PACSI NAL type and SEI

[phdzwei]

Hi, everyone:

There are two questions in my work, Could you explaint them for me? Thank you.

1. SEI NAL tyep
Is there max size for payloadsize?

2. About PACSI NAL type
In PACSI NALU, it can include more SEI NALUs, before SEI NALU, there are NAL unit size(16 bits). Is this mean the SEI NAL have limit size.

Thank you

[Shevach]

As far as I know the standard there is no explicit restriction on SEI payload size.
On the other hand the access unit size is constrained by MaxCBP value (which is specified in Table A-1). According to H264 standard access unit is set of NAL units (including SEI NAL units) always containing one and only one primary coded picture.
So, implicitely H264 constrains SEI payload size to be less than MAX CPB.

[phdzwei]

Thank you:)