Whole screen capture and render in DirectX [PERFORMANCE]

Question

I need some way to get screen data and pass them to DX9 surface/texture in my aplication and render it at at least 25fps at 1600*900 resolu

Answer 1

Starting with Windows 8, there is a new desktop duplication API that can be used to capture the screen in video memory, including mouse cursor changes and which parts of the screen actually changed or moved. This is far more performant than any of the GDI or D3D9 approaches out there and is really well-suited to doing things like encoding the desktop to a video stream, since you never have to pull the texture out of GPU memory. The new API is available by enumerating DXGI outputs and calling DuplicateOutput on the screen you want to capture. Then you can enter a loop that waits for the screen to update and acquires each frame in turn.

To encode the frames to a video, I'd recommend taking a look at Media Foundation. Take a look specifically at the Sink Writer for the simplest method of encoding the video frames. Basically, you just have to wrap the D3D textures you get for each video frame into IMFSample objects. These can be passed directly into the sink writer. See the MFCreateDXGISurfaceBuffer and MFCreateVideoSampleFromSurface functions for more information. For the best performance, typically you'll want to use a codec like H.264 that has good hardware encoding support (on most machines).

For full disclosure, I work on the team that owns the desktop duplication API at Microsoft, and I've personally written apps that capture the desktop (and video, games, etc.) to a video file at 60fps using this technique, as well as a lot of other scenarios. This is also used to do screen streaming, remote assistance, and lots more within Microsoft.

Answer 2

If you don't like the FrontBuffer, try the BackBuffer:

LPDIRECT3DSURFACE9  surface;
surface = GetBackBufferImageSurface(&fmt);

to save it to a file use

D3DXSaveSurfaceToFile(filename, D3DXIFF_JPG, surface, NULL, NULL);