fftools/opt_common: add time and datetime log flags

This commit adds two logging flags: 'time' and 'datetime'.

Usage:

ffmpeg -loglevel +time

or

ffmpeg -loglevel +datetime

Signed-off-by: softworkz <softworkz@hotmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/fftools-common-opts.texi

@@ -226,6 +226,10 @@ and the "Last message repeated n times" line will be omitted.
 Indicates that log output should add a @code{[level]} prefix to each message
 line. This can be used as an alternative to log coloring, e.g. when dumping the
 log to file.
+@item time
+Indicates that log lines should be prefixed with time information.
+@item datetime
+Indicates that log lines should be prefixed with date and time information.
 @end table
 Flags can also be used alone by adding a '+'/'-' prefix to set/reset a single
 flag without affecting other @var{flags} or changing @var{loglevel}. When

fftools/opt_common.c

@@ -1292,6 +1292,18 @@ int opt_loglevel(void *optctx, const char *opt, const char *arg)
             } else {
                 flags |= AV_LOG_PRINT_LEVEL;
             }
+        } else if (av_strstart(token, "time", &arg)) {
+            if (cmd == '-') {
+                flags &= ~AV_LOG_PRINT_TIME;
+            } else {
+                flags |= AV_LOG_PRINT_TIME;
+            }
+        } else if (av_strstart(token, "datetime", &arg)) {
+            if (cmd == '-') {
+                flags &= ~AV_LOG_PRINT_DATETIME;
+            } else {
+                flags |= AV_LOG_PRINT_DATETIME;
+            }
         } else {
             break;
         }