[FFmpeg-user] ffmpeg mp4 encoding with cfr is not working

[Carl Eugen Hoyos]

Sangsu Baek <sangsu.baek <at> gmail.com> writes:

> Is there any hint to fix this matching problem ?

Which problem?
You reported that you need 15fps output and provided 
the following status line:

 frame=  194 fps= 17 q=5.3 Lsize=     401kB time=00:00:12.93

As explained, this status line indicates that your 
output is exactly 15fps (194 / 12.93).
(Apart from the fact that ffmpeg ... out.mp4 can 
only produce constant frame rate because the mp4 
muxer does not support anything else.)
If you are worried about the fps indicator in the 
status line: It is a performance indicator that 
cannot work for v4l2 input.
(It works insofar as you know the encoding does 
not work if the performance indicator indicates 
a lower performance than the fps rate that you 
requested.)

Carl Eugen