Starting from an MP4 file produced by my Flip Ultra HD video camera, is it possible to (a) edit/increase the volume and (b) export as an MP4 file? I have version 4.1 and am wondering if this feature is available in a later version. Thank you for your time. Mia Doucet
The 1.3 versions of Audacity (with the ffmpeg library installed ) will rip the audio from an MPEG4 video.
I suspect combining the modified (amplified) audio with a copy of the original video images will require a video editing programme, (Audacity only edits audio , i.e. edits sound not images).
You need a “real” video editor to put them back together. I think the simplest way is QuickTime Pro on the Macs. The Pro upgrade from normal Player lets you do simple editing and capture. One of the things you can do is lay in a new sound track in an existing video. You can export in either MPEG4 or H.264.
QuickTime is available as a free download on Windows machines. I don’t know if you can upgrade to Pro. The upgrade is money-based software.