After Cobalt 11.88772 which solves animated webp rendering and with blitter/DirectFB, the application takes the whole CPU resource to just handle the current tile animation (c.f. cobalt timed trace showing high cpu load)
Is it expected to have CPU fully loaded with animated webp? Due to this, the tile transition performance are getting very low.
Yes, animated WebP is CPU-intensive. It must decode each frame before it is due to be rendered, and then composite that onto the previous frame. Even at 10 fps, that's a lot of software decoding.
For OpenGL the composition is performed on the GPU, so that part isn't too bad. I don't know the status of that on the Blitter, though.
If you have a VP8 hardware decoder, you may be able to implement a hardware WebP decoder, which, even if not any faster, will at least offload the CPU. If SbImageDecode() supports it, it will try to use the hardware decoder first.