生成WAV并添加第二个（立体声）频道

Question

我在stackoverflow上发现了以下不合适的代码。请有人可以帮我添加第二个通道（立体声）

会有nchannels = 2 文件大小必须（以某种方式）增加，并且必须添加2.数组（即样本2）。

当我尝试我只能达到更高的频率。很多来自德国

感谢：马丁

$freqOfTone = 440; 
$sampleRate = 44100; 
$samplesCount = 80000; 

$amplitude = 0.25 * 32768; 
$w = 2 * pi() * $freqOfTone/$sampleRate; 

$samples = array(); 
for ($n = 0; $n < $samplesCount; $n++) { 
$samples[] = (int)($amplitude * sin($n * $w)); 
} 

$srate = 44100; //sample rate 
$bps = 16; //bits per sample 
$Bps = $bps/8; //bytes per sample /// I EDITED 

$str = call_user_func_array("pack", 
array_merge(array("VVVVVvvVVvvVVv*"), 
    array(//header 
     0x46464952, //RIFF 
     160038,  //File size 
     0x45564157, //WAVE 
     0x20746d66, //"fmt " (chunk) 
     16, //chunk size 
     1, //compression 
     1, //nchannels 
     $srate, //sample rate 
     $Bps*$srate, //bytes/second 
     $Bps, //block align 
     $bps, //bits/sample 
     0x61746164, //"data" 
     160000 //chunk size 
    ), 
    $samples //data 
) 
); 
$myfile = fopen("sine.wav", "wb") or die("Unable to open file!"); 
fwrite($myfile, $str); 

Answer 1

从问题

感动的解决方案来回答：

SELF SOLUTION：我查了一下recorder.js Web工作，发现了SPEC以及如何使用它。这里有一个稍微修改的代码，用于在1秒内从右侧扬声器发向左侧的音调。也许它有助于某人。

$freqOfTone = 440; 
$sampleRate = 44100; 
$samplesCount = 80000; 

$amplitude = 0.25 * 32768; 
$w = 2 * pi() * $freqOfTone/$sampleRate; 

$samples = array(); 
$samples2 = array(); 
for ($n = 0; $n < $samplesCount; $n++) { 
    $samples[] = (int)($amplitude*($n/$samplesCount) * sin($n * $w)); 
    $samples2[] = (int)($amplitude*(1-$n/$samplesCount) * sin($n * $w)); 
} 

function interleave($l,$r){ 
$data=array(); 
$ix=0; 
for($i=0;$i<count($l);$i++){ 
    $data[$ix++]=$l[$i]; 
    $data[$ix++]=$r[$i]; 
} 
return $data; 
} 

$stereo=interleave($samples,$samples2); 


echo(count($samples)); 
echo(count($stereo)); 

$srate = 44100; //sample rate 
$bps = 16; //bits per sample 
$Bps = $bps/8; //bytes per sample /// I EDITED 


$samples_merge=array_merge($samples,$samples2); 

$str = call_user_func_array("pack", 
    array_merge(array("VVVVVvvVVvvVVv*"), 
     array(//header 
      0x46464952, //RIFF 
      80000*2*2+36,  //File size *2*Channels +36 
     0x45564157, //WAVE 
     0x20746d66, //"fmt " (chunk) 
     16, //chunk size 
     1, //compression 
     2, //nchannels 
     $srate, //sample rate 
     $Bps*$srate, //bytes/second 
     $Bps, //block align 
     $bps, //bits/sample 
     0x61746164, //"data" 
     80000 * 2 *2 //chunk size (filesize * 2 *Channels) 
    ), 
    $stereo // Stereo tone left[0], right[0], left[1], right[1], ... 
) 
); 
$myfile = fopen("sine.wav", "wb") or die("Unable to open file!"); 
fwrite($myfile, $str); 
fclose($myfile);