Best way to show image sequence as a movie in Adobe AIR - apache-flex

I need to show an image sequence as a movie in an Adobe AIR application - i.e. treat lots of images as video frames and show the result. For now I am going to try simply loading them and displaying in a movie clip but this might be too slow. Any advanced ideas how to make it work? Images are located on a hard drive or very fast network share, so the bandwidth should be enough. There can be thousands of them, so preloading everything to memory doesn't seem feasible.
Adobe AIR is not 100% decided, I am open to other ideas how to create a cross-platform desktop application for this purpose quickly enough.

You could have an image control as your movie frame, then load up a buffer of BitmapData objects. Fill the BitmapData objects with the images as they come in, and then call the image load function to load the next image in the buffer.
private drawNextImage(bitmapData:BitmapData):void {
movieFrame.load(new Bitmap(bitmmapData));
}

In case the images aren't big but you have a lots of them it can be interesting to group sequences on single bitmaps (à la mipmap). This way you can load in say, one bitmap containing say, 50 images forming 2 seconds of video playback at 25 fps.
This is method is specially useful online as you want to limit the amount of pings and handshakes causing slowness but I reckon it can also be useful in order to optimize loading, unloading and memory access.

Related

High Resolution Capture and Encoding

I'm using two custom push filters to inject audio and video (uncompressed RGB) into a DirectShow graph. I'm making a video capture application, so I'd like to encode the frames as they come in and store them in a file.
Up until now, I've used the ASF Writer to encode the input to a WMV file, but it appears the renderer is too slow to process high resolution input (such as 1920x1200x32). At least, FillBuffer() seems to only be able to process around 6-15 FPS, which obviously isn't fast enough.
I've tried increasing the cBuffers count in DecideBufferSize(), but that only pushes the problem to a later point, of course.
What are my options to speed up the process? What's the right way to do live high res encoding via DirectShow? I eventually want to end up with a WMV video, but maybe that has to be a post-processing step.
You have great answers posted here to your question: High resolution capture and encoding too slow. The task is too complex for the CPU in your system, which is just not fast enough to perform realtime video encoding in the configuration you set it to work.

How to Save an Image of a Large Flex Component (EX: 25000px by 3000px # 72dpi)

My application consists of displaying a large custom tree like structure to the user that can eventually grow to massive proportions like the dimensions listed in the question. I allow them to export the image with the following line of code tied to a button click event:
var image:ImageSnapshot = ImageSnapshot.captureImage(this, 72, new PNGEncoder(), false);
I've managed to export images close to the dimensions listed but around there it start to get the error message listed below after spinning for close to 15 seconds:
Error: Error #1000: The system is out of memory.
at flash.utils::ByteArray/writeBytes()
at mx.graphics::ImageSnapshot$/mergePixelRows()[E:\dev\4.x\frameworks\projects\framework\src\mx\graphics\ImageSnapshot.as:511]
at mx.graphics::ImageSnapshot$/captureAll()[E:\dev\4.x\frameworks\projects\framework\src\mx\graphics\ImageSnapshot.as:482]
at mx.graphics::ImageSnapshot$/captureImage()[E:\dev\4.x\frameworks\projects\framework\src\mx\graphics\ImageSnapshot.as:318]
at vertical/saveChart()[C:\devel\workspace\vertical\src\CustomObject.mxml:501]
at vertical/__saveImageBtn_click()[C:\devel\workspace\vertical\src\CustomObject.mxml:574]
Is the flashplayer plugin for my browser running out of memory? I noticed in my task manager it got up to about 1.2GB of memory usage(I have 4GB on my system). If that is the case is it possible to limit the memory usage for a given function like the ImageSnapshot.captureImage() call above?
Is there maybe a way to generate the component into 2 or 4 ImageSnapshot objects and piece them together afterward?
Any advice would be greatly appreciated.
I believe the latest Flash Player 11 has a new feature to solve this issue:
"Enhanced high resolution bitmap support — BitmapData objects are no longer limited to a maximum resolution of 16 megapixels (16,777,215 pixels), and maximum bitmap width/height is no longer limited to 8,191 pixels, enabling the development of apps that utilize very large bitmaps." from this PDF
If you are using BitmapData, it makes a difference which FlashPlayer you are targetting:
versions VS maximum bitmapsize
flashplayer -9 : 2880x2880 px
flashplayer 10 : 4096x4096 px
flashplayer 11 : unlimited
I don't know what you exactly are trying to do with this huge capture, but I would recommend using tiles. Break it down to chunks of relative small bitmaps. Create them separately, so you don't have to open/create that huge amount of data in your memory.
Anyway, it would be nice to know if it is possible to encode that big-ass sized image, without Error #1000 out of memory errors.

BitmapData and JpegEncoder Limitations

I am trying to save out a large image from flash using bitmapdata and the jpegencoder. I am looking into the limitations of this process and have noticed you can only set bitmapdata pizel width and height to a certain amount and this might be flexible with what you set the jpegencoder quality to (1-100).
Does anyone know what the specific limitations of these two things are? I'm basically trying to see just how large of an image I can save out (because I need to use the image exported for printing purposes, so I need it as high quality as possible).
I have read articles that say in fp 10 you can render up to something like 16,000 px. But I tried an image that is 3500 x 3500 and it timed out. So not sure if this is correct information.
The image size limit up to Flash Player 9 is 2880x2880, Flash 10 increased this limit to 4096x4096. This applies also for the Stage, Sprites and MovieClips.
The quality used for the JPGEncoder class does not circumvent this limitation as this is tied to the Flash core.

Generate flv, mpg or some other movie format from an ActionScript movie clip

I am working on a Flex application/game where a lot of UIComponents are moved around on a canvas.
I would like to "record" an flv movie of the movement on the canvas. Is there anyway this can be accomplished ?
I essentially want my users to be able to record small flv videos of their games to be uploaded on youtube.
Any ideas or suggestions about how to do this ?
There is SimpleFlvWriter (for AIR). You may modify it to get a non-AIR version. But memory management will be an issue since BitmapData will take up a lot of memory... It may be possible for a few seconds flv but definite not for several minutes.
Usually we stream things to a Flash server (eg. Flash Media Server, Red5) and let the server create the flv. But you need to find a way to convert the screen captures to NetStream. Or you may find other server side technology that can create flv from sequence of BitmapData. But in anyway it will consume a lot of bandwidth.
An alternative I can think of, is to save all the game commands(in XML, or other text format) and send it to the server. And you write a program in server-side to generate the flv from only the game commands. But it will be the most difficult solution to be implemented.

How to create a large Compatible Memory DC in GDI programming?

I want to create a large CompatibleDC, draw a large image on it, then bitblt part of the image to other DC, in order to achieve high performance. I am using the following code to create compatible Memory DC. But when the rect becomes very large, etc: 5000*5000, the CompatibleDC created become unstable. sometimes it is OK, sometimes it failed. is there any thing wrong with my code?
input :pInputDC
output:pOutputMemDC
{
pOutputMemDC=new CDC();
VERIFY(pOutputMemDC->CreateCompatibleDC(pInputDC));
CRect rect(0,0,nDCWidth,nDCHeight);
CBitmap bitmap;
if (bitmap.CreateCompatibleBitmap(pInputDC, rect.Width(), rect.Height()))
{
pOutputMemDC->SetViewportOrg(-rect.left, -rect.top);
m_pOldBitmap = pOutputMemDC->SelectObject(&bitmap);
}
CBrush brush;
VERIFY(brush.CreateSolidBrush(RGB(255,0, 0)));
brush.UnrealizeObject();
pOutputMemDC->FillRect(rect, &brush);
}
Instead of creating a large DC and then blitting a portion of it another, smaller DC, create a DC the same size as the destination DC, or at least the same size as the blit destination. Then, offset all your drawing commands by the (-x,-y) of the sub section you want to copy. If your destination is (100,200)-(400,400) on the source then create a DC (300x200) and offset everything by (-100,-200).
This has two big advantages: firstly, the memory required is much smaller. Secondly, GDI will clip your drawing operations to the size of the DC (it always clips anyway). Although the act of clipping takes CPU time, the time saved by not drawing pixels that aren't seen more than makes up for it.
Now, if this large DC is something like an image (JPEG for example) then you need to look into other methods. One technique used by many image editing programs is to split the image into tiles and page the tiles to/from memory/hard disk. Each tile is its own DC and you only have enough source DCs to fill the target DC. As the view window moves across the large image, unload tiles that have moved out of the target rectangle and load tiles that have become visible.
Each 5000x5000 pixel image needs ca. 100MB of RAM. Depending on how much RAM your PC has, this might already be the problem.
If you have 1GB of RAM or more, then that's probably not the issue. In this case, you must have a memory leak. Where do you free the allocated bitmap? I see that you unrealize the brush but how about the bitmap?
Note that increasing your swap won't help since that will kill your performance.
Make sure you are selecting all original GDI objects to the DCs.
The problem may be that your Bitmap is still selected into the pOutputMemDC when it is being destroyed and one of them or both can't be deleted properly. Thus problems with memory might begin.

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