How to convert audio byte to samples

manpreet Best Answer 3 years ago

This is my struct

/* wave data block header */
typedef struct wavehdr_tag {
    LPSTR       lpData;                 /* pointer to locked data buffer */
    DWORD       dwBufferLength;         /* length of data buffer */
    DWORD       dwBytesRecorded;        /* used for input only */
    DWORD_PTR   dwUser;                 /* for client's use */
    DWORD       dwFlags;                /* assorted flags (see defines) */
    DWORD       dwLoops;                /* loop control counter */
    struct wavehdr_tag FAR *lpNext;     /* reserved for driver */
    DWORD_PTR   reserved;               /* reserved for driver */
} WAVEHDR, *PWAVEHDR, NEAR *NPWAVEHDR, FAR *LPWAVEHDR;

I have this variable WAVEHDR waveHeader;

I record 10 secs from microphone and waveHeader->lpData has my raw recorded data, and waveHeader->dwBytesRecorded is the raw data's length

Now I want to calculate the volume in each second to say which second has highest volume and which one has the lowest.

I know I should sum the absolute values and divide by the number of samples

I used sum += abs(waveHeader->lpData[i]); for i from 0 to length of one secs data, but it doesn't give me a good result

it always gives me the same result for each second, but I am silent in some seconds and speak in some...

I read I have to add samples, not bytes How should I convert waveHeader->lpData[i] to samples?

//len = length of one secs data (waveHeader->dwBytesRecorded/10)
for (int i=0; i<len; i++)
{
    sum += abs(waveHeader->lpData[i]);
}