Performing Arts Advisory

["Feghali, Jose" <>]

Agreed. Unfortunately, most performing arts institutions do not have anywhere near 250 Mbps available (most still run 100 Mbps Ethernet connections in their building) and such a connection here, for instance, would take up half of our available bandwidth with the Gigapop providing our Internet2 connection – assuming we replaced our current 100 Mbps routers in the music building with Gbit ones.

 

What ConfXP does now that no other solution appears to do (save maybe Vic and Rat, which are very complicated for non-technical people to use) is actually to allow for LESS video bandwidth, not more, but including uncompressed audio – thus filling a gap which exists at the moment between DVTS and normal video conferencing. Until institutions have updated their network connections and acquired Internet2 or similar connections with high available bandwidth, a lot of them here in the US but specially abroad will continue to be “bandwidth-challenged” and cannot work with DVTS, let alone dream about SD or uncompressed HD. ConferenceXP opens up the possibilities of video conferencing now with CD and higher quality audio.

 

For most of what we do in music (masterclasses, lectures, demonstrations, etc…) the 350 ms or so of latency does not really matter, and the “doubly-compressed” video (DV + WMV) is also not a concern. I am pleased however that CXP appears to have reduced the latency of the “straight” DV25 stream to about half of what DVTS displays.

 

José

 

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From: Michael C. Wellings [mailto:]
Sent: Saturday, March 08, 2008 2:54 PM
To: Feghali, Jose
Cc: ;
Subject: RE: ConferenceXP update

 

The DV CoDec  (http://www.nssn.org/search/DetailResults.aspx?docid=280521&selnode=) does frame-based compression at 25mbps.  Uncompressed SD video varies between 100 and 250 mbps depending upon the sample format.  Current standard broadcast/production data rate is 250mbps.  The point of transporting uncompressed video (SD in this case) is to lower the latency.  DV compression adds 100 or so ms per end.  For arts-related use lower latency would be pretty important.  The point is to get ConferenceXP to transport video at uncompressed rates…indeed at a suite of rates...to make it more scalable and useful for multiple applications. I really appreciate your continued interest in ConferenceXP and ip video…it’s really important for us to understand the needs of the community and to engage others in continued development

 

mike

 

From: Feghali, Jose [mailto:]
Sent: Saturday, March 08, 2008 12:43 PM
To: Michael C. Wellings
Cc: ;
Subject: RE: ConferenceXP update

 

What I am saying is that ConfXP appears to do what DVTS does – i.e. send the firewire DV stream from the camera out via IP uncompressed by a codec on the computer.

 

I know that the DV codec has “theoretically” got some compression on it, but I got the same data rates for both DVTS and ConfXP. I have not dealt with any *really* uncompressed video format and do not intend to experiment with uncompressed HD or other “cutting edge” technologies anytime soon.

 

 

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From: Michael C. Wellings [mailto:]
Sent: Saturday, March 08, 2008 2:35 PM
To: Feghali, Jose
Cc: ;
Subject: RE: ConferenceXP update

 

That data rate is too low to be uncompressed SD video.  What is your input format? Must be compressed…

 

From: Feghali, Jose [mailto:]
Sent: Saturday, March 08, 2008 12:33 PM
To: Michael C. Wellings
Cc: ;
Subject: RE: ConferenceXP update

 

About the same as DVTS – almost 30 Mbps with video and audio (around 25 Mbps just video) using DV.

 

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From: Michael C. Wellings [mailto:]
Sent: Saturday, March 08, 2008 2:31 PM
To: Feghali, Jose
Cc: ;
Subject: RE: ConferenceXP update

 

What is your output data rate?

 

From: Feghali, Jose [mailto:]
Sent: Saturday, March 08, 2008 12:20 PM
To: Michael C. Wellings
Cc: ;
Subject: RE: ConferenceXP update

 

Under video settings, you can choose “uncompressed video” in the advanced box. It switches off the Windows Media encoding engine.

 

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From: Michael C. Wellings [mailto:]
Sent: Saturday, March 08, 2008 2:18 PM
To: Feghali, Jose
Cc: ;
Subject: RE: ConferenceXP update

 

I understand...fred mentioned you.  What hasn’t been there is support for multiple codecs, and for uncompressed HD video.  We are looking at the ConferenceXP front end for iHDTV.

 

ConferenceXP natively supports Windows Media encoding…what support for uncompressed video are your referring to?

 

From: Feghali, Jose [mailto:]
Sent: Saturday, March 08, 2008 12:13 PM
To: Michael C. Wellings
Cc: ;
Subject: RE: ConferenceXP update

 

Michael,

 

I have been in touch with Fred Videon at your CS department and Paul Oka at MSoft on this over the last few weeks. According to Fred, the code changes I made which allow for uncompressed audio without glitches and for synching audio and video will be incorporated into CXP version 5.0.

 

Uncompressed video has always worked, and HDV also worked yesterday. In order to get DV and HDV to work properly with ConfXP, one needs to “downgrade” to Windows Media 10, as there appears to be a problem under Windows Media 11 which doesn’t allow for compressed video in CXP.

 

José

 

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From: Michael C. Wellings [mailto:]
Sent: Saturday, March 08, 2008 1:26 PM
To: Feghali, Jose; Petr Holub;
Cc:
Subject: RE: ConferenceXP update

 

Jose

Along with our CS Department we got the grant from Microsoft Research to continue development work on ConferenceXP.  In a mtg the other day we discussed this prospect as well as plugging live HDV into ConferenceXP, and opening it up to other CoDecs and – Uncompressed video.  If there is interest in the community to do this is may help with the decision process

 

mike

University of Washington

 

 

From: Feghali, Jose [mailto:]
Sent: Saturday, March 08, 2008 10:20 AM
To: Petr Holub;
Cc:
Subject: RE: ConferenceXP update

 

I tried RAT a while back and couldn’t get it to work right uncompressed.

 

Do you know what is the max resolution that VIC supports? Is there a FAQ that you know of that explains how to setup RAT and VIC for IP-to-IP conferencing?

 

Thanks,

 

José

 

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From: Petr Holub [mailto:]
Sent: Saturday, March 08, 2008 12:14 PM
To: Feghali, Jose;
Cc:
Subject: RE: ConferenceXP update

 

RAT from MBone Tools (or AccessGrid) can do also uncompressed audio at this level.

 

Petr

 

================================================================

                            Petr Holub

CESNET z.s.p.o.                       Supercomputing Center Brno

Zikova 4                             Institute of Compt. Science

162 00 Praha 6, CZ                            Masaryk University

Czech Republic                     Botanicka 68a, 60200 Brno, CZ

e-mail:                phone: +420-549493944

                                             fax: +420-541212747

                                       e-mail:

 

From: Feghali, Jose [mailto:]
Sent: Saturday, March 08, 2008 6:28 PM
To:
Cc:
Subject: ConferenceXP update

 

Colleagues,

 

We have know successfully tested ConferenceXP with uncompressed stereo audio (16/44.1 and 16/48) using both compressed and uncompressed video. The latency with all uncompressed appears to be lower than DVTS, but there is some question as to the video quality. One of the testing sites reported the video being slightly less sharp with ConfXP using an HDV camera. It appears that an optimum bandwidth with compressed video/uncompressed audio is in the order of around 2.5 to 3.5 Mbps, but we have gotten good results down to around 2 Mbps.

 

If there are any other performing arts institutions or others that would like to test ConfXP in full uncompressed audio with or without compressed video, please get in touch with me off-list at (j DOT Feghali AT tcu DOT edu).

 

If anyone here knows of any other conferencing solution currently available that allows for full, 44.1/48 KHz uncompressed audio to be paired with compressed video I would appreciate the input.

 

José Feghali

Artist-in-Residence

Coordinator of Internet Technologies

TCU School of Music