[Mp4-tech] This may affect your decoder. Are Stuffing macroblocks considered Coded macroblocks?

[Lefan Zhong]

Dear All, 
If a P-frame start with 1 not-coded macroblock, then a stuffing macroblock and then a not-coded macroblock, then a INTRA+Q macroblock, my question is that INTRA+Q is the 1st coded macroblock in VOP or the 2nd coded macroblock in the VOP?
The 1st or 2nd may affect the currentQp or previousQp for INTR_VLC_DC_THR switch, which simple profile should always supported. 
>From the document 14496-2(2001), I haven't found any sentence claim that stuffing macroblock should be counted as NOT-Coded. So restrictly follow the spec, the stuffing macroblock is 1st coded, the INTRA+Q should be the 2nd coded macroblock. 
Reference decoders definitely take the INTRA+Q macroblock as the 1st coded macroblock in the VOP. 
Maybe we need an amendment for the Spec 14496-2. 
Lefan