H264 NAL unit prefixes

Question

I need some clarification on H264 NAL unit delimiter prefixes (00 00 00 01 and 00 00 01), I am using Intel Media SDK to generate a H264 and pack it

Answer 1

From H.264 spec, B.1.2 Byte stream NAL unit semantics:

zero_byte is a single byte equal to 0x00.

When any of the following conditions are fulfilled, the zero_byte syntax element shall be present.

• the nal_unit_type within the nal_unit( ) is equal to 7 (sequence parameter set) or 8 (picture parameter set)
• the byte stream NAL unit syntax structure contains the first NAL unit of an access unit in decoding order, as specified by subclause 7.4.1.2.3.