iFrame (video format)
From Wikipedia, the free encyclopedia
iFrame is a constraint of the H.264 codec specified by Apple to ensure ease of consumer video editing.
It provides a square-pixel 16:9 image format of 960 horizontal by 540 vertical pixels, with progressive scanning at 30 frames per second and can be identified as the format "540p30". These parameters are one-half the spatial resolution of 1080p in each direction, one-quarter the total number of pixels. iFrame has 1.5 times the number of pixels in standard definition 4:3 720×480 CCIR 601 NTSC video. However, its progressive scanning increases the approximate perceived resolution advantage over 480i to roughly a factor of 2.
The 30 fps frame rate used for iFrame may result in increased "judder" with moving images, when compared to the nominal frame rate of 60 fields per second (30 fps interlaced with even and odd lines) used in North America for professional video.
The audio is AAC-encoded.
The video sub-sampling, bit-depth, and the video, audio and aggregate bit-rates are not yet publicly known.
At introduction in October of 2009, two camera models from Sanyo supported the format.
