[M4IF Technotes] Few Queries on streaming video profile!!!

[Ramkishor Korada]

Hi,
 The decoder can use the max. packet size to detect errors i.e., when
bit-corruption happens decoder may not detect packet end and may start
parsing next packet also. In this case, decoder can come of out parsing once
it recognises that it has parsed more than 2048 bits. The max packet size
can be used to detect errors by decoder.
-ramkishor
Architect - Video
Multimedia Technologies Division
Emuzed India
Bangalore
www.emuzed.com
----- Original Message -----
From: "Peter Haighton" <Peter.Haighton   m4if.org>
To: "Gautam Kumar" <gautam   noida.hcltech.com>; <technotes   lists.m4if.org>
Sent: Tuesday, November 20, 2023 2:01 AM
Subject: RE: [M4IF Technotes] Few Queries on streaming video profile!!!
> Hello Gautum,
>
> The maximum is indeed 2048 bits.
>
> Of course the packet size is only used when dealing with data
> partitioning.
>
> Peter
> --
> Peter Haighton
> VideoSpheres Inc.
> 84 Hines Road
> Kanata, Ontario
> Canada, K2K 3G3
> Tel: (613) 270-9646 x3022
> Fax: (613) 271-9442
> email: peterh   VideoSpheres.com
>
> See http://www.m4if.org for the latest on MPEG-4
>
> -----Original Message-----
> From: technotes-admin   lists.m4if.org
> [mailto:technotes-admin   lists.m4if.org]On Behalf Of Gautam Kumar
> Sent: Monday, November 19, 2023 1:19 AM
> To: technotes   lists.m4if.org
> Subject: RE: [M4IF Technotes] Few Queries on streaming video profile!!!
>
>
> Dear All,
>  Thanks to Mr. Rob and Mr. Peter Haighton for their reply.
> I am wondering at the encoder end for Simple Profile level 1 the Maximum
> Video Packet length is given as 2048 bits
> in ISO/IEC 14496?2:1999/FDAM 1:2000(E), page 497, table N-1.
>
> Is that the maximum size or we can add one more Macroblock data or
> some more bits in that at the Encoding Side?
>
> In ISO reference code for decoder, it adds one more macroblock after it
> exceeds the Video Packet lengtht. But there the Video Packet lengh is well
> below 2048 bits.
> Awaiting reply
> Warm Rgds
> Gautam
>
>
>
>
> -----Original Message-----
> From: Rob Koenen [mailto:rkoenen   intertrust.com]
> Sent: Saturday, November 10, 2023 7:32 AM
> To: Gautam Kumar; technotes   lists.m4if.org
> Subject: RE: [M4IF Technotes] Few Queries on streaming video profile!!!
>
>
> Gautam,
>
>
> > 1) level 0 specification is in amd 3 or amd 4, as i can infer from
> > http://mpeg.telecomitalialab.com/workplan.htm
> > that amd 4 is not in the list.
>
> That is because amendments got renumbered as new versions are issued.
> Difficult to follow at times, but we need to live with it.
> The numbers in the workplan are now relative to the 2001 edition
> of MPEG-4 Visual. You are now looking at AMD2 (Simple   L0) and
> AMD3 (Simple Scalable @ L0)
>
> > 2) does level 0 puts restriction on the size of frame to be
> > multiple of 16 ?
> > (ofcourse size should not be more that QCIF)
>
> yes.
>
> Length <= 176
> Height <= 144
> It only works in multiples of full macroblocks.
>
> MPEG-4 Simple Profile Level 0 has the following restrictions
> when compared to Level 1:
>
>  a) The maximum frame rate shall be 15 frames per second;
>  b) The maximum f_code shall be 1;
>  c) The intra_dc_vlc_threshold shall be 0;
>  d) The maximum horizontal luminance pixel resolution shall be 176
>  pels/line;
>  e) The maximum vertical luminance pixel resolution shall
>  be 144 pels/VOP;
>  f) If AC prediction is used, the following restriction
>  applies : QP value
>  shall not be changed within a VOP (or within a video packet if video
>  packets are used in a VOP). If AC prediction is not used, there are no
>  restrictions to changing QP value.
>
> > 3) Regarding motion estimation and compensation, does it support:
> > a) mb_type = 2 ; that is does it support different motion vectors
> > for all 4 luminance blocks within the same macroblock,
>
> Yes
>
> > b) half pel motion compensation and
>
> yes
>
> > c) unrestricted motion compensation.
>
> yes
>
> Best,
> Rob
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