macOS Automator ffmpeg help

[jms2k]

I'm very new to using Automator (and ffmpeg), but I will try to explain what I'm trying to do.

I need to concatenate 3 .mp3 files (Intro, File, Outro). I want to create an automated process that will allow me to drop any file into the directory and automator will automatically execute the ffmpeg process.

Here is what I have tried (but not working):
*edit* this is using Applescript */edit*

on run {input, parameters}
	tell application "Terminal"
		do script "cd /Users/xxxxxxx/Documents/itunesu/automator/step2/"
		do script "for f in *.mp3
			do
			cat ../files/intro.mp3 \"$f\" ../files/outro.mp3 > ../step3/\"$f\"
			done" in window 1
	end tell
end run

I've placed the intro/outro.mp3 in a separate directory and am wanting to call them into the concatenate process. Ideally, it would concatenate intro.mp3, $f, outro.mp3 and store it in the next directory (step3), with the same file name that it started with.

*edit 2* I'd also like to remove the .mp3 in directory "step2" once the process is done

Can anyone give me a hand, or point me in a better direction? Please don't flame me too hard! Thanks!!!

 

[jms2k]

I just tried this line in Terminal and it seemed to work:

for f in *.mp3; do cat ../files/intro.mp3 $f ../files/outro.mp3 > ../step3/$f; done

And then I needed to clean the headers, so I ran this in terminal as well:

for f in *.mp3; do ffmpeg -i $f ../step4/$f; done

This seemed to work, but I can't get Automator to successfully run it. It seems to rush into the next command too quickly, or something?

 

[jms2k]

Sorry, I'm kind of talking to myself here, but it's helping me figure things out. I directly copied what I used in Terminal into my Applescript, and it seems to have worked... so far. I don't need quotes around the variable, for starters. Also, putting everything in one line and using the semi-colons must prevent it from skipping ahead or something.

 

[jms2k]

Ok, stuck again. I decided to consolidate my first step (that was working) with the rest of my workflow. I came up with this:

on run {input, parameters}
	tell application "Terminal"
		do script "cd /Users/xxxxxx/Documents/itunesu/auto/step1/"
		do script "for f in *.m4a; do ffmpeg -i \"$f\" -acodec libmp3lame -ab 128k \"../step2/${f%.m4a}.mp3\"; rm $f; done" in window 1
		do script "cd /Users/xxxxxx/Documents/itunesu/auto/step2/" in window 1
		do script "for f in *.mp3; do cat ../files/intro.mp3 $f ../files/outro.mp3 > ../step3/$f; rm $f; done" in window 1
		do script "cd /Users/xxxxxx/Documents/itunesu/auto/step3/" in window 1
		do script "for f in *.mp3; do ffmpeg -i $f ../step4/$f; rm $f; done" in window 1
	end tell
end run

The first step (converting m4a files to mp3) works fine, but then it completely stops after that.

 

[jms2k]

Turns out, I don't need all those "do scripts"

on run {input, parameters}
	tell application "Terminal"
		do script "cd /Users/xxxxxx/Documents/itunesu/auto/step1/; for f in *.m4a; do ffmpeg -i \"$f\" -acodec libmp3lame -ab 128k \"../step2/${f%.m4a}.mp3\"; rm $f; done; cd ../step2/; for f in *.mp3; do cat ../files/intro.mp3 $f ../files/outro.mp3 > ../step3/$f; rm $f; done; cd ../step3/; for f in *.mp3; do ffmpeg -i $f ../step4/$f; rm $f; done"
	end tell
end run

Appears to have worked. If anyone has a better way, Please let me know. It would be nice if I could work within one directory, but I couldn't figure out a good way to do that yet.