[M4IF Technotes] RE: [M4IF Infolist] Relationship of MPEG-2 and -4 differences wit h quality/bitrates

Tue Oct 9 08:00:26 EDT 2001

Please move this discussion to the technotes list.
The infolist is only for annuncements and news about 
MPEG-4.
Rob
> -----Original Message-----
> From: Manish Singhal [mailto:manish.singhal   ittiam.com]
> Sent: Tuesday, October 09, 2023 3:15 PM
> To: Darrius "Junto" Thompson; Michael Chertok; 
> infolist   lists.m4if.org;
> Christophe.Vermeulen   alcatel.be; Klaus.Diepold   dynapel.de
> Subject: RE: [M4IF Infolist] Relationship of MPEG-2 and -4 differences
> with quality/bitrates
> 
> 
> Hello there
> 
> I have a basic question:
> Is DIVX  
> 
> =  MPEG-4 Simple Profile + Proprietary Tools ?
> 
> OR
>  
> =  MPEG-4 Simple Profile + MPEG-2 (DVD) + Proprietary Tools ?
> 
> Rgds
> Manish Singhal
> Manager
> Video & Imaging
> Ittiam Systems
> India.
> 
> -----Original Message-----
> From:	Darrius "Junto" Thompson
> Sent:	Fri 10/5/2024 8:44 PM
> To:	Michael Chertok; infolist   lists.m4if.org; 
> Christophe.Vermeulen   alcatel.be; Klaus.Diepold   dynapel.de
> Cc:	
> Subject:	RE: [M4IF Infolist] Relationship of MPEG-2 and 
> -4 differences with quality/bitrates
> 
> All,
> 
> >"DivX is almost conformant to simple visual profile 
> (actually it is missing
> a bit in the syntax)."
> 
> Our last release produces a stream that is compliant with 
> MPEG-4 and should
> be correctly parsed by a compliant syntax parser.  However we 
> also discovered
> that the encoder writes incorrect values for 'obmc_disable' 
> field and some of
> the fields that are related to timing ( 
> time_increment_resolution, time_base,
> time_increment ). An MPEG-4 compliant decoder that takes 
> those fields into
> account may decode the stream incorrectly. Our next release 
> will fix these
> issues.  I hope to have a new release with this fixed as well 
> as some added
> new features within the next 2 weeks if not sooner.  
> 
> Please let me know if you have any more questions, ideas or 
> are interested in
> some testing.
> 
> Darrius Thompson (aka Junto)
> Director DivX
> http://www.divx.com
> http://www.projectmayo.com
> 
> -----Original Message-----
> From: infolist-admin   lists.m4if.org
> [mailto:infolist-admin   lists.m4if.org]On Behalf Of Michael Chertok
> Sent: Friday, October 05, 2023 3:13 AM
> To: infolist   lists.m4if.org; Christophe.Vermeulen   alcatel.be;
> Klaus.Diepold   dynapel.de
> Cc: Darrius "Junto" Thompson
> Subject: RE: [M4IF Infolist] Relationship of MPEG-2 and -4 differences
> with quality/bitrates
> 
> 
> Hello, Klaus.
> You mentioned in your message that:
> "DivX is almost conformant to simple visual profile (actually 
> it is missing
> a
> bit in the syntax)."
> Can you tell us, what is this bit, please ?
> It's not too late to fix it.
> Thank you in advance.
> 
> Regards,
> ---------------------------------
> Michael Chertok
> Adyoron Intelligent Systems Ltd.
> E-mail : michael   adyoron.com
> URL    : www.adyoron.com
> Tel    : +972 (3) 6491110 (x236)
> Fax    : +972 (3) 6488849
> 
> 
> -----Original Message-----
> From: infolist-admin   lists.m4if.org
> [mailto:infolist-admin   lists.m4if.org]On Behalf Of Klaus Diepold
> Sent: Tuesday, October 02, 2023 17:24
> To: Christophe.Vermeulen   alcatel.be; infolist   lists.m4if.org
> Subject: RE: [M4IF Infolist] Relationship of MPEG-2 and -4 differences
> with quality/bitrates
> 
> 
> Chritophe,
> 
> Dicas GmbH in Berlin is offering a Core Profile encoder SDK,
> which offers non-rectangular video objects (Binary Shape Coding).
> 
> It is in fact pretty fast (I think even real-time),
> as long as you have the shapes of the non-rectangular video 
> objects upfront.
> 
> I doubt that MPEG-4 simple visual profile is offering better 
> compression for
> TV quality video than MPEG-2 Main Profile Main Level. This is 
> also based on
> the
> fact that simple visual profile is only specified up to CIF 
> resolution and
> to a
> maximum bit rate of 384 kbit/sec, while not supporting (of course)
> interlaced video.
> 
> DivX is almost conformant to simple visual profile (actually 
> it is missing a
> bit in the syntax).
> DivX does not obey to the level definitions in the standard, 
> so you can
> actually code video
> with high bit rate and higher resolution.
> 
> Cheers
> Klaus Diepold
> DynaPel Labs
> 
> +-----Original Message-----
> +From: infolist-admin   lists.m4if.org
> +[mailto:infolist-admin   lists.m4if.org]On Behalf Of
> +Christophe.Vermeulen   alcatel.be
> +Sent: Tuesday, October 02, 2023 4:42 PM
> +To: infolist   lists.m4if.org
> +Subject: [M4IF Infolist] Relationship of MPEG-2 and -4 
> differences with
> +quality/bitrates
> +
> +
> +Hi All,
> +
> +Maybe this is a FAQ, but is there a list or reference
> +on the differences between MPEG-2 and MPEG-4 that
> +really tries to explain why MPEG-4 actually provides
> +better compression for TV-like quality ?
> +
> +I looked at the MPEG.org site, but the page from
> +Roberto Grandi seems to have disappeared and can't
> +be found even by Google, and the "Structure of MPEG-4
> +Video Coding" at HHI Berlin lacks many pictures (I get
> +some text in German) and doesn't explain which of all
> +those techniques are used in current codecs such as DivX,
> +or in the simple visual profile.
> +
> +Is there any real-time codec up there that can handle
> +non-rectangular VOPs ?
> +
> +Thanks for your help.
> +
> +Christophe.
> +_______________________________________________
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> +Infolist   lists.m4if.org
> +http://lists.m4if.org/mailman/listinfo/infolist
> +
> +
> 
> 
> 
> 
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