Apple has taken the first step to officially add support to AV1

Core Media is Apple’s framework that manages the types of content and codecs that can then be managed by AVFoundation and by the various operating systems. The latest change to the list of supported codecs saw the introduction of a new constant, kCMVideoCodecType_AV1: we are facing the first step towards adding full support for the AV1 codec within Apple operating systems.

The management of the various codecs by the Cupertino company has always been very particular, especially as regards the codecs intended for the reproduction of distribution formats: the HEVC hardware decoder, for example, was also present inside the A10 but Apple decided not to disclose this information by keeping it off and disabled until the A11’s launch the following year, when the format was more mature. It was then unlocked on all products.

No one today can tell if an AV1 hardware decoder is present within the media engine of the M1, M2 or A15 processor, but what we do know is that in addition to the Core Media modification within iOS 16, iPadOS 16 and macOS Ventura the AV1SW.videodecoder is connected to an ARM build of the well-known opensource decoder dav1dwith some elements that also refer to the GPU acceleration given by Metal.

One of these is, for example, the “film grain”, that is the noise and disturbances typical of old films. In AV1 compressed content this noise can be generated in overlay by the decoder based on a parameter that indicates the amount of noise to be added, and is therefore not encoded together with the content to avoid an excess of artifacts. In the beta of the new OS there are several libraries such as “/System/Library/VideoDecoders/AV1SW.metallib” which exploit the shaders of the GPU through Metal to generate elements such as the film grain.

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If things don’t change, we’re still in beta, iOS 16 and macOS Ventura will have a partially GPU accelerated AV1 decoder on board for some components, a decoder that will also work on older iPhone and iPad models, as long as they have an ARM processor inside. From the tests done on M1 Dav1d, the most famous AV1 codec, it manages to be decidedly lean in terms of resources required when working on Apple Silicon therefore it may not be necessary to add a real hardware encoder / decoder within the media engine, where we find the ProRes and HEVC decoders. In fact, it is difficult to think of AV1 as the default format for the timeline of an editing software such as Resolve, Premiere or FinalCut: it was not created for this, but to save bandwidth while maintaining high quality within streaming services.



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