[FFmpeg-cvslog] doc/utils/eval: clarify meaning of random* seed value

[Stefano Sabatini]

ffmpeg | branch: master | Stefano Sabatini <stefasab at gmail.com> | Mon Jan  1 20:38:03 2024 +0100| [8ceb37d5ad730b93e4a277b74a5279c5d1f7864a] | committer: Stefano Sabatini

doc/utils/eval: clarify meaning of random* seed value

Possible address trac issue:
http://trac.ffmpeg.org/ticket/10763

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8ceb37d5ad730b93e4a277b74a5279c5d1f7864a
---

 doc/utils.texi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/doc/utils.texi b/doc/utils.texi
index 76e704fc3c..2f18a61bfd 100644
--- a/doc/utils.texi
+++ b/doc/utils.texi
@@ -944,11 +944,23 @@ Return a pseudo random value between 0.0 and 1.0. @var{idx} is the
 index of the internal variable which will be used to save the
 seed/state.
 
+To initialize the seed, you need to store the seed value as a 64-bit
+unsigned integer in the internal variable with index @var{idx}.
+
+For example, to store the seed with value @code{42} in the internal
+variable with index @code{0} and print a few random values:
+ at example
+st(0,42); print(random(0)); print(random(0)); print(random(0))
+ at end example
+
 @item randomi(idx, min, max)
 Return a pseudo random value in the interval between @var{min} and
 @var{max}. @var{idx} is the index of the internal variable which will
 be used to save the seed/state.
 
+To initialize the seed, you need to store the seed value as a 64-bit
+unsigned integer in the internal variable with index @var{idx}.
+
 @item root(expr, max)
 Find an input value for which the function represented by @var{expr}
 with argument @var{ld(0)} is 0 in the interval 0.. at var{max}.