DURATION_FIRST    186 libavfilter/af_amix.c         { "first",    "Duration of first input.",    0, AV_OPT_TYPE_CONST, { .i64 = DURATION_FIRST    }, INT_MIN, INT_MAX, A|F, "duration" },
DURATION_FIRST    381 libavfilter/af_amix.c         (s->duration_mode == DURATION_FIRST && s->input_state[0] == INPUT_OFF) ||