[Mp4-tech] [H.264] Question about "Allowed collective macroblocktypes for slice types"

[daniele renzi (bsoft)]

Hi David,
in section 7.4.5 you can find for P and SP slices, right before table 7-13, 
the following sentence:
"The macroblock types for P and SP slices are specified in Table 7-13 and 
7-11. mb_type values 0 to 4 are specified in Table 7-13 and mb_type values 5 
to 30 are specified in Table 7-11, indexed by subtracting 5 from the value 
of mb_type.",
and for B and SB slices, right before table 7-14, the following sentence:
"The macroblock types for B slices are specified in Table 7-14 and 7-11. The 
mb_type values 0 to 22 are specified in Table 7-14 and the mb_type values 23 
to 48 are specified in Table 7-11, indexed by subtracting 23 from the value 
of mb_type."
Hope this answer your question.
Best regards,
Daniele
Daniele Renzi
bSoft -- www.bsoft.info
+39-0733-57707  (tel/fax)
----- Original Message ----- 
From: "David Wu" <david_t_wu hotmail.com>
To: "mp4_h264" <mp4-tech lists.mpegif.org>
Sent: Tuesday, November 06, 2023 11:24 PM
Subject: [Mp4-tech] [H.264] Question about "Allowed collective 
macroblocktypes for slice types"
>
> Hi Experts,
>
> In section 7.4.5 Macroblock layer semantics, table 7-10 (h.264 03/2005),
> it is indictaed that,
>
> For P slice, a macrobloc type may be P (table 7-13) or I (table 7-11)
> For B slice, a macrobloc type may be B (table 7-14) or I (table 7-11)
> ....................
>
> My question is that, the mb_type code id used in 7-13 & 7-11 or 7-14 & 
> 7-11 are ovelapped integers,
> so how can one tell whether a macroblock in P slice is of  P or I 
> macroblock types ?
>
> Thanks for your help.
>
> Regards
>
> David Wu
>
> david_t_wu hotmail.com
>
> Fremont CA
> _________________________________________________________________
> Peek-a-boo FREE Tricks & Treats for You!
> http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=us
> _______________________________________________
> NOTE: Please use clear subject lines for your posts. Include [audio, 
> [video], [systems], [general] or another apppropriate identifier to 
> indicate the type of question you have.
>
> Note: Conduct on the mailing list is subject to the Antitrust guidelines 
> found at 
> http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php
>
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database: 269.15.23/1114 - Release Date: 06/11/07 
> 20.05
>
>