ABSTRACT
Audio & Video Overlays The overlay part of creating audio and video overlays is quite simple. As with most overlays, it’s the pre - work that requires the effort. Audio and video files are passed through to the folio unchanged as are audio controller files. As is the case with any files destined for digital delivery, audio and video files should be optimized to achieve the best possible balance between quality and file size. For video, 10 –12 MB per minute of film is a good starting point. The best format for audio files is MP3 and your best option for video is MP4 with h.264 encoding. iOS supports both inline and full - screen video which makes it a natural for inclusion in other overlays. Inline videos should be the exact dimensions desired for output, but, for video that will show full - screen, you may be able to get away with 1024 x 768 px across devices. If you find the quality of the 1024 x 768 px video to be unacceptable on an HD iPad, you could include a video as large as 1920 x 1080 px-the maximum allowed by Apple. A video of this size will of course substantially increase the size of your folio. If testing shows that your HD video plays successfully on an SD iPad, you could reduce the overall file size of your folio by omitting the SD video entirely.
