Apple photo editing session
When you need to do motion estimation at that half pixel or quarter pixel boundary, you need to be able to generate those pixels with accuracy and precision because those don't exist. For example, you know, something could have moved five pixels over but it could have moved five-and-a-half pixels over or five-and-a-quarter pixels over. Sometimes you don't always land in a pixel's boundary. And what you can do is say, you know what? This block is that same block from the past but moved over by a certain number of pixels. And this is where you try to find - you basically have a block in your current image that you're trying to predict from a previous image. While H.264 had up to nine, HEVC has up to 35.Ī key part of being able to do a high degree of compression involves motion estimation or motion compensation. To get better spatial compression, HEVC introduces additional directional modes. And similarly, with the coding block sizes for the transform blocks, it also goes up to 32 x 32. Similarly, H.264 had 4 x 4 and 8 x 8 DCT or discrete cosine transform, whereas HEVC not only uses a discrete cosine transform, it also uses a DST, distribute sine transform. And these it start down at 4 x 4 and go all the way up to 64 x 64.Īnd it's when you can use these larger sizes is when you realize the greater compression benefit.Īnd this is especially true when you're dealing with high resolution videos and images. HEVC introduces notion of CTUs or coding tree units. Now H.264 has a notion of macro blocks, which are 16 x 16 size blocks that are used within the codec for processing. And it uses temporal and spatial compression techniques to get the compression benefits. Now HEVC is similar to H.264 in that it is a codec that processes videos and frames in blocks. So we'll spend a couple of minutes talking about what makes HEVC such a great codec. And Apple is adopting it as its next-generation codec. We're going to be calling it and referring to it as HEVC.
#Apple photo editing session iso#
It was ratified by ISO as MPEG-H part 2 and by ITU as H.265. It is a state-of-the-art industry standard that was adopted and approved in 2013. HEVC stands for High Efficiency Video Coding. So having evaluated our options, we decided to select HEVC. And we were looking for something that was going to give us significant benefits over what exists today. We were looking for a next-generation codec that we could use both for movies and for photos or images. There are limits to what these codecs can do in this evolving landscape with these new challenges.
So we've been using H.264 and JPEG for a while. And anything we can do to reduce the bandwidth requirements really helps out those use cases. And certain applications and use cases like over-the-top video delivery and wireless networks place a premium on the amount of bandwidth. The nature of media is also changing with, you know, our personal favorite being live photos but there's lots of content out there, short-form video and so one.īandwidth continues to be at a premium. Not only that, the content is taking new forms like high resolution 4K video, HDR video, wide color or wide gamut video and so on. And both consumers and producers are generating more and more video and media related content. The world is becoming more and more visual. And then finally, we'll give an overview of how we've adopted these technologies within the Apple ecosystem and then also provide some guidance on how you can take advantage of these within your apps for your use cases. We'll talk about what are HEVC and HEIF and why we decided to adopt them here at Apple. So we're going to be going over the landscape of media as it is today, why we need to change.
Later on in the presentation, Gavin will talk to you about the specifics of our platforms and how we support these technologies in hardware and in software. And if you pay close attention, you'll notice that these files are a lot smaller than they used to be. In particular, we're going to be talking about a new codec for video and image compression called HEVC and a file format for images that we're adopting called HEIF.īut before we get into the details, if you've downloaded the developer seed, the latest build, then on certain iOS devices you are already capturing and using these new technologies and file formats. And we at Apple are really excited to talk to you today about two new media technologies.
#Apple photo editing session software#
And I'm a manager here at Apple in the core media software team. Welcome everyone and thank you for coming to this session.