[FFmpeg-devel] [PATCH] avformat/matroskaenc: do not write timebase as framerate

Carl Eugen Hoyos ceffmpeg at gmail.com
Sat Apr 28 22:18:47 EEST 2018

2018-04-28 20:05 GMT+02:00, wm4 <nfxjfg at googlemail.com>:
> On Sat, 28 Apr 2018 19:52:38 +0200
> Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>> 2018-04-28 19:24 GMT+02:00, wm4 <nfxjfg at googlemail.com>:
>> > If the API user doesn't set avg_frame_rate, matroskaenc will write the
>> > current timebase as "default duration" for the video track. This makes
>> > no sense, because the "default duration" implies the framerate of the
>> > video. Since the timebase is forced to 1/1000, this will make the
>> > resulting file claim 1000fps.
>> >
>> > Drop it and don't write the element. It's optional, so it's better not
>> > to write it if the framerate is unknown.
>> (Isn't it default frame duration?)
> The Matroska "spec" calls it DefaultDuration.

Which sounds more similar to "default frame duration" than

>> Please mention ticket #6386 if you commit.
> So if this was known to you, and you even made a patch, why
> did you never send the patch to the list?

I am not convinced the patch is correct and the OP claimed
that it did not fix the reported issue completely.

(And this was of course not known "to me" but to everybody.)

Carl Eugen

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