PHP implements the method of converting WAV files to image files and displaying them in a page, _php tutorial

PHP implements the method of converting a WAV file into an image file and displaying it in a page.

The examples in this paper are the methods that PHP implements to convert WAV files into image files and display them in a page. Share to everyone for your reference. The specific analysis is as follows:

Requirements: Convert WAV files to PNG files and display them.

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, + $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 = $, $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, $n);   if ($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 is helpful to everyone's PHP programming.

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