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Re: [ns] How to create trace files?



Dear Adnan

    Sequence generators (or whatever it is called) have their internel spec.
They
might encode with fixed frame pattern of IBBPBBPBBPBB with 24 frames per
second.
Or they might generate sequence at variable frame patterns, with which the
real MPEG
world goes on. This is absolutely dependent on that 'utility.' In case of
above fixed
frame pattern, they usually use 1/24 frame time without regarding to the
amount of
real traffic. In case of real world video encoder, they have internal fields
regarding to time stamp.
I guess if you cannot utilize the internal timing value, you probably have
to use the
fixed frame pattern and fixed frame time, that is to say, IBBPBBPBBPBB with
1/24 sec.
Please refer to README of your 'utility.'

I hope this can be a little bit of help to you.

- Jiwoong Lee.
Hansol M.com, Korea

----- Original Message -----
From: Adnan H. Sabuwala (96007029) <[email protected]>
To: Lee, Jiwoong <[email protected]>
Sent: Friday, March 24, 2000 3:06 PM
Subject: Re: [ns] How to create trace files?


>
> Hi,
>    Thank you very much for your help. I had some doubts still. Look
> firstly to create a video sequence trace file I need to know two things
> about the sequence viz. the packet size of each I,P or B frame and the
> time at which these frames were coded. I have a utility which tells me
> the first part i.e packet size of the encoded frames but I have no clue
> whatsoever of how to find the times at which the frames are coded. So
> please tell me how can I find that out... Thank you once again.
> --- Adnan Sabuwala.
>
>
> On Fri, 17 Mar 2000, Lee, Jiwoong wrote:
>
> > Dear Adnan
> >
> > When dealing with video in data networks, people usually use video
sequence
> > files which
> > includes the sequence of numbers meaning the generated bytes at each
frame.
> > A frame can be one of the I,P,B pictures when you use MPEG series.
> > You may have those sequence files already. In your case you need obtain
> > video sequence file of different coded rates. And please refer to the
> > description of
> > format of tracefile in NS manual. The format of tracefile is very simple
and
> > you can code
> > it by yourself. You may use different time spacing rather than 1/30 sec,
> > normal case.
> > If you have any problem in coding, you can search established codes in
this
> > mailing list by
> > keyword search in NS2 homepage.
> >
> > Jiwoong Lee
> > Hansol M.com, Korea
> >
> > ----- Original Message -----
> > From: Adnan H. Sabuwala (96007029) <[email protected]>
> > To: <[email protected]>
> > Sent: Thursday, March 16, 2000 1:59 PM
> > Subject: [ns] How to create trace files?
> >
> >
> > >
> > > Hi everyone,
> > >             I am currently working on a project titled "Low bit rate
video
> > > coding for adaptive videoconferencing". For this I am supposed to
create
> > > trace files containing video sequences coded at different rates. I
don't
> > > know how to create a trace file. Please help...
> > > --- Adnan.
> > > IIT Bombay.
> > >
> >
>