SILENCE_DETECT 135 libavfilter/af_silencedetect.c SILENCE_DETECT(flt, float) SILENCE_DETECT 136 libavfilter/af_silencedetect.c SILENCE_DETECT(s32, int32_t) SILENCE_DETECT 137 libavfilter/af_silencedetect.c SILENCE_DETECT(s16, int16_t)