[FFmpeg-user] Trying to cut 5 sec of beginning and ending of mp4 files

[Jim Shupert, Jr.]

> Hi
>
> I am been trying almost every combination of switches to be able to cut 5
> sec from the start and 5 sec from the ending of variable length mp4 files.
>
> I have not been successful at doing either.  I guess I really don't
> understand the usage.  I have more than 100 files to do.
>
> Can anyone suggest a command string that will work?
>

read
https://www.ffmpeg.org/ffmpeg.html
about
-ss position
and
-t duration (input/output)

    When used as an input option (before -i), limit the duration of data
read from the input file




so what you really want is a sh script to loop



5 sec fro top is easy cause they all start at 0
so approx something like : and you
ffmpeg -i < inFile> -ss 05.000 -vcodec $$  -acodec $$ <outfile>

you now have outFile  with the top 5 sec off

and I think you HAVE to reEncode to trim , or is that just for video
filters (-vf) ??????

or can one do -codec copy -acodec copy :: reckon I am not sure - try it

so what you really want is a sh script to loop
and you have to get the total duration in seconds
subtract 5 sec from that
start at the top and and your new duration is ( totalSec- 5 sec

try some of this
## this is NOT a fuctioning sh script but a sketch
a copy & paste from some things I *have done
It may help you get started ( or be very wrong )


i think you strat 5 sec deep
with a ss- 5
and then you want your duration [ -t ]  to be 10 sec less that the running
time of the org
5 sec from top and then short another 5 - so as not all the way to end ..

#!/bin/bash
Src=<yourPathhere>
etn=mp4

###  for a file 2.mp4   I get seconds
##ffprobe -i 2.mp4 -show_entries format=duration -v quiet -of csv="p=0"
##yields
##865.365000
## but maybe you want to take just the whole sec
## so use some awk

cd $Src

for f in *.$etn ; do

durT=$(ffprobe -i $Src/$f -show_entries format=duration -v quiet -of
csv="p=0")

echo $durT
## get the whole sec NNN  of NNN.mmm
echo $durT | awk -F'.' '{print $1}'
durT1=$(echo $durT | awk -F'.' '{print $1}')

echo my sec = $durT1
## yields a number like so 865

####

durT=$(ffprobe -i $Src/$f -show_entries format=duration -v quiet -of
csv="p=0")

echo $durT
## get the whole sec NNN  of NNN.mmm
echo $durT | awk -F'.' '{print $1}'
durT1=$(echo $durT | awk -F'.' '{print $1}')

echo my sec = $durT1

#####-----------/ do a subtract ..tot time in sec - 10 sec
durTless10=$(($durT1 - 600))
echo $durTless10

## i think is then your -t $durTless10

ffmpeg -ss 5 -i <inFile>${f%.*}.mp4 -t $durTless10 videocodec etc etc
<outfileFinal>${f%.*}_short.mp4


done