php实现将wav文件转换成图像文件并在页面中显示的方法

本文实例讲述了php实现将wav文件转换成图像文件并在页面中显示的方法。分享给大家供大家参考。具体分析如下：

需求：将wav文件转换成png文件并且显示出来。

wav_to_png.php：

<?php function wav_graph($file, $f=0, $w=0) {  global $data_dir;  if(!is_file($file))   return 0;  $fp = fopen($data_dir.$file, 'r');  $raw = fread($fp, 36);  $str = '';  $header = unpack('a4riff/vsize/a4wav/a4head/vheadsize/vpcm/vchannels/vsamplerate/vbyterate/vblockalign/vsampl有理数复习ebits', $ra眼中钉什么意思w);  foreach($header as $k=>$v)   $str .= $k.': '. $v.' ';  fek($fp, 36 + $header['headsize'] - 16);  $raw = fread($fp, 8);  $dat文明演讲稿a = unpack('a4data/vdatasize', $raw);  foreach($data as $k=>$v)   $str .= $k.': '. $v.' ';  $b = $header['samplebits'];  $c = $header['channels'];  $l = $b * $c / 8;最强大脑黄胜华 // sample frame length in bytes  $s = $data['datasize'] / $l; // total number of samples  $r = $header['samplerate'];  if($f)   $h = pow(2, $b) / $f暑期学习心得;  el   { $h = 200; $f = pow(2, $b - 1) / $h; }  if($w == 0)   $w = round($r / 1000); // default to show 1k sample frames per minute  header("content-type: image/png");  $im = imagecreate($s / $w, $h * $c * 2);  imagecolorallocate($im, 0xff, 0xff, 0xff); // white bg  $color = imagecolorallocate($im, 0, 0, 255); // black  imagestring($im, 5, 5, 5, $str, $color);  $x=0; $y = array(); $yn = array();  for($i = 0; $i < $c; $i++) $y[$i] = $h * $i + $h;  $n = $l * $w;  while(1)  {   if($s == 0)     break;   if($s < $n)     $n = $s;   $samples = fread($fp, 1000 * $n);   if($samples === fal)    break;   $packed = unpack("s*", $samples);   foreach($packed as $k=>$v)   {    $cnt = ($k-1) % ($w * $l) ;    if( $cnt > $c - 1)      continue;    $yn[$cnt] = $h * $cnt + $h - $v / $f;    imageline($im, $x, $y[$cnt], $x+1, $yn[$cnt], $color);    $y[$cnt] = $yn[$cnt];    $x++;   }   $s -= $n;  }  imagepng($im);  imagedestroy($im); } wav_graph('getwave.wav');?>

效果图如下：

希望本文所述对大家的php程序设计有所帮助。