我需要构建一个将 mp3 文件转换为波形图像的网络脚本，我遇到了这个网站。
我已将 PHP 文件.dll和 .exe 文件从 LAMB 上传到我的网站（由 host monster 托管）。
但是当我尝试在网站上上传 MP3 文件时，它只会生成黑色图像而不是波形图像。
我对PHP知之甚少，所以我不完全知道出了什么问题，但我猜它与程序的上传部分有关。
谁能告诉我出了什么问题以及如何克服它？
以下是原样的 php 代码（也可以在 GitHub 上的这个存储库中找到）。
<?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){
$byte1 = hexdec(bin2hex($byte1));
$byte2 = hexdec(bin2hex($byte2));
return ($byte1 + ($byte2*256));
}
/**
* Great function slightly modified as posted by Minux at
* http://forums.clantemplates.com/showthread.php?t=133805
*/
function html2rgb($input) {
$input=($input[0]=="#")?substr($input, 1,6):substr($input, 0,6);
return array(
hexdec(substr($input, 0, 2)),
hexdec(substr($input, 2, 2)),
hexdec(substr($input, 4, 2))
);
}
if (isset($_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
}