[FFmpeg-user] Question about file size changes

[Jerome Martinez]

On 18/06/2019 15:01, Moritz Barsnick wrote:
> I don't know why mediainfo determines different video bit rates (1817 vs.
> 1870), ffmpeg claims to have copied exactly the same amount of video
> into the target containers. I don't trust mediainfo on this.

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.
I'll fix that in MediaInfo for at least having the same video bitrate 
output when one changes from MTS to M2TS (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), so you would avoid such kind 
of question about the video bitrate (the question about the overall 
bitrate and file size change will stay though, due to the good reasons 
you provided).

Jérôme, developer of MediaInfo.