[Mp4-tech] Slice mapping in h.264

[Gary Sullivan]

Anil,
It would help if you adhered more closely to the language of the
standard so that it is easier to understand what you are saying.  (There
is nothing in the standard called "slice number" or "slice mapping" in
the standard.)
I think you are saying that you used slice_group_map_type equal to 6,
and changed the value of some of the slice_group_id[i] entries from
picture to picture.  Yes, that is permitted (if you are using the
Baseline or Extended profile and all slice_group_id[i] values are in the
range of 0 to num_slice_groups_minus1 and num_slice_groups_minus1 is in
the range of 0 to 7).
You say that the bitstream that you generated caused the decoding
process to fail in some way (although you don't seem to describe exact
symptoms -- did the decoder put out an error message?  Exactly what
happened?).
If I understand you correctly, I think there must be some problem in the
software that you are using (although it isn't completely clear to me
whether that problem is in the encoder or the decoder).
Best Regards,
Gary Sullivan
+> -----Original Message-----
+> From: mp4-tech-bounces lists.mpegif.org 
+> [mailto:mp4-tech-bounces lists.mpegif.org] On Behalf Of Anil M S
+> Sent: Tuesday, February 01, 2024 9:38 PM
+> To: mp4-tech lists.mpegif.org
+> Subject: [Mp4-tech] Slice mapping in h.264
+> 
+> hi, 
+> I am working on H.264(JM86).I need to change the slice mapping for
+> each frame,i.e I have to dynamically change the slice number of each
+> macroblock which is different than the first frame or prev frame.
+> Is that permitted?Can we have different slice mappings for different
+> frames.When I did this by using "pps"(Explicit mode(6)),I 
+> was not able
+> to decode the encoded stream correctly.So pls suggest me the correct
+> direction.
+> Thanking You,
+> Anil
+> _______________________________________________
+> 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-Ant
itrust.php
+>