stevenhowes/PHP-Codecs
1
0
Fork 0
mirror of https://github.com/stevenhowes/PHP-Codecs.git synced 2026-05-26 15:53:43 +01:00
Code Issues Packages Projects Releases Wiki Activity

Create ulaw.php

Browse Source
This commit is contained in:
Steve Howes
2021-11-05 17:41:19 +00:00
committed by GitHub
parent 2a3e79c0fd
commit 62916f9255
1 changed files with 16 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
ulaw.php
+16
View File
@@ -0,0 +1,16 @@
<?php
define ("SIGN_BIT" ,0x80);
define ("QUANT_MASK" ,0xf);
define ("BIAS" ,0x84);
define ("SEG_SHIFT" ,4);
define ("SEG_MASK" ,0x70);
// Converts ulaw to 16 bit signed lin
function ulaw2lin($u_val)
{
$u_val = ~$u_val;
$t = (($u_val & QUANT_MASK) << 3) + BIAS;
$t <<= ($u_val & SEG_MASK) >> SEG_SHIFT;
return /*pack("s",*/intval(($u_val & SIGN_BIT) ? (BIAS - $t) : ($t - BIAS))/*)*/;
}
?>