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 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "android-framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-framework?hl=en -~----------~----~----~----~------~----~------~--~---
