Splitting MP4 Files

Tom asks, “Where can I get a program which will let me cut a MP4 in half. I have made some movies using your [PSP tutorial] but then cannot fit everything all on my memory stick. Have you found any programs like this?”
Depending on how much your time is worth, buying a bigger memory stick might be worth the extra dollars. There is more than one way to attack this problem, depending on what solutions you already have at your disposal. The obvious solution is to divide the MP4 file into smaller files. Another option to consider is splitting the AVI file before you convert it to the PSP-ready MP4. In either case, expect additional time for the conversion process.

VirtualDub is the obvious choice for splitting the AVI into two parts. After opening the AVI file in VirtualDub, make some setting changes prior to splitting the file. On both the Video and Audio menus, make sure Direct stream copy is selected. Failure to do this results in VirtualDub re-rendering your AVI files, potentially adding an extra hour (or more) to the process. Drag the slider to the point in the movie where you want the split to occur. From the File menu, choose save segmented AVI. Assuming you are only splitting the file into two pieces, set the maximum number of frames to the size of your first part of the movie. Convert the individual files to MP4 for playback on your PSP.
If you opt to split the finished MP4 files, the easiest solution I found was QuickTime Pro. The upgrade from the free QuickTime Player is $29.99, which allows you to split MP4 files, in addition to a number of other features. To split a file using QuickTime Pro, first open the video file in QuickTime. Drag the right slider below the play control to the point where you want to make the split. From the Edit menu choose Trim. Then Export the movie as MPEG-4. Make sure you name the exported file something different than your original file or you will be starting from scratch converting your DVD. To create a new file for the second half of the movie, re-open the original file in QuickTime, first dragging the right Trim marker to the end of the file, followed by the left Trim marker at the point where you made the first half split. Trim the file and Export the second half as a new file.