[Mp4-tech] Re: [jvt-experts] gaps_in_frame_num_value_allowed_flag...???

[Deepak Singh]

Hi Expert,
ya Gary there was error in my first example.Sorry for the mistake.
Thanks for correcting me.
My next query on this issue is .....based on your reply
>  I think the sequence of frame_num values for the second case would be:
>
>  0,1,2,3,4,4,4,5,6,7,0
>
>  So for the frames that actually "exist", the frame_num values that you would observe is:
>
>  0,1,3,4,4,6,7,0.
>
Why the Non -existing frame are considered as "used for reference"
when those frames are non- existing and why this is affecting the
"frame_num".
Why not Non -existing frame are considered as "Not used for reference" .
Actually I am working over "Frame Loss Recovery"....
For detecting the Frame Loss I am using "frame_num" to detect the
reference frame and if frame_num is not in order I am considering it
as unintentional loss of frame as for example...
(gap =0)
frame_num :  0,1,3,3,4,5,0 ...
So there is loss of  frame having frame_num = 2.
I am referring the IEEE paper  Saurav K. Bandyopadhyay and Zhenyu Wu,
Purvin Pandit, Jill M. Boyce "AN ERROR CONCEALMENT SCHEME FOR ENTIRE
FRAME LOSSES FOR H.264/AVC" Circuits and Systems, 2006. ISCAS 2006.
Proceedings. 2006 IEEE International Symposium on Publication Date:
21-24 May 2006
But if  gap =1.
How to detect the loss of frames...????
On Fri, Apr 4, 2024 at 9:48 PM, Gary Sullivan
<garysull windows.microsoft.com> wrote:
>
>  I think there is an error in your first example (gaps = 0).
>
>  Rather than:
>
> 0,1,2,3,3,4,5,0
>  I think the frame_num values will be:
>  0,1,2,3,3,3,4,0
>
>  I think the sequence of frame_num values for the second case would be:
>
>  0,1,2,3,4,4,4,5,6,7,0
>
>  So for the frames that actually "exist", the frame_num values that you would observe is:
>
>  0,1,3,4,4,6,7,0.
>
>  Best Regards,
>
>  Gary Sullivan
>
>  +> -----Original Message-----
>  +> From: jvt-experts-bounces lists.rwth-aachen.de
>  +> [mailto:jvt-experts-bounces lists.rwth-aachen.de] On Behalf
>  +> Of Deepak Singh
>  +> Sent: Friday, April 04, 2024 4:17 AM
>  +> To: jvt-experts lists.rwth-aachen.de; mp4-tech lists.mpegif.org
>  +> Subject: [jvt-experts] gaps_in_frame_num_value_allowed_flag...???
>  +>
>  +> Dear Experts,
>
>
> +>
>  +>   I have query related to
>  +> gaps_in_frame_num_value_allowed_flag and frame_num.
>  +>
>  +>   As per my understanding of standard when
>  +>   gaps_in_frame_num_value_allowed_flag is 0 then frame_num will be in
>  +>  non decreasing order and increases till next IDR frame.
>  +>
>  +> The value of frame_num  increase with plus 1 with respect to previous
>  +>  reference frame.
>  +>
>  +>   Let me put an example for it.
>  +>
>  +>   Lets assume B- frame is not used for reference.
>  +>   In h.264 coded bitstream the frames are : (frame_num as per my
>  +>   understanding it will be)
>  +>   Note: gaps_in_frame_num_value_allowed_flag = 0
>  +>
>  +>   Coded Frame  :  IDR -> P-> P-> B->B-> P-> P->IDR->....
>  +>   Frame_num    :  0         1    2     3    3    4    5     0
>  +>
>  +>   My question is for the same sequence if
>  +>   gaps_in_frame_num_value_allowed_flag = 1 and non- existing frame
>  +>   exists as
>  +>
>  +>   Note: gaps_in_frame_num_value_allowed_flag = 1, NE = Non
>  +> Existing Frame.
>  +>   Coded Frame : IDR -> P-> NE->P-> B->B->NE->NE-> P-> P->IDR->....
>  +>   Frame_num   :  0       1     ?      ?     ?    ? ?     ?
>  +>     ?     ?     0
>  +>
>  +>   How the frame_num value will behave for the above situation???
>  +>
>  +>
>  +>   --
>  +>   Regards,
>  +>   Deepak Singh
>  +>
>  +>
>  +>
>  +>  --
>  +>  Regards,
>  +>  Deepak Singh
>  +>
>  +>  Visit my blog for cool stuff...
>  +> http://www.thinknaturally.blogspot.com/
>  +>
>  +>
>  +>
>  +> *************************************************************
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>  +>  in this world"
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>  +>   With caresss.
>  +>
>  +>
>  +>
>  +> --
>  +> Regards,
>  +> Deepak Singh
>  +>
>  +> Visit my blog for cool stuff...
>  +> http://www.thinknaturally.blogspot.com/
>  +>
>  +>
>  +> *************************************************************
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>  +> "If u really aspire for the FIRST place ,then there is no
>  +> second place
>  +> in this world"
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>

-- 
Regards,
Deepak Singh