'JPEG encoder super slow, how to Optimize it?

I'm building an App with actionscript 3.0 in my Flash builder. This is a followup question this question.

I need to upload the bytearray to my server, but the function i use to convert the bitmapdata to a ByteArray is super slow, so slow it freezes up my mobile device. My code is as follows:

var jpgenc:JPEGEncoder = new JPEGEncoder(50);
trace('encode');
//encode the bitmapdata object and keep the encoded ByteArray

    var imgByteArray:ByteArray = jpgenc.encode(bitmap);
temp2 = File.applicationStorageDirectory.resolvePath("snapshot.jpg");
    var fs:FileStream = new FileStream();
    trace('fs');
    try{     
     //open file in write mode     
     fs.open(temp2,FileMode.WRITE);
          //write bytes from the byte array

     fs.writeBytes(imgByteArray);
          //close the file

     fs.close();
         }catch(e:Error){

Is there a different way to convert it to a byteArray? Is there a better way?

iphoneiosactionscript-3flash-builderimage-conversion


Solution 1:[1]

Try to use blooddy library: http://www.blooddy.by . But i didn't test it on mobile devices. Comment if you will have success.

Solution 2:[2]

Use BitmapData.encode(), it's faster by orders of magnitude on mobile http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/display/BitmapData.html#encode%28%29

Solution 3:[3]

You should try to find a JPEG encoder that is capable of encoding asynchronously. That way the app can still be used while the image is being compressed. I haven't tried any of the libraries, but this one looks promising:

http://segfaultlabs.com/devlogs/alchemy-asynchronous-jpeg-encoding-2

It uses Alchemy, which should make it faster than the JPEGEncoder from as3corelib (which I guess is the one you're using at the moment.)

Solution 4:[4]

A native JPEG encoder is ideal, asynchronous would be good, but possibly still slow (just not blocking). Another option:

var pixels:ByteArray = bitmapData.getPixels(bitmapData.rect);
pixels.compress();

I'm not sure of native performance, and performance definitely depends on what kind of images you have.

Solution 5:[5]

The answer from Ilya was what did it for me. I downloaded the library and there is an example of how to use it inside. I have been working on getting the CameraUI in flashbuilder to take a picture, encode / compress it, then send it over via a web service to my server (the data was sent as a compressed byte array). I did this:

by.blooddy.crypto.image.JPEGEncoder.encode( bmp, 30 );

Where bmp is my bitmap data. The encode took under 3 seconds and was easily able to fit into my flow of control synchronously. I tried async methods but they ultimately took a really long time and were difficult to track for things like when a user moved from cell service to wifi or from tower to tower while an upload was going on.

Comment here if you need more details.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Ilya Zaytsev
Solution 2 matthias_buehlmann
Solution 3 david.emilsson
Solution 4 Michael Brewer-Davis
Solution 5 Jesse Rallo

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