PHP は .wav ファイルを解析し、png 形式で波形を描画します

1 2

3 function wav_graph($file, $f=0, $w= 0 )

4 {

5 global $DATA_DIR;

6

7 if(!is_file($file)) return 0;

8 $fp = fopen($DATA_DIR.$file, 'r');

9 $raw = fread($fp, 36);

10 $str = '' ;

11 $header = unpack('A4Riff/VSize/A4Wav/A4Head/VHeadSize/vPCM/vChannels/VSampleRate/VByteRate/vBlockAlign/vSampleBits', $raw);

12 foreach( $ header as $k=>$v)

13 $str .= $k.': '. $v.' ';

14 fseek($fp, 36 + $ header ['HeadSize'] - 16);

15 $raw = fread($fp, 8);

16 $data = unpack('A4Data/VDataSize', $raw); 🎜>

28

29 header("Content-type: image/png");

30 $im = imagecreate($s / $w, $h * $c * 2);

31 imagecolorallocate($im, 0xff, 0xff, 0xff); // 白 bg

32 $color = imagecolorallocate($im, 0, 0, 255); black

33 //imagestring($im, 5, 5, 5, $str, $color);

34

35 $x=0; array(); $yn = array();

36 for($i = 0; $i

37 $n = $l * $w;

38 while(1)

39 {

40 if($s == 0 ) Break;

41 if($s < $n) $n = $s;

42 $samples = fread($fp, 1000 * $n);

43 if($samples === FALSE) Break;

44 $packed = unpack("s*", $samples);

45 foreach($packed as $k = >$v)

46 {

47 $cnt = ($k-1) % ($w * $l) ;

48 if( $cnt > ; $c - 1) continue;

49 $yn[$cnt] = $h * $cnt + $h - $v / $f;

50 imageline($im, $ x, $y[$cnt], $x+1, $yn[$cnt], $color);

51 $y[$cnt] = $yn[$cnt];

52 $x++;

53 }

54 $s -= $n; 57 imagepng($im);

58 imagedestroy($im);

59 }

60

61 //wav_graph('audio2.wav ');

62 ?>