h.264 - How to decide using MTAP over STAP in h264 rtp payload -

I'm digging into encoding and streaming H.264 last week. At night I am implementing the RTP H.264 payload. Many new NALUs were introduced according to

(" RTP payload format for H.264 video - February 2005 ") Among them MTAP (multi-time aggregation packet) and STAP (Single Time aggregation ...).

In the form of names that are indicated in STAP mode, all units are estimated to have the same timestamp. Does not mean that we can not use SAP for VCL NAL units?

For example, SATP may be used to transmit NAL type 7 or 8 (SPS, PPS), but STAP can not be used for type 1, can be used for 2,3? You can use STAP packets to collect both VCL and non-VCL NRU, who have the same presentation time, if they are part of the same frame, then this should be the case.

You should provide a series of NRUs for the encoder for frames and they should have the same presentation time.

I have worked with encoders who produces NALU byte stream containing all NALUs for the frame, this byte stream was given a single presentation time. I have also seen the encoder, which produces the individual NRUO, which will be the time for the same presentation if they were part of the same frame.