Do you need to transcode media files or just change the container? The standard (non-streaming) MOV container will / should be compatible with the MP4 container (checking several test files from iOS shows that they are identical). Perhaps you can just rename the file to MP4. This assumes that the media in the container is supported by the MP4 container. FYI, the ISO specification for MP4 is based on the Quicktime file format. In addition, if you are recording media to the device, you can select MP4 as the container for media.