Ok, I wanted to put some music videos onto my Sony Ericsson K530i so they had to be converted to .3gp with the AAC audio codec. After a lot of googling for GUI tools, I found WinFF. Looked like a great tool, but I got the error “unknown codec ‘libamr_nb’” while trying to convert files from .avi to .3gp

Had to fall back on Command Line. I tried to use this guide for a few files, but they didn’t play on my phone.
DUH it didn’t support mp3 audio for videos I suppose. I needed the AAC codec according to my phone specifications, so after replacing mp3 with aac the command would be

ffmpeg -i inputfile.avi -s qcif -vcodec h263 -acodec aac -ac 1 -ar 8000 -r 25 -ab 32 -y outputfile.3gp

(use ‘-acodec libfaac’ if you get unknown encoder error)
And I had a lot of files, so this is how I managed to convert them using WinFF:

Open WinFF (Click here to go to download page if don’t already have WinFF)

Go to EDIT > PRESETS

Give the new Preset a Name and Label

then edit the Preset command line to

-s qcif -vcodec h263 -acodec aac -ac 1 -ar 8000 -r 25 -ab 32 -y

Output extension of course will be

3gp

And whatever Category Name you want

Click Add/Update and then Save

Now Back on WinFF, Add your files. Select your category in “Convert to” and the Preset. Select Save directory. And just hit Convert!

At this point I get a Box named FFmpeg Command line filled with code in it(Not sure if its supposed to do this, but anyway…). Now copy+paste the lines that begin with /usr/bin/ffmpeg one by one into a terminal and the videos will be converted.

I’m sure this could be done more easily with some kind of scripting, But I’m no good at it