None
* @retval None
*/
void WaveRecorderProcess(void)
{
/* Current size of the recorded buffer */
uint32_t byteswritten = 0;
WaveCounter = 0;
LEDsState = LEDS_OFF;
/* Remove Wave file if it exists on USB Flash Disk */
f_unlink(REC_WAVE_NAME);
/* Open the file to write on it */
if((AppliState == APPLICATION_IDLE) || (f_open(&WavFile, REC_WAVE_NAME, FA_CREATE_ALWAYS | FA_WRITE) != FR_OK))
{
while(1)
{
/* Toggle LED5 in infinite loop to signal that: USB Flash Disk is not connected/removed
or an issue has occurred when creating/opening Wave file */
BSP_LED_Toggle(LED5);
}
}
else
{
WaveRecStatus = 1;
}
/* Initialize header file */
WavProcess_EncInit(DEFAULT_AUDIO_IN_FREQ, pHeaderBuff);
/* Write the header Wave */
f_write(&WavFile, pHeaderBuff, 44, (void *)&byteswritten);
/* Increment the Wave counter */
BufferCtl.fptr = byteswritten;
BufferCtl.offset = BUFFER_OFFSET_NONE;
BSP_AUDIO_IN_Init(DEFAULT_AUDIO_IN_FREQ, DEFAULT_AUDIO_IN_BIT_RESOLUTION, DEFAULT_AUDIO_IN_CHANNEL_NBR);
BSP_AUDIO_IN_Record((uint16_t*)&InternalBuffer[0], INTERNAL_BUFF_SIZE);
/* Reset the time recording base variable */
TimeRecBase = 0;
ITCounter = 0;
LEDsState = LED3_TOGGLE;
while(AppliState != APPLICATION_IDLE)
{
/* Wait for the recording time */
if(TimeRecBase <= DEFAULT_TIME_REC)
{
/* Check if there are Data to write in Usb Key */
if(AUDIODataReady == 1)
{
/* write buffer in file */
res = f_write(&WavFile, (uint8_t*)(WrBuffer+AUDIOBuffOffset), WR_BUFFER_SIZE, (void*)&byteswritten);
if(res != FR_OK)
{
Error_Handler();
}
BufferCtl.fptr += byteswritten;
AUDIODataReady = 0;
}
/* User button pressed */
if(CmdIndex != CMD_RECORD)
{
/* Stop Audio Recording */
WaveRecorderStop();
/* Switch Command Index to Play */
CmdIndex = CMD_PLAY;
/* Toggoling LED6 to signal Play */
LEDsState = LED6_TOGGLE;
break;
}
}
else /* End of recording time DEFAULT_TIME_REC */
{
/* Stop Audio Recording */
WaveRecorderStop();
/* Change Command Index to Stop */
CmdIndex = CMD_STOP;
/* Toggoling LED4 to signal Stop */
LEDsState = LED4_TOGGLE;
AUDIODataReady = 0;
break;
}
}
/* Update the data length in the header of the recorded Wave */
f_lseek(&WavFile, 0);
/* Parse the wav file header and extract required information */
WavProcess_HeaderUpdate(pHeaderBuff, &WaveFormat);
f_write(&WavFile, pHeaderBuff, 44, (void*)&byteswritten);
/* Close file and unmount MyFilesystem */
f_close (&WavFile);
f_mount(NULL, 0, 1);
/* Change Command Index to Play */
CmdIndex = CMD_PLAY;
}
/**
* @brief Calculates the remaining file size and new position of the pointer.
* @param None
* @retval None
*/
void BSP_AUDIO_IN_TransferComplete_CallBack(void)
{
/* PDM to PCM data convert */
BSP_AUDIO_IN_PDMToPCM((uint16_t*)&InternalBuffer[INTERNAL_BUFF_SIZE/2], (uint16_t*)&RecBuf[0]);
/* Copy PCM data in internal buffer */
memcpy((uint16_t*)&WrBuffer[ITCounter * (PCM_OUT_SIZE*2)], RecBuf, PCM_OUT_SIZE*4);
BufferCtl.offset = BUFFER_OFFSET_NONE;
if(ITCounter == (WR_BUFFER_SIZE/(PCM_OUT_SIZE*4))-1)
{
AUDIODataReady = 1;
AUDIOBuffOffset = 0;
ITCounter++;
}
else if(ITCounter == (WR_BUFFER_SIZE/(PCM_OUT_SIZE*2))-1)
{
AUDIODataReady = 1;
AUDIOBuffOffset = WR_BUFFER_SIZE/2;
ITCounter = 0;
}
else
{
ITCounter++;
}
}
/**
* @brief Manages the DMA Half Transfer complete interrupt.
* @param None
* @retval None
*/
void BSP_AUDIO_IN_HalfTransfer_CallBack(void)
{
/* PDM to PCM data convert */
BSP_AUDIO_IN_PDMToPCM((uint16_t*)&InternalBuffer[0], (uint16_t*)&RecBuf[0]);
/* Copy PCM data in internal buffer */
memcpy((uint16_t*)&WrBuffer[ITCounter * (PCM_OUT_SIZE*2)], RecBuf, PCM_OUT_SIZE*4);
BufferCtl.offset = BUFFER_OFFSET_NONE;
if(ITCounter == (WR_BUFFER_SIZE/(PCM_OUT_SIZE*4))-1)
{
AUDIODataReady = 1;
AUDIOBuffOffset = 0;
ITCounter++;
}
else if(ITCounter == (WR_BUFFER_SIZE/(PCM_OUT_SIZE*2))-1)
{
AUDIODataReady = 1;
AUDIOBuffOffset = WR_BUFFER_SIZE/2;
ITCounter = 0;
}
else
{
ITCounter++;
}
}
/**
* @brief Encoder initialization.
* @param Freq: Sampling frequency.
* @param pHeader: Pointer to the WAV file header to be written.
* @retval 0 if success, !0 else.
*/
static uint32_t WavProcess_EncInit(uint32_t Freq, uint8_t* pHeader)
{
/* Initialize the encoder structure */
WaveFormat.SampleRate = Freq; /* Audio sampling frequency */
WaveFormat.NbrChannels = 2; /* Number of channels: 1:Mono or 2:Stereo */
WaveFormat.BitPerSample = 16; /* Number of bits per sample (16, 24 or 32) */
WaveFormat.FileSize = 0x001D4C00; /* Total length of useful audio data (payload) */
WaveFormat.SubChunk1Size = 44; /* The file header chunk size */
WaveFormat.ByteRate = (WaveFormat.SampleRate * \
(WaveFormat.BitPerSample/8) * \
WaveFormat.NbrChannels); /* Number of bytes per second (sample rate * block align) */
WaveFormat.BlockAlign = WaveFormat.NbrChannels * \
(WaveFormat.BitPerSample/8); /* channels * bits/sample / 8 */
/* Parse the wav file header and extract required information */
if(WavProcess_HeaderInit(pHeader, &WaveFormat))
{
return 1;
}
return 0;
}
/**
* @brief Initialize the wave header file
* @param pHeader: Header Buffer to be filled
* @param pWaveFormatStruct: Pointer to the wave structure to be filled.
* @retval 0 if passed, !0 if failed.
*/
static uint32_t WavProcess_HeaderInit(uint8_t* pHeader, WAVE_FormatTypeDef* pWaveFormatStruct)
{
/* write chunkID, must be 'RIFF' ------------------------------------------*/
pHeader[0] = 'R';
pHeader[1] = 'I';
pHeader[2] = 'F';
pHeader[3] = 'F';
/* Write the file length ---------------------------------------------------*/
/* The sampling time: this value will be be written back at the end of the
recording operation. Example: 661500 Bytes = 0x000A17FC, byte[7]=0x00, byte[4]=0xFC */
pHeader[4] = 0x00;
pHeader[5] = 0x4C;
pHeader[6] = 0x1D;
pHeader[7] = 0x00;
/* Write the file format, must be 'WAVE' -----------------------------------*/
pHeader[8] = 'W';
pHeader[9] = 'A';
pHeader[10] = 'V';
pHeader[11] = 'E';
/* Write the format chunk, must be'fmt ' -----------------------------------*/
pHeader[12] = 'f';
pHeader[13] = 'm';
pHeader[14] = 't';
pHeader[15] = ' ';
/* Write the length of the 'fmt' data, must be 0x10 ------------------------*/
pHeader[16] = 0x10;
pHeader[17] = 0x00;
pHeader[18] = 0x00;
pHeader[19] = 0x00;
/* Write the audio format, must be 0x01 (PCM) ------------------------------*/
pHeader[20] = 0x01;
pHeader[21] = 0x00;
/* Write the number of channels, ie. 0x01 (Mono) ---------------------------*/
pHeader[22] = pWaveFormatStruct->NbrChannels;
pHeader[23] = 0x00;
/* Write the Sample Rate in Hz ---------------------------------------------*/
/* Write Little Endian ie. 8000 = 0x00001F40 => byte[24]=0x40, byte[27]=0x00*/
pHeader[24] = (uint8_t)((pWaveFormatStruct->SampleRate & 0xFF));
pHeader[25] = (uint8_t)((pWaveFormatStruct->SampleRate >> 8) & 0xFF);
pHeader[26] = (uint8_t)((pWaveFormatStruct->SampleRate >> 16) & 0xFF);
pHeader[27] = (uint8_t)((pWaveFormatStruct->SampleRate >> 24) & 0xFF);
/* Write the Byte Rate -----------------------------------------------------*/
pHeader[28] = (uint8_t)((pWaveFormatStruct->ByteRate & 0xFF));
pHeader[29] = (uint8_t)((pWaveFormatStruct->ByteRate >> 8) & 0xFF);
pHeader[30] = (uint8_t)((pWaveFormatStruct->ByteRate >> 16) & 0xFF);
pHeader[31] = (uint8_t)((pWaveFormatStruct->ByteRate >> 24) & 0xFF);
/* Write the block alignment -----------------------------------------------*/
pHeader[32] = pWaveFormatStruct->BlockAlign;
pHeader[33] = 0x00;
/* Write the number of bits per sample -------------------------------------*/
pHeader[34] = pWaveFormatStruct->BitPerSample;
pHeader[35] = 0x00;
/* Write the Data chunk, must be 'data' ------------------------------------*/
pHeader[36] = 'd';
pHeader[37] = 'a';
pHeader[38] = 't';
pHeader[39] = 'a';
/* Write the number of sample data -----------------------------------------*/
/* This variable will be written back at the end of the recording operation */
pHeader[40] = 0x00;
pHeader[41] = 0x4C;
pHeader[42] = 0x1D;
pHeader[43] = 0x00;
/* Return 0 if all operations are OK */
return 0;
}
/**
* @brief Initialize the wave header file
* @param pHeader: Header Buffer to be filled
* @param pWaveFormatStruct: Pointer to the wave structure to be filled.
* @retval 0 if passed, !0 if failed.
*/
static uint32_t WavProcess_HeaderUpdate(uint8_t* pHeader, WAVE_FormatTypeDef* pWaveFormatStruct)
{
/* Write the file length ----------------------------------------------------*/
/* The sampling time: this value will be be written back at the end of the
recording operation. Example: 661500 Bytes = 0x000A17FC, byte[7]=0x00, byte[4]=0xFC */
pHeader[4] = (uint8_t)(BufferCtl.fptr);
pHeader[5] = (uint8_t)(BufferCtl.fptr >> 8);
pHeader[6] = (uint8_t)(BufferCtl.fptr >> 16);
pHeader[7] = (uint8_t)(BufferCtl.fptr >> 24);
/* Write the number of sample data -----------------------------------------*/
/* This variable will be written back at the end of the recording operation */
BufferCtl.fptr -=44;
pHeader[40] = (uint8_t)(BufferCtl.fptr);
pHeader[41] = (uint8_t)(BufferCtl.fptr >> 8);
pHeader[42] = (uint8_t)(BufferCtl.fptr >> 16);
pHeader[43] = (uint8_t)(BufferCtl.fptr >> 24);
/* Return 0 if all operations are OK */
return 0;
}
/**
* @}
*/