avfilter/vf_scale: add more aliases for "range" options

Signed-off-by: Paul B Mahol <onemda@gmail.com>

doc/filters.texi

@@ -13086,13 +13086,13 @@ a specific value used for the output and encoder. If not specified, the
 range depends on the pixel format. Possible values:
 
 @table @samp
-@item auto
+@item auto/unknown
 Choose automatically.
 
 @item jpeg/full/pc
 Set full range (0-255 in case of 8-bit luma).
 
-@item mpeg/tv
+@item mpeg/limited/tv
 Set "MPEG" range (16-235 in case of 8-bit luma).
 @end table
 

libavfilter/vf_scale.c

@@ -578,7 +578,9 @@ static const AVOption scale_options[] = {
     {  "in_range", "set input color range",  OFFSET( in_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, "range" },
     { "out_range", "set output color range", OFFSET(out_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, "range" },
     { "auto",   NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 0, FLAGS, "range" },
+    { "unknown", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 0, FLAGS, "range" },
     { "full",   NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
+    { "limited",NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
     { "jpeg",   NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
     { "mpeg",   NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
     { "tv",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },