Software to trim seconds from a large batch of clips.

Here is an Automator workflow that does it. You will have to first select any number of files by clicking "Add" in the first action ("Get Specified Finder Items").

Then click the ▶️ button at the top right to run the workflow.

Sorry that noone else has come up with different suggestions.

I had a look at ffmpeg, and it is very easy to trim the first ten seconds; but I could not find a way to specify ten seconds from the end of the clip.

If I can come up with a simple solution, I will report back.

A few notes about the above workflow:

1) The original files are not changed in any way.

2) The trimmed files are created in the same folder, and have "-trimmed" added to the name, before the extension. For example, file.mov yields file-trimmed.mov.

It is trivial to move these files and then rename them in Finder all at once, if, for example, you want to eliminate "-trimmed" from the name

3) I intended this to work as a Quick Action, so that you could control-click any files in Finder and run it (without even opening Automator). For some reason, it was not working (a permission error), so I decided to go with this version.

The workflow only removes 10 seconds from the start of each clip.

Also, it assumes that ffmpeg is installed in /usr/local/bin.

I built ffmpeg from source on my mac, and that is where it gets installed; but if you use other ways to install (homebrew and macports are alternatives) it may get installed elsewhere - in which case you need to adjust the text accordingly.

Do let us know how things progress, and don't hesitate to ask for help if needed.

This sounds like a job for ffmpeg. Sorry, I can't check the details just now.

Maybe someone else can chime in.

Let me try:

1) You need to have the developer tools accessible in Terminal. This should be done by running a command in Terminal. Copy and paste the following line into a Terminal window.

xcode-select --install

2) Most open source software can be built from the downloaded source with just 3 commands in Terminal. That is the case with ffmpeg

2a) You should have downloaded a file called ffmpeg-7.1.zip or similar; if it did not automatically expand to create a folder with name ffmpeg-7.1, double-click the file to expand.

2b) In Terminal:

2b-1) Type "cd " WITOUT the quotes but with the trailing SPACE; do NOT press enter

2b-2) Drag the folder from 2a) from the Finder, and drop it on the Terminal window.

[At this point, the Terminal should show

  cd /Users/yourname/Downloads/ffmpeg7.1

(where your username should show instead of "yourname", of course)]

2b-3) Press enter

Your Terminal session is now "sitting" at the folder containing the software distribution

2c) Copy and paste each of the following three lines to Terminal. Each may take a while to run.

./configure

make

sudo make install

The last one will ask your for your password, type it and press enter (Note: nothing shows as you type the password, that is normal).

If you succeed in the previous steps, you now have ffmpeg available to you.

You can confirm by typing

which ffmpeg

the output of the last command should now be

/usr/local/bin/ffmpeg