Splice/replace/transcode audio for projector, iPhone 6/iPad

It's common for us to transcode media files, edit video settings to meet different visual requirements. But what if you have some files with the audio part to be edited? Like removing the original audio tracks and adding your own dubbing/explanation, splicing/merging several audio tracks, splitting audio part, or transcoding them into another format. http://www.multipelife.com/splice-replace-transcode-audio-files.html