Google Cloud Speech API using php

Question

I am trying to call Google Cloud Speech API by using PHP and got a problem.

$stturl = "https://speech.googleapis.com/v1beta1/speech:syncrecognize?key=xxxxxxxxxxxx";
$upload = file_get_contents("1.wav");
$upload = base64_encode($upload);

$data = array(
    "config"    =>  array(
        "encoding"      =>  "LINEAR16",
        "sampleRate"    =>  16000,
        "languageCode"  =>  "en-US"
    ),
    "audio"     =>  array(
        "Content"       =>  $upload,
    )
);

$jsonData = json_encode($data);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $stturl);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/json"));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $jsonData);

$result = curl_exec($ch);

The result says that it is INVALID JSON PAYLOAD.

{ "error": { "code": 400, "message": "Invalid JSON payload received. Unknown name \"content\" at 'audio': Cannot find field.", "status": "INVALID_ARGUMENT", "details": [ { "@type": "type.googleapis.com/google.rpc.BadRequest", "fieldViolations": [ { "field": "audio", "description": "Invalid JSON payload received. Unknown name \"content\" at 'audio': Cannot find field." } ] } ] } } "

I think this is because $upload isn't configured correctly. According Google Cloud Speech API, it should be "A base64-encoded string". https://cloud.google.com/speech/reference/rest/v1beta1/RecognitionAudio

That's why I used base64_encode function, but it seems JSON doesn't process this value correctly. Any thoughts?

You should base64_encode($upload) and also change Content to content. Should work fine. — BadHorsie

Matt Matt · Accepted Answer · 2016-09-14T06:49:05

You need to construct the properly formatted input as an array and then json encode it. For example, to send a file, base64encode it as "content" and submit to the API as shown:

$data = array(
    "config" => array(
        "encoding" => "LINEAR16",
        "sample_rate" => $bitRate,
        "language_code" => "en-IN"
    ),
   "audio" => array(
        "content" => base64_encode($filedata)
    )
);

$data_string = json_encode($data);                                                              

$ch = curl_init($googlespeechURL);                                                                      
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");                                                                     
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);                                                                  
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);                                                                      
curl_setopt($ch, CURLOPT_HTTPHEADER, array(                                                                          
   'Content-Type: application/json',                                                                                
   'Content-Length: ' . strlen($data_string))                                                                       
);                                                                                                                   

$result = curl_exec($ch);
$result_array = json_decode($result, true);

Google Cloud Speech API using php

2 Answers