Interoperability with Direct3D : strange block effect

Accelerated Computing CUDA CUDA Programming and Performance
1

Hi all,

I have recently been interested to use the interoperability with Direct3D. My objective is to use Direct3D9 to display stereoscopic images processed with CUDA. However, I noticed a strange blocky effect one the rendering done. When I play a movie I can clearly see small block boundaries. These block are also smaller that my CUDA blocks. They seem to have a 12 by 12 pixels dimension. I am sure it is only related to the rendering part because before using D3D my program worked fine.
Also my source video does not present any blocky artifacts due to video compression.

I post an sample but it might be difficult to see the blocks.

Has someone had the same problem before ?

Thank a lot.

Sample.png
Sample.png1424×442 1.09 MB

2

I can spot the blocks, but these really look like the typical artefacts of a block based image coder at low bitrate.

Do you also get these when you output the images differently? i.e. save to disk as a monoscopic image sequence.

I did not get any of these blocks when I used that DirectX code to display stereoscopic buddhabrot fractals.

3

Thanks your reply. My video file is uncompressed. But yesterday I noticed something. My video images have a dimension 720x480 pixels and to display them I created a video window of size 1440x480 (for 2 images side by side). Unfortunately I didn’t paid attention to the border width and height of the window. The client area and the window area are different and you cannot set the client area directly using CreateWindowEx(). This morning I readjusted the size of my window and that corrected some artifacts. Unfortunately I can still see the horizontal borders of the blocks.

So I am still searching :)

4

I am giving a new example of this blocky effect. I have played with all the texture filtering options but it didn’t correct it. I am still struggling to find a solution.

Thanks for any help.
Example.png