[Mp4-tech] [video][H.264] Regarding disable_deblocking_filter_idc

[Alexis Michael Tourapis]

Dear Joseph,
Actually the reference software also supports case 2. We just missed from
saying this in the encoder.cfg and in the associated manual. In case you
have doubts about parameters and their range, sometimes double checking the
file configfile.h could help (i.e. the range is specified in columns 6 and 7
in the Map structure).
Setting this parameter to 2 implies that no deblocking will be performed
across slice boundaries if multiple slices are present within one picture.
See section 8.7 for more details.
Best regards,
Alexis
-----Original Message-----
From: mp4-tech-bounces lists.mpegif.org
[mailto:mp4-tech-bounces lists.mpegif.org] On Behalf Of Smitha Joseph
Sent: Thursday, April 07, 2024 1:01 AM
To: mp4-tech lists.mpegif.org
Subject: Re: [Mp4-tech] [video][H.264] Regarding
disable_deblocking_filter_idc
Hi,
Thanks for the replies. I had an additional doubt. 
In the JVT code, the encoder configuration file has aparameter which
sets the value disable_deblocking_filter_idc  to 1 or 0. But the
standard specifies that disable_deblocking_filter_idc can have a value
2 also, when does encoder set this parameter value to 2.
Thanks,
Smitha Joseph
On Apr 7, 2024 12:31 PM, Adarsh Golikeri <golikeri gmail.com> wrote:
> Hi,
> 
> In the encoder congiguration file, there are parameters for "Loop
> filter" which allow for enabling/disabling the deblocking filter. If
> the filter is enabled, then the boundary strength is chosen according
> to :
> 
> boundary is an intra-intra / inter-intra MB boundary : strength = 4
(strongest)
> boundary is an intra-inter / inter-inter non-MB boundary (i.e within
> an MB) : strength = 3
> boundary is an inter-inter boundary, with coded coefficients : strength =
2
> boundary between MBs using different reference pictures / different
> number of reference pictures / have MV values differing by more than
> one luma sample : strength = 1
> otherwise : strength = 0.
> 
> Hope that helped,
> 
> Bye !
> 
> Adarsh
> 
> On Apr 6, 2024 3:02 AM, Smitha Joseph <smithajo gmail.com> wrote:
> > Hi,
> >
> > The H.264 standard specifies the parameter
> > disable_deblocking_filter_idc in the slice header which specifies
> > whether the deblocking filter is disabled for the
> > macroblock/macroblock edges in that slice. The details of how the
> > parameter disables filtering at the decoder side for the different
> > values is clear from the standard. My doubt is how does the encoder
> > decide whether to enable or disable filtering for each
> > macroblock/macroblock edges in a slice?
> >
> > Thanks,
> > Smitha Joseph
> > _______________________________________________
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