cemp

Per pixel alpha blending (alpha compositing) to blend video and graphics layers on Firegl boards?

Discussion created by cemp on Aug 11, 2011
Latest reply on Sep 5, 2011 by cemp

We have a graphics application development project on RedHat (RHEL6). We are looking for a professional workstation graphics board (NVDIA Quadro, AMD FireGL) in the middle segment.  In our project a streamed h264 video is used. We need to use hardware acceleration to display the video.

We have a specific need to display a graphics symbology (OpenGL or GUI) over a video window (hardware overlay). The graphics symbology includes semi transparent regions and transparent gradient bars. We need to apply alpha blending on the symbology to obtain different transparency regions. Therefore, we cannot simply use global alpha blending or color keying.

I know that some old ATI chips (M9, rv250) have an per pixel alpha mode for the overlay layer. In this mode, video (overlay) can be drawn on the background and the pixels on the graphics (GUI) layer are blended with the pixels in the overlay according to the alpha values of the pixels of the graphics layer.

I would like to know if per pixel alpha mode feature is still supported on the new AMD graphics cards.

Are there any public documentation for the new FireGL cards that I can check this feature?

We can decide to choose AMD cards if this feature is supported.

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