Bluetooth AVRCP Volume fix for Anna, Belle, Belle Refresh.
v2026.02.19

Variant 1: btvolumefix.rmp patch.
Forces AVRCP 1.4 support to enable absolute volume control.

1. Copy btvolumefix.rmp to your patches folder
2. Open RomPatcher+, add btvolumefix.rmp to Auto
3. Reboot the phone

Variant 2: Relative volume control workaround (Not recommended)
Enables legacy bluetooth volume control from pre-^3.
Volume buttons +/- will be passed directly to headset.

1. Add and enable CRepository4all.rmp in RomPatcher+ (do not add it to autorun)
2. Install btlegacyvolume.sis
3. Open "Bluetooth Volume Workaround" that appears in applications menu
4. You should see "Bluetooth legacy volume control enabled" note
5. Disable CRepository4all.rmp
6. Reboot the phone

Why this bug exists:
Device attributes were being read incorrectly, leading to broken AVRCP 1.4 support.
This bug is fixed in Belle FP1 & FP2, do not apply this patch on these versions.

Use at your own risk.
Check https://nnproject.cc/btvolumefix/ for updates.
