Microphone module header. More...

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Macros
#define	ERR_OPEN 12

#define	ERR_READ 15

Functions
int	startRecording ()
	Records a 2 second .wav audio from microphone. More...

int	processAudio (double *loudness)
	Processes the audio to check whether the baby is crying. More...

Detailed Description

Microphone module header.

Author: José Carvalho, João Carneiro

Date: 2022-01-13

Copyright: Copyright (c) 2022

Definition in file microphone.h.

Macro Definition Documentation

◆ ERR_OPEN

#define ERR_OPEN 12

Error when opening audio file

Definition at line 13 of file microphone.h.

◆ ERR_READ

#define ERR_READ 15

Error when reading audio file

Definition at line 14 of file microphone.h.

Function Documentation

◆ processAudio()

int processAudio ( double * loudness )

Processes the audio to check whether the baby is crying.

The loudness of the audio samples is calculated and, if the predefined threshold is passed, a counter is incremented. At 3 consecutive samples that have breached the threshold, it is considered that the baby is crying.

Returns: int

Definition at line 73 of file microphone.c.

◆ startRecording()

int startRecording ( )

Records a 2 second .wav audio from microphone.

Recording is possible by using FFmpeg. The parameters used are: -f alsa : force audio input device to be of ALSA -ac 1 : set audio channel to 1 -ar 44100 : set audio sampling rate to 44100 Hz -i plughw:0,0 : select the audio card referencing the microphone -c:a copy : set audio codec to copy (copies the frames directly instead of decoding/filtering/encoding) -t 2 : recording duration -y : overwrite output files audiorecord.wav output file

Returns: int

Definition at line 18 of file microphone.c.

Macros