[Nexus 6P General] Namelesswonder:
OK everyone, there seems to be mass confusion on what to do to get Viper4Android running, this guide should help clear that confusion.

DO NOT USE THESE FILES UNLESS YOU HAVE A NEXUS 6P. SO MANY PEOPLE HAVE ISSUES BECAUSE THEY USE FILES DESIGNED FOR OTHER PHONES.

Firstly: Are you running normal root or systemless root?

If you are running systemless root I suggest you switch over to normal root to get things working. So far, systemless root has been a roadblock for some people and Viper4Android starts acting up with systemless root installed.

Secondly: Have you flashed any of the billion V4A recovery flashable zips?

If yes, restore your system partition as those have a billion and one differently modified files that will probably screw over how your phone functions.

Thirdly: Do you have enough room in the /system and /vendor partitions?

Install the Busybox binaries (linked below) and open a terminal (using your favorite terminal app, or Terminal Emulator) and run

df

and make sure that you have enough room for the files.

If your /system partition is full, try deleting common apps like Chrome or Drive and install them from the Play Store as user apps instead.

If your /vendor partition is full, there isn't much to fix other than if you installed overlays for Layers, try uninstalling one (some overlays can go up to 400KB, like ones for Chrome). However, it may seem that you don't need to worry about the /vendor partition, more on that below.

OK, now it is time to continue.

If you don't want to follow this guide, then you can use Lollviper's recovery flashable zip, as it works just fine. Use the standard zip, and not the surround zip: http://xdaforums.com/google-nexus-5/themes-apps/discussion-viper4android-t2543796

Choose your favorite v2.3.4.0 version of V4A and install it to /system/priv-app/. Just create a folder with the same name as the APK, give it the same permissions as the other folders, and drop the APK in it making sure to also give it the permissions that the other APKs get. If you encounter issues with a customized version of V4A, I suggest you use the standard version. So far, Lolliviper seems to work.

Make sure to install BusyBox, I recommend this one: https://play.google.com/store/apps/details?id=stericson.busybox

If the files linked below can't be downloaded, use the zip file at the bottom of this post and continue following the guide.

Now, download this file (49_viper4android.sh) : https://www.dropbox.com/s/rcp77ul41m...ndroid.sh?dl=0

And create a folder called su.d in /system/. The path should be /system/su.d/, and then give it permissions 0700 with root:root, and drop the script into the folder with permission 0755 with root:root. This script will allow V4A access to mediaserver, so it can see audio to do it's magic. You can make sure that the script worked on boot by checking /data/v4a_script.txt for if it exists, or, was modified recently to correlate with you booting your phone.

Now do the same for this file (audio_effects.conf) : https://www.dropbox.com/s/57y44o74dk...ects.conf?dl=0

And drop the file in /system/etc/ AND in /system/vendor/etc/ (alternatively you can go to /vendor/etc/ as it's actually the same folder). Both of the files should have permissions 0644 with root being the owner and group. This modified file will allow V4A to be used as an equalizer and allow it to do magic in your audio. Quick note, if V4A keeps asking to install the driver, then delete the audio_effects.conf in /system/vendor/etc/ and don't worry about it.

Now the file which will allow V4A to work system-wide, like in YouTube (audio_policy.conf) : https://www.dropbox.com/s/yi8u3j91z3...licy.conf?dl=0

And drop it in /system/etc/ and give it permissions 0644 with root being owner and group, and you are good to go. This modified file removes the "deep_buffer" module that made it so apps that don't hook into Viper4Android (apps that aren't music players) wouldn't have their audio processed. Some of the flashable zips included modified files, but usually only for the Nexus 5.

Now disable or delete the app MusicFX:

This is necessary as Google Play Music will use MusicFX over Viper4Android if the app isn't disabled.

That should be it, you can now continue with your installation of Viper4Android and it should work.

Issues:

Are you sure you followed the guide correctly? Wipe everything and start fresh because if you used recovery flashables they do stuff they really shouldn't.

Another potential issue with random recovery flashables, suggest you wipe and start again.

Install Viper4Android to /system/priv-app/ and that should fix your issue.

OR

Delete the audio_effects.conf file from /system/vendor/etc/.

Remove the MusicFX app.

Make sure you did the proper steps for the audio_policy.conf file.