iFrame is a digital video format developed by Apple. It is based on existing industry standards, such as AVC/H.264, AAC and QuickTime, and can be used with compatible Mac and PC applications.[1]
The format has been created to simplify video editing. Many non-Apple editing tools do not require conversion of video from source to intermediate format, instead allowing to edit the original videos directly.
Traditionally, Apple video editing tools like Final Cut Pro and iMovie have required conversion of video from its original format into intermediate format such as ProRes 422 or AIC for editing. With iFrame such conversion is no longer needed starting from iMovie '09.[1]
Overview
iFrame video and audio is encoded using lossy compression. Only intraframe compression is enabled; every frame is a stand-alone i-frame. Video is encoded with the AVC/H.264 compression scheme. Audio is encoded with the AAC codec. The compressed audio and video are multiplexed into a QuickTime file.
To reduce data rate and hardware requirements, video frame has size of 960 horizontal by 540 vertical pixels with pixel aspect ratio of 1:1, which results in 16:9 display aspect ratio. Progressive scanning at 30 or 25 frames per second reduces data rate even further, but may result in increased “judder” when compared to the traditional rate of 60 or 50 images per second (fields or complete frames depending on scanning type) used for television broadcast.
As of 2013, Apple has not made detailed information about this recording format publicly available.
Relation to other technologies
Frame size of 960 by 540 pixels – nicknamed qHD – became popular among manufacturers of smartphones, including Apple's own iPhone.
