Galaxy S3 GT I9300 users can now rejoice over the release of yet another custom ROM firmware with Android 4.2 (Jelly Bean) stock Apps ported into it. In other words, users no longer have to wait for the official Android 4.2 firmware release from Samsung to enjoy the latest features of Jelly Bean.

The Android 4.1.2 firmware is based on the Nexus 4 Styled Codec ROM, which brings exciting features like Beats Audio and Apollo music player that should please music buffs.  Here is the complete list of features supported on the Nexus 4 Styled Codec ROM.

Features of Codec ROM Nexus 4 Styled:

Nexus 4 Styled Codec ROM Brings Android 4.2 Jelly Bean Apps for Galaxy S3 GT I9300 [How to Install]
Nexus 4 Styled Codec ROM Brings Android 4.2 Jelly Bean Apps for Galaxy S3 GT I9300
  • Deodexed
  • Zipaligned
  • Rooted (CF SuperSU 0.97)
  • BusyBox
  • Call Record
  • No SMS In Logs
  • Disabled Scrolling Cache
  • Extended Power Menu
  • Aroma Installer (Custom Install) - Updated Aroma Installer to 2.56
  • Modded Camera
  • Build Prop Tweaks
  • SQLite3
  • Faster GPS Fix
  • 761mb rom
  • 15 Toggles (Choice)
  • Silent Camera
  • Disabled Increasing Ringtone In Phone
  • Ad Blocking
  • Removed Multiple Tones (low battery,usbconnection etc)
  • Centered clock on statusbar or stock
  • Full GPU Acceleration in UI

Key Points to Note

  • The Android 4.1.2 Nexus 4 Styled Codec ROM and the instructions given in this guide are only applicable to the international version Galaxy S3 GT I9300 model and will not work with any other device. Verify your device's model number by navigating to Settings > About Phone.
  • Users are advised to back up apps, important data and settings to avoid risk of data loss while flashing the Nexus 4 Styled Codec ROM on their Galaxy S3.
  • Ensure that your phone is rooted with ClockworkMod Recovery (CWM) installed on it before proceeding with the ROM installation procedure. Verify if your phone is actually rooted or not by downloading and installing the Root Checker app from Google Play Store.
  • Download ROM Manager app from Google Play Store and install it on your phone.
  • Verify that your phone battery is at least 85 percent charged to prevent unexpected device shutdown (due to battery drain) while installing the Android 4.2 Jelly Bean apps via the Nexus 4 Styled Codec ROM firmware update.
  • The instructions provided in this guide are meant for reference purpose only and do not cover any warranty claims involving device damage or issues arising out of using the Android 4.1.2 Jelly Bean firmware update. Users are advised to proceed at their own risk.

How to Update Galaxy S3 GT I9300 to Android 4.2 Jelly Bean Apps with Nexus 4 Styled Codec ROM

  • Download the Nexus 4 Styled Codec ROM with Android 4.2 Apps Package from here to your computer. Once the ROM is downloaded, connect your phone to the computer with an USB cable and copy the zip file to the root folder on your phone's SD card.
  • Unplug the phone from the computer and launch the ROM Manager app in your phone so that it can boot into recovery mode. As an alternative, the recovery mode can also be entered with a button sequence given below.
  • Press and hold the Volume Up and Home key buttons (the middle button) and simultaneously tap the Power button for powering the device ON, when the phone is still in recovery mode.
  • In recovery mode, choose Wipe data/factory reset and click Wipe Cache partition. Then, hit advanced and wipe the Dalvik cache too if you are updating from another custom ROM firmware.
  • Choose install zip from SD Card and locate all the zip files that you copied to your Galaxy S3 device in step 1. Select the Nexus 4 Styled Codec ROM Firmware package to initiate the process of firmware update.
  • Once the firmware update completes, you will see a notification message: "install from sd card complete". Now, hit Go Back and click Reboot System Now. The first boot may take about 4 to 5 minutes to complete.

NOTE: If you get any force close errors just select Wipe data/factory reset and Wipe Cache partition options in the recovery mode. In case if the device fails to boot or show the home screen then remove the battery and reinsert it to boot the device again in normal mode.

Nexus 4 Styled Codec ROM based Android 4.2 Jelly Bean apps package is now successfully installed on your Galaxy S3 GT I9300. Go to Settings > About Phone to verify the firmware version installed.

For further assistance check out the video tutorial below:

[Source: Android Advices]