diff --git a/doc/filters.texi b/doc/filters.texi
index b5265d9297..192a81a075 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -17897,7 +17897,23 @@ Set if channels should be drawn separately or overlap. Default value is 0.
 Set colors separated by '|' which are going to be used for drawing of each channel.
 
 @item scale
-Set amplitude scale. Can be linear @code{lin} or logarithmic @code{log}.
+Set amplitude scale.
+
+Available values are:
+@table @samp
+@item lin
+Linear.
+
+@item log
+Logarithmic.
+
+@item sqrt
+Square root.
+
+@item cbrt
+Cubic root.
+@end table
+
 Default is linear.
 @end table
 
diff --git a/libavfilter/avf_showwaves.c b/libavfilter/avf_showwaves.c
index 05aa995561..aadc5c1c2a 100644
--- a/libavfilter/avf_showwaves.c
+++ b/libavfilter/avf_showwaves.c
@@ -676,6 +676,8 @@ static const AVOption showwavespic_options[] = {
     { "scale", "set amplitude scale", OFFSET(scale), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, SCALE_NB-1, FLAGS, .unit="scale" },
         { "lin", "linear",         0, AV_OPT_TYPE_CONST, {.i64=SCALE_LIN}, .flags=FLAGS, .unit="scale"},
         { "log", "logarithmic",    0, AV_OPT_TYPE_CONST, {.i64=SCALE_LOG}, .flags=FLAGS, .unit="scale"},
+        { "sqrt", "square root",   0, AV_OPT_TYPE_CONST, {.i64=SCALE_SQRT}, .flags=FLAGS, .unit="scale"},
+        { "cbrt", "cubic root",    0, AV_OPT_TYPE_CONST, {.i64=SCALE_CBRT}, .flags=FLAGS, .unit="scale"},
     { NULL }
 };