Re: [libdc1394-devel] Re: Latest frame
Capture and control API for IIDC compliant cameras
Brought to you by:
ddouxchamps,
gordp
From: Martin M. <mar...@vi...> - 2004-05-14 14:27:26
|
Hi, > Could you please give a bit more information on how exactly you know > that you are getting the previously captured frame? If I do a dma_*_capture I will get a frame from the previous dma_*_capture. For example, my program is a network server that sends an image to a client whenever the clien request it. If the client requests an image and the camera was previously pointing at a box (and is now pointing at a circle), the client will receive an image with a box (and not a circle!). When the client sends another request, he will receive a circle (even if the cam is now pointing at a triangle) and so on... This causes a lot of issues and the only way I have found to fix this is to do two consecutive dma_*_capture/ dma_done_with_buffer ? wich I find kind of ugly... > > > From what I understand dma_ring_buffer points to the first DMA > buffer > > containing frames, right? > > Not quite. It points to the start of the DMA ring buffer whether > there are frames in it or not. > > Maybe you mean capture_buffer, which points to the next received frame > each time a capture function returns. > From what I understand capture_buffer point to : dma_ring_buffer+dma_frame_size*dma_last_buffer If I assing 4 buffers for capture and I activate DROP_FRAMES, are all the 4 other buffers empty? Is there a way to access these buffers in memory? Thank you Martin Morissette |