[FFmpeg-user] FFmpeg manual - asking for clarification of a definition

[Carl Eugen Hoyos]

2017-10-23 23:29 GMT+02:00 ILJA SHEBALIN <iljashebalin2 at gmail.com>:
> FFmpeg manual - Main options;
>
> -t duration (*input/output*)
>
> When used as an input option (before -i), limit the duration of data read
> from the input file.
>
> I have a hard time understanding what the formulation was supposed to
> denote. Is the option limiting the data to the *duration *or is the data
> that's out of the scope of the *duration *is read?

(I don't understand this question, sorry)

Normally, -t is used like:
$ ffmpeg -i input -t 10 output
Only ten seconds are encoded.
The following is possible:
$ ffmpeg -i input -t 10 output1 output2
output2 has the duration of the input file
$ ffmpeg -t 10 -i input output1 output2
All output files are ten seconds long.

The input option may have issues (although I didn't find
any on the bug tracker, I mixed it up with the input
option -r).

Carl Eugen