[Mp4-tech] Error concealment method: frame copy

[Karsten Suehring]

Hi,
the JM code contains two independent error concealment algorithms. One 
is taking care of slice losses (by using the surrounding area), the 
other algorithm is taking care of whole picture losses (with options 
frame-copy and motion copy).
The first algorithm is described in VCEG-N62, the other should be JVT-P072.
Best regards,
Karsten
ashfiqua tahseen wrote:
> Hi Mr. Saurav,
>  
> Thank you.
>  
> What I meant, if slices are lost, then what does the decoder do? It 
> copies only those slices from the previous reference frame?  I am 
> confused reading the methods prior to JM9.8 and after that.
> I highly appreciate your suggestion.
>  
> Thanking you,
> Ashfiqua
>  
> 
> 
> */Saurav Bandyopadhyay <skbandyopadhyay gmail.com>/* wrote:
> 
>     Ashfiqua,
> 
>     I am trying to understand your question. A frame can consist of
>     multiple slices. Why would you need entire frame loss concealment, if
>     you loose a slice? The algorithms "frame-copy' and 'motion-copy' are
>     meant to conceal entire frame losses.
> 
>     Best regards,
> 
>     Saurav
> 
> 
> 
> 
>     -- 
>     Saurav Bandyopadhyay, Ph.D.
> 
>     Senior Video Engineer
>     W&W Comm. Inc./DSP Research Inc.
>     640 W. California Avenue, Suite 200,
>     Sunnyvale, CA 94086, USA
> 
>     Tel: +1 (408) 481 0264 x203 (Off)
>     Email: sauravb wwcoms.com
> 
> 
>     On Feb 6, 2024 11:31 AM, ashfiqua tahseen wrote:
>      > Hi,
>      >
>      > I want to know about the error concealment method of the decoder.
>     In the
>      > frame copy concealment method, when a slice is lost, does it
>     discard the
>      > whole frame and copies the previous reference frrame? I have read
>     that prior
>      > to JM9.8, the concealment was on slice level i.e. in case of a
>     lost slice,
>      > the slice was copied from the previous frame. But that version
>     could not
>      > determine the picture loss. So now the JM uses frame copy. But
>     does it
>      > replace slices when slice is lost or does it copy the whole frame
>     even only
>      > one slice is lost?
>      >
>      > I'll highly appreciate any suggestion.
>      >
>      > Regards,
>      > Ashfiqua
>      >
>      >
>      > ________________________________
>      > Looking for last minute shopping deals? Find them fast with
>     Yahoo! Search.
>      > _______________________________________________
>      > 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-Antitrust.php
>      >
> 
> 
> ------------------------------------------------------------------------
> Looking for last minute shopping deals? Find them fast with Yahoo! 
> Search. 
> <http://us.rd.yahoo.com/evt=51734/*http://tools.search.yahoo.com/newsearch/category.php?category=shopping> 
> 
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> 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-Antitrust.php