[Mp4-tech][H264]

[Gary Sullivan]

It means 16 motion vectors.  The syntax would support up to 32, but that
statement restricts it.
You might want to double check to make sure you have the latest draft of
the standard, since the method of counting motion vectors was made more
precise in corrigendum work.
Best Regards,
Gary Sullivan
+> -----Original Message-----
+> From: mp4-tech-bounces lists.mpegif.org 
+> [mailto:mp4-tech-bounces lists.mpegif.org] On Behalf Of Yu-Bin Zhu
+> Sent: Monday, April 04, 2024 11:29 AM
+> To: mp4-tech lists.mpegif.org
+> Subject: [Mp4-tech][H264]
+> 
+> Dear Experts,
+> 
+> I'd like to ask the following question:
+> 
+> In H.264 specification A.3 Levels, MaxMvsPer2Mb = 16 for 
+> Level number 4 or 4.1.
+> Does the "16" mean 16 motion vectors or 16 pair of(32) 
+> motion vectors since common
+> sense tells me that 16 motion vectors are needed for P-type 
+> Mb with 4x4 motion compensation
+> block size, 32 motion vectors are required for B-type Mb(16 
+> for forward and 16 for backward)?
+> 
+> Please let me know your answer.
+> 
+> thanks a lot!
+> 
+> Yubin
+> 
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