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

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/vSampleBits', $raw);
 foreach($header as $k=>$v)
 $str .= $k.': '. $v.' ';
 fseek($fp, 36 + $header['HeadSize'] - 16);
 $raw = fread($fp, 8);
 $data = unpack('A4Data/VDataSize', $raw);
 foreach($data as $k=>$v)
 $str .= $k.': '. $v.' ';
 $b = $header['SampleBits'];
 $c = $header['Channels'];
 $l = $b * $c / 8; // sample frame length in bytes
 $s = $data['DataSize'] / $l; // total number of samples
 $r = $header['SampleRate'];
 if($f)
 $h = pow(2, $b) / $f;
 else
 { $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 === FALSE)
 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。

php wav文件 转换 图像文件 页面显示