Re: Opus Patent Pool
Reply #14 – 2023-01-20 14:33:26
So, first of all, I'm just some dummy somewhere on the internet. Don't take my word, this is all based on information available to the public.
I've looked at the European Patents. - EP2207170, "System for audio decoding with filling of spectral holes". Expires halfway 2023. It seems this would be applicable to both encoding and decoding. I have no clue whether this applies to Opus. Even if it does, the patent expires soon. - EP1873754, "Audio encoder, audio decoder and audio processor having a dynamically variable warping characteristic". Expires 2026. I have no clue whether this applies. - EP2144171, "Audio encoder and decoder for encoding and decoding frames of a sampled audio signal". Expires 2028. I have no clue whether this applies - EP2352147 and EP2304723, expire 2029. Apply to encoding and decoding, one patent for each. This patent specifically states using bandwidth extension. As far as I know, Opus doesn't do that. The Opus specification says: The output of the Opus decode is the sum of the outputs from the SILK and CELT decoders with proper sample rate conversion and delay compensation on the SILK side, and optional decimation (when decoding to sample rates less than 48 kHz) on the CELT side. So there is no clever combining like the patents claim, simply added together. - EP3364414, "Audio bandwidth extension decoder, corresponding method and computer program". Expires 2029. As far as I know Opus doesn't use bandwidth extension. - EP3605534, EP2589046, EP3079153, EP3422346, EP3079152 and EP2757560, "Audio decoding with selective post-filtering ". Expires 2031. Applies to decoding. This first of these patents was filed at a point where the Opus specification wasn't final, but the draft was already 160 pages long, excluding the appendices. - EP2625688, "Apparatus and method for processing an audio signal and for providing a higher temporal granularity for a combined unified speech and audio codec (usac)". Expires 2031, filed even later than the previous entry on this list. It seems to apply at least to decoding. As noted before, the numbers of these European patents have been 'copied' as being French, British, Italian, Dutch patents, but these patent numbers do not seem to exist or are completely unrelated.