Thank you for you answer. I want to use buffers of VPBE as output of previewer and than perhaps output of resizer to avoid memcpy operation. Previewing task will be synchronized with VPBE.I have realized that it is not possible to do it with FB driver I need to use V4L2 to get offsets for previewer.
The requirement is to reduce latency. Now I am using pipe of CCDC, PREVIEWER(for demosaicing), memcpy and FB. And the latency is about 160ms. Best regards Ondrej Pindroch SoftHard Technology ltd. -----Original Message----- From: "Jerry Johns" <[email protected]> To: <[email protected]> Date: Tue, 12 May 2009 20:48:49 -0700 Subject: How to use buffers from FB as output buffer from previewer Let me get this correct: you want to take the output from the previewer engine in the CCDC module, and drive the VPBE display device with the same memory buffers? Although this is theoretically possible, it does not make sense from an implementation perspective – the CCDC module operates on an input clock that is absolutely asynchronous (and possibly at a different rate) with the display output clock. In that regard, the VPBE hardware will continually pick-up at its native display rate data from that memory location; since the production of data into the buffer by the CCDC is not in ‘sync’ with the VPBE, you’ll definitely get tearing at the VPBE output. What is driving this requirement for single buffer access? Is it memory usage? Latency? Jerry Johns Design Engineer Nuvation Research Corp - Canada Tel: (519) 746-2304 ext. 221 www.nuvation.com [http://www.nuvation.com/]
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