[FFmpeg-devel] Why the tag “DURATION” is a necessity in Matroska files?

[21naown at gmail.com]

Le 16/06/2017 à 12:55, wm4 a écrit :
> On Fri, 16 Jun 2017 02:32:10 +0200
> 21naown at gmail.com wrote:
>
>> Hello,
>>
>>
>> I would like to know why the tag “DURATION” in Matroska files (.mkv) is
>> a necessity? Even mkvmerge lets the choice to use it or not with
>> “--enable-durations”, in addition it is written “Write durations for all
>> blocks. This will increase file size and does not offer any additional
>> value for players at the moment.” (source
>> https://mkvtoolnix.download/doc/mkvmerge.html#d4e535).
>>
>> Possibly linked to
>> http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=31852540d4fba0c4e8a16d0b3ddff08fc98e48fd
> As far as I'm aware, the linked commit does not do the same thing as
> the mkvmerge option you pointed out.

Yes that is why I wrote “possibly”, also because this commit is the one 
which adds the tag “DURATION” as a necessity, but a necessity that no 
software seems to use and it is not even a standard in the Matroska’s 
documentation if I am not mistaken. So the fact that it is a necessity 
and not a choice is the main problem.