Why xHE-AAC is being embraced at Meta (opens in new tab)

Reduced bandwidth obviously leads to better quality at the same target bit rate. Phone speakers are good enough to reproduce some obvious compression artifacts of, say, 32k/64k HE-AAC, let alone higher end headphones. ABR could definitely help.

Their web version seems to be the fallback (h264 etc) that is guaranteed to run on every device from the last 20 years pretty much. Then again, they clearly don't care about anything outside of their apps, the web experience (instagram especially) is a complete disaster of a walled garden with highly gimped functionality and extreme limitations everywhere.

The only good customer is one that willingly opts into all ads I guess.

Opus really is great. My first choice almost all the time.

Except... I wanted to stream music across the network to another computer with the lowest possible latency. I didn't care about the extra quality you get from lossless (opus sounded fine to me at 96kbps), but chose flac because it has almost no latency. Opus (and for that matter, all other codecs) added noticeable latency.

Chrome has supported xHE-AAC since 2020 on Android, 2022 on macOS, and added support on Windows last week.

They specifically mention that one of the advantage for them is the loudness management, to avoid having video with widely different range when their user are scrolling through their timeline.

I think Opus also has loudness management, but they seem fairly specific about the one that xHE-AAC provide : > Instead of burning in a specific target level and dynamic range compression (DRC) profile during encoding, xHE-AAC allows us to leave the original audio characteristics untouched and delegate loudness management processing to the client via loudness metadata, for the optimal audio experience based on context.

So maybe the xHE-AAC does provide a tangible benefit in this department.

Well less bandwidth and storage is also good for users.

Less bandwidth. Some users pay for bandwidth. Or have a monthly cap. So less bandwidth is a monetary advantage for users. It also may decrease time to play.

Similar, but less ctitical, for storage.

One rule of thumb when switching codecs is "don't decrease quality". I buy that Meta did that. Which would result in a slight improvement in quality (of course sold as big snd noticable) while getting storage and bandwidth down (or allow for better quality in the bandwidth adaptive case).

That saud. Yes. OPUS! Although other aites got quite some bad press for low bitrate opus.

Why can’t it be supported in web browsers? Is there a technical limitation or it just hasn’t been done because only Meta uses it?

People will often use the same bluetooth headphones to listen to music regardless of what kind of computer they’re using. I don’t think it’s safe to assume mobile devices have worse sound.

>This codec isn’t supported on the web. So it is Android and iOS only.

So it is supported on the web.

>This was probably done to reduce storage and bandwidth, not to improve audio quality.

Packing more information into the same amount of data is the literal definition of better quality.

>Phone speakers aren’t good enough to notice.

Maybe not, but phones can be connected to headphones and speakers which can. Especially if they connect via 3.5mm audio jack.

Built in sound level management sounds like a good enough reason

This change breaks video in stories on the website.

don't people wear headphones?

It's sort of bonkers that we've quietly gotten to the point that codecs for music are getting compared at the 32 kbps level, for full stereo. Audiophiles used to constantly be making comparisons between codecs to see what's superior, but that whole field seems to have died when Opus became very difficult to ABX at 128 kbps. There hasn't been a HydrogenAudio multiformat test in nearly a decade [1], and that one was 96 kbps.

These days even YouTube videos get transcoded to 128 kbps Opus, which is astonishing. Provided that the source is high enough quality, you can listen to transparent audio on the lowest-tier streaming platform.

[1] https://wiki.hydrogenaud.io/index.php?title=Hydrogenaudio_Li...

Yeah, opus is incredible for speech, but at those bitrates it gives music a kind of sibilant buzzing that I find really hard to listen to, whereas the muffled/underwater effect of mp3 and aac isn't much worse than just a lowpass filter.

What I found a few years ago was that explicitly lowpassing beforehand to match the other encoders (around 4-8kHz) gets rid of the buzzing. Apparently opus' threshold for automatically doing this is a lot lower than the other encoders; it keeps higher frequencies at the cost of more artifacts. I concluded that decimating or setting the encoder to 8kHz/"wideband" or lower was an improvement, with a similar resulting quality to AAC, but I still slightly preferred Fraunhofer at 12-28kbps.

By default, 12 and 24kbps are particularly bad; at 16k the quality goes up from going mono-only, and by 8k bandpassing is automatic.

>Looks like xHE-AAC beats opus on <32 kbps/s

to be fair that tester indicated only voice being ok, and everything else just bearable under condition you are consciously working under severe bw constrain "EDGE poor network is still enough to stream music without issue (in a tunnel, on mountain…)"

>xHE-AAC has no advantages over Opus

The main features focused on in this article are loudness management and adaptive bitrate audio. From what I can tell Opus supports neither of those things.

20 years.

Do you have the Facebook container extension?