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/**
******************************************************************************
* @file Audio/Audio_playback_and_record/Src/waverecorder.c
* @author MCD Application Team
* @brief This file provides the Audio In (record) interface API
******************************************************************************
* @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 "waverecorder.h"
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
uint8_t pHeaderBuff[44];
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
static AUDIO_IN_BufferTypeDef BufferCtl;
extern WAVE_FormatTypeDef WaveFormat;
/* Private function prototypes -----------------------------------------------*/
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);
/* Private functions ---------------------------------------------------------*/
/*
A double MEMS microphone MP45DT02 mounted on STM324X9I-EVAL 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
microphones 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 DMA mode.
DMA is configured in circular mode
In order to avoid data-loss, a 128 bytes buffer is used (BufferCtl.pdm_buff):
- When a DMA half transfer is detected using the call back BSP_AUDIO_IN_HalfTransfer_CallBack()
PDM frame has been received (64 bytes), a conversion to PCM is done
and then this PCM frame is saved in RecBuf.
- After converting/filtering samples from PDM to PCM, the samples are stored in USB buffer.
- These two steps are repeated when the DMA Transfer complete interrupt is detected
- When half of internal USB buffer is reach, an evacuation though USB is done.
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;
- The processing time of converting/filtering samples from PDM to PCM
PDM_Filter_64_LSB()) should be lower than the time required to fill a
single buffer.
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 Starts Audio streaming.
* @param None
* @retval Audio error
*/
AUDIO_ErrorTypeDef AUDIO_REC_Start(void)
{
uint32_t byteswritten = 0;
uint8_t str[FILEMGR_FILE_NAME_SIZE + 20];
/* Create a new file system */
if(f_open(&WavFile, REC_WAVE_NAME, FA_CREATE_ALWAYS | FA_WRITE) == FR_OK)
{
/* Initialize header file */
WavProcess_EncInit(DEFAULT_AUDIO_IN_FREQ, pHeaderBuff);
/* Write header file */
if(f_write(&WavFile, pHeaderBuff, 44, (void*)&byteswritten) == FR_OK)
{
AudioState = AUDIO_STATE_RECORD;
BSP_LCD_SetTextColor(LCD_COLOR_WHITE);
sprintf((char *)str, "Recording file: %s",
(char *)REC_WAVE_NAME);
BSP_LCD_ClearStringLine(4);
BSP_LCD_DisplayStringAtLine(4, str);
BSP_LCD_SetTextColor(LCD_COLOR_CYAN);
sprintf((char *)str, "Sample rate : %d Hz", (int)DEFAULT_AUDIO_IN_FREQ);
BSP_LCD_ClearStringLine(6);
BSP_LCD_DisplayStringAtLine(6, str);
sprintf((char *)str, "Channels number : %d", (int)DEFAULT_AUDIO_IN_CHANNEL_NBR);
BSP_LCD_ClearStringLine(7);
BSP_LCD_DisplayStringAtLine(7, str);
sprintf((char *)str, "File Size :");
BSP_LCD_ClearStringLine(8);
BSP_LCD_DisplayStringAtLine(8, str);
BSP_LCD_DisplayStringAt(250, LINE(14), (uint8_t *)" [RECORD]", LEFT_MODE);
{
if(byteswritten != 0)
{
BSP_AUDIO_IN_Init(DEFAULT_AUDIO_IN_FREQ, DEFAULT_AUDIO_IN_BIT_RESOLUTION, DEFAULT_AUDIO_IN_CHANNEL_NBR);
BSP_AUDIO_IN_Record((uint16_t*)&BufferCtl.pdm_buff[0], AUDIO_IN_PDM_BUFFER_SIZE);
BufferCtl.fptr = byteswritten;
BufferCtl.pcm_ptr = 0;
BufferCtl.offset = 0;
BufferCtl.wr_state = BUFFER_EMPTY;
return AUDIO_ERROR_NONE;
}
}
}
}
return AUDIO_ERROR_IO;
}
/**
* @brief Manages Audio process.
* @param None
* @retval Audio error
*/
AUDIO_ErrorTypeDef AUDIO_REC_Process(void)
{
uint32_t byteswritten = 0;
AUDIO_ErrorTypeDef audio_error = AUDIO_ERROR_NONE;
uint32_t elapsed_time;
static uint32_t prev_elapsed_time = 0xFFFFFFFF;
uint8_t str[16];
switch(AudioState)
{
case AUDIO_STATE_RECORD:
/* MAX Recording time reached, so stop audio interface and close file */
if(BufferCtl.fptr >= REC_SAMPLE_LENGTH)
{
AudioState = AUDIO_STATE_STOP;
break;
}
/* Check if there are Data to write in Usb Key */
if(BufferCtl.wr_state == BUFFER_FULL)
{
/* write buffer in file */
if(f_write(&WavFile, (uint8_t*)(BufferCtl.pcm_buff + BufferCtl.offset),
AUDIO_IN_PCM_BUFFER_SIZE,
(void*)&byteswritten) != FR_OK)
{
BSP_LCD_SetTextColor(LCD_COLOR_RED);
BSP_LCD_DisplayStringAtLine(16, (uint8_t *)"RECORD FAIL");
return AUDIO_ERROR_IO;
}
BufferCtl.fptr += byteswritten;
BufferCtl.wr_state = BUFFER_EMPTY;
}
/* Display elapsed time */
elapsed_time = BufferCtl.fptr / (DEFAULT_AUDIO_IN_FREQ * DEFAULT_AUDIO_IN_CHANNEL_NBR * 2);
if(prev_elapsed_time != elapsed_time)
{
prev_elapsed_time = elapsed_time;
sprintf((char *)str, "[%02d:%02d]", (int)(elapsed_time /60), (int)(elapsed_time%60));
BSP_LCD_SetTextColor(LCD_COLOR_CYAN);
BSP_LCD_DisplayStringAt(263, LINE(8), str, LEFT_MODE);
sprintf((char *)str, "%4d KB", (int)((int32_t)BufferCtl.fptr/1024));
BSP_LCD_DisplayStringAt(83, LINE(8), str, LEFT_MODE);
}
break;
case AUDIO_STATE_STOP:
/* Stop recorder */
BSP_AUDIO_IN_Stop();
if(f_lseek(&WavFile, 0) == FR_OK)
{
/* Update the wav file header save it into wav file */
WavProcess_HeaderUpdate(pHeaderBuff, &WaveFormat);
if(f_write(&WavFile, pHeaderBuff, sizeof(WAVE_FormatTypeDef), (void*)&byteswritten) == FR_OK)
{
audio_error = AUDIO_ERROR_EOF;
}
else
{
audio_error = AUDIO_ERROR_IO;
BSP_LCD_SetTextColor(LCD_COLOR_RED);
BSP_LCD_DisplayStringAtLine(16, (uint8_t *)"RECORD FAIL");
}
}
else
{
BSP_LCD_SetTextColor(LCD_COLOR_RED);
BSP_LCD_DisplayStringAtLine(16, (uint8_t *)"RECORD FAIL");
audio_error = AUDIO_ERROR_IO;
}
AudioState = AUDIO_STATE_IDLE;
/* Close file */
f_close(&WavFile);
break;
case AUDIO_STATE_PAUSE:
BSP_LCD_DisplayStringAt(250, LINE(14), (uint8_t *)" [PAUSE] ", LEFT_MODE);
BSP_AUDIO_IN_Pause();
AudioState = AUDIO_STATE_WAIT;
break;
case AUDIO_STATE_RESUME:
BSP_LCD_DisplayStringAt(250, LINE(14), (uint8_t *)" [RECORD] ", LEFT_MODE);
BSP_AUDIO_IN_Resume();
AudioState = AUDIO_STATE_RECORD;
break;
case AUDIO_STATE_VOLUME_UP:
if(AudioInVolume <= 90)
{
AudioInVolume += 10;
}
BSP_AUDIO_IN_SetVolume(AudioInVolume);
AudioState = AUDIO_STATE_RECORD;
break;
case AUDIO_STATE_VOLUME_DOWN:
if(AudioInVolume >= 10)
{
AudioInVolume -= 10;
}
BSP_AUDIO_IN_SetVolume(AudioInVolume);
AudioState = AUDIO_STATE_RECORD;
break;
case AUDIO_STATE_NEXT:
case AUDIO_STATE_PREVIOUS:
AudioState = AUDIO_STATE_RECORD;
break;
case AUDIO_STATE_WAIT:
case AUDIO_STATE_IDLE:
case AUDIO_STATE_INIT:
default:
/* Do Nothing */
break;
}
return audio_error;
}
/**
* @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*)&BufferCtl.pdm_buff[AUDIO_IN_PDM_BUFFER_SIZE/2],
&BufferCtl.pcm_buff[BufferCtl.pcm_ptr]);
BufferCtl.pcm_ptr+= AUDIO_IN_PDM_BUFFER_SIZE/4/2;
if(BufferCtl.pcm_ptr == AUDIO_IN_PCM_BUFFER_SIZE/2)
{
BufferCtl.wr_state = BUFFER_FULL;
BufferCtl.offset = 0;
}
if(BufferCtl.pcm_ptr >= AUDIO_IN_PCM_BUFFER_SIZE)
{
BufferCtl.wr_state = BUFFER_FULL;
BufferCtl.offset = AUDIO_IN_PCM_BUFFER_SIZE/2;
BufferCtl.pcm_ptr = 0;
}
}
/**
* @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*)&BufferCtl.pdm_buff[0],
&BufferCtl.pcm_buff[BufferCtl.pcm_ptr]);
BufferCtl.pcm_ptr+= AUDIO_IN_PDM_BUFFER_SIZE/4/2;
if(BufferCtl.pcm_ptr == AUDIO_IN_PCM_BUFFER_SIZE/2)
{
BufferCtl.wr_state = BUFFER_FULL;
BufferCtl.offset = 0;
}
if(BufferCtl.pcm_ptr >= AUDIO_IN_PCM_BUFFER_SIZE)
{
BufferCtl.wr_state = BUFFER_FULL;
BufferCtl.offset = AUDIO_IN_PCM_BUFFER_SIZE/2;
BufferCtl.pcm_ptr = 0;
}
}
/*******************************************************************************
Static Functions
*******************************************************************************/
/**
* @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 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 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;
}