Originally Posted by akosnitzky
As far as transcoding, you taught me a new word. I will definitely look again
Ahh, cool - lemme try and give the 2 second primer so you can hit the ground running.
transcoding: taking an already compressed (usually already lossy, like MP3) file and simply shuffling the digital bits around to change it into a different format (like to an AAC file). A slight of hand trick, if you will.
re-encoding: taking an already compressed file, decompressing it (i.e. MP3 -> raw audio WAV file) then recompressing it in the new (usually lossy) format (i.e. WAV -> AAC). The brute force method, if you will.
Re-encoding works with almost anything - you decompress the source into a common format then recompress (incurring more loss) into a new format, so there are a ton of programs which are available for all operating systems. Very common.
Transcoding is a lot more (programming) work, and you can't always transcode from format X to format Y - it depends on the specific program. Not as many transcoding programs are available due to the higher code complexity, but transcoding is always a better choice since you don't incur the same quality loss as re-encoding.