[Xiaomi Redmi Note 4 Questions & Answers] knreddy:
aptx working solution on Redmi Note 4 (india) snapdragon

[Aptx was already working on my Redmi 2, 8GB ROM, 1GB RAM (Model HM 2014811) after installing CM 14.1 & Aptx through TWRP, (but it was not working on MIUI 6, CM11)]

In case of Redmi Note 4 the following method is successful.

Existing conditions:

Phone: Redmi Note 4 (India, i.e. Snapdragon), MIUI 10 from mido_global_images_8.7.26_20180726.0000.00_7.0_global_9529295baa.tgz

Fresh installed without setting any screen lock, password, finger print , google account Mi account (this is suspected to lead to data corruption, if it happens we have to flash above MIUI10 full fastboot ROM again, hence all files better to be saved on external SD Card)

Windows : Windows 10 v1707, 64 bit , Pda net installed.

Apps / programs required : may be googled and downloaded

Major Activities Involved

A.	Unlocking of boot loader

B.	(i) Installation of TWRP v3.2.2.0-mido.img (recovery suitable to Redmi Note 4 SnapDragon)

(ii) Installation of [Mido][Material][Twrp-Treble][3.2.1-10].zip (recovery suitable to Redmi Note 4 SnapDragon by Jairus980)

C.	(i) Installation of lineage-15.1-20180807-nightly-mido-signed.zip (ROM suitable to Redmi Note 4 SnapDragon)

(ii) Installation of open_gapps-arm64-8.1-nano-20180812.zip (gapps suitable to arm64)

(iii) Installation of Magisk-v16.7_Bundle.zip (both magisk & magisk manager for getting rooted)

(iv) Installation of REVOLT.EAS-R13-20180722-2040.zip (kernel after 20.07.2018)

(v) Installation of aptX-oreo.zip

(vi) Installation of Apt-X_HD_Port_by_androidexpert35.zip

(vii) Installation of aptX-HD_OreoEnabler.zip

(viii) Installation of lazyflasher-no-verity-opt-encrypt.zip (for no-verity-opt-encrypt)

A.	Unlocked boot loader

Official method (The process is simplified and the permission is granted automatically. You don't have to fill in any application form or wait for the SMS anymore)-successful on my Redmi Note 4 SD.

1. Settings---> About phone---> MIUI Version (Keep tapping it to enable developer option).

2. Settings---> Additional settings---> Developer option and bind your approved Mi account under Mi Unlock Status.

3. Go to https://en.miui.com/unlock/ and click on unlock now , change english , log in to mi your account (on pc_) , Download mi unlock to pc, unzip it , open mi unlock (on PC) log into the Mi account which has acquired unlocking permission on your device.

4. When you logged into the Mi Unlock Tool, tap on the top right gear icon to check the update for both USB driver and Mi Unlock Tool. Make sure you're running the latest version.

5. Turn off your device, press the Power button and Volume - button at the same time to enter bootloader mode

6. Log into the unlocking tool on PC with the same Mi account. Connect the device to the PC using USB cable

7. Press 'Unlock'. Press Unlock anyway, The unlocking process will complete in about 10 seconds (sr no 4, 5, 6 & 7 repeated twice, as unlocking hanged at 99% )

B.	(i) Installation of TWRP (img file)

1.	Install minimal_adb_fastboot_v1.4_setup.exe on PC and note down the installed directory.

2.	Copy twrp v3.2.2.0-mido.img (recovery suitable to Redmi Note 4 SnapDragon) to above directory and rename it to recovery.img (all small letters without any spaces in between) or any other name for the sake of easiness.

3.	Bring the Phone to fastboot (i.e. bootloader) mode (method: while the phone is in switched off condition press volume down and power button simultaneously still the phone is entered into fastboot mode [Bunny picture appears])

4.	Launch Minimal ADB and Fastboot on PC execute command

fastboot flash recovery recovery.img

5.	Press and hold volume up and power button simultaneously but release only power button after 8 to 15 seconds of restart and appearance mi logo and release volume button after TWRP appears.

(ii) Installation of TWRP by Jairus980

1.	Install [Mido][Material][Twrp-Treble][3.2.1-10].zip (recovery suitable to Redmi Note 4 SnapDragon by Jairus980) and wipe catche

2.	Press and hold volume up and power button simultaneously but release only power button after 8 to 15 seconds of restart and appearance mi logo and release volume button after TWRP Recovery Project (i.e. TWRP by Jairus980) appears.

C.	(i) wipe>advanced>select all except internal storage>wipe

(ii) Install “ lineage-15.1-20180807-nightly-mido-signed.zip” (ROM suitable to Redmi Note 4 SnapDragon) and wipe catche

(iii) Install “open_gapps-arm64-8.1-nano-20180812.zip” (gapps suitable to arm64) and wipe catche

(iii) Install “Magisk-v16.7_Bundle.zip” (both magisk & magisk manager for getting rooted) and wipe catche

(iv) Install (only after installation magisk) “REVOLT.EAS-R13-20180722-2040.zip” (kernel after 20.07.2018) and wipe catche

(v) Install (only after installation magisk) “aptX-oreo.zip” and wipe catche

(vi) Install (only after installation magisk) “AptX_HD_Port_by_ androidexpert 35.zip” and wipe catche

(vii) Install (only after installation magisk) “aptX-HD_OreoEnabler.zip” and wipe catche

(viii) Install at last but very important “lazyflasher-no-verity-opt-encrypt.zip” (for no-verity-opt-encrypt to be installed at last to avoid any over writing) and wipe catche

Reboot system

It will restart once, if taking more time switch off and switch on once

After the phone is on, click 7 times on build number to enable Developer options (settings>about phone> build number)

Redmi Note 4 SD Oreo 8.1 connected to Avantree Oasis (restart phone if any Bluetooth connection problem happens) in AptX mode can be seen picture

Not yet checked, but expect it will function even if unrooted.