ff_log2_q15        91 libavcodec/acelp_pitch_delay.c         quant_energy[0] = (6165 * ((ff_log2_q15(gain_corr_factor) >> 2) - (13 << 13))) >> 13;
ff_log2_q15        62 libavcodec/celp_math.h int ff_log2_q15(uint32_t value);