+ { "allx", "set all channel's x spread", OFFSET(all_x), AV_OPT_TYPE_FLOAT, {.dbl=-1}, -1, 15, FLAGS },
+ { "ally", "set all channel's y spread", OFFSET(all_y), AV_OPT_TYPE_FLOAT, {.dbl=-1}, -1, 15, FLAGS },
+ { "fcx", "set front center channel x spread", OFFSET(fc_x), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "flx", "set front left channel x spread", OFFSET(fl_x), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "frx", "set front right channel x spread", OFFSET(fr_x), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "blx", "set back left channel x spread", OFFSET(bl_x), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "brx", "set back right channel x spread", OFFSET(br_x), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "slx", "set side left channel x spread", OFFSET(sl_x), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "srx", "set side right channel x spread", OFFSET(sr_x), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "bcx", "set back center channel x spread", OFFSET(bc_x), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "fcy", "set front center channel y spread", OFFSET(fc_y), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "fly", "set front left channel y spread", OFFSET(fl_y), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "fry", "set front right channel y spread", OFFSET(fr_y), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "bly", "set back left channel y spread", OFFSET(bl_y), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "bry", "set back right channel y spread", OFFSET(br_y), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "sly", "set side left channel y spread", OFFSET(sl_y), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "sry", "set side right channel y spread", OFFSET(sr_y), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "bcy", "set back center channel y spread", OFFSET(bc_y), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 15, FLAGS },
+ { "win_size", "set window size", OFFSET(win_size), AV_OPT_TYPE_INT, {.i64 = 4096}, 1024, 65536, FLAGS },