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

[21naown at gmail.com]

Le 16/06/2017 à 14:25, wm4 a écrit :
> On Fri, 16 Jun 2017 13:51:20 +0200
> 21naown at gmail.com wrote:
>
>> 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.
> Who says it's a necessity or standard? It's just what mkvmerge does.
> Since the patch is by google, I assume google has some use for it
> (there might also be a discussion about it on the ML).

Sorry for the bad word “necessity”, it is better with “imposed”. Could 
you let the choice to the user like mkvmerge with 
“--disable-track-statistics-tags”?