Re: [Linphone-developers] [sr #105016] Wish: video call support

[Simon Morlat]

Hi,

There is non finished code for mpeg4 support. Streaming video over RTP is 
complex. There are standarts to encapsulate the bitstream before putting it 
into RTP packets. 
For H263 this is RFC2190 (deprecated)
For H263-1998 and H263-2000 this is RFC2429
For mpeg4 (MP4V) this is another one I did not look at yet.

H263+ is a different name for H263-1998

H263-1998 provides a quality similar to mpg4 (the techniques are very 
similar).

Instead of extending linphone with patented codecs such as MPEG4 or H264 I 
would prefer linphone to use the free video codec from vorbis. But I did not 
look at it yet.

Simon


Le Jeudi 12 Janvier 2006 19:05, Mike Lee a écrit :
> Hi Simon,
>    After looking in the codes, there should be mpeg4 streaming. Why
> not use mpeg4 instead of H263?
>    AFAIK, compression power of Mpeg4 should be between H263 and H263+.
>  I don't know whether they are the same with what you mention. Does
> H263+ equal to H263-1998? or a new one?
>
> Mike,Lee
>
> On 1/12/06, Simon Morlat <address@hidden> wrote:
> > > Thanks!
> > > Out of curiosity: any plan to include support for H261 as well ?
> > > Not that i know anything about it, but kphone uses both H261 and
> > > H263...
> >
> > Well, H261 is a prior version of H263, designed for very low bandwidth
> > communications. I don't think it is valuable to spend time on this.
> >
> > There exists three versions of H263: H263, H263-1998 and H263-2000.
> > Linphone only supports H263-1998. Normally H263 is supposed to be
> > outdated and new implementations should implement it only for backward
> > compatibility. But I don' t know what the existing implementation over
> > the world are currently supporting. There seems to be still many ones
> > using H263. So maybe I'll need to add H263 support, depending on the
> > users feedback.
> >
> > Simon
> >
> > > --strk;
> > >
> > >
> > > _______________________________________________
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> >
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>
> --
> -----------------------------------------------
> Mike Lee