Thread concept Vs Video Rendering

[Dave1024]

Hai All
I was just implement the thread concept in video rendering.To render the video one thread and convertion and frame by frame set up done by another thread. The following algorithm used for full fill the concept.
Thread 1.
Read a Frame.
Lock the rectangle area for render.
Pack the data as per the format supported by display
Unlock the rectangle area for render.
Thread 2.
Begin a scene
Set The Texture
Draw use the primitivesUP macro
End the scene
Present.
Exit from the thread.
I am using system memory and never use video cards.My system memory nearly 760 MB and processor speed 1.7 GHz.
The above algorithm for thread consistently work for small video files.But when large file come rendering fails after 100 frames.
I am setting the thread loop by total number of frames.
Can someone interested just replay how i solve the problem.

[jagabo]

Watch your process with Task Manager. If "Mem Usage" goes up and up as the program runs you have a memory leak.

[Dave1024]

No memory problem.
Suppose same texture use with multiple times with same device then any type of problem.
This breakage is the aftermath of the above reason.