In some cases, Presentation Video Trimmer will not be able to trim the videos that you use in your presentations:
Password protected files
When you save your presentation as a password protected file, PowerPoint creates a file in a format which is different than that of a password-free presentation. This different file format is unreadable to Presentation Video Trimmer and the app could not open and embed fonts into it.
To work around this limitation, you can save your presentation in a password-free format, use Presentation Video Trimmer to trim the videos in the file, and then use PowerPoint again to load the trimmed output and re-save it, this time in a password-protected format.
Beginning with the 2007 version, Microsoft introduced new file formats for the Office suite products and set those new formats as the default for saving files. Presentation Video Trimmer supports these new file formats (e.g. files ending with a ‘pptx’ extension) and does not support any files created by prior versions (e.g. ‘ppt’ extension, usually referred to as PowerPoint 97-2004 format). See Supported File Types for more information.
If you would like to to trim videos in a PowerPoint 97-2004 file, you can easily convert it to the new format with a recent Office product (including the Mac® versions). Simply open the 97-2004 format file and perform a Save as in the new format. The newly saved file can be trimmed using Presentation Video Trimmer.
Presentation Video Trimmer can only trim videos in media formats that your PowerPoint can play on your Mac. If you have a presentation that was created on a Windows PC with a WMV video in it for example, it is most likely that your Mac PowerPoint won’t be able to play that file, and Presentation Video Trimmer will too, therefore, not be able to trim it.