这篇文章主要介绍了php实现将wav文件转换成图像文件并在页面中显示的方法,涉及php中unpack、fopen、fread等方法及图形操作的相关技巧,需要的朋友可以参考下

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：

1. <?php
2. function wav_graph($file, $f=0, $w=0)
3. {
4. global $DATA_DIR;
5. if(!is_file($file))
6. return 0;
7. $fp = fopen($DATA_DIR.$file, 'r');
8. $raw = fread($fp, 36);
9. $str = '';
10. $header = unpack('A4Riff/VSize/A4Wav/A4Head/VHeadSize/vPCM/vChannels/VSampleRate/VByteRate/vBlockAlign/vSampleBits', $raw);
11. foreach($header as $k=>$v)
12. $str .= $k.': '. $v.' ';
13. fseek($fp, 36 + $header['HeadSize'] - 16);
14. $raw = fread($fp, 8);
15. $data = unpack('A4Data/VDataSize', $raw);
16. foreach($data as $k=>$v)
17. $str .= $k.': '. $v.' ';
18. $b = $header['SampleBits'];
19. $c = $header['Channels'];
20. $l = $b * $c / 8; // sample frame length in bytes
21. $s = $data['DataSize'] / $l; // total number of samples
22. $r = $header['SampleRate'];
23. if($f)
24. $h = pow(2, $b) / $f;
25. else
26. { $h = 200; $f = pow(2, $b - 1) / $h; }
27. if($w == 0)
28. $w = round($r / 1000); // default to show 1k sample frames per minute
29. header("Content-type: image/png");
30. $im = imagecreate($s / $w, $h * $c * 2);
31. imagecolorallocate($im, 0xff, 0xff, 0xff); // white bg
32. $color = imagecolorallocate($im, 0, 0, 255); // black
33. imagestring($im, 5, 5, 5, $str, $color);
34. $x=0; $y = array(); $yn = array();
35. for($i = 0; $i < $c; $i++) $y[$i] = $h * $i + $h;
36. $n = $l * $w;
37. while(1)
38. {
39. if($s == 0)
40. break;
41. if($s < $n)
42. $n = $s;
43. $samples = fread($fp, 1000 * $n);
44. if($samples === FALSE)
45. break;
46. $packed = unpack("s*", $samples);
47. foreach($packed as $k=>$v)
48. {
49. $cnt = ($k-1) % ($w * $l) ;
50. if( $cnt > $c - 1)
51. continue;
52. $yn[$cnt] = $h * $cnt + $h - $v / $f;
53. imageline($im, $x, $y[$cnt], $x+1, $yn[$cnt], $color);
54. $y[$cnt] = $yn[$cnt];
55. $x++;
56. }
57. $s -= $n;
58. }
59. imagepng($im);
60. imagedestroy($im);
61. }
62. wav_graph('GetWave.wav');
63. ?>