Since an MP4 file is limited to MPEG-4 or H.264 video with AAC audio, and MP4 source file will loose nothing but copying an M4V file with AC3 and/or chapter track will filter these tracks from the target MP4 container. If an M4V source file contains an AC3 secondary audio track and/or a chapter track, then the edited file should be copied to the MOV file container to retain the all of the data tracks. MPEG Streamclip will allow you to copy the edited data to either an MP4 or MOV file container. QT 7 Pro will allow you to edit the files and copy the edited content to a new MOV file container. If the source files you wish to edit/trim are alredy in M4V or MP4 file containers, then you should be using either the QT 7 Pro app or the free MPEG Streamclip app here. Since the H.264 codec is both highly efficient and context adaptive, it is not the fastest encoder on the block. Using QT X v10.3 invokes an export routine which, by definition, re-encodes the file. Am I missing some sort of codec or plugin, or is Quicktime just not made to handle exporting large files? I've searched all around and can't seem to find out how to get Quicktime to export a large file in a reasonable amount of time. Once I do this and go to export it, however, I am met with insanely long export times. Here's my perdicament: I'm wanting to remove some scenes using Quicktime 10 from a movie I ripped from DVD.

Why does handbrake take so long