You must still do the copy, even (especially) if you are using USAGE_SHARED. It is not guaranteed to actually share memory for the bitmaps, so you are indeed not doing the necessary copies on the Nexux 6.
Steve On Friday, June 10, 2016 at 3:18:32 AM UTC-7, Ruppesh Nalwaya wrote: > > Hi > I started exploring the HelloComputeNDK example that uses Renderscript in > C++ to change the saturation of an image, converting it to gray image. I > noticed that after running the script on allocations, the output alloc is > copied to the outputPtr buffer, which is very "*time consuming operation"*. > I also noticed that the allocations are created with > RS_ALLOCATION_USAGE_SHARED > flag (I understand from this that buffer and allocation are sharing > memory). So I skipped the copying statements > > //inputAlloc->copy2DRangeFrom(0, 0, X, Y, inputPtr); > > //outputAlloc->copy2DRangeTo(0, 0, X, Y, outputPtr); > > > This reduces the time of execution. This works on samsung galaxy s6. But on > nexus 6 phone, this *does not work*. I get a a blank image in case of nexus > 6. What is going wrong here. What is the proper way to avoid copying the > allocation to buffer and reduce the execution time. > > > Thanks > > Ruppesh > > -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/android-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/android-developers/727d6b21-beb6-4080-8d4a-136296335dbe%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
