[FFmpeg-user] Question about file size changes

[Dennis Mungai]

On Sun, 16 Jun 2019 at 22:26, David Shuman <d.shuman at att.net> wrote:

> I have a video recorder that outputs files with an .mts suffix.  mediainfo
> identifies these files as BDAV more commonly .m2ts files  I attempt to copy
> these files with the following commands
>
> ffmpeg           -i
> "D:\Dave\Videos\010-raw\mts\Charge-05082019-2255.mts" -c
> copy
> "D:\Dave\Videos\020-fix\mts\Charge-05082019-2255.mts"                2>&1
> | wtee    "D:\Dave\Videos\log\mts\ffFIX-Charge-05082019-2255.txt"
> I renamed the file to have a .m2ts suffix and tried again
> ffmpeg           -i
> "D:\Dave\Videos\010-raw\m2ts\Charge-05082019-2255.m2ts" -c
> copy
> "D:\Dave\Videos\020-fix\m2ts\Charge-05082019-2255.m2ts"
> 2>&1  | wtee    "D:\Dave\Videos\log\m2ts\ffFIX-Charge-05082019-2255.txt"
> The resulting output files according to mediainfo have had their video bit
> rates increased     The original is 1778 kb/s regardless of file suffix,
> the .mts copy is 1817 kb/s and the .m2ts copy is 1870 kb/s.
>
> Why do the copies have higher video bit rates?  Nothing else significant
> appears to have changed  the .mts claims format is mpeg-ts  on the output,
> all other formats both input and the .m2ts output claim to be BDAV.
> Is there a way I can keep the bit rate the same so the copy matches the
> original except for corrections made during the copy for missing franes,
> etc?
>
>
>
Most likely you're seeing the effects of muxer overheads.

>From your console: muxing overhead: 9.707805%