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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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migrated from photo.stackexchange.com Sep 14 '12 at 23:38

This question came from our site for professional, enthusiast and amateur photographers.

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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 '12 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 '12 at 12:59
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1 Answer 1

up vote 2 down vote accepted

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 '12 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 '12 at 13:40
    
Does it affect perceivable quality or it is mostly to make the material more editing-friendly? –  Dmitry Pashkevich Sep 14 '12 at 14:03
1  
@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 '12 at 1:54
    
Thanks to all for explanations! –  Dmitry Pashkevich Sep 17 '12 at 7:52
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