C++: Convert float[] to unsigned char* or BYTE* - c++

Question

I'm developing a project where I need to convert PCM 16-bits 2 channels sound into a IEEE Float 32-bits 2 channels.
To do this I'm using the following code:
void CAudioConverter::ConvI16ToF32(BYTE* pcmFrom, BYTE* floatTo, int length)
{
short* src = reinterpret_cast<short*>(pcmFrom);
float* dst = reinterpret_cast<float*>(floatTo);
for (int n = 0; n < length; n++)
{
dst[n] = static_cast<float>(src[n]) / 32768.0f;
}
}
I have initialized the variable __pcm32_bytesPerFrame with:
WAVEFORMATEX* closestFormat;
ws->default_pb_dev->GetMixFormat(&closestFormat);
__pcm32_bytesPerFrame = closestFormat->nAvgBytesPerSec * (prm->samples_per_frame * 1000 / (prm->clock_rate * closestFormat->nChannels)) / 1000;
strm->pb_max_frame_count is:
hr = ws->default_pb_dev->GetBufferSize(&ws->pb_max_frame_count);
I have a while loop in a dedicated thread the does something like:
hr = strm->default_pb_dev->GetCurrentPadding(&padding);
incoming_frame = __pcm32_bytesPerFrame / 4;
frame_to_render = strm->pb_max_frame_count - padding;
if (frame_to_render >= incoming_frame)
{
frame_to_render = incoming_frame;
} else {
/* Don't get new frame because there's no space */
frame_to_render = 0;
}
if (frame_to_render > 0)
{
pjmedia_frame frame;
hr = strm->pb_client->GetBuffer(frame_to_render, &cur_pb_buf);
if (FAILED(hr)) {
continue;
}
void* destBuffer = (void*)malloc(strm->bytes_per_frame*frame_to_render*sizeof(pj_uint16_t));
if (strm->fmt_id == PJMEDIA_FORMAT_L16) {
/* PCM mode */
frame.type = PJMEDIA_FRAME_TYPE_AUDIO;
frame.size = strm->bytes_per_frame;
frame.timestamp.u64 = strm->pb_timestamp.u64;
frame.bit_info = 0;
frame.buf = destBuffer;
}
status = (*strm->pb_cb)(strm->user_data, &frame);
CAudioConverter* conv = new CAudioConverter();
conv->ConvI16ToF32((BYTE*)destBuffer, cur_pb_buf, frame_to_render);
hr = strm->pb_client->ReleaseBuffer(frame_to_render, 0);
(...)
But, to send the sound to the WASAPI capture buffer I need a BYTE*.
How can I fill my 'floatTo' argument?
Any ideas?
Thanks

Answer 1

What about this:
void CAudioConverter::ConvI16ToF32(BYTE* pcmFrom, BYTE* floatTo, int length)
{
short* src = reinterpret_cast<short*>(pcmFrom);
float* dst = reinterpret_cast<float*>(floatTo);
for (int n = 0; n < length; n++)
{
dst[n] = static_cast<float>(src[n]) / 32768.0f;
}
}
Additionally make sure length indicates the number of elments in pcmFrom and floatTo, and not the number of bytes allocated. In you case pcmFrom should have allocated length*2 bytes and floatTo needs room for length*4 bytes.