<?php

ini_set("max_execution_time", "30000");

// how much detail we want. Larger number means less detail

// (basically, how many bytes/frames to skip processing)

// the lower the number means longer processing time

define("DETAIL", 5);

define("DEFAULT_WIDTH", 500);

define("DEFAULT_HEIGHT", 100);

define("DEFAULT_FOREGROUND", "#FF0000");

define("DEFAULT_BACKGROUND", "#FFFFFF");

/**

* GENERAL FUNCTIONS

*/

function findValues($byte1, $byte2){

}

/**

* Great function slightly modified as posted by Minux at

* http://forums.clantemplates.com/showthread.php?t=133805

*/

function html2rgb($input) {

}

if (isset($_FILES["mp3"])) {

/**

* PROCESS THE FILE

*/

// temporary file name

$tmpname = substr(md5(time()), 0, 10);

// copy from temp upload directory to current

copy($_FILES["mp3"]["tmp_name"], "{$tmpname}_o.mp3");

// support for stereo waveform?

$stereo = isset($_POST["stereo"]) && $_POST["stereo"] == "on" ? true : false;

// array of wavs that need to be processed

$wavs_to_process = array();

/**

* convert mp3 to wav using lame decoder

* First, resample the original mp3 using as mono (-m m), 16 bit (-b 16), and 8 KHz (--resample 8)

* Secondly, convert that resampled mp3 into a wav

* We don't necessarily need high quality audio to produce a waveform, doing this process reduces the WAV

* to it's simplest form and makes processing significantly faster

*/

if ($stereo) {

// scale right channel down (a scale of 0 does not work)

exec("lame {$tmpname}_o.mp3 --scale-r 0.1 -m m -S -f -b 16 --resample 8 {$tmpname}.mp3 && lame -S --decode {$tmpname}.mp3 {$tmpname}_l.wav");

// same as above, left channel

exec("lame {$tmpname}_o.mp3 --scale-l 0.1 -m m -S -f -b 16 --resample 8 {$tmpname}.mp3 && lame -S --decode {$tmpname}.mp3 {$tmpname}_r.wav");

$wavs_to_process[] = "{$tmpname}_l.wav";

$wavs_to_process[] = "{$tmpname}_r.wav";

} else {

exec("lame {$tmpname}_o.mp3 -m m -S -f -b 16 --resample 8 {$tmpname}.mp3 && lame -S --decode {$tmpname}.mp3 {$tmpname}.wav");

$wavs_to_process[] = "{$tmpname}.wav";

}

// delete temporary files

unlink("{$tmpname}_o.mp3");

unlink("{$tmpname}.mp3");

// get user vars from form

$width = isset($_POST["width"]) ? (int) $_POST["width"] : DEFAULT_WIDTH;

$height = isset($_POST["height"]) ? (int) $_POST["height"] : DEFAULT_HEIGHT;

$foreground = isset($_POST["foreground"]) ? $_POST["foreground"] : DEFAULT_FOREGROUND;

$background = isset($_POST["background"]) ? $_POST["background"] : DEFAULT_BACKGROUND;

$draw_flat = isset($_POST["flat"]) && $_POST["flat"] == "on" ? true : false;

$img = false;

// generate foreground color

list($r, $g, $b) = html2rgb($foreground);

// process each wav individually

for($wav = 1; $wav <= sizeof($wavs_to_process); $wav++) {

$filename = $wavs_to_process[$wav - 1];

/**

* Below as posted by "zvoneM" on

* http://forums.devshed.com/php-development-5/reading-16-bit-wav-file-318740.html

* as findValues() defined above

* Translated from Croation to English - July 11, 2011

*/

$handle = fopen($filename, "r");

// wav file header retrieval

$heading[] = fread($handle, 4);

$heading[] = bin2hex(fread($handle, 4));

$heading[] = fread($handle, 4);

$heading[] = fread($handle, 4);

$heading[] = bin2hex(fread($handle, 4));

$heading[] = bin2hex(fread($handle, 2));

$heading[] = bin2hex(fread($handle, 2));

$heading[] = bin2hex(fread($handle, 4));

$heading[] = bin2hex(fread($handle, 4));

$heading[] = bin2hex(fread($handle, 2));

$heading[] = bin2hex(fread($handle, 2));

$heading[] = fread($handle, 4);

$heading[] = bin2hex(fread($handle, 4));

// wav bitrate

$peek = hexdec(substr($heading[10], 0, 2));

$byte = $peek / 8;

// checking whether a mono or stereo wav

$channel = hexdec(substr($heading[6], 0, 2));

$ratio = ($channel == 2 ? 40 : 80);

// start putting together the initial canvas

// $data_size = (size_of_file - header_bytes_read) / skipped_bytes + 1

$data_size = floor((filesize($filename) - 44) / ($ratio + $byte) + 1);

$data_point = 0;

// now that we have the data_size for a single channel (they both will be the same)

// we can initialize our image canvas

if (!$img) {

// create original image width based on amount of detail

// each waveform to be processed with be $height high, but will be condensed

// and resized later (if specified)

$img = imagecreatetruecolor($data_size / DETAIL, $height * sizeof($wavs_to_process));

// fill background of image

if ($background == "") {

// transparent background specified

imagesavealpha($img, true);

$transparentColor = imagecolorallocatealpha($img, 0, 0, 0, 127);

imagefill($img, 0, 0, $transparentColor);

} else {

list($br, $bg, $bb) = html2rgb($background);

imagefilledrectangle($img, 0, 0, (int) ($data_size / DETAIL), $height * sizeof($wavs_to_process), imagecolorallocate($img, $br, $bg, $bb));

}

}

while(!feof($handle) && $data_point < $data_size){

if ($data_point++ % DETAIL == 0) {

$bytes = array();

// get number of bytes depending on bitrate

for ($i = 0; $i < $byte; $i++)

$bytes[$i] = fgetc($handle);

switch($byte){

// get value for 8-bit wav

case 1:

$data = findValues($bytes[0], $bytes[1]);

break;

// get value for 16-bit wav

case 2:

if(ord($bytes[1]) & 128)

$temp = 0;

else

$temp = 128;

$temp = chr((ord($bytes[1]) & 127) + $temp);

$data = floor(findValues($bytes[0], $temp) / 256);

break;

}

// skip bytes for memory optimization

fseek($handle, $ratio, SEEK_CUR);

// draw this data point

// relative value based on height of image being generated

// data values can range between 0 and 255

$v = (int) ($data / 255 * $height);

// don't print flat values on the canvas if not necessary

if (!($v / $height == 0.5 && !$draw_flat))

// draw the line on the image using the $v value and centering it vertically on the canvas

imageline(

$img,

// x1

(int) ($data_point / DETAIL),

// y1: height of the image minus $v as a percentage of the height for the wave amplitude

$height * $wav - $v,

// x2

(int) ($data_point / DETAIL),

// y2: same as y1, but from the bottom of the image

$height * $wav - ($height - $v),

imagecolorallocate($img, $r, $g, $b)

);

} else {

// skip this one due to lack of detail

fseek($handle, $ratio + $byte, SEEK_CUR);

}

}

// close and cleanup

fclose($handle);

// delete the processed wav file

unlink($filename);

}

header("Content-Type: image/png");

// want it resized?

if ($width) {

// resample the image to the proportions defined in the form

$rimg = imagecreatetruecolor($width, $height);

// save alpha from original image

imagesavealpha($rimg, true);

imagealphablending($rimg, false);

// copy to resized

imagecopyresampled($rimg, $img, 0, 0, 0, 0, $width, $height, imagesx($img), imagesy($img));

imagepng($rimg);

imagedestroy($rimg);

} else {

imagepng($img);

}

imagedestroy($img);

} else {

?>

<form method="post" action="<?php print $_SERVER["REQUEST_URI"]; ?>" enctype="multipart/form-data">

<p>MP3 File:<br />

<input type="file" name="mp3" /></p>

<p>Image Width:<br />

<input type="text" name="width" value="<?php print DEFAULT_WIDTH; ?>" /></p>

<p>Image Height:<br />

<input type="text" name="height" value="<?php print DEFAULT_HEIGHT; ?>" /></p>

<p>Foreground Color: <small>(HEX/HTML color code)</small><br />

<input type="text" name="foreground" value="<?php print DEFAULT_FOREGROUND; ?>" /></p>

<p>Background Color: (Leave blank for transparent background) <small>(HEX/HTML color code)</small><br />

<input type="text" name="background" value="<?php print DEFAULT_BACKGROUND; ?>" /></p>

<p>Draw flat-line? <input type="checkbox" name="flat" /></p>

<p>Stereo waveform? <input type="checkbox" name="stereo" /></p>

<p><input type="submit" value="Generate Waveform" /></p>

</form>

<?php

}