I Frame
An I frame is encoded as a single image, with no reference to any past or future frames. Often video editing programs can only cut MPEG-1 or MPEG-2 encoded video on an I frame since B frames and P frames depend on other frames for encoding information.



I-MPEG
Intraframe MPEG. An unofficial variation of MPEG video encoding that uses only intraframe compression. I-MPEG is used by DV equipment.



Interlace
Each frame of a video picture is scanned twice. Firstly, all the odd lines are broadcast, then all the even lines are broadcast. Each set of odd/even lines is known as a field. Two fields therefore make up a frame. The point of doing this is to reduce flicker, and not increase bandwidth.



Inverse Telecine
Inverse telecine (IVTC) is when a codec takes a 29.97 frames per second interlaced NTSC video that has gone through the telecine process and reconstructs the original 24 frames per second progressive FILM video.

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