From Gerardo.Rosiles motorola.com Mon Sep 15 11:36:08 2003 From: Gerardo.Rosiles motorola.com (Rosiles Gerardo-ra9355) Date: Tue Sep 16 05:29:06 2003 Subject: [MPEGIF Discuss] FW: [MPEGIF News] News on AVC Licensing Terms Message-ID: <6728517EECE7D511981B00D0B782903106322D09@az33exm27.corp.mot.com> Rob, Are there going to be two license fees and/or licensing models for H.264? Are MPEG-LA and Via working together or competing against each other? If there will be two entities requiring royalty payment, doesn't this complicate the whole licensing process? Thanks, Gerardo > -----Original Message----- > From: Rob Koenen \(MPEGIF\) [mailto:rob.koenen@mpegif.org] > Sent: Friday, September 12, 2023 3:51 AM > To: MPEGIF news > Subject: [MPEGIF News] News on AVC Licensing Terms > Importance: High > > > MPEGIF News Readers, > > One of the nmost hotly debated issues surrounding the > adoption of MPEG technoloy is licensing. The debate recently > focused on Advanced Video Coding licensing, for which the > market eagerly seeks reassurances. No doubt, this will be the > issue of many discussions at IBC the coming 5 days. > > Yesterday and today, important announcements were made by two > agents working on AVC licensing. Copying from > our home page, > http:///www.m4if.org: > > * > Joint Patent License for H.264/MPEG-4 AVC Continues to Advance; MPEG LA and Essential IP Owners to Meet Twice in September [MPEG LA, 11 Sept 03] * Via Licensing Announces Preliminary AVC Licensing Terms [Via tml> Licensing, 12 Sept 03] * Preliminary Licensing Terms for AVC from VIA Licensing [Via tml> Licensing, 12 Sept 03] While I will leave it to the reader to read and interpret the news, I will say that it is encouraging to see that licensors understand the urgence of getting this resolved, and it is equally encouraging that the concerns over the MPEG-4 part 2 joint license are apparently recognized and addressed. Kind Regards, Rob From rob.koenen mpegif.org Thu Sep 18 13:32:01 2003 From: rob.koenen mpegif.org (Rob Koenen (MPEGIF)) Date: Thu Sep 18 15:42:07 2003 Subject: [MPEGIF Discuss] News on AVC Licensing Terms In-Reply-To: <6728517EECE7D511981B00D0B782903106322D09@az33exm27.corp.mot.com> Message-ID: Gerardo, There is a general desire for there to be only one pool that covers all essential patents. How that is going to be brought about is unclear to me at the moment. One would hope that the licensors recognize the importance of easy access to essential patents; I've talked to many people over recent days who mentioned they hoped there wouldn't be different pools with potentially different structures and fees that add up. NB - This list has been dormant for a while, but it is still open for these types of discussions. Rob > -----Original Message----- > From: discuss-bounces@lists.mpegif.org > [mailto:discuss-bounces@lists.mpegif.org] On Behalf Of > Rosiles Gerardo-ra9355 > Sent: Monday, September 15, 2023 10:36 > To: 'discuss@lists.mpegif.org' > Subject: [MPEGIF Discuss] FW: [MPEGIF News] News on AVC > Licensing Terms > > > > > Rob, > > Are there going to be two license fees and/or licensing > models for H.264? Are MPEG-LA and Via working together or > competing against each other? > > If there will be two entities requiring royalty payment, > doesn't this complicate the whole licensing process? > > Thanks, > > Gerardo From ray webcastgroup.com Thu Sep 18 17:03:07 2003 From: ray webcastgroup.com (Ray Harris) Date: Thu Sep 18 17:05:30 2003 Subject: [MPEGIF Discuss] News on AVC Licensing Terms In-Reply-To: Message-ID: <003b01c37e1f$e1433570$6401a8c0@LAPTOP1> The patent holders are really putting a damper on the use of MPEG4. We wanted to switch from Windows Media but there is no way we are willing to deal with this uncertainty and cost structure.\ The only way it will work is if there are free software decoders, free usage and a fee for encoders. Placing a fee on decoders will be too big of a barrier to ever allow adoption of a software/PC based player. Ray Harris ray@webcastgroup.com Direct Line 216-431-7777 X 202 Cell 216-410-1508 Webcast Group, Inc. http://www.webcastgroup.com Join us every Wednesday at 2:00PM EST for a live NetPoint demo! NetPoint is the web seminar answer. > -----Original Message----- > From: discuss-bounces@lists.mpegif.org [mailto:discuss- > bounces@lists.mpegif.org] On Behalf Of Rob Koenen (MPEGIF) > Sent: Thursday, September 18, 2023 3:32 PM > To: 'Rosiles Gerardo-ra9355'; discuss@lists.mpegif.org > Subject: RE: [MPEGIF Discuss] News on AVC Licensing Terms > > Gerardo, > > There is a general desire for there to be only one pool that covers all > essential patents. How that is going to be brought about is unclear to me > at > the moment. One would hope that the licensors recognize the importance of > easy access to essential patents; I've talked to many people over recent > days who mentioned they hoped there wouldn't be different pools with > potentially different structures and fees that add up. > > NB - This list has been dormant for a while, but it is still open for > these > types of discussions. > > Rob > > > -----Original Message----- > > From: discuss-bounces@lists.mpegif.org > > [mailto:discuss-bounces@lists.mpegif.org] On Behalf Of > > Rosiles Gerardo-ra9355 > > Sent: Monday, September 15, 2023 10:36 > > To: 'discuss@lists.mpegif.org' > > Subject: [MPEGIF Discuss] FW: [MPEGIF News] News on AVC > > Licensing Terms > > > > > > > > > > Rob, > > > > Are there going to be two license fees and/or licensing > > models for H.264? Are MPEG-LA and Via working together or > > competing against each other? > > > > If there will be two entities requiring royalty payment, > > doesn't this complicate the whole licensing process? > > > > Thanks, > > > > Gerardo > > > _______________________________________________ > Discuss mailing list > Discuss@lists.mpegif.org > http://lists.mpegif.org/mailman/listinfo/discuss From rob.koenen mpegif.org Thu Sep 18 16:39:22 2003 From: rob.koenen mpegif.org (Rob Koenen (MPEGIF)) Date: Thu Sep 18 18:45:30 2003 Subject: [MPEGIF Discuss] News on AVC Licensing Terms In-Reply-To: Message-ID: Ray, While many will agree with the fact that there need to be free PC decoders to end-users, one should not confuse patent licenses with technology licenses, or (end-user) product pricing with license pricing. Windows Media doesn't come with free decoder licenses to implementers either, and while MPEG-4 part 2 has patent licenses on the decoder, many companies make available MPEG-4 decoders for free. Apple is just one of them, probably the largest in terms of decoders deployed. As a matter of fact, for smaller technology suppliers there *is* a possibility to supply decoders free of license fees in MPEG-4. The decoder fee for MPEG-4 does not seem to be what most people have issues with. Best, Rob > -----Original Message----- > From: discuss-bounces@lists.mpegif.org > [mailto:discuss-bounces@lists.mpegif.org] On Behalf Of Ray Harris > Sent: Thursday, September 18, 2023 13:03 > To: discuss@lists.mpegif.org > Subject: RE: [MPEGIF Discuss] News on AVC Licensing Terms > > > The patent holders are really putting a damper on the use of MPEG4. We > wanted to switch from Windows Media but there is no way we are willing > to deal with this uncertainty and cost structure.\ > > The only way it will work is if there are free software decoders, free > usage and a fee for encoders. Placing a fee on decoders will > be too big > of a barrier to ever allow adoption of a software/PC based player. > > Ray Harris ray@webcastgroup.com > Direct Line 216-431-7777 X 202 > Cell 216-410-1508 > Webcast Group, Inc. http://www.webcastgroup.com > Join us every Wednesday at 2:00PM EST for a live NetPoint demo! > NetPoint is the web seminar answer. > > > -----Original Message----- > > From: discuss-bounces@lists.mpegif.org [mailto:discuss- > > bounces@lists.mpegif.org] On Behalf Of Rob Koenen (MPEGIF) > > Sent: Thursday, September 18, 2023 3:32 PM > > To: 'Rosiles Gerardo-ra9355'; discuss@lists.mpegif.org > > Subject: RE: [MPEGIF Discuss] News on AVC Licensing Terms > > > > Gerardo, > > > > There is a general desire for there to be only one pool that covers > all > > essential patents. How that is going to be brought about is > unclear to > me > > at > > the moment. One would hope that the licensors recognize the > importance > of > > easy access to essential patents; I've talked to many people over > recent > > days who mentioned they hoped there wouldn't be different pools with > > potentially different structures and fees that add up. > > > > NB - This list has been dormant for a while, but it is > still open for > > these > > types of discussions. > > > > Rob > > > > > -----Original Message----- > > > From: discuss-bounces@lists.mpegif.org > > > [mailto:discuss-bounces@lists.mpegif.org] On Behalf Of > > > Rosiles Gerardo-ra9355 > > > Sent: Monday, September 15, 2023 10:36 > > > To: 'discuss@lists.mpegif.org' > > > Subject: [MPEGIF Discuss] FW: [MPEGIF News] News on AVC > > > Licensing Terms > > > > > > > > > > > > > > > Rob, > > > > > > Are there going to be two license fees and/or licensing > > > models for H.264? Are MPEG-LA and Via working together or > > > competing against each other? > > > > > > If there will be two entities requiring royalty payment, > > > doesn't this complicate the whole licensing process? > > > > > > Thanks, > > > > > > Gerardo > > > > > > _______________________________________________ > > Discuss mailing list > > Discuss@lists.mpegif.org > > http://lists.mpegif.org/mailman/listinfo/discuss > > > _______________________________________________ > Discuss mailing list > Discuss@lists.mpegif.org > http://lists.mpegif.org/mailman/listinfo/discuss > From Jani.Huoponen hantro.com Fri Sep 19 10:55:14 2003 From: Jani.Huoponen hantro.com (Jani Huoponen) Date: Fri Sep 19 06:51:05 2003 Subject: [MPEGIF Discuss] News on AVC Licensing Terms Message-ID: Hi, So, the general desire is to have just one pool but is the current situation such that there might be two different pools, one from MPEG LA and one from Via? BR, Jani > > > -----Original Message----- > > > From: discuss-bounces@lists.mpegif.org [mailto:discuss- > > > bounces@lists.mpegif.org] On Behalf Of Rob Koenen (MPEGIF) > > > Sent: Thursday, September 18, 2023 3:32 PM > > > To: 'Rosiles Gerardo-ra9355'; discuss@lists.mpegif.org > > > Subject: RE: [MPEGIF Discuss] News on AVC Licensing Terms > > > > > > Gerardo, > > > > > > There is a general desire for there to be only one pool > that covers > > all > > > essential patents. How that is going to be brought about is > > unclear to > > me > > > at > > > the moment. One would hope that the licensors recognize the > > importance > > of > > > easy access to essential patents; I've talked to many people over > > recent > > > days who mentioned they hoped there wouldn't be different > pools with > > > potentially different structures and fees that add up. > > > > > > NB - This list has been dormant for a while, but it is > > still open for > > > these > > > types of discussions. > > > > > > Rob > > > > > > > -----Original Message----- > > > > From: discuss-bounces@lists.mpegif.org > > > > [mailto:discuss-bounces@lists.mpegif.org] On Behalf Of > > > > Rosiles Gerardo-ra9355 > > > > Sent: Monday, September 15, 2023 10:36 > > > > To: 'discuss@lists.mpegif.org' > > > > Subject: [MPEGIF Discuss] FW: [MPEGIF News] News on AVC > > > > Licensing Terms > > > > > > > > > > > > > > > > > > > > Rob, > > > > > > > > Are there going to be two license fees and/or licensing > > > > models for H.264? Are MPEG-LA and Via working together or > > > > competing against each other? > > > > > > > > If there will be two entities requiring royalty payment, > > > > doesn't this complicate the whole licensing process? > > > > > > > > Thanks, > > > > > > > > Gerardo > > > > > > > > > _______________________________________________ > > > Discuss mailing list > > > Discuss@lists.mpegif.org > > > http://lists.mpegif.org/mailman/listinfo/discuss > > > > > > _______________________________________________ > > Discuss mailing list > > Discuss@lists.mpegif.org > > http://lists.mpegif.org/mailman/listinfo/discuss > > > > > _______________________________________________ > Discuss mailing list > Discuss@lists.mpegif.org > http://lists.mpegif.org/mailman/listinfo/discuss > From rob.koenen mpegif.org Fri Sep 19 10:11:54 2003 From: rob.koenen mpegif.org (Rob Koenen (MPEGIF)) Date: Fri Sep 19 13:01:10 2003 Subject: [MPEGIF Discuss] News on AVC Licensing Terms In-Reply-To: Message-ID: > Hi, > > So, the general desire is to have just one pool but is the current > situation such that there might be two different pools, one from > MPEG LA and one from Via? > > BR, Jani The general desire is to have a single pool and the current situation is that there are two parallel initiatives. Rob From vsathe multiratesystems.com Fri Sep 19 12:36:52 2003 From: vsathe multiratesystems.com (vsathe@multiratesystems.com) Date: Fri Sep 19 15:03:09 2003 Subject: [MPEGIF Discuss] News on AVC Licensing Terms In-Reply-To: Message-ID: <3F615C480000483C@mta9.wss.scd.yahoo.com> While guesses might be hazardous at this time, any thoughts regarding reach of this licensing to cover other MPEG-4 profiles such as scalable video coding (if it ends up being based on AVC base layer)? Regards, Vinay Sathe Multirate Systems > >The general desire is to have a single pool and the current situation >is that there are two parallel initiatives. > >Rob > >_______________________________________________ >Discuss mailing list >Discuss@lists.mpegif.org >http://lists.mpegif.org/mailman/listinfo/discuss From rob.koenen mpegif.org Fri Sep 19 13:37:28 2003 From: rob.koenen mpegif.org (Rob Koenen (MPEGIF)) Date: Fri Sep 19 15:53:05 2003 Subject: [MPEGIF Discuss] News on AVC Licensing Terms In-Reply-To: <3F615C480000483C@mta9.wss.scd.yahoo.com> Message-ID: For scalable coding covered by MPEG-4 part 2, the current licensing pool seeks to include as much IP as possible. For scalable coding based on AVC - any pool covering scalable coding would be facilitated by a specification. There isn't currently any such specification, and I am not aware of non-spec related initiatives to set up any pool. Regards, Rob > -----Original Message----- > From: vsathe@multiratesystems.com > [mailto:vsathe@multiratesystems.com] > Sent: Friday, September 19, 2023 11:37 > To: discuss@lists.mpegif.org > Subject: RE: [MPEGIF Discuss] News on AVC Licensing Terms > > > While guesses might be hazardous at this time, any thoughts > regarding reach > of this licensing to cover other MPEG-4 profiles such as > scalable video > coding (if it ends up being based on AVC base layer)? > > Regards, > > Vinay Sathe > Multirate Systems > > > > >The general desire is to have a single pool and the current situation > >is that there are two parallel initiatives. > > > >Rob > > > >_______________________________________________ > >Discuss mailing list > >Discuss@lists.mpegif.org > >http://lists.mpegif.org/mailman/listinfo/discuss > > > > _______________________________________________ > Discuss mailing list > Discuss@lists.mpegif.org > http://lists.mpegif.org/mailman/listinfo/discuss > From ben interframemedia.com Fri Sep 19 15:15:02 2003 From: ben interframemedia.com (Ben Waggoner) Date: Fri Sep 19 17:45:57 2003 Subject: [MPEGIF Discuss] AVC-derived scalable video coding? In-Reply-To: Message-ID: Rob, Speaking of that, is there anything going on with that which can be shared publicly. I've said for the while that the lack of a good scalable implementation is keeping MPEG-4 from being competitive in real-time streaming over the public internet. In the interview I did with Leonardo Chiariglione at NAB, he said a good scalable MPEG technology might not arrive until 2006. Ben Waggoner Compressed Video Consulting, Training, and Encoding My Book: Cleaner e-book: on 9/19/03 12:37 PM, Rob Koenen (MPEGIF) at rob.koenen@mpegif.org wrote: > For scalable coding covered by MPEG-4 part 2, the current > licensing pool seeks to include as much IP as possible. > > For scalable coding based on AVC - any pool covering scalable > coding would be facilitated by a specification. There isn't > currently any such specification, and I am not aware of > non-spec related initiatives to set up any pool. From rob.koenen mpegif.org Fri Sep 19 15:37:40 2003 From: rob.koenen mpegif.org (Rob Koenen (MPEGIF)) Date: Fri Sep 19 17:49:16 2003 Subject: [MPEGIF Discuss] RE: AVC-derived scalable video coding? In-Reply-To: Message-ID: Ben, > Speaking of that, is there anything going on with that > which can be shared publicly. The nature of all the work going on in MPEG can be shared publicly, although some working documents may be kept internal and ISO does not allow publication of draft standards beyond a certain stage of completion. MPEG is working on scalable video coding and initial evidence is very promising. A call for proposals is being readied, and may go out in a few meetings (there are two more meetings this year, one in October and one in December). It may be possible to arrive at completion of such a standard sometime in 2005, I guess, but this is going out on a limb. I am not 100% sure what the thoughts in the JVT are about adding some sort of scalability to AVC. I know the idea has been coined a couple of times. That said, the AVC codec does allow seamless switching between streams of different rates, which would not qualify as true scalability (being able to derive useful video from subsets of the bitstream), but it does effectively provide the same functionality in many services and applications. MPEG-4 part 2 has some scalability and it seems that there is interest in Simple Scalable Visual Profile in mobile environments. But for many types of scalability, including the Fine Grain Scalability currently in MPEG-4 part 2, the market seems to perceive the bitrate penalty on the highest quality as still too much. Regards, Rob > -----Original Message----- > From: Ben Waggoner [mailto:ben@interframemedia.com] > Sent: Friday, September 19, 2023 14:15 > To: rob.koenen@mpegif.org; vsathe@multiratesystems.com; > discuss@lists.mpegif.org > Subject: AVC-derived scalable video coding? > > > Rob, > > Speaking of that, is there anything going on with that > which can be > shared publicly. I've said for the while that the lack of a > good scalable > implementation is keeping MPEG-4 from being competitive in real-time > streaming over the public internet. > > In the interview I did with Leonardo Chiariglione at NAB, > he said a good > scalable MPEG technology might not arrive until 2006. > > Ben Waggoner > Compressed Video Consulting, Training, and Encoding > > My Book: > Cleaner e-book: > > > > > on 9/19/03 12:37 PM, Rob Koenen (MPEGIF) at > rob.koenen@mpegif.org wrote: > > For scalable coding covered by MPEG-4 part 2, the current > > licensing pool seeks to include as much IP as possible. > > > > For scalable coding based on AVC - any pool covering scalable > > coding would be facilitated by a specification. There isn't > > currently any such specification, and I am not aware of > > non-spec related initiatives to set up any pool. > > > From ben interframemedia.com Fri Sep 19 16:21:33 2003 From: ben interframemedia.com (Ben Waggoner) Date: Fri Sep 19 18:28:42 2003 Subject: [MPEGIF Discuss] Re: AVC-derived scalable video coding? In-Reply-To: Message-ID: on 9/19/03 2:37 PM, Rob Koenen (MPEGIF) at rob.koenen@mpegif.org wrote: > MPEG is working on scalable video coding and initial evidence is very > promising. A call for proposals is being readied, and may go out in a few > meetings (there are two more meetings this year, one in October and one in > December). It may be possible to arrive at completion of such a standard > sometime in 2005, I guess, but this is going out on a limb. Sure. And with products following sometime behind that... As bullish as I am about MPEG-4 in general, it makes me nervous that MPEG-4 is likely at least three years out from having streaming as good as competing formats had two years ago. > I am not 100% sure what the thoughts in the JVT are about adding some sort > of scalability to AVC. I know the idea has been coined a couple of times. > That said, the AVC codec does allow seamless switching between streams of > different rates, which would not qualify as true scalability (being able to > derive useful video from subsets of the bitstream), but it does effectively > provide the same functionality in many services and applications. That would probably be a "good enough" solution, if it is dynamic. > MPEG-4 part 2 has some scalability and it seems that there is interest in > Simple Scalable Visual Profile in mobile environments. But for many types of > scalability, including the Fine Grain Scalability currently in MPEG-4 part > 2, the market seems to perceive the bitrate penalty on the highest quality > as still too much. I've heard this compliant a lot, and I think it is largely unfounded. Even if FGS has a 25% bitrate penalty, it'd be worth it. Today, if one wants to make a real-time streaming MPEG-4 file for the public internet, it has to use the lowest common denominator data rate. Thus, if connection speeds were a bell-shaped distribution around 400 Kbps, one might pick a data rate of 200 Kbps in order to get 90% of users. Assuming the 25% performance penalty, that means that the 200 Kbps straight would look as good as 250 Kbps. So for the ~75% or so of users who could sustain 250 Kbps or higher, they actually get a worse result than without FGS. And those unlucky 10% who are at less than 200 Kbps will definitely be better than FGS. And this isn't even counting what happens with variable connection speeds. Those using cable modems, or a shared connection in an office, can see data rates vary between 100-3000 Kbps during a single session. Sure, FGS is slightly sub-optimal when you know the exact available data rate in advance. But since real-world data rates are so unknowable, a FGS solution would be extremely useful. Scalability can beat raw compression efficiency in a wide class of situations. Ben Waggoner Compressed Video Consulting, Training, and Encoding My Book: Cleaner e-book: From rbleidt hdtv.com Fri Sep 19 16:54:41 2003 From: rbleidt hdtv.com (Robert Bleidt) Date: Fri Sep 19 19:50:44 2003 Subject: [MPEGIF Discuss] AVC-derived scalable video coding? In-Reply-To: References: Message-ID: <5.2.1.1.2.20030919153228.03678208@localhost> Perhaps I'm just adding confusion, but I'm guessing what you want is stream scalability, not scalable coding. Unless there's something new, (which I'd like to learn about), most of the proprietary codecs seem to use stream switching, not scalable coding. To explain: (you might also take a look at the illustration in http://www.eet.com/story/OEG20011112S0043) Generally, you can achieve scalable coding in three ways: 1. Switching from a stream to one encoded at a lower rate. (stream switching) 2. Dropping B-frames (temporal scalability) 3. Dropping enhancement layers (scalable coding or fine-grained scalability) Scalable coding has the feeling of being the intellectually "right" way to do it, and gets a lot of interest from the research community. Unfortunately, in practice, as far as I know, it tends to work best over only a one-octave or so range of bitrates, after which the coding overhead of the enhancement streams starts to hurt the perceived quality. Stream switching doesn't have this efficiency loss and is fairly simple to implement - that's why it's used in practice. This is true both in audio and video coding - The BSAC audio codec using an coefficient encoding scheme very similar to the FGS profile of part 2 video. I haven't done any work in this area, so I'm just repeating what I've heard and seen. Please voice your opinion... Except for issues of switching streams (which the Extended AVC profile is supposed to have tools to address), there is no additional IP needed to do stream switching in AVC. There is room for innovation outside the standard in deciding when and how to switch streams. At 02:15 PM 9/19/2003 -0700, you wrote: >I've said for the while that the lack of a good scalable >implementation is keeping MPEG-4 from being competitive in real-time >streaming over the public internet. Robert Bleidt - www.streamcrest.com From ben interframemedia.com Fri Sep 19 23:30:47 2003 From: ben interframemedia.com (Ben Waggoner) Date: Sat Sep 20 01:41:24 2003 Subject: [MPEGIF Discuss] AVC-derived scalable video coding? In-Reply-To: <5.2.1.1.2.20030919153228.03678208@localhost> Message-ID: Robert, I'm looking for some kind of scalability in deployed MPEG-4 technologies. If I can't have FGS, or even enhancement layers, I'll at least take stream scalability (which is all that RealMedia and Windows Media offer today). As it is, none of the mainstream MPEG-4 solutions support streaming scalability of any sort (well, maybe dynamically dropping B-frames, but that's quite limited in the range of data rates it can provide). PacketVideo obviously has Simple Scalable in their products, but I'm looking for something that could compete with Windows Media and RealMedia (QuickTime also lacks meaningful scalability). While scalable coding does have some theoretical efficiency disadvantages, it's important to realize that stream scalability only offers discreet bands. So if there are 500 and 750 Kbps bands, at 700 Kbps, scalable coding might offer better quality than the 500 Kbps band that would otherwise be delivered. It'd take an efficiency hit of 40% before the 700 Kbps scalable wouldn't be better than the 500 stream. And sure, one can put more and more scalable streams in there, but each is a significant hit for file size and encoding time, and makes multicasting more problematic. Codec engineers seem to focus on the specific compression efficiency at a given data rate, when the important measure is the delivered quality across the range of possible data rates. In essence, I don't care which technology is better at 500 Kbps, I care which technology has the best mean quality in the range of 100-1000 Kbps. Ben Waggoner Compressed Video Consulting, Training, and Encoding My Book: Cleaner e-book: on 9/19/03 3:54 PM, Robert Bleidt at rbleidt@hdtv.com wrote: > Perhaps I'm just adding confusion, but I'm guessing what you want is stream > scalability, not scalable coding. Unless there's something new, (which I'd > like to learn about), most of the proprietary codecs seem to use stream > switching, not scalable coding. > > To explain: (you might also take a look at the illustration in > http://www.eet.com/story/OEG20011112S0043) > Generally, you can achieve scalable coding in three ways: > 1. Switching from a stream to one encoded at a lower rate. (stream switching) > 2. Dropping B-frames (temporal scalability) > 3. Dropping enhancement layers (scalable coding or fine-grained scalability) > > Scalable coding has the feeling of being the intellectually "right" way to > do it, and gets a lot of interest from the research community. > Unfortunately, in practice, as far as I know, it tends to work best over > only a one-octave or so range of bitrates, after which the coding overhead > of the enhancement streams starts to hurt the perceived quality. Stream > switching doesn't have this efficiency loss and is fairly simple to > implement - that's why it's used in practice. This is true both in audio > and video coding - The BSAC audio codec using an coefficient encoding > scheme very similar to the FGS profile of part 2 video. > > I haven't done any work in this area, so I'm just repeating what I've heard > and seen. Please voice your opinion... > > Except for issues of switching streams (which the Extended AVC profile is > supposed to have tools to address), there is no additional IP needed to do > stream switching in AVC. There is room for innovation outside the standard > in deciding when and how to switch streams.