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Comment by Neil44 | Hacker News Reader

If you had to bet on Apple supporting APTX Lossless or inventing their own thing that won’t work with other peoples stuff, you already know what they’re going to do.

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Well, AptX is shit (non-lossless), the only okay codec in use is LDAC, and it's by brute force - 990kbps is awfully close to flac typical bitrate (you'll also get connectivity issues for obvious reasons). Also legal reasons - everyone wants $$$$ for their shit codec

I don't know why the whole ecosystem is so fucked up, even AAC ~256kbps can pass double blind test against lossless source, assuming properly encoded and decoded - this assumption is not fulfilled in a slightest in Bluetooth land.

P.S. I really want to see some good and open codec, like .opus, properly implemented - this will close major source of frustration for everyone involved and will drive whole industry forward

I feel like the real improvement in aptx is not the audio quality, but the latency for keeping audio and video in sync when watching tv (or computers for that matter). I used to work in the bluetooth chip industry and there really were very few players who were competitive in the audio headset business. I don't have any real insight into the players these days, but I would be very surprised if there were more than 4 chip makers who were competitive in that space. CSR was the dominant player for audio, so it's not surprising that Qualcomm who bought CSR offers this proprietary solution. So I think it's going to be really hard for someone to make an open codec solution that competes in terms of size, battery life, cost with an IC that's targeted to the market.

>but the latency for keeping audio and video in sync when watching tv (or computers for that matter).

realistically speaking latency only matters in games/calls. For any sort of media playback you can just delay the video stream to compensate.

... Which are incredibly common everyday use cases for the majority of users. I don't see why latency should be sloughed off as unimportant.

Afaik that solution isn't available on any existing consumer electronics for legacy bt audio e.g. a2dp.

There's also LHDC/HWA from Huawei/Savitech(?) for the two headphones that support it. It's approved by the Hi-Res society or whatever like LDAC.

Good luck finding a system that can play back LHDC though. At least thr LDAC encoder is free (to my knwoledge) and Android and PipeWire have support for it. LHDC, you'd better get the one of three phones that support it (from Huawei, Xiaomi, maybe OnePlus I think). I mean, Savitech has their forked fluoride Bluetooth stack + aarch64 LHDC binary blob and wrapper library source code on GitLab but I guess you'd have to hack something together to try it.

I'm very much in favour of Opus on Bluetooth and if you browse Reddit you will find someone has attempted to work on it but no details past that: https://www.reddit.com/r/hardware/comments/enad1t/comment/fd....

What is the latency for something like AAC? How much power does it take to encode and decode?

It seems to me like some of the big constraints on codec choice are power, latency and then quality. Maybe “spectral efficiency” too, but I don’t really know.

Could be why they are using a high rate lossless codec? Maybe said codec is super efficient to encode on a tiny airpod with a tiny power source?

I guess what I’m saying is maybe there are additional constraints specific to this problem domain that aren't a concern for the rest of us?

That doesn’t mean it can’t be an unencumbered, open source codec though. It just might mean the “common” ones out there don’t fit the constraints of the system.

AptX adaptive is an adpcm codec, so there is no artifact except for a higher noise level.

At 460kbps it's very very similar to LDAC at 990kbps.

It's also unlike AAC a truly adaptive codec.

If you really need it AptX also has a lossless mode iirc.

The best codec would obviously be to just use Opus, yeah. But AptX adaptive pretty much solves Bluetooth audio.

No idea how it supposed to work in theory, in practice every device combo i tried works noticably worse with AptX (than LDAC, even non-990 one). Don't have any device capable of AptX lossless.

Re: solve - as long as there are licensing issues, it can't solve BT Audio even if it was such great codec

P.S. Random link from google with measurements of some actual device using AptX, AAC, LDAC

https://www.audiosciencereview.com/forum/index.php?threads/t...

Again, that is AptX, not AptX HD or AptX adaptive. I don't think the lossless mode is in any product yet.

How are you able to know which codec is being used over the Bluetooth link?

E.g. my device (Fiio BTR5) tells me on its builtin display. Also for LDAC there's separate toggle in UI. Also Developer Tools stuff

Aptx is actually pretty good, certainly for ear pods. It's a time-domain codec which is great for acoustical instruments (the frequency-domain codecs can fail there, AAC too).

The signal-to-noise ratio is lower than CD quality but still good enough so that noise is not audible:

http://soundexpert.org/articles/-/blogs/audio-quality-of-blu...

I'm not sure compatibility with other people stuff is something that apple would concern itself about, I think that might be true for anyone else, but apple supporting only apple ecosystem the best way it can, I think according to its history, is the preferred way, and I think next iteration might be like that, first they had to show what potential apple sound would be like, once people know its top of the top, they can restrict it to apple only, personally I've known a lot of apple users, and people with an iPhone or a mac, have also an iPhone, a Mac, and an iPad, and AirPods

Apple could sell some of their devices - like air pods - to people that are not already Apple customers. But that requires compatibility.

Have you bought airpods without iphone? You can't even see the battery level reliably without third party apps, which don't even consistently work? I'm an android user and had them for a couple of weeks, before returning them, they're already part of a closed ecosystem

Is APTX Lossless an open standard? It doesn't look like it to me. I don't know why Apple would depend on a non-open standard that they don't have to.

It isn't, but there are reverse-engineered encoders and decoders, at least, in the form of libopenaptx and libfreeaptx. This is what PipeWire on Linux uses to play aptX audio (specifically it uses libfreeaptx).

Nobody uses AirPods with an Android phone do they? I mean why would you, I thought the whole point of the AirPods is the advanced Apple integration?

No, they’re good ear buds on their own. The integration actually is minor. I use mine with my Windows devices too.

I'm by no means an Apple fan, but AAC on Android is worse due to using SOC-builtin encoders a lot of the time (sometimes they use the Fraunhofer AAC encoder, which sounds better). Apple's AAC encoder is unparalleled and the difference is 100% tangible, so the listening experience will be better on iOS, followed by whatever uses the Fraunhofer encoder (PipeWire on Linux is pretty damn solid in AAC Bluetooth for this reason, but not as good).

They work just fine on Android. The important (IMO) features of noise cancellation and detecting when in/out of ear work flawlessly.

I also have family members who use them with windows for video calls, they work with just about any Bluetooth source afaik

I'm using them, both with my Android phone and on my Win laptop. I experienced two issues tho.

First one was that you can't see a charge percent by default, but I managed to fix it by installing an app from Play Store. Second one is that sometimes, when they connect to my phone, volume somehow glitches, so even if it's on the half the strength, you can barely hear them.

I use them with my Android phone. Seems to work well.

Linus Sebastian has been doing so for years now.

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