PHP - Data structures - Tree - Chained processing units

<?php

/**
 * Chained processing units (tree structure)
 * @author Ionut Bodea
 */


/*
 * Tree Nodes (adiacent list)
 */
$aNodes = array(
    1 => array(2, 3),
    3 => array(4, 5, 6),
    5 => array(7, 8)
);


$oTree = new Core_DataStructure_Tree($aNodes);

echo 'Tree (recursive, multi level array):';
print_r($oTree->getTree());

echo 'Tree (horizontal representation):';
print_r($oTree->getTreeHorizontal());


class Core_DataStructure_Tree
{
    private $adiacentList;
    private $tree   = array();
    ## private $isTree = false;

    public function __construct($adiacentList)
    {
        $this->adiacentList = $adiacentList;
        $this->computeTree();
    }

    private function computeTree()
    {
        $this->tree = array();
        foreach($this->adiacentList as $sParent => $aChildren)
        {
            if(empty($aChildren))
            {
                $this->addNode($sParent);
            }
            else
            {
                foreach($aChildren as $sChild)
                {
                    $this->addNode($sParent, $sChild);
                }
            }
        }
    }

    private function addNode($sParent, $sChild = null)
    {
        ## echo 'Add node - parent: '.$sParent.', child: '.$sChild.'<br/>';

        if(!$this->nodeExists($sParent))
        {
            $this->tree[] = array(
            'node'       => $sParent,
            'children'   => array()
            );
        }

        if(null === $sChild)
        {
            return;
        }

        if($this->nodeExists($sChild))
        {
            ## move existing child under a new parent (move an entire branch under a new parent)
            ## echo 'node exists: [[[[' . $sChild . ']]]]';
            $aXpathResult = $this->getNodeXPath($sParent);
            $aXPathParent = $aXpathResult['xPath'];
            $aXpathResult = $this->getNodeXPath($sChild);
            $aXPathChild  = $aXpathResult['xPath'];

            $sVarParent   = "\$this->tree[".implode('][\'children\'][', $aXPathParent)."]";
            $sVarChild    = "\$this->tree[".implode('][\'children\'][', $aXPathChild)."]";

            $sStringEval = "$sVarParent" . "['children'][] = $sVarChild;";
            eval($sStringEval);
            $sStringEval = "unset($sVarChild);";
            eval($sStringEval);
        }
        else
        {
            $aXpathResult = $this->getNodeXPath($sParent);
            $aXPath = $aXpathResult['xPath'];
            $aEntry = array('node' => $sChild, 'children' => array());
            ## printr($aEntry);
            $sStringEval = "\$this->tree[".implode('][\'children\'][', $aXPath)."]['children'][] = \$aEntry;";
            eval($sStringEval);
        }

        ## printr($this->tree);
        ## echo '<hr/>';
    }

    private function nodeExists($sNode, $aNodes = null)
    {
        $aNodes = null === $aNodes ? $this->tree : $aNodes;
        foreach($aNodes as $aNode)
        {
            if(isset($aNode['node']) && $aNode['node'] == $sNode)
            {
                return true;
            }
            if(isset($aNode['children']) && !empty($aNode['children']))
            {
                return $this->nodeExists($sNode, $aNode['children']);
            }
        }
        return false;
    }

    private function getNodeXPath($sNode, $aNodes = null, $aXPath = array())
    {
        ## printr($this->tree);
        $aNodes = null === $aNodes ? $this->tree : $aNodes;
        foreach($aNodes as $k => $aNode)
        {
            if(isset($aNode['node']) && $aNode['node'] == $sNode)
            {
                $aXPath[] = $k;
                return array('nodeFound' => true, 'xPath' => $aXPath);
                ## return $aXPath;
            }
            if(isset($aNode['children']) && !empty($aNode['children']))
            {
                ## $aXPath[] = $k;
                ## $aResult = $this->getNodeXPath($sNode, $aNode['children'], $aXPath);
                $aResult = $this->getNodeXPath($sNode, $aNode['children'], array_merge($aXPath, array($k)));
                if(isset($aResult['nodeFound']) && $aResult['nodeFound'])
                {
                    return $aResult;
                }
                ## return $this->getNodeXPath($sNode, $aNode['children'], array_merge($aXPath, array($k)));
            }
        }
        return array('nodeFound' => false, 'xPath' => $aXPath);
    }

    /* public function isTree()
     {
    return $this->isTree;
    } */

    /**
     * @return array
     */
    public function getTree()
    {
        return $this->tree;
    }

    /**
     * Get a horizontal representation of the tree
     * Array
     *     [] -> level 0 nodes
     *     [] -> level 1 nodes
     *     ....
     * @return array
     */
    public function getTreeHorizontal($aNodes = null, $nLevel = null, &$aResults = array())
    {
        $aNodes = null === $aNodes ? $this->tree : $aNodes;
        $nLevel = null === $nLevel ? 0 : $nLevel + 1;
        foreach($aNodes as $aNode)
        {
            !isset($aResults[$nLevel]) ? $aResults[$nLevel] = array() : '';
            $aResults[$nLevel][] = $aNode['node'];
            $this->getTreeHorizontal($aNode['children'], $nLevel, $aResults);
        }
        return $aResults;
    }

}

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Linux/Ubuntu - Video editing - video/audio merging, soundtrack replacing

1) Merge multiple mp3 files into one
sudo apt-get install mp3wrap
mp3wrap onemp3.mp3 file1.mp3 file2.mp3 file3.mp3 ...
mp3wrap onemp3.mp3 -a file1-append.mp3 file1-append.mp3 ...

2) Change video file soundtrack
mencoder -ovc copy -nosound video.avi -o video_nosound.avi
mencoder -ovc copy -audiofile soundtrack.mp3 -oac copy video_nosound.avi -o video_new.avi

3) Merge multiple video files into one
sudo apt-get install mencoder
mencoder -oac copy -ovc copy -idx -o megavideo.avi *.avi

4) Resize video
mencoder input.avi -o output.avi -ovc xvid -xvidencopts bitrate=3000 -oac mp3lame

5) Speed up video (with Avidemux)
sudo apt-get install avidemux
Avidemux - Menu: Video -> Frame rate (set it to 100 for example) -> Save video  

Observation: Speeding up the video should be performed on a video file with the soundtrack removed (see above how to achieve this).

Ubuntu (>12.04) - install ADT, Eclipse, Android SDK

$ sudo apt-get install eclipse-jdt
$ sudo apt-get install ia32-libs
Download Android SDK from http://developer.android.com/sdk/index.html
$ cd tools/
$ ./android
Install the Eclipse ADT Plugin: http://developer.android.com/sdk/installing/installing-adt.html