I'm not sure you can. My understanding of moderm ARM SOCs is this. The kernel maintains separate pipelines for graphics and video. It is only in the ARM SOC hardware, directly before sending output to the display, that the two pipelines are merged.
Note that the video pipeline is often referred to as a video overlay, and Android has liboverlay as a hardware abstraction library. You might be able to trace down more information by looking there. -Eric On Sun, Nov 13, 2011 at 12:34 PM, Ron M <[email protected]> wrote: > so where would be the place to capture the entire display? e.g. if I wanted > to implement something like "cp /dev/fb0" in order to later deserialize it > in another place (something like taking a screenshot)? > acheiving something like this should be straight forward, and I know that in > the first android versions it was implemented somewhere natively because > they did a vnc hook, but I don't knoe where to start from. > > thanks. > > On Nov 10, 2011 6:56 PM, "Matt Shao" <[email protected]> wrote: >> >> image there are more than one display buffer(let's say two frame buffer), >> the hardware will merge two buffer and send to the screen >> in most modern arm cpu, such kind of hardware is always exist.... >> >> 2011/11/10 Girish H T <[email protected]> >>> >>> Hi, >>> >>> Sorry for cross posting. Stuck up with a problem , hope to get the >>> solution at this forum. >>> >>> I am trying to capture the frame from framebuffer device. >>> /dev/graphics/fb0 in a rooted device. It works well to some extent. But when >>> i try to play a video and , capture frame buffer the trouble starts. That is >>> there is a black hole in the captured frame i can see. >>> >>> As i read from the google groups there is hardware overlay which the >>> decoded data is directly rendered to, this part i cant understand. As there >>> is only one display logically everything should be muxed and given to >>> display. But i am still not able to understand how the video buffer is >>> rendered seperately without frame buffer memory area. >>> >>> Could some one clarify how exactly the hardware overlaid rendering >>> happens without directly writing to the frame buffer memory area. Is that >>> area be accessible ? >>> >>> Regards >>> Girish >>> >>> -- >>> unsubscribe: [email protected] >>> website: http://groups.google.com/group/android-porting >> >> -- >> You received this message because you are subscribed to the Google Groups >> "android-platform" 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-platform?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "android-platform" 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-platform?hl=en. > -- unsubscribe: [email protected] website: http://groups.google.com/group/android-porting
