All things related to multicast

["Richard Mavrogeanes" <>]

MPEG-4 is and should be lower quality than MPEG-2....it is much lower
bandwidth, 320 x 240, and is pt 2, SP. Per the standard, the audio with
the MPEG-4 is AAC.  Both are coming in loud and clear here.
 

-----Original Message-----
From: Tim Chown 
[mailto:]
 
Sent: Friday, August 18, 2006 10:33 AM
To: wg-multicast
Cc: David C Tarrant; Nicholas J Humfrey
Subject: Re: Another multicast test

Hi Frank,

I think the MPEG2 and MPEG4 SAP announcements may be muddled?

For what's labelled as MPEG4 I get a lower quality stream with sound.

For MPEG2 I get a higher quality with no sound.

Maybe the IPs and ports got switched accidentally?  Or is it just me? :)

The video quality at MPEG4 is excellent though.

We'll try to run our RTP tools on the sources to see what actual losses
we see (as per http://www.multicast.org.uk/ under Tools, Net::RTP).

Tim

On Fri, Aug 18, 2006 at 09:35:06AM -0400, Frank Fulchiero wrote:
> The session name in the SAP list is ConnecticutCollege MPEG4.
> Thanks to everyone for the feedback, and to CEN for fixing things.
> Incidentally, right now much of the video is from miniDV source, made 
> into a DVD (compressed to MPEG2), and then analog out of a DVD player 
> to VBrick, which compresses again to MPEG2 or MPEG4.
> So, there are quite a few bottlenecks compromising quality. There are 
> better possible signal paths, which we did not have time to implement 
> yet.
> 
> Frank
> 
> On Aug 18, 2006, at 6:08 AM, Tim Chown wrote:
> 
> >On Thu, Aug 17, 2006 at 10:50:04AM -0800, Jeff Harrison wrote:
> >>
> >>   Can anyone see our streams, and is there any packet loss?
> >>
> >>   MPEG2 at 233.88.214.138, port 4443 (5 mbps)
> >
> >This is perfect here in Southampton, England.  Very good quality on 
> >vlc.
> >
> >>   MPEG4  at  233.88.214.137, port 4444 for video and 4644 for audio

> >>(400
> >>   kbps)
> >
> >Not working directly from vlc, will check SAP - what's the session 
> >name?
> >
> >We've also been receiving OSTN here recently very nicely, so the 
> >multicast quality US->UK seems good :)
> 

--
Tim/::1