Do you know if/why on apple silicon Macs there’s a difference between videotoolbox and videotoolbox-copy ? I thought the SoC memory is shared and that there wou

Do you know if/why on apple silicon Macs there’s a difference between videotoolbox and videotoolbox-copy ? I thought the SoC memory is shared and that there wouldn’t be a need for copying data from VRAM to RAM.