[FFmpeg-user] Question about file size changes

Moritz Barsnick barsnick at gmx.net
Tue Jun 18 20:11:10 EEST 2019

On Tue, Jun 18, 2019 at 16:31:45 +0200, Jerome Martinez wrote:
> On 18/06/2019 15:01, Moritz Barsnick wrote:
> > I don't know why mediainfo determines different video bit rates (1817 vs.
> As it is not possible to compute the bitrate per stream in MTS/M2TS
> without parsing the whole file, MediaInfo does an estimation, and in
> this case the estimation is unfortunately different depending on the
> container used.

That's what I thought. I believe it's no different for ffmpeg, which
does warn regarding duration estimation for some codecs (notably MP3),
but otherwise does not indicate whether a displayed bitrate is from
metadata or from knowledge or from estimation. (I may be wrong here,
too lazy to check.)

> (I plan to add "estimated" later when relevant so more explicit that
> it could be different for the same stream, but more complex in the
> code),

As to not confuse people, that's probably better. But multimedia coding
is so complex anyway, it tends to confuse people. ;-)

> (the question about the overall bitrate and file size change will
> stay though, due to the good reasons you provided).

Yes, it wasn't 100 % clear from the original posting what the complaint

> Jérôme, developer of MediaInfo.

Thanks for pitching in,

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