Extract lg bridge (lbf) backups - G4 Original Android Development

LG bridge is a nice utility to backup and restart app data on an lg phone. The problem is it can only restore to another lg phone . If you have a LG Bridge backup and then your phone dies like the boot loop of death then if your only backups are google and lg bridge there might be data you can't restore on a new non LG phone.
I've done a lot of searching and have not found a tool that would let you extract the contents of the backup. I did notice that 7zip was able to find one apps worth of the backup. after some digging it looks like for the most part the lbf file is a series of tar files combined. I've started working on a tool to extract the tar's out of the file. Right now my method is very crude and works more like a file carver then anything else. I'm able to extract most of the data from a backup but not all of it. consider this a v0.0.1. I wanted to share what I have now in it's current state because it might be useful for others. I do currently plan on improving the code (and likely hosting it on github) and then porting it to java or some other language that's a little easier to run on windows.
For v1 I would like to figure out the data structure some more to see if they have some sort of file table that I didn't see last night when I wrote this.
I'm not going to provide much documentation right now other then below is the php script and it looks for your backup called LGBackup.lbf in the same folder. The tars will be named something like "data_app_com.netflix.mediaclient-2_base.ap.tar" so it gives you an idea of what's inside each tar. I know it's not extracting the whole tar for each app and there's some apps that are larger then they should be like I said earlier this is not finished code but it should mostly work.
Code:
<?php
$handle = fopen("LGBackup.lbf", "rb");
$chunkSize = 4096;
$tarFooter = str_repeat(chr (0), $chunkSize);
$cnt = 0;
$tar = "";
$lastBuff = "";
while (($buffer = fread($handle, $chunkSize)) !== false) {
if ($buffer == "") {
exit('finished');
}
$lastBuff = $buffer;
$cnt++;
if ($buffer === $tarFooter) {
$footBuffer = $buffer;
while ($buffer === $tarFooter) {
$buffer = fread($handle, $chunkSize);
$cnt++;
$footBuffer .= $buffer;
}
for ($i = 0; $i < strlen($buffer); $i++) {
if ($buffer[$i] !== chr(0)) {
break;
}
}
$tar .= substr($buffer, 0, $i - 1);
for ($b = 0; $b < 200; $b++) {
if ($tar[$b] === chr(0)) {
break;
}
}
$filename = str_replace("/", "_",substr($tar, 0, $b - 1)) . '.tar';
var_dump($filename);
if (strpos($filename, 'data_') === 0){
$fp = fopen($filename, 'w');
fwrite($fp, $tar);
fclose($fp);
}
$tar = substr($buffer, $i);
} else {
$tar .= $buffer;
}
}
fclose($handle);

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I've done some more digging and it looks like reading the data at the very start and end of the file is going to be a lot more complex then I'm interested. My personal urgency has deceased as lg has supposedly repaired my boot looping g4 . I made some minor tweaks to my code and it works a little better now I found I got the most data back by running my updated script and then using gnu tar to extract the tar's it made. for some reason it was able to overcome some of the corruption that 7zip didn't want to deal with. I'll attach a new file to the first post.
I think the next and possibly last thing I'm going to try is parse the tar file so I know how long each file is. Right now I'm just looking for 1k of null bytes but that's not always right as some times there's less and some times there could be 1k of null bytes inside of the zip.

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LBF tool
Hi! I have looked into lbf files recently and here are my findings (including simple way to extract data).
https://forum.xda-developers.com/android/general/tool-lg-restore-com-lge-bnr-lbf-file-t4053579
I am new to XDA, but please let me know what you think.