PHP method to convert wav files into image files and display them on the page, _PHP tutorial

PHP implements the method of converting wav files into image files and displays them on the page.

This article describes the example of php converting wav files into image files and displaying them on the page. method. Share it with everyone for your reference. The specific analysis is as follows:

Requirement: Convert wav files to png files and display them.

Wav_To_Png.php:

<&#63;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');
&#63;>

The rendering is as follows:

I hope this article will be helpful to everyone’s PHP programming design.

http://www.bkjia.com/PHPjc/987892.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/987892.htmlTechArticlephp implements the method of converting wav files into image files and displaying them on the page. The example of this article describes how to implement php to convert wav files into image files and display them on the page. A method to convert wav files into image files and display them on the page. Share with everyone...