{"slev", "sourround mix level" , OFFSET(slev) , AV_OPT_TYPE_FLOAT, {.dbl=C_30DB}, 0, 4, 0},
{"rmvol", "rematrix volume" , OFFSET(rematrix_volume), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, -1000, 1000, 0},
{"flags", NULL , OFFSET(flags) , AV_OPT_TYPE_FLAGS, {.dbl=0}, 0, UINT_MAX, 0, "flags"},
+{"swr_flags", NULL , OFFSET(flags) , AV_OPT_TYPE_FLAGS, {.dbl=0}, 0, UINT_MAX, 0, "flags"},
{"res", "force resampling", 0, AV_OPT_TYPE_CONST, {.dbl=SWR_FLAG_RESAMPLE}, INT_MIN, INT_MAX, 0, "flags"},
{"dither_scale" , "dither scale" , OFFSET(dither_scale ), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, INT_MAX, 0},
{"dither_method", "dither method" , OFFSET(dither_method), AV_OPT_TYPE_INT , {.dbl=0}, 0, SWR_DITHER_NB-1, 0, "dither_method"},