lz4decodeframes.php

<?php
function lz4decodeframes($in) {
  if (substr($in, 0, 4) !== "\x04\x22\x4d\x18") {
    throw new Exception();
  }
  $o = 6;
  $f = ord($in[4]);
  if ($f & 8) {
    $o += 8;
  }
  if ($f & 1) {
    $o += 4;
  }
  $o += 1; // HC
  for (;;) {
    $blockSize = unpack('V', substr($in, $o, 4))[1];
    $o += 4;
    if (!$blockSize) {
      break;
    }
    if ($blockSize & 0x80000000) {
      yield substr($in, $o, $blockSize & 0x7fffffff);
    } else {
      yield lz4decode($in, $o, $o + $blockSize + 4);
    }
    $o += $blockSize;
    if ($f & 16) {
      $o += 4;
    }
  }
}

foreach (lz4decodeframes(file_get_contents('php://stdin')) as $block) {
  echo $block;
}