Php converts a wav file into an image file and displays it on the page

This article mainly introduces how php converts wav files into image files and displays them on pages. it involves unpack, fopen, fread, and other methods in php and related graphics operations, for more information about how to convert a wav file into an image file and display it on the page, see the example in this article. Share it with you for your reference. The specific analysis is as follows:

Requirement: convert a wav file to a png file and display it.

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');?>

As follows:

I hope this article will help you with php programming.