How to manipulate audio data buffers correctly? - c++

Question

I have implemented recording and playing back audio from a microphone in C++. The next step is to process the audio data for speech recognition. For this I want to write them to large buffers so that there are no word breaks. To do this, I implemented copying to large buffers using the memcpy function. Unfortunately, it doesn't work because only part of words can be recognized. What is my mistake and can this buffer manipulation be done in a more convenient way?
My code:
#include <stdio.h>
#include <Windows.h>
#include <mmsystem.h>
#include <iostream>
#include <fstream>
using namespace std;
#pragma comment(lib, "winmm.lib")
#define Samples 16000
#define NUM_FRAMES Samples*2
#define Channels 1
const int NUM_BUF = 4;
int main()
{
HWAVEIN inStream;
HWAVEOUT outStream;
WAVEFORMATEX waveFormat;
WAVEHDR buffer[NUM_BUF];
waveFormat.cbSize = 0;
waveFormat.wFormatTag = WAVE_FORMAT_PCM;
waveFormat.nChannels = Channels;
waveFormat.nSamplesPerSec = Samples;
waveFormat.wBitsPerSample = 16;
waveFormat.nBlockAlign = waveFormat.nChannels * waveFormat.wBitsPerSample / 8;
waveFormat.nAvgBytesPerSec = waveFormat.nBlockAlign * waveFormat.nSamplesPerSec;
HANDLE event = CreateEventA(NULL, TRUE, FALSE, "waveout event");
MMRESULT res = MMSYSERR_NOERROR;
res = waveInOpen(&inStream, WAVE_MAPPER, &waveFormat, (unsigned long)event, 0, CALLBACK_EVENT);
if (res != MMSYSERR_NOERROR) {
printf("error in waveInOpen\n");
return -1;
}
res = waveOutOpen(&outStream, WAVE_MAPPER, &waveFormat, (unsigned long)event, 0, CALLBACK_EVENT);
if (res != MMSYSERR_NOERROR) {
printf("error in waveOutOpen\n");
return -2;
}
short int *_pBuf;
size_t bpbuff = 16000*2;
_pBuf = new short int [bpbuff * NUM_BUF];
for ( int i = 0; i < NUM_BUF; i++ )
{
buffer[i].lpData = (LPSTR)&_pBuf [i * bpbuff];
buffer[i].dwBufferLength = bpbuff*sizeof(*_pBuf);
buffer[i].dwFlags = 0L;
buffer[i].dwLoops = 0L;
waveInPrepareHeader(inStream, & buffer[i], sizeof(WAVEHDR));
}
ResetEvent(event);
for (int index = 0; index < NUM_BUF; index++) // queue all buffers for input
waveInAddBuffer(inStream, &buffer[index], sizeof(WAVEHDR));
waveInStart(inStream);
int len_buff = buffer[0].dwBufferLength*6 + 1;
int limit_buff = buffer[0].dwBufferLength*5 + 1;
int size = buffer[0].dwBufferLength;
int rl = 0;
int flagg = 0;
char * buff1 = new char[len_buff];
char * buff2 = new char[len_buff];
int flag_buf = 0;
int flag1 = 0, flag2 = 0;
int i = 0;
int inIndex = 0, outIndex = 0; // the next input and output to watch
while (true) {
if (buffer[inIndex].dwFlags & WHDR_DONE & flagg!=1)
{
flagg = 1;
waveInAddBuffer(inStream, &buffer[inIndex], sizeof(WAVEHDR));
inIndex = (inIndex + 1) % NUM_BUF;
}
if (buffer[outIndex].dwFlags & WHDR_DONE & flagg!=0) {
flagg = 0;
if (flag_buf == 0)
{
if (rl<limit_buff)
{
cout << rl << endl;
if (flag1 == 0)
{
//strcpy(buff1, buffer[outIndex].lpData);
memcpy(buff1, buffer[outIndex].lpData, size);
flag1 = 1;
rl = size + 1;
}
else
{
//strcat(buff1, buffer[outIndex].lpData);
memcpy(buff1 + rl, buffer[outIndex].lpData, size);
rl = rl + size;
}
}
else
{
//recognize buff1
flag_buf = 1;
flag1 = 0;
rl = 0;
}
}
else
{
if (rl<limit_buff)
{
if (flag2 == 0)
{
memcpy(buff2, buffer[outIndex].lpData, size);
flag2 = 1;
rl = size + 1;
}
else
{
memcpy(buff2 + rl, buffer[outIndex].lpData, size);
rl = rl + size;
}
}
else
{
//recognize buff2
flag_buf = 0;
flag2 = 0;
rl = 0;
}
}
waveOutWrite(outStream, &buffer[outIndex], sizeof(WAVEHDR));
outIndex = (outIndex + 1) % NUM_BUF;
printf("N_buff_%i %i\n",outIndex , i);
i++;
}
}
for (int index = 0; index < 4; index++)
waveInUnprepareHeader(inStream, &buffer[inIndex], sizeof(WAVEHDR));
free(buffer);
}