As this site deals a lot with audio and video processing, I thought it was handy to have a few commands documented that ease my life tremendously.
Audio File Format Conversion
ffmpeg -i file.wav -ar 320000 file.mp3 file.flac -c alac
Audio CD creation from *.wav files
cdrecord -v -pad -audio *.wav
Video File Format Conversion
ffmpeg -i $1.mp4 -y -target pal-dvd -sameq -aspect 16:9 -s hd1080 $.mpg $.avi
In case of dct coefficient errors, -q [0-32] can help to reduce quality until errors disappear. 0 being max Q, and 32 being lowest Q. A value of 5, i.e. adding the option of -q 5 gave a very good compromise between quality and file size.