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performanceactionscript-3flashvideobitmapdata

What's the fastest way to access video pixels in as3?

I would like to copy pixels from a 1080p video from one location to another efficiently/with as little CPU impact as possible.

So far my implementation is fairly simple:

  • using BitmapData's draw() method to grab the pixels from the video
  • using BitmapData's copyPixels() to shuffle pixels about

Ideally this would have as little CPU impact as possible but I am running out of options and could really use some tips from experienced actionscript 3 developers.

I've profiled my code with Scout and noticed the CPU usage is mostly around 70% but goes above 100% quite a bit. I've looked into StageVideo but one of the main limitations is this:

The video data cannot be copied into a BitmapData object (BitmapData.draw).

Is there a more direct way to access video pixels, rather than rasterizing a DisplayObject ?

Can I access each video frame as a ByteArray directly and plug it into a BitmapData object ? (I found appendBytes but it seems to do the reverse of what I need in my setup).

What is the most CPU friendly way to manipulate pixels from an h264 1080p video in actionscript 3 ?

Also, is there a faster way to moving pixels around other than copyPixels() using Flash Player ?Also, I see Scout points out that video is not hardware accelerated( .rend.video.hwrender: false ). Shouldn't h264 video be hardware accelerated (even without stage video) according to this article (or is this for the fullscreen mode only) ?

Solution

  • Latest AIR beta introduced video as texture support which you could possibly use to manipulate the video on GPU (and do that way faster than with BitmapData). But keep in mind that it is currently available for AIR on Windows only and there are some other limitations.