Video/Animation Playback

Hi,

I'm currently writing a library (for XNA/DirectX) for

animation/soundless video playback, and I have a few design questions

for the pros out there if you don't mind answering them:

1. I'm having my animation class inherit from game component, and

   update the frame depending on game time in the overriden Update method,

   and render it in the overidden Draw method, but even when I preload my

   textures to render, playback is choppy. Not sure exactly why, but I

   notice this only when I have significant number of frames (I noticed it

   with 100 frames, but *not* with 10/15). This problem may be linked and

   solved by the 2nd point, so please read on.

2. When I preload all the textures for the frames in the animation

   (and the no. of frames is small, as explained in point 1), the

   animation plays back perfectly. Now I've also added the capability

   for future frame textures to be loaded on-the-fly asynchronously (using

   delegates) whilst the animation is playing, in order to a) I can't

   preload all the textures for a big video since they can have 1000s of

   frames... ba) To minimize loading time. From this I've discovered

   that the problem is caused by the slow loading time of frame textures

   in comparison to the playback rate (typically about 300ms compared to

   30ms). Clearly the playback will overtake the on-the-fly preloading

   rather quickly, causing playback to wait up, making it appear choppy.

   So all I want to do it somehow quicken the preloading time for

   textures. This is my current code:

' Create new frame texture and store it in the array.
Dim creationParams As New TextureCreationParameters( _
0, 0, 0, 0, SurfaceFormat.Unknown, ResourceUsage.None, ResourcePool.Managed, _
Nothing, FilterOptions.None, FilterOptions.None)

_frameTextures(frame) = Texture2D.FromFile(graphicsDevice, _dataStream, byteLength, creationParams)

As you can see I'm loading from a stream (FileStream in my tests).

I've fiddled around with the parameters quite a bit but this code makes

it the quickest - still not quick enough.

I hope that some of you may have ideas on how video rendering is

done by other programs, or more likely just some new ideas. Thanks in

advance for any help!

Alex

P.S. If there are any premade animation playback libraries for XNA

already please do let me know, but I've searched and I doubt it anyway

since XNA is still very young.