ffmpeg audio format conversions

How to Convert Audio format in linux..

 Audio

1.1. WAV - Waveform Audio File Format

1.1.1. wav to mp3

Convert wav to mp3 with ffmpeg:

ffmpeg -i audio.wav -acodec libmp3lame audio.mp3

1.1.2. wav to ogg

Convert wav to ogg with ffmpeg:

ffmpeg -i audio.wav  -acodec libvorbis audio.ogg

1.1.3. wav to aac

Convert wav to acc with ffmpeg:

ffmpeg -i audio.wav  -acodec libfaac audio.aac

1.1.4. wav to ac3

Convert wav to ac3 with ffmpeg:

ffmpeg -i audio.wav -acodec ac3 audio.mp3

1.2. OGG - Free, open standard container

1.2.1. ogg to mp3

Convert ogg to mp3 with ffmpeg:

ffmpeg -i audio.ogg -acodec libmp3lame audio.mp3

1.2.2. ogg to wav

Convert ogg to wav with ffmpeg:

ffmpeg -i audio.ogg audio.wav

1.2.3. ogg to aac

Convert ogg to aac with ffmpeg:

ffmpeg -i audio.ogg  -acodec libfaac audio.aac

1.2.4. ogg to ac3

Convert ogg to ac3 with ffmpeg:

ffmpeg -i audio.ogg -acodec ac3 audio.ac3

1.3. AC3 - Acoustic Coder 3

1.3.1. ac3 to mp3

Convert ac3 to mp3 with ffmpeg:

ffmpeg -i audio.ac3 -acodec libmp3lame audio.mp3

1.3.2. ac3 to wav

Convert ac3 to wav with ffmpeg:

ffmpeg -i audio.ac3 audio.wav

1.3.3. ac3 to aac

Convert ac3 to aac with ffmpeg:

ffmpeg -i audio.ac3  -acodec libfaac audio.aac

1.3.4. ac3 to ogg

Convert ac3 to ogg with ffmpeg:

ffmpeg -i audio.ac3 -acodec libvorbis audio.ogg

1.4. AAC - Advanced Audio Coding

1.4.1. aac to mp3

Convert aac to mp3 with ffmpeg:

ffmpeg -i audio.aac -acodec libmp3lame audio.mp3

1.4.2. aac to wav

Convert aac to wav with ffmpeg:

ffmpeg -i audio.aac audio.wav

1.4.3. aac to ac3

Convert aac to ac3 with ffmpeg:

ffmpeg -i audio.aac  -acodec ac3 audio.ac3

1.4.4. aac to ogg

Convert aac to ogg with ffmpeg:

ffmpeg -i audio.aac -libvorbis audio.ogg

how to convert mp4 to mp3 on ubuntu...

If you wanna export the audio from the .MP4 video file then use ffmpeg,
you can do this all the time from FLV files. Firstly install ffmpeg,
with command bellow:

sudo apt-get install ffmpeg libavcodec-unstripped-*

and then use this command here:
ffmpeg -i video.mp4 -f mp3 -ab 192000 -vn music.mp3

It might say that your missing some codecs for MP4, in that case just run below,
find it and install.

aptitude search codecname

How to RecordMyDesktop in Ubuntu

Using Recordmydesktop to recording and "mencoder" to convert ogg files to avi

You need to install recordmydesktop and mencoder by typing in terminal:
sudo apt-get install gtk-recordmydesktop mencoder
you can find it in Applications menu --> sound and video --> gtk-recordmydesktop

or in command line console type the command recordmydesktop
you can stop the recording by pressing ctrl-c
or in gui-front just click record, and just click the white square on system tray to stop
the output is in ogg video format however you can convert it to avi by mencoder

example
mencoder -idx input.ogg -ovc lavc -oac mp3lame -o output.avi
*note install mencoder if its not installed by doing
Code:
sudo aptitude install mencoder

then you can upload it to youtube or wherever.