Wireless headphones and earphones typically use a variety of different codecs to connect to your smartphone. There's SBC, which pretty much all devices support as a baseline, AAC, which is a higher quality licensed codec, and a litany of proprietary formats such as LDAC. One such codec that was also proprietary and required licensing to incorporate into a smartphone was aptX, a codec developed by Qualcomm. That's changing though, as Qualcomm recently open-sourced its aptX and aptX HD encoders by submitting them to the Android Open Source Project.

This discovery was made by Mishaal Rahman, who contacted Qualcomm in November 2022 and confirmed that its addition to AOSP was done "to enable people to distribute the encoders as part of their finished products." This is useful to both smartphone manufacturers and custom ROM developers alike, as custom ROM developers had to rip the shared libraries from a pre-compiled build and incorporate them in the ROM, which was questionable on a legality level.

As for how it will work, aptX and aptX HD encoders will be compiled as part of the Bluetooth APEX, the Bluetooth Mainline module. It's important to recognize too that this doesn't mean audio product manufacturers will be able to license their products as aptX compatible for free, as this only pertains to the software running on smartphones. There are quite a few devices that don't support aptX HD out of the box, which is why this change benefits Qualcomm. aptX and aptX HD support across the Android ecosystem serves to benefit the company in the long run, as it makes audio products with support for both of them more appealing.

It seems likely that this will change will be in place from Android 14 and newer, meaning that devices that launch with it should have support, especially given that a test in the Mainline Test Suite was added to confirm aptX is working and in place. Keep in mind the existence of a test doesn't mean that it's mandatory, though, and devices like the Samsung Galaxy S23 series don't support aptX HD. Nevertheless, if you have audio products that support the aptX or aptX HD codecs, then this will be a welcome change for you.


Source: Mishaal Rahman