the most recent OpenCV release has gained support for hardware accelerated decoding.
- Video IO hardware acceleration · opencv/opencv Wiki · GitHub
- videoio: HW decode/encode in FFMPEG backend; new properties with support in FFMPEG/GST/MSMF by mikhail-nikolskiy · Pull Request #19460 · opencv/opencv · GitHub
datasheet for that atom processor says
Video decode hardware acceleration including support for H.263, MPEG4, H.264, H.265 (HEVC), VP8, VP9, MVC, MPEG2, VC1, JPEG.
but also:
so that’s the frame rate you can expect.