[vbox-dev] IFramebuffer changes from 4.x to 5.0

Rūdolfs Bundulis rudolfs.bundulis at gmail.com
Tue Jan 5 13:53:53 UTC 2016

Hi Vitali,

thanks for clearing all of this out - this should be sufficient to make the

2016-01-05 11:22 GMT+02:00 Vitali Pelenjow <Vitali.Pelenjow at oracle.com>:

> Hi Rudolfs,
> if you are launching the machine inside you own process, then use
> notifyUpdate. You are right that in this case you get the pointer to the
> framebuffer bitmap using the IDisplaySourceBitmap interface.
> You should call IDisplaySourceBitmap::queryBitmapInfo from notifyChange
> handler (see implementations in src\VBox\Frontends). The returned bitmap
> info is valid until the next notifyChange call.
> notifyUpdateImage is used to get bitmap updates in a different process.
> Thanks,
> Vitali
> Rūdolfs Bundulis wrote:
>> Hi,
>> I am porting my custom frontend to VirtualBox 5.0 and had a couple of
>> questions about how IFramebuffer works now. I see that all the stuff
>> regarding VRAM and implementing it inside the framebuffer is gone, which I
>> was told would happen. What confuses me is usage of notifyUpdate vs
>> notifyUpdateImage. I am launching the machine inside my own process - so
>> then which is the most efficient way to receive notifications about
>> updates? Which one is more efficient? As I understand if I use notifyUpdate
>> (and do not retur the UpdateImage capability) I must get the pointer to the
>> bitmap and all the data from the IDisplaySourceBitmap interface? Is that
>> thread safe? Can I read the pixels without any explicit locking? And what
>> about changes to the pixel format - they are no longer part of the
>> notifications. Does that mean I need to call
>> IDisplaySourceBitmap::queryBitmapInfo() each time i receive a notifyUpdate
>> call?
>> Best Regards,
>> Rudolfs Bundulis
>> _______________________________________________
>> vbox-dev mailing list
>> vbox-dev at virtualbox.org
>> https://www.virtualbox.org/mailman/listinfo/vbox-dev
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