As devices get newer and more powerful, the software comes with them gets bigger and more complex. In the olden days, the ROMs were often smaller than 100 MB. Now, on the newest devices, the stock ROM can be over 1 GB in size.
As a result, the uploading a ROM, or downloading ROMs take a longer time. Even storing the ROMs on your device take a lots of space. Now, here is a tutorial at below to cut back on those file sizes.
Full credits will goes to the XDA recognized developer and TV Producer AdamOutler who has come up with the tutorial to decrease the size of stock tar ROMs that users can flash via Odin3 v3 and higher.
This will be very useful at the situation, you want to keep a stock tar around in case of emergencies. By following this guide you can make your file to smaller and more manageable for those with limited storage. It will also help the developers who upload the tars frequently, it can shorten the upload times, as well as lower download times for the end user.
Please keep in mind that once the tar.md5.gz is run through Odin, it loses the .gz and is extracted into a standard tar file again. This results in a full sized Odin ROM. It is not really an issue, but it is something to keep in mind.
Adam also gives an important warning for Verizon Galaxy Note 2 owners to be cautious about flashing after an IROM unlock. He said that, the Verizon Galaxy Note 2 users should stay away from using Odin after IROM unlock as flashing a package intended for another device.
This will permanently-lock your device into another carrier’s bootloaders especially stay away from GS3 as the displays are not compatible.
1. You will need a linux computer and
2. Your ROM (we will call it MyROM)
DISCLAIMER : Best Android Blog would not held responsible/liable for any damages takes to your device by following this procedure. So, do everything at your own risk.
How to pack Odin on Windows:
First turn the ROM into a single tar file and then make sure changes are written to the disk.
tar -H ustar -c boot.img hidden.img modem.bin param.bin recovery.img system.img tz.img sboot.bin>./MyROM.tar;sync;
Next add an MD5 to the file so Odin can check its consistency.
md5sum MyROM.tar >> MyROM.tar;
Now, change that into a tar.md5 file so Odin knows it has an MD5 attached to it.
mv MyROM.tar MyROM.tar.md5; sync;
Now, finally we will compress it with GZip. It is the only compression method supported by Odin.
gzip MyROM.tar.md5 -c -v > MyROM.tar.md5.gz;
You will now have a file called MyROM.tar.md5.gz.
NOTE : The first time the file is flashed, Odin will uncompress it into MyROM.tar.md5, then check its consistency, then flash the file.