AVIF is a format that puts an AV1 bitstream into a HEIF container. You're thinking about what AOM said about AV1 [6], not AVIF; they should not (and in fact do not) make that claim for AVIF -- which builds on HEIF that isn't their work -- though you ought to judge the situation for yourself [7].
I am not a lawyer, and I realize there's a fine line between genuine concern and spreading FUD, but in the spring of 2019 I looked into the patent situation around the HEIF container itself [1] -- the container upon which AVIF builds -- and skimmed through the 5 US patents I found, which cover some techniques that can be used in the format.
Most of them can probably be avoided for the purposes of an AVIF file, but patent US20160232939A1 [2] in my reading seems to be about in-container signalling to express relationships between a "static media item" and "one or more entities" that together "form a group", and "indicating, in the file, a grouping type for the group". The patent appears to be written in a way to allow this definition to encompass, say, a thumbnail and a bunch of frames thereafter, or, say a master image and a set of pictures derived from it, or alternate camera angles of the same thing. Some of these techniques sound like stuff we've seen before, but as is common in patents, the precise wording of claims is often key, and this is where patent lawyers come in.
A thorough look of the AVIF specification [3] and the patents registered with the MPEG LA about this format [1] is likely wise before any widespread deployment that makes use of advanced features of the HEIF container; using it to hold exactly 1 'one-layer' still-image is probably fine.
Additionally, in my reading [5], the HEIF reference software released by Nokia [4] includes a patent grant for non-commercial evaluation, testing and academic research only.
I had that question before too, still not sure why they picked HEIF for AVIF, instead of using some more obviously free container. They could easily avoid all the above.
I am not a lawyer, and I realize there's a fine line between genuine concern and spreading FUD, but in the spring of 2019 I looked into the patent situation around the HEIF container itself [1] -- the container upon which AVIF builds -- and skimmed through the 5 US patents I found, which cover some techniques that can be used in the format. Most of them can probably be avoided for the purposes of an AVIF file, but patent US20160232939A1 [2] in my reading seems to be about in-container signalling to express relationships between a "static media item" and "one or more entities" that together "form a group", and "indicating, in the file, a grouping type for the group". The patent appears to be written in a way to allow this definition to encompass, say, a thumbnail and a bunch of frames thereafter, or, say a master image and a set of pictures derived from it, or alternate camera angles of the same thing. Some of these techniques sound like stuff we've seen before, but as is common in patents, the precise wording of claims is often key, and this is where patent lawyers come in.
A thorough look of the AVIF specification [3] and the patents registered with the MPEG LA about this format [1] is likely wise before any widespread deployment that makes use of advanced features of the HEIF container; using it to hold exactly 1 'one-layer' still-image is probably fine.
Additionally, in my reading [5], the HEIF reference software released by Nokia [4] includes a patent grant for non-commercial evaluation, testing and academic research only.
[1] https://news.ycombinator.com/item?id=19874321 [2] https://patents.google.com/patent/US20160232939A1/ [3] https://aomediacodec.github.io/av1-avif/ [4] https://github.com/nokiatech/heif/blob/master/LICENSE.TXT [5] https://news.ycombinator.com/item?id=19874368 [6] https://en.wikipedia.org/w/index.php?title=AV1&oldid=9976507... [7] https://github.com/AOMediaCodec/av1-avif/issues/2