Flash -> ByteArray -> AMFPHP -> Invalid Image? - actionscript-3

Question

Im loading images into Flash and using JPGEncoder to encode the image to a ByteArray and send this to AMF PHP which writes out the bytearray to a file. This all appears to work correctly and I can download the resulting file in Photoshop CS4 absolutely fine. When i try to open it from the desktop or open it back in Flash it doesnt work... Picasa my default image browser says "Invalid"
Here is the code i use to write the bytearray to a file -
$jpg = $GLOBALS["HTTP_RAW_POST_DATA"];
file_put_contents($filename, $jpg);
That's it ... I use the NetConnection class to connect and call the service, do I need to say Im sending jpg data? I assumed that JPGEncoder took care of that. How can I validate the bytearray before writing the file? Do I need to set MIME type or something .. excuse the slightly noob questions, a little knowledge can be a dangerous thing.
Thanks
--------------------------------------- PART II ------------------------------------------
Here is some code -
1) load the image into Flash player
item.load();
function _onImageDataLoaded(evt:Event):void {
var tmpFileRef:FileReference=FileReference(evt.target);
image_loader=new Loader ;
image_loader.contentLoaderInfo.addEventListener(Event.COMPLETE, _onImageLoaded);
image_loader.loadBytes(tmpFileRef.data);
}
function _onImageLoaded(evt:Event):void {
bitmap=Bitmap(evt.target.content);
bitmap.smoothing=true;
if (bitmap.width>MAX_WIDTH||bitmap.height>MAX_HEIGHT) {
resizeBitmap(bitmap);
}
uploadResizedImage(bitmap);
}
function resizeBitmap(target:Bitmap):void {
if (target.height>target.width) {
target.width=MAX_WIDTH;
target.scaleY=target.scaleX;
} else if (target.width >= target.height) {
target.height=MAX_HEIGHT;
target.scaleX=target.scaleY;
}
}
function uploadResizedImage(target:Bitmap):void {
var _bmd:BitmapData=new BitmapData(target.width,target.height);
_bmd.draw(target, new Matrix(target.scaleX, 0, 0, target.scaleY));
var encoded_jpg:JPGEncoder=new JPGEncoder(90);
var jpg_binary:ByteArray=encoded_jpg.encode(_bmd);
_uploadService=new NetConnection();
_uploadService.objectEncoding=ObjectEncoding.AMF3
_uploadService.connect("http://.../amfphp/gateway.php");
_uploadService.call("UploadService.receiveByteArray",new Responder(success, error), jpg_binary, currentImageFilename);
}
Many thanks for you help

Answer 1

can you check the endian type of the bytearray? maybe it is defaulted to big endian

Answer 2

Your problem is in your PHP service. In AMFPHP the POST data is abstracted, so what you need in your AMFPHP UploadService script is a function that accepts the two input arguments in your _uploadService.call --jpg_binary and currentImageFilename-- like this:
<?php
class UploadService {
function receiveByteArray( $ba, $filename ) {
$result = file_put_contents($filename, $ba->data);
if ( $result == FALSE ) {
trigger_error( "File save failed" );
}
}
}
?>

Answer 3

var dataToBeSent:ByteArray =jpgEncoder.encode(theBitmapData);
var url:String = "upload.php";
var urlReq:URLRequest = new URLRequest(url);
urlReq.data = dataToBeSent;
urlReq.method = URLRequestMethod.POST;
urlReq.contentType = "application/octet-stream";
var urlLoader:URLLoader = new URLLoader();
urlLoader.load(urlReq);
Please mind the contentType line
PHP
$fp = fopen( $fname, "wb" );
fwrite( $fp, $GLOBALS[ 'HTTP_RAW_POST_DATA' ] );
fclose( $fp );
For me it works perfectly!
Oliver