, Android’s Bluetooth latency requirements a main overhaul for authentic-time articles, Next TGP

A lengthier edition of this post was originally printed at our sister web site SoundGuys.

Android and audio can not seem to be to get along. Google has put in many years slowing correcting the round-excursion latency problem, however some OEMs continue to have not gotten the memo. Even worse nonetheless, the world’s most preferred mobile OS is not addressing this looming challenge for wireless headphones. Currently, Bluetooth audio adoption is immediately expanding, however very long latencies protect against these headphones from staying appropriate for true-time use cases. This can consist of using movie phone calls, streaming motion pictures, and participating in video games.

In scenario you haven’t observed (someway), latency is that minimal hold off you’ll hear involving pressing pause and the music in fact halting. Or between viewing an opponent and only then hearing their footsteps in PUBG Cellular. At best, long latency is inconvenient, at worst it ruins the knowledge. Ideally, latency ought to be under 20ms in which human beings simply cannot notice it. Between 40ms and 80ms, it’s really really hard to detect, but over 150ms and you’re into distraction territory.

For the reason that of the extra wi-fi transmission and audio packaging delay, Bluetooth products are specifically prone to lag, hold off, or latency, or whichever you want to phone it. Sadly, Android’s intricate audio chain provides in its have share of delays, and some handset brands are notably even worse than some others.

Some smartphones have lessen latency than some others

To exam latencies on current Android equipment, we grabbed a assortment of handsets, a Bluetooth receiver with assistance for all of today’s Bluetooth codecs, and a Teensy LC microcontroller to use with Google’s WALT latency testing application. We ran 100 tests on just about every handset for each and every Bluetooth codec, so our success made 2,800 knowledge points.

For starters, there’s a great deal of variation amongst handsets and codecs. Google’s Pixel 3 XL offers the lowest total latency and also the smallest variation concerning check operates. The OnePlus 6T produces similar outcomes, although it reveals a better variance with AAC, SBC, and aptX High definition. Even although these phones are, by far, the best I have tested, their average latency arrives out to 244ms and 250ms respectively. Absolutely not excellent enough for serious-time content material.

, Android’s Bluetooth latency requirements a main overhaul for authentic-time articles, Next TGP

The Huawei Mate 20 Pro showcases the aforementioned Android computer software challenges. Its average Bluetooth latency is a staggering 484ms, practically double that of the Google Pixel 3. It also displays appreciable variance in Bluetooth latency, averaging 47ms among its swiftest and slowest hold off. The Samsung Galaxy S10 is unquestionably greater but also exhibits a deficiency of consistency in its Bluetooth latency. All are rather horrible for true-time content.

>250ms latency is very inadequate, and a lot of telephones have a extremely high latency variation as well.

The clarification for these variations harkens back to the Android audio chain mentioned before. There is no way to enforce the use of the reduce latency AAudio API over the additional variable OpenSL ES APIs. The ALSA motorists, audio and Bluetooth HAL, and AudioFlinger buffer dimensions are all variable relying on how the OEM implements them in its model of Android. Additionally, intense CPU gating can involve even lengthier buffers way too. The base line is that Android does not provide a speedy-observe, low-latency audio path that is confirmed to do the job on all telephones.

, Android’s Bluetooth latency requirements a main overhaul for authentic-time articles, Next TGP

Small latency matters if Bluetooth is to rival wired headphones

Wired headphones aren’t likely any where whenever soon, but if Google and its associates are certain about sooner or later transferring to a wi-fi they have to get significant about Bluetooth audio. Not just in conditions of new music high quality, but also matching the person practical experience for phone calls, movies, and gaming. Wired headsets offer zero latency, and Bluetooth execution wants to close the gap to be regarded practical. Part of this will have to appear from alterations to the Bluetooth normal by itself, but it’s crystal clear that Android and OEMs can do greater also.

The bottom line is that Android’s Bluetooth audio latency continues to be really unpredictable dependent on the handset producer. Google is foremost the way by implementing its most current small latency sign routing, but other suppliers are still sluggish on the uptake.

Android Bluetooth latency differs a large amount by maker, and that’s a major difficulty.

Just like with Bluetooth audio quality, Huawei handsets surface to appear out worse in latency too. Your ideal bet is to adhere to smartphones that offer a inventory or in the vicinity of inventory Android knowledge. This involves phones from OnePlus, Google, and Nokia.

Regretably, there is not a typical codec for consumers to select if they are after good reduced latency (aptX Low Latency is out of date). Qualcomm’s approaching aptX Adaptive codec promises just 80ms of latency and could be the wireless option for minimal-latency shopper wants. But we’ll have to hold out to get solutions in our arms just before building any judgment phone calls, as latency could nicely differ by device as effectively.


Robert Triggs