3 ms·
They capture a second or two of (lower-resolution) video frames before and after the photo itself, plus audio. The UI on the iphone is that you hold your finger
by karatestomp 6y ago
They capture a second or two of (lower-resolution) video frames before and after the photo itself, plus audio. The UI on the iphone is that you hold your finger on the photo and it plays the "live" version. Under the hood IIRC it's just a short video + still bundled together in a container. The effect is reminiscent of the magical photos in the Harry Potter films, and when looking back at photos of one's kids from years prior it really is magical. To take them, the UI is the same as taking any other photo, except that you must know to keep the camera steady a second or two before and after taking the photo itself (it'll still be captured just fine regardless, but the "live" part will be a blurry mess if the camera's moving) which is the real genius of it—no extra effort, really, and it's automatic, provided live photos are enabled, so you don't have to decide whether you want to take a video versus a photo, you just take the photo and get a tiny little video to go with it.
- euoia 6y agoAre the other frames lower resolution? The short videos are quite low frame rate. On iPhone X at least you can choose a different frame to use as the “main” photo. They don’t seem to be lower resolution.
- mceachen 6y agoThey were 1080p/24, last time I checked when I was adding support for them for PhotoStructure. Picking a different frame doesn't impact visual quality on a mobile screen, but it was quite a noticeable IQ drop on a 4k/5k display. Things might be different on newer iPhones and the latest iOS.
- nonesuchluck 6y agoI don't have any specific knowledge of Apple's actual implementation, but I've always assumed it used the full-resolution still image as a keyframe (I-frame), and the video clip as B-frames before and afterwards, compensating for changes over time. Choosing a new key photo may be full resolution, but is likely to be degraded in sub-perceptual ways. It does pull multiple full frames off the sensor in rapid exposure tho, and chooses whichever one it thinks best (blur, ML, whatever) for the initial key photo.
- karatestomp 6y agoI think there's a (totally normal and full-res) photo and separate video, if you look at the actual files. I don't know how that works with the ability to choose a different still.
- karatestomp 6y agoOn my iPhone 7 Pro, yeah, they're much lower-res. Might be different on newer phones, I don't know.
- bigyikes 6y agoYou made me realize that I’ve had live photos disabled for a long time. Sad that I missed out on so many “magic” moments but I’m glad it’s on now!
- agumonkey 6y agoOk, I forgot the term. I did see that on my cousin's phone and it felt "special". In these days where nothing jaded me it was quite a surprise.