need help understanding demux & remux

[jdefed]

first off, i've done this process and had it work. but, while thinking about it theres some things i don't understand. when i extract the audio wave file from an avi file with virtualdub, am i really extracting it or am i just copying it. i think i' m just copying it, which then brings up the question as to what happens when you remux it. lets say i extract the audio file and convert it from wave to ac3, then add it back to the original video. am i adding another audio file or is it overwriting the file that was there, assuming it was never really removed before just copied.:thanks:

[random asshat]

Depends what software you're using, but typically demuxing
is 'making a copy of the stream(s) you want out of an existing file'
and remuxing is 'mixing stream(s) of your choice into a new file'

Basically what you said in your original post.

[Wilbert]

Depends what software you're using, but typically demuxing is 'making a copy of the stream(s) you want out of an existing file'
Demuxing is moving a stream (ie, video, audio, subs, or whatever) outside your clip (outside the container to be more precise). If your video editing application calls it extracting, i assume does the same thing.