谁写过 PHP的 demo？ 我写了一个 返回3301 求助

$dizhi='SST.wav';

$data_temp = file_get_contents($dizhi);
$len=strlen($data_temp);
$data_temp=base64_encode($data_temp);

$ch = curl_init();
$url = 'http://vop.baidu.com//server_api?lan=zh&cuid=54-04-A6-CE-2C-F6&token=24.d48fd4313b4a7b23bd83155d3222e803.2592000.1452503921.282335-5716345';
$header = array(
'Content-Type:audio/wav;rate=8000;Content-length=$len',
'Referer: http://vop.baidu.com//server_api?lan=zh&cuid=54-04-A6-CE-2C-F6&token=24.d48fd4313b4a7b23bd83155d3222e803.2592000.1452503921.282335-5716345',
'Content-length=0',
'Accept: */*',
'Content-length=0',
'Accept-Language: zh-cn',
);

$data = 'format=wav&rate=8000&channel=1&cuid=54-04-A6-CE-2C-F6&token=24.d48fd4313b4a7b23bd83155d3222e803.2592000.1452503921.282335-5716345&lan=zh&len=$len&speech='.$data_temp;


// 添加apikey到header
curl_setopt($ch, CURLOPT_HTTPHEADER , $header);
// 添加参数
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_temp);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
// 执行HTTP请求
curl_setopt($ch , CURLOPT_URL , $url);
$res = curl_exec($ch);


$temp_var = json_decode($res,true);


echo "jg：";var_dump($temp_var);
//var_dump($data);