If you listen to older versions of Opus @ 32kbps, you'll hear the distortion more pronounced and then when you slowly upgrade versions you can hear it go away and then when comparing to uncompressed, you'll notice just because you know what you're looking for.
Xiph is amazing; I hope Daala actually becomes commonplace, but with the recent Apple announcements it's looking like a chance to usurp h.265 is basically gone.
Many pieces of Daala are being folded into AV1, which is an industry effort supported by most large software and hardware companies to produce an HEVC replacement. This post summarizes the results of the different experiments: https://people.xiph.org/~jm/daala/revisiting/
Unfortunately some of the most innovative techniques around frequency-domain prediction ended up not panning out. :(
The AOM patent license covers any implementation of the format. It additionally covers the reference implementation, because the encoder may use techniques that aren't part of the bitstream format, and it's important to grant rights to those too.
Indeed, the whole point of Daala and AV1 is to do a really good job on the IP front so as to make it much harder for patent trolls to hold everyone hostage [0].
Yes. They have applied for a patent on ANS and video compression - ANS is one of the biggest advances in lossless encoding in the last 10 years. The inventor wants to keep it freely available, has helped Google for three years to incorporate ANS in AV1 - their reward is to try to patent his invention. More details here:
Anyway, as TD-Linux said above, any implementation is allowed.
> 1.1. Patent License. Subject to the terms and conditions of this License, each Licensor, on behalf of itself and successors in interest and assigns, grants Licensee a non-sublicensable, perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as expressly stated in this License) patent license to its Necessary Claims to make, use, sell, offer for sale, import or distribute any Implementation.
> 2.6. Implementation. “Implementation” means any implementation, including the Reference Implementation, that is an Encoder and/or a Decoder. An Implementation also includes components of an Implementation only to the extent they are used as part of an Implementation.
The two big Internet streaming companies have chosen VP9 over h.265 and are both developing AV1 to use instead of h.265's successor. Apple's announcement is unlikely to change anything as far as what gets used on the Internet.
I predict a lot of angry smart TV owners - I have a 4K TV that can't decode certain VP9 profiles in hardware, so YouTube on the TV itself is very limited. Not sure what's available in S90x chipsets, though. Does anything do VP9.2 + Opus in hardware?
I think the solution there is to get a streaming stick or a streaming set top box that supports VP9 to plug into the TV. Or alternatively a small form factor PC like a Zotac mini pc, or palmtop if it's strong enough:
Such people can either use lower quality H.264 versions which are commonly provided, or as others said, get an external device to decode modern free codecs.
That was expected, since Apple are part of MPEGLA cartel and they strongly oppose free codecs. But it doesn't really mean anything, since everyone else would have to pay arm and leg to use it, so the pressure to adopt free codec is still here. I hope AV1 will come out soon enough. Daala itself isn't really ready as is.
Apple held off on adoption of HEVC and they certainly don't make as much money as they pay. As much as I hate Apple's love for proprietary technology, had AV1 been released on schedule Apple might have adopted it.
Apple probably held off adoption so that HEVC patent license situation improves a bit (at least most companies with patents join in some pool or start to offer licenses).
If AV1 would be released sooner it wouldn't be even as good as HEVC, which would be bad. VP9 is already that free-but-not-as-good-as-HEVC codec. Also they would need to release AV2 in 1 or 2 years (as the better-than-HEVC codec), which is just too soon after AV1 and would put a big question on why AV1 was released at all...
I'm actually unsure what's meant by reference here. But VP9/10 is the base codec on which AV1 is being built, but many of the most significant innovations from Daala are being folded into AV1.
Daala isn't dead and will continue to have value, at the very least as an experimental/development codec, but it may also form the base of a future static image format (it compares very well against JPG and HEVC/BPG.
This is comparison is over a year old so it's even better now: https://people.xiph.org/~jm/daala/revisiting/compare.html
I don't think it can move fully, since Daala is by design a different type of codec (using lapped transforms), while AV1 is more "classic" / block-DCT type of codec.
I.e. it makes sense to develop Daala further. Not sure what's going on in practice though. I guess it's better to ask Xiph / Mozilla.
We may return to Daala in the long term: it has competitive performance with HEVC on perceptual metrics despite a vastly simpler design than AV1 or even VP9, and despite being less mature than the classic block-based approaches and missing many tools that we simply didn't have a chance to implement (e.g., Daala has only basic MPEG2-style B-frames with no bi-prediction, as just one example).
Like the old adage says, if you have two baseball players who can run to first base in the same time, and one has perfect form while the other one looks lousy, which one do you pick? The guy with lousy form, because teach him the right form...
However, a lot of Daala's design is predicated on having a very constrained legal budget and not being able to rely on anyone else's patents. With the Alliance for Open Media, both of those constraints are relaxed. So even in the best case the result is likely to look pretty different from the way Daala looks today. Ultimately we're interested in making a codec people will actually use, and that means working with our partners.
The threshold for "transparency" varies a great deal across users. Some people I know cannot ABX 64 kb/s Opus from the uncompressed original, yet once in a while we hear of someone being able to ABX one particular sample all the way up 192 kb/s. There's also the issue of whether you have the reference to compare. Personally, I stop being able to ABX Opus somewhere around 128 kb/s, but I won't be able to tell that a song has been compressed with Opus at 96 kb/s unless I have the original to compare it to.
Listening through all of them, 32 and 48 do have noticeable artifacting if you are using a good sound setup. On my phone though, even 48 was "as good as it gets" for its speaker.
It is still pretty crazy that I find a sub 100 kbps sound sample to be indistinguishable from lossless. Definitely considering transcoding my flac library to 96 vbr opus for backup purposes.
I have a local backup of native files, but I also have some external 1TB drives I usually get access to once a year and store at relatives places in case my house burns down. They aren't big enough to store my entire media library so I usually end up downsampling to "good enough" copies in case of a disaster.
It's really amazingly impressive that it also holds well across the different musical pieces and different frequencies / timbres. Is this yet another order of magnitude improvement in audio file size?
I wonder why the MP3 at low bitrate sounds a bit like a lowpass filter.
At low bit-rate, lame applies a low-pass and resamples to a lower sampling rate. If it didn't to that, MP3 would end up completely starved of bits (trying to code all frequencies) and have really atrocious artefacts. Based on personal experience and the results from a few listening tests I saw, I think you can assume that Opus can now give you about the same quality as MP3 for about 60% of the bits. For example, 76 kb/s Opus should be around the same quality as 128 kb/s MP3.
I wasn't able to hear a difference on that website, but I tried some songs on my computer and there was audible hissing in some parts (it mostly sounded great to me, though). All that was gone at 48kbps, though. It's kind of crazy to see a full-length album sounding amazing at 20MB. I think if I were to convert everything I'd go a little higher (64?) to be safe, but wow.
Xiph is amazing; I hope Daala actually becomes commonplace, but with the recent Apple announcements it's looking like a chance to usurp h.265 is basically gone.