[x264-devel] about single layer video coding and scalable video coding

[武南龚]

thank you

in fact, my purpose is simple
I just want to encode a sequence into four or more layers
and obtain sizes of each frame(or a layer segment)
time duration of each frame
and use such information for network simulation
and then compute PSNR
is there any good method?


you said :
Using the --b-pyramid option, it is also probably possible to generate
a 3 layers stream, the first layer containning I/P frames, the second
reference B frames and the third non-reference B frames.
_______________________________________________

can we treat I frame as the first layer
P frame as the second one
B frame as the third while the third non-refrence B(let's call it b) as the
forth layer?

besides, I didn't see any difference between single layer and such temporal
SVC
we just regard different frames as different layers
I guess we can still treat these frames as in the same single layer?




On Fri, Jun 19, 2009 at 9:24 AM, Loic Le Loarer
<lll+vlc at m4x.org<lll%2Bvlc at m4x.org>
> wrote:

> Hi,
>
> On Thursday June 18 2009 at 12:30:26 PM +0200, 武南龚 wrote:
> > thank you so much. I'm a little puzzled by the sentence below, can you
> give
> > me some explanation.
> >
> > Yes, temporal scalability is just a single layer with non-reference
> > frames at regular intervals.
> > _______________________________________
> >
> > besides, x264 doesn't support SVC, can I treat the single layer coded
> video
> > as a temporal scalable video coded one?
>
> Yes, you can do that if the coded stream has the correct properties. For
> example, do be a correct temporal scalable video sequence with 2 layers,
> the base layer at 15fps and the second at 30fps, it is enough to have
> the following sequence of pictures in display order (using old MPEG2
> style for references):
>
> I B P B P B P...
>
> The base layer contains only the I and P pictures, the second layer adds
> the B pictures.
>
> Using x264, it is possible to generate such a sequence using the
> following options (or similar):
>
>  --bframes 1 --b-adapt 0 --ref 2
>
> Using the --b-pyramid option, it is also probably possible to generate
> a 3 layers stream, the first layer containning I/P frames, the second
> reference B frames and the third non-reference B frames.
>
> Once you have the generated the sequence using x264, you can turn it to
> a real SVC sequence with temporal scalability by just adding the correct
> SEI messages and may be changing some SPS or PPS parameters. I don't
> know any tools whch can to this, but it isn't difficult to write this,
> it could even be done directly in x264 and proposed for inclusion I
> guess if there is interess in such a feature.
>
> Best regards.
>
> --
> Loic
>
> Only a very small fraction of our DNA does anything; the rest is all
> comments and ifdefs.
>
> > and is there any other tools similar to x264 that support SVC?
> >
> > thank you!
> >
> >
> >
> > 2009/6/18 Måns Rullgård <mans at mansr.com>
> >
> > > 武南龚 <nangergong at gmail.com> writes:
> > >
> > > > hi,all
> > > >
> > > >   I'm using x.264 in linux now, I want to know which command line
> > > argument
> > > > decides whether the encoding is single layer video coding or scalable
> > > video
> > > > coding?
> > > > and how to encode videos using different scalable video coding
> (temporal
> > > > ,spatial and PSNR)?
> > >
> > > SVC is not supported in x264.
> > >
> > > > besides, is there any difference between single layer video coding
> and
> > > > temporal scalable video coding? I thought they are the same
> > >
> > > Yes, temporal scalability is just a single layer with non-reference
> > > frames at regular intervals.
> > >
> > > --
> > > Måns Rullgård
> > > mans at mansr.com
> > > _______________________________________________
> > > x264-devel mailing list
> > > x264-devel at videolan.org
> > > http://mailman.videolan.org/listinfo/x264-devel
> > >
> >
> >
> >
> > --
> >                                       此致
> >                         敬礼
> >
> >                            龚武南
> >
> > GongWunan
> >
> > School of Electronic and Information Engineering
> > Xi'an Jiaotong University,
> > Xi'an 710049, People's Republic of China
> > ^
> > Computer and Communication Networks Engineering
> > Politecnico di Torino,
> > TORINO 10138,Italy
> > Tel:+39-3881278481
>
> > _______________________________________________
> > x264-devel mailing list
> > x264-devel at videolan.org
> > http://mailman.videolan.org/listinfo/x264-devel
>
> _______________________________________________
> x264-devel mailing list
> x264-devel at videolan.org
> http://mailman.videolan.org/listinfo/x264-devel
>



-- 
                                      此致
                        敬礼

                           龚武南

GongWunan

School of Electronic and Information Engineering
Xi'an Jiaotong University,
Xi'an 710049, People's Republic of China
^
Computer and Communication Networks Engineering
Politecnico di Torino,
TORINO 10138,Italy
Tel:+39-3881278481
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