sigmoid_approx   1251 libavfilter/af_arnndn.c             output[i] = sigmoid_approx(output[i]);
sigmoid_approx   1280 libavfilter/af_arnndn.c         z[i] = sigmoid_approx(WEIGHTS_SCALE * sum);
sigmoid_approx   1289 libavfilter/af_arnndn.c         r[i] = sigmoid_approx(WEIGHTS_SCALE * sum);
sigmoid_approx   1301 libavfilter/af_arnndn.c             sum = sigmoid_approx(WEIGHTS_SCALE * sum);