[FFmpeg-user] Joining mp4 files did not yield the expected file

[Lou]

On Tue, 29 Dec 2015 12:44:48 -0700
jd1008 <jd1008 at gmail.com> wrote:

> Command:
> 
> ffmpeg \
> -i Discourse_1_Part_1.mp4 \
> -i Discourse_1_Part_2.mp4 \
> -i Discourse_2_Part_1.mp4 \
> -i Discourse_2_Part_2.mp4 \
> -i Discourse_3_Part_1.mp4 \
> -i Discourse_3_Part_2.mp4 \
> -strict -2 -y All_Discourses.mp4

Complete console output is missing. This is required.

> Yielded a result much smaller than expected (in size) and
> when played, does not contain the contents of all the parts.

What are you trying to do exactly?

Default stream selection behavior is to select one stream of each type:
http://ffmpeg.org/ffmpeg.html#Stream-selection