Function plan_packet_copy 

pub fn plan_packet_copy(
    request: &PacketCopyRequest<'_>,
) -> Result<PacketCopyPlan, String>

Decides whether request can be served by copying packets.

Hosts planning several runs use one PacketCopyPlanner, which reads each source once.

Errors

Names the container, codec, size, color or frame timing a copy would not reproduce, or a run that does not start at an IDR picture.