[FFmpeg-devel] [PATCH 1/4] doc/utils: Rewrite doc for time duration syntax

[Timothy Gu]

Signed-off-by: Timothy Gu <timothygu99 at gmail.com>
---
 doc/utils.texi | 39 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/doc/utils.texi b/doc/utils.texi
index 243973d..e098ab6 100644
--- a/doc/utils.texi
+++ b/doc/utils.texi
@@ -96,14 +96,43 @@ year-month-day.
 @anchor{time duration syntax}
 @section Time duration
 
-The accepted syntax is:
+There are two accepted syntaxes for expressing time duration. Either
+one is perfectly valid.
+
+ at example
+[-][@var{HH}:]@var{MM}:@var{SS}[. at var{m}...]
+ at end example
+
+ at var{HH} expresses the number of hours, @var{MM} the number of minutes
+for a maximum of 2 digits, and @var{SS} the number of seconds for a
+maximum of 2 digits. The @var{m} at the end expresses decimal value for
+ at var{SS}.
+
+ at emph{or}
+
 @example
-[-][HH:]MM:SS[.m...]
-[-]S+[.m...]
+[-]@var{S}+[. at var{m}...]
 @end example
 
- at var{HH} expresses the number of hours, @var{MM} the number a of minutes
-and @var{SS} the number of seconds.
+ at var{S} expresses the number of seconds, with the optional decimal part
+ at var{m}.
+
+In both expressions, the optional @samp{-} indicates negative duration.
+
+ at subsection Examples
+
+The following examples are all valid time duration:
+
+ at table @samp
+ at item 55
+55 seconds.
+
+ at item 12:03:45
+12 hours, 03 minutes and 45 seconds.
+
+ at item 23.189
+23.189 seconds.
+ at end table
 
 @anchor{video size syntax}
 @section Video size
-- 
1.8.1.2