slow memcpy

OlivierG — Tue, 11 Mar 2025 09:56:00 GMT

i tried this code

unfortunately the call to memcpy from
buffers[buf.index].start[0]
is very slow about 10 ms with an image size 640*480

i thing it is due to the VB2_MEMORY_MMAP mode

i tried with V4L2_MEMORY_DMABUF but ioctl failed

Is the slow memcpy due to the memory mode ?
Is there a working exemple with V4L2_MEMORY_DMABUF and V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE ?

Greeting

Olivier

Re: slow memcpy

OlivierG — Thu, 13 Mar 2025 14:16:27 GMT

i use this code to use DMA instead of MMAP

I also verified that this patch is applied

It works, memcpy time is less than 1 ms

Olivier