Why are the transcoded AVI files often bigger or smaller than adjusted?
Modern video codecs (like DivX) work with variable bitrate encoding. So the desired bitrate is in fact an average bitrate. But currently most codecs have problems hitting this bitrate overall. Regularly the effective bitrate is somewhat smaller, which is no problem, but sometimes it’s bigger, so the files won’t fit on the desired number of discs. You can enable multipass encoding for optimizing this. But often the effective bitrate differs nevertheless. We just can wait on better codecs, which hopefully solve this problem finally.
