Making applescript to batch shorten MP4's using quicktime player- 95% done

Question

Hey guys, soo this is my first post and I'm hoping someone here could help me..
I downloaded a short script from someone, here it is:
+with timeout of 86400 seconds+
+ +
+ display dialog "Before beginning batch processing, make sure QuickTime Player is set to the desired export settings, and all videos to be processed are in a folder named ‘Input’ on the desktop." with icon note+
+ +
+ tell application "Finder"+
+ set the startup_disk to the name of the startup disk+
+ end tell+
+ +
+ set user to do shell script "whoami"+
+ set inputfoldername to "Input"+
+ set input_folder to startup_disk & ":Users:" & user & ":Desktop:" & inputfoldername & ":"+
+ set user_desktop to startup_disk & ":Users:" & user & ":Desktop:"+
+ set output_folder to startup_disk & ":Users:" & user & ":Desktop:Output:"+
+ set file_extension to "_export.mp4"+
+ +
+ try+
+ tell application "Finder"+
+ make new folder at user_desktop with properties {name:"Output"}+
+ end tell+
+ end try+
+ +
+ try+
+ set thefolderlist to list folder input_folder without invisibles+
+ repeat with x from 1 to count of thefolderlist+
+ set the_file to input_folder & item x of thefolderlist+
+ set output_file to output_folder & item x of thefolderlist & file_extension+
+ tell application "QuickTime Player"+
+ activate+
+ open the_file+
+ export front document to output_file as MPEG4 using most recent settings with replacing+
+ close front document+
+ end tell+
+ end repeat+
+ on error+
+ display dialog "This script requires a folder named ‘" & inputfoldername & "‘ located on the desktop." with icon stop+
+ end try+
+ +
+ beep+
+ +
+end timeout+
That script is meant to export files as MPEG4. That is not what I want to do, I just want to shorten the video to -1 second, or 99% or something like that, then save it into the output folder. I would imagine doing this just takes 1 line in the right place but I am lost, I searched google but I can't find anything
can anyone help me please.. Here are the lines I think I need changed
+ tell application "QuickTime Player"+
+ activate+
+ open the_file+
+ export front document to output_file as MPEG4 using most recent settings with replacing+
+ close front document+
+ end tell+
how can I change that to trim the video???

Answer 1

That isn't working for me. When I hit 'compile', I get 'Expected end of line, etc. but found "from".'
Here is the code I have so far, I have changed it a bit. However my problem now is that it *never trims*
tell application "QuickTime Player"
activate
try
close front window
end try
open the_file
delay 3
set time_scale to get the time scale of the front document
set movie_length to get the duration of the front document
set time_original to movie_length / time_scale
set timetotrim to amounttotrim
set new_time to (time_original - timetotrim) * time_scale
select at 0 to new_time
trim
delay 1
export front document to output_file as MPEG4 using most recent settings with replacing
close front document
end tell