Bluetooth audio quality has improved significantly over the last decade or so, somewhat offsetting the mobile industry's frustrating decision to get rid of the headphone jack. High-clarity codecs like Qualcomm’s aptX HD have led the charge on this front, but in order to use the feature, your phone must be able to encode audio in the format in addition to your wireless headphones or earbuds being able to decode it. Thankfully, a recent move by Qualcomm could make aptX codecs more widely accessible.

Like Sony’s AAC, the aptX codec requires licensing. In a neat explainer about the matter on Reddit, Android expert Mishaal Rahman specifies that device manufacturers need to pay Qualcomm a pretty high licensing fee before they can use the aptX and aptX HD encoders in their devices. A few months ago, Rahman found an Android Open Source Project (AOSP) patch from Qualcomm engineers pertaining to the aptX encoders, originally filed in November.

The Bluetooth A2DP stack has included support for proprietary encoding like AAC, LDAC, and aptX HD since Android 8.0 Oreo five years ago, but companies still needed to pay the likes of Qualcomm for the encoder. With these encoders now integrated into AOSP, they are a part of the Bluetooth APEX. In a statement to Rahman, Qualcomm confirmed Android OEMs don’t need to pay the company for licensing to access aptX and aptX HD encoders. They are now a part of the AOSP Apache license, and free to use.

We made the decision a few months back to include the encoders for classic aptX and aptX HD in the Android Open Source Project.

...

We are excited to say that under license from Qualcomm, these encoders are indeed now available under AOSP pursuant to the [license agreements] in place.

...

As per our usual business processes, the licensing of aptX [will remain] unchanged apart from contributing the aptX and aptX HD encoders to AOSP.

This means any developer creating a custom Android-based ROM can now add support for Qualcomm aptX or aptX HD without ripping them from a licensed build. We may soon see many custom ROMs and Android OEMs finally embracing these high-end audio features.

This change to AOSP isn’t nearly as significant for the average Android user. But before this, manufacturers were all paying as much as a $6,000 one-time payment alongside a per-device fee for access to the encoder. So it's possible we could soon see support for the encoders in Samsung and Honor phones, which reportedly have not supported aptX HD before now.

However, Qualcomm specifies that the only aptX products being included in AOSP are the encoders, so companies will still have to pay licensing fees to use other aspects of aptX such as the decoder on the receiving end of the Bluetooth connection. It is also still the ROM developers’ responsibility to use these now-open-source aptX and aptX HD encoders from AOSP. Nonetheless, there's one fewer hurdle, so we should hopefully see more devices supporting the hi-fi wireless audio format going forward.