avfilter/vf_scale: add more color_matrix aliases

Add more color_matrix aliases to make vf_scale consistent with e.g. vf_setparams aliases.

libavfilter/vf_scale.c

@@ -1075,10 +1075,12 @@ static const AVOption scale_options[] = {
         { "bt601",       NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_BT470BG},        0, 0, FLAGS, .unit = "color" },
         { "bt470",       NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_BT470BG},        0, 0, FLAGS, .unit = "color" },
         { "smpte170m",   NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_BT470BG},        0, 0, FLAGS, .unit = "color" },
+        { "bt470bg",     NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_BT470BG},        0, 0, FLAGS, .unit = "color" },
         { "bt709",       NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_BT709},          0, 0, FLAGS, .unit = "color" },
         { "fcc",         NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_FCC},            0, 0, FLAGS, .unit = "color" },
         { "smpte240m",   NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_SMPTE240M},      0, 0, FLAGS, .unit = "color" },
         { "bt2020",      NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_BT2020_NCL},     0, 0, FLAGS, .unit = "color" },
+        { "bt2020nc",    NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_SPC_BT2020_NCL},     0, 0, FLAGS, .unit = "color" },
     {  "in_range", "set input color range",  OFFSET( in_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, .unit = "range" },
     { "out_range", "set output color range", OFFSET(out_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, .unit = "range" },
         { "auto",        NULL, 0, AV_OPT_TYPE_CONST, {.i64=AVCOL_RANGE_UNSPECIFIED }, 0, 0, FLAGS, .unit = "range" },