/* Do window management once we have a complete window, including mangling
* the current window. */
static int process_window(reddata_t data, int chan_num, int num_chans,
st_sample_t *obuf, int len) {
int j;
float* nextwindow;
int use = min(len, WINDOWSIZE)-(WINDOWSIZE/2);
chandata_t *chan = &(data->chandata[chan_num]);
int first = (chan->lastwindow == NULL);
nextwindow = (float*)calloc(WINDOWSIZE, sizeof(float));
memcpy(nextwindow, chan->window+WINDOWSIZE/2,
sizeof(float)*(WINDOWSIZE/2));
reduce_noise(chan, chan->window, data->threshold);
if (!first) {
for (j = 0; j < use; j ++) {
float s = chan->window[j] + chan->lastwindow[WINDOWSIZE/2 + j];
if (s < -1 || s > 1) {
float news;
if (s > 1)
news = 1;
else
news = -1;
st_warn("noisered: Output clipped from %f to %f.\n",
s, news);
}
obuf[chan_num + num_chans * j] =
ST_FLOAT_DWORD_TO_SAMPLE(s);
}
free(chan->lastwindow);
} else {
for (j = 0; j < use; j ++) {
assert(chan->window[j] >= -1 && chan->window[j] <= 1);
obuf[chan_num + num_chans * j] =
ST_FLOAT_DWORD_TO_SAMPLE(chan->window[j]);
}
}
chan->lastwindow = chan->window;
chan->window = nextwindow;
return use;
}
u::bytes microphone::read_data()
{
REQUIRE(_d);
if(!_d) return {};
INVARIANT(_i);
auto len = _i->bytesReady();
if(len <= 0) return {};
if(static_cast<size_t>(len) > MAX_SAMPLE_BYTES) len = MAX_SAMPLE_BYTES;
u::bytes data;
data.resize(len);
auto l = _d->read(data.data(), len);
if(l <= 0) return {};
data.resize(l);
//decimate and add to buffer
decimate(data, _buffer, _channels, _skip);
if(_buffer.size() < MIN_BUF_SIZE) return {};
//once we have enough data, do noise reduction
reduce_noise(_buffer, MIN_BUF_SIZE);
//copy buffer to result
u::bytes r(_buffer.begin(), _buffer.begin() + MIN_BUF_SIZE);
//copy extra to front and resize. Probably a better idea to use a circular buf here.
auto final_buf_size = _buffer.size() - MIN_BUF_SIZE;
std::copy(_buffer.begin() + MIN_BUF_SIZE, _buffer.end(), _buffer.begin());
_buffer.resize(final_buf_size);
return r;
}
