thanks for the advise but writing it directly on to fb0 wud mean it would'n be a part of android framework.
On Sun, Mar 1, 2009 at 7:52 AM, Prajnashi S <[email protected]> wrote: > Hi, > You can write raw data to /dev/graphics/db0 directly. Just same as what > you do in formal linux frame buffer device. > > > On Thu, Feb 26, 2009 at 5:57 PM, bhoj <[email protected]> wrote: > >> >> Hi Syed, >> >> >> I wanted to know if its possible to do it in c++ . Can I create a >> bitmap object in c++ without JNI ? >> >> On Feb 25, 6:17 am, iblues <[email protected]> wrote: >> > Hi Bhoj, >> > >> > If you looking to render some YUV dump on the screen from your >> > application, you can do it using Canvas object. >> > >> > You will need to convert your YUVs to RGB and then to Color Pixel >> > array and create a Bitmap object using the array data. And render the >> > same. If you are talking of rendering YUVs in real-time buffering, >> > this would not be an apt solution. >> > >> > I do remember someone trying this approach with the Camera Raw data in >> > Android-Developers forum. Plz do check over that. You will have some >> > idea. >> > >> > Have a nice day! >> > >> > Regards, >> > Syed Ibrahim >> > >> > On Feb 25, 2:11 pm, bhoj <[email protected]> wrote: >> > >> > > iblues, >> > >> > > I am trying to display some yuv dump on to the screen .Can you tell me >> > > how u did it in ur case ? did u write a jni wrapper to access the >> > > display surface ? Is it possible to render on to the display without a >> > > jni wrapper ? I don't want to introduce JNI at present . I know one >> > > cannot access the display from a native application but I have read >> > > that it is possible which myt not work later. As of now i just want to >> > > display something on the screen. >> > >> > > On Jan 23, 6:21 am, iblues <[email protected]> wrote: >> > >> > > > Thanks Dave. >> > >> > > > Regards, >> > > > iblues >> > >> > > > On Jan 23, 10:40 am, Dave Sparks <[email protected]> wrote: >> > >> > > > > 1. ISurface is the remote interface for SurfaceFlinger. When you >> call >> > > > > an ISurface method like postBuffer, you are executing an RPC in >> > > > > SurfaceFlinger. There is only one way to render 2D graphics >> through >> > > > > the window system and that is using SurfaceFlinger. In the future, >> you >> > > > > could use the overlay interface, but that is aimed more at >> hardware >> > > > > pipelined video rather than software rendering. >> > >> > > > > 2. ashmem and pmem are very similar. Both are used for sharing >> memory >> > > > > between processes. ashmem uses virtual memory, whereas pmem uses >> > > > > physically contiguous memory. One big difference is that with >> ashmem, >> > > > > you have a ref-counted object that can be shared equally between >> > > > > processes. For example, if two processes are sharing an ashmem >> memory >> > > > > buffer, the buffer reference goes away when both process have >> removed >> > > > > all their references by closing all their file descriptors. pmem >> > > > > doesn't work that way because it needs to maintain a physical to >> > > > > virtual mapping. This requires the process that allocates a pmem >> heap >> > > > > to hold the file descriptor until all the other references are >> closed. >> > >> > > > > 3. You have the right idea for using shared memory. The choice >> between >> > > > > ashmem and pmem depends on whether you need physically contiguous >> > > > > buffers. In the case of the G1, we use the hardware 2D engine to >> do >> > > > > scaling, rotation, and color conversion, so we use pmem heaps. The >> > > > > emulator doesn't have a pmem driver and doesn't really need one, >> so we >> > > > > use ashmem in the emulator. If you use ashmem on the G1, you lose >> the >> > > > > hardware 2D engine capability, so SurfaceFlinger falls back to its >> > > > > software renderer which does not do color conversion, which is why >> you >> > > > > see the monochrome image. >> > >> > > > > On Jan 22, 8:46 pm, iblues <[email protected]> wrote: >> > >> > > > > > Hi Dave, >> > >> > > > > > I was able to display the YUV frame onto the ISurface. But as >> you had >> > > > > > mentioned, the emulator is considering only the Y-data and >> displaying >> > > > > > a gray-scale video. I just have few clarifications from my above >> > > > > > exercise : >> > >> > > > > > 1. In most of the posts and also in the source code, whenever we >> talk >> > > > > > to posting to the display, all talk of Surface Flinger whereas >> the >> > > > > > Camera and the Media Player uses ISurface to render the display >> images >> > > > > > onto the screen. I also see the implementation of the Surface >> Flinger >> > > > > > to be more of a wrapper to the ISurface. Which of these objects >> would >> > > > > > you recommend to be used for real-time rendering of YUV data? >> > >> > > > > > 2. I seem to not to understand the difference between ashmemory >> and >> > > > > > pmem memory. Can you point out some overall differences between >> the >> > > > > > same? >> > >> > > > > > 3. In my requirement, I would have a native library A render the >> YUV >> > > > > > frames and map it to a Memory Heap. If another library say B >> wants to >> > > > > > have access to this memory heap , as per my understanding, I >> will have >> > > > > > to wrap the memory heap into IMemory and pass the same via a >> callback >> > > > > > from A to B right? If so, should my memory heap type be ashmem >> or >> > > > > > pmem? >> > >> > > > > > Please correct me if my understandings are wrong anywhere. >> > >> > > > > > Regards, >> > > > > > Syed Ibrahim M >> > >> > > > > > -------------------------- >> > >> > > > > > On Jan 22, 12:33 am, Dave Sparks <[email protected]> >> wrote: >> > >> > > > > > > Yes, you need to make your class a friend of SurfaceHolder.- >> Hide quoted text - >> > >> > > > > - Show quoted text -- Hide quoted text - >> > >> > > - Show quoted text - >> > >> > >> >> > > > -- > -- Prajnashi > > > > > -- with regards vishal --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "android-framework" group. 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