I’ve tried my best to narrow down the case:
Gapless playback doesn’t work with OPUS files when playing via Bluetooth device (and that device is not Airpods)
UPDATE. I did some more testing and found out that the problem lies in 48khz sampling and not in OPUS, it’s just a coincidence that OPUS is 48khz-only, so is affected as well. I tested 44.1 AAC — it worked fine, i tested 48k FLAC — it also failed. So my current workaround is to (a) not use OPUS (b) resample my music to 44.1
So i tested several cases:
-
MP344.1khz files — gapless works fine both via iPhone speaker and via Bluetooth -
OPUS48khz files — gapless works fine via iPhone speaker, but for Bluetooth devices a very much audible gap (200–300 ms) is heard between tracks. Tested on two devices (Fiio BTR5, Plantronics Backbeat Pro 2) - When using Airpods Pro (and I assume the usual Airpods as well, but haven’t been able to test), strangely
OPUS48khz works fine via Bluetooth as well. But that might be some special Apple magic - Wanted to test whether it’s Apple bug so used another player app (Foobar for iOS) to test the same files — both
MP344.1khz andOPUS48khz worked fine even via bluetooth. So I conclude it‘s a VOX bug
Files used for testing: https://drive.google.com/drive/folders/1Gb8wOo5iCcFsIiR1ErwqMBwEvlx3zLkp?usp=sharing
iPhone 11, occurs in both the latest VOX store version + latest beta from TestFlight