Posting FLAC to Google Voice Recognition API from PHP

I am quite experienced in PHP but I've always had troubles with connection between servers like "post". I have a FLAC audio file that I need to post to Google's Speech Recognition API server. I don't know neither how to "listen" to its response. I would like a script like that, assuming that this kind of function exists :

<?php

   $fileId = $_GET['fileId'];
   $filepath = $fileId . ".flac";
   recognize($filepath);

  function recognize($pathToFile) {

      //It's the following function that I'm looking for 
      $response = $pathToFile->post("http://www.google.com/speech-api/v1/.....&client=chromium"); 

      //The $response would be the short JSON that Google feed back.
      echo $response;

  }

?>

EDIT

I've followed a tutorial to create a Shell Script that posts my FLAC file using Wget --post. I would like to post like this, but in PHP. Also, at the end of the command, there is this > answer.ret line, so that Google's answer would be written to this file. I was wondering if there was an alternate method to it in PHP. Here's the command line :

wget -q -U "Mozilla/5.0" --post-file audio1.flac --header="Content-Type: audio/x-flac; rate=16000" -O - "http://www.google.com/speech-api/v1/recognize?lang=fr-fr&client=chromium" > trancription1.ret

EDIT 2

I figured out how to do it, with @hakre 's answer and baked up a little Gist for curious people. Here it is: https://gist.github.com/chlkbumper/4969389. Don't forget that the FLAC file must be a 16k bitrate FLAC

Solution

A POST request is just a standard HTTP request, just with the POST method specified. The rest of the HTTP Request and HTTP Response is pretty much the same.

You get the response of a request in form of a HTTP Response btw.. It is absolutely normaltiv defined in RFC 2616 - just relate to this document and it explains everything.

A function in PHP to send HTTP requests is file_get_contents, it returns the requests response. This is done via the HTTP stream wrapper that offers some options you need to send a POST request (default is GET). See HTTP context options.

Another popular PHP extension for sending HTTP requests are the Curl bindings.