About QuickTime movies
Motion supports QuickTime movies using any file format (codec) installed on your computer.
Although you can import movies in nearly any codec, avoid using highly compressed clips in projects. Excessively compressed clips can display undesirable visual artifacts. Fortunately, QuickTime provides many codecs ideal for moving uncompressed or minimally compressed video files between applications, including Apple ProRes 4444 XQ, Apple ProRes 4444, Apple ProRes 422 HQ, Apple ProRes 422, Uncompressed 8- and 10-bit 4:2:2, Pixlet, None, Animation, Apple M-JPEG A and B, DVCPRO-50, and DV/DVCPRO.
Some codecs support alpha channels, which define areas of transparency in the clip. If a QuickTime clip has an alpha channel, Motion uses the alpha channel in your project.
You can combine clips that are compressed with different codecs in the same project. You can also combine clips that have different frame sizes, pixel aspect ratios, and interlacing.