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How to increase video performance from camera source on i.Mx35 ?

Question asked by Kai Eckardt on Aug 15, 2013
Latest reply on Dec 10, 2013 by Kai Eckardt

Hello everyone,

 

we use an i.Mx35 and have to display a video from a camera without wasting cpu cycles. There are two examples provided in freescales BSP CAMAPP and TVIN. Both use DirectDraw and overlay to show the picture. But they still use a memcpy() to copy every line seperate into the overlay buffer.

 

from CameraWindow.cpp line 671 in CAMAPP example:

 

            // If height in bmiHeader is negative, the image is top-up, we just copy it.
            // Or esle the captured image should be bottom-up, so we vertically flip the image.
            if(pCamWin->m_PreviewDataFormat.VideoInfoHeader.bmiHeader.biHeight < 0)
            {
                for (height = 0; height < displayHeight; height++)
                {
                    memcpy(pbyDstBuffer,pbySrcBuffer,(displayWidth * pCamWin->m_ibiBitCount) / 8);

                    pbySrcBuffer += (pCamWin->m_DisplayInfo.imageWidth * pCamWin->m_ibiBitCount) / 8;
                    pbyDstBuffer += (displayWidth * pCamWin->m_ibiBitCount) / 8;
                }
            }

 

can anyone tell me if it is possible to do this using dma or another cpu cycles saving technique ? An example would be great..

 

best regards,

Kai

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