readme.txt

基于GM8180的OSD源代码.从SDK包中挑出来的,是很不错的资料.

Sample Code Description
========================
  . This sample is running on GM8180 Platform.
  . This 'osd_display' sample will do alpha blending of user-specifed image with
    background image and display the result image to 720x480 LCD/TV. Both 
    user-specified and background image must be in packed CbYCrY 422 image format.
    Please put 'display_cbycry_*.yuv' and 'welcome_256x64_cbycry.yuv.yuv' in the 
    same directory.
    This sample uses 'display_cbycry_*.yuv' as background image and 'welcome_256x64_cbycry.yuv.yuv'
    as overlay image. There is one precompiled OSD driver called 'fmpeg4_osd_drv.ko' and
    precompiled sample application called 'osd_display' for user's convenience in 
    the 'pattern' directory.
    
  . To see the OSD effect, just type the following commands in the console :
      
    Make sure you'are not using MPEG4 engine:
      #rmmod fmpeg4_drv
      #rmmod fmjpeg_drv
      #insmod fmpeg4_osd_drv.ko
      
    Make sure the device node is created:
      #mknod /dev/fosd c 10 24
    
    Run the sample and display in TVE, please put the pattern (display*.yuv) in the same directory.
      #./osd_display -s welcome_256x64_cbycry.yuv -ws 256 -hs 64 -ulx 32 -uly 32 -alpha 128 -f 4
  
    And it will display the background image with 'welcome' logo alpha blended on TV or LCD.


Overlay Performance
========================
       - CbYCrY performace evaluated by ffplay (decoding a .avi file with 720x480 resolution) 
            - one overlay image 176x144 : 30.47 (frames/per sec) 
            - one overlay image 352x288 : 30.2 (frames/per sec) 
            - one overlay image 480x480 : 20.35 (frames/per sec) 
            - one overlay image 640x480 : 16.47 (frames/per sec) 

            - two overlay images 176x144 : 30.61(frames/per sec) 
            - two overlay images 352x288 : 21.76 (frames/ pre sec)