Get image from frame

[Altera_Forum]

I am working on a project and need to process image frames acquainted before it goes to display. From the VIP Camera example, I found this: 

 display = alt_video_display_only_frame_init(// ALT_VIDEO_DISPLAY_SGDMA_NAME, // char* sgdma_name  FRAME_BUF_W, // int width  FRAME_BUF_H, // int height  ALT_VIDEO_DISPLAY_COLOR_DEPTH, // int color_depth  SDRAM_BASE + 0x00800000, // int buffer_location  1 ); // int num_buffers    I wish to process the image obtained in 3D arrays(R,G,B ) but I have difficulty extracting the values from "display" and also how to put back the processed image into "display". Can someone help to guide me? I am quite new in NIOS II, is there any documentation or guide on this alt_video_display library?  Thank You

[Altera_Forum]

Check: http://www.altera.com/literature/an/an527.pdf (http://www.altera.com/literature/an/an527.pdf) 

 All of the functions (as far as I can tell) are listed there as well as descriptions for each function.

[Altera_Forum]

--- Quote Start ---  Check: http://www.altera.com/literature/an/an527.pdf (http://www.altera.com/literature/an/an527.pdf)  All of the functions (as far as I can tell) are listed there as well as descriptions for each function.  --- Quote End ---    Thank You for the link. It was certainly helpful but I still quite confuse with this function:  ======== int alt_video_display_buffer_is_available(alt_video_display* display); This function returns the next free frame buffer available for display. The function returns a condition code of 0 if an empty buffer is found; any other return value indicates failure. The function accepts the following parameter: ■ display: This variable is a pointer to a data structure that keeps track of all of the frame buffer information, including the start addresses for all of the frame buffers. ========  It says that it return 0 or other number indicates failure. Then, my question is, where is the frame I want goes? I need the frame to do analysis before display. Thank you.