[FFmpeg-devel] [PATCH v2] lavfi/drawtext: Add localtime_ms for millisecond precision

[Nicolas George]

Thilo Borgman (12022-01-14):
> v6 does:
> 
> $> ffmpeg ... drawtext="fontfile=...:text='%{localtime   \:%a %b %d %Y %S}'"           (seconds)
> $> ffmpeg ... drawtext="fontfile=...:text='%{localtime_ms\:%a %b %d %Y %S}'"           (milliseconds)
> 
> I suggest v7 should according to your remark:
> 
> $> ffmpeg ... drawtext="fontfile=...:text='%{localtime   \:%a %b %d %Y %S}'"           (seconds)
> $> ffmpeg ... drawtext="fontfile=...:text='%{localtime   \:%a %b %d %Y %S}':show_ms=1" (milliseconds)
> 
> Good?

I dislike both versions, from a user interface point of view: if there
is a format string, then it stands to reason, for the user, that the
resulting text is governed by the format string, not by an extra option
somewhere else.

There is no "use_four_digit_year=1" option, there is %Y instead of %y.

There is no "use_slashes=1" option, you write %Y/%m/%d instead of
%Y-%m-%d.

There are no "omit_date=1" and "omit_hour=1" options, you just write
what you want in the format string.

My proposal goes the same way:

$> ffmpeg ... drawtext="fontfile=...:text='%{localtime   \:%a %b %d %Y %S.%3N}'"

It has several merits over your proposal:

- It can be extended later to support printing the milliseconds at
  another place than the end (for example to put the time in brackets).

- It can be extended to support microseconds or centiseconds (%6N, %2N).

- It is somewhat compatible with GNU date and possibly a few others.

And I do not think it is harder to implement.

Regards,

-- 
  Nicolas George
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