CONFIGURABLE NAL AND SLICE CODE POINT MECHANISM FOR STREAM MERGING

A video decoding apparatus includes processing circuitry configured to perform operations comprising: receiving, from a video data stream, a sequence parameter set (SPS); parsing, from the SPS, an extra slice header bit map; mapping one or more bits in the extra slice header bit map to one or more flags that indicate presence or non-presence corresponding to a syntax element in a slice header; determining a number of extra slice header bits based on an amount of the one or more flags that indicate presence; and parsing, from the video data stream, the syntax element in the slice header based on the determined number of extra slice header bits.