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I've started seeing this term mentioned in camera specs but have no idea what it means. It somehow relates to recording video.

Can somebody please explain where does it come from and what it means?

Here's all I found: http://www.dslrnewsshooter.com/2012/03/02/canon-launch-5d-mkiii-headphone-jack-all-i-recording-and-better-controls/

The compression system is the same as the 1D X and supports the higher bitrate ALL-I compression system alongside a more regular IPB option. The ALL-I mode is supposed to offer easier editing due to it’s less compressed nature, whether it also offers improved quality over standard IPB remains to be seen.

Also, the upcoming Panasonic GH3 has

Video Bitrate 50Mbps (72Mbps ALL-I)

Never seen this thing before...

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    This is the Photography SE: there is an AV SE that will be much more likely to yield a decent answer for you. Flagged for migration.
    – ElendilTheTall
    Sep 14, 2012 at 11:54
  • Could you please link the SE you are talking about? I can't find it in the footer...
    – Dmitry Pashkevich
    Sep 14, 2012 at 12:59

1 Answer 1

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This will get migrated but the short answer is that ALL-I stores every frame in it's entirety, whereas other methods store a certain number of keyframes in entirety, with the other frames stored as the difference to the keyframe.

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  • Thanks! Does the abbreviation decode to something?
    – Dmitry Pashkevich
    Sep 14, 2012 at 12:53
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    @DmitryPashkevich it just means "All intraframe", in other words every frame is a completely coded picture (as opposed to predictive frames, which are based on I-frames and cannot be decoded into a picture on their own).
    – Matt Grum
    Sep 14, 2012 at 13:40
  • Does it affect perceivable quality or it is mostly to make the material more editing-friendly?
    – Dmitry Pashkevich
    Sep 14, 2012 at 14:03
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    @DmitryPashkevich Whether it affects perceivable quality depends on which codec, mostly. What is can often mean is when pausing the video, odd artefacts appear. It is definitely more editing-friendly, however, regardless of the codec.
    – nchpmn
    Sep 15, 2012 at 1:54
  • @nchpmn: If you get odd artifacts when pausing, your decoder sucks. >.< I-only video is more editting friendly because you can seek more quickly to any arbitrary frame, instead of having to decode from the previous keyframe. You can also cut / merge at any frame, because every frame is a keyframe, but that's only useful if you weren't going to re-encode for distribution.
    – Peter Cordes
    Jun 5, 2015 at 19:36

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