Yes, the problem seems to be that the "libpisp/helpers" library (which is trying to help!) is creating new buffers; then you have to copy the data in and out using the "read_plane()" and "write_plane()" functions -- there is the copy.
Some of that code would need to be rewritten or bypassed to avoid this. The PiSP conversion should work from dmabufs. I will take a look to see if I can suggest any quick hacks...
Of course the hardware conversion is still a "copy in memory", i.e. it will consume some SDRAM cycles and indirectly impact CPU performance a little, even if the CPU itself is not involved.
Some of that code would need to be rewritten or bypassed to avoid this. The PiSP conversion should work from dmabufs. I will take a look to see if I can suggest any quick hacks...
Of course the hardware conversion is still a "copy in memory", i.e. it will consume some SDRAM cycles and indirectly impact CPU performance a little, even if the CPU itself is not involved.
Statistics: Posted by njh — Fri Dec 05, 2025 10:29 am