Does VSX support 2 live video streams?

[cedi]

Hi.

I hope I can get an answer here first-hand.

I'm not sure if the VSX can transmit (receive) 2 live video streams simoultaneously. If there are 2 cameras in the room, can it transmit both pictures or only one at a time? Oh, and both video streams are CIF format I guess.
How does that affect the frame-rate and picture quality? How are they encoded; H.263 or H.264?

Any experience with Sony, Tandberg or Aethra in this case?

Thank you for your opinions.

BR,
Cedi

[qxm]

Hi.

I hope I can get an answer here first-hand.

I'm not sure if the VSX can transmit (receive) 2 live video streams simoultaneously. If there are 2 cameras in the room, can it transmit both pictures or only one at a time? Oh, and both video streams are CIF format I guess.
How does that affect the frame-rate and picture quality? How are they encoded; H.263 or H.264?

Any experience with Sony, Tandberg or Aethra in this case?

Thank you for your opinions.

BR,
Cedi


hi,

I only know that Tandberg can do that , it's called duo video, the bandwidth divided by 2 to transmit both video, video using CIF and if you showing presentation directly from your laptop/pc with RGB cable, the video format suppose to be XGA but video protocol must be change to H263+ ... I dont know with sony and aethra....I think polycom can do transmit both video... (correct me if I'm wrong :) )

[tom9933]

Cedi,
The short answer is no, the VSX codec only supports sending 1 full motion video stream at a time. Now what qxm is talking about is using the content stream as a secondary video source. This will work, but you will most likely find that the frame rate is unacceptable since in most cases the frame rate on the content channel is at or below 15 fps. Having said that the good news is that most current systems now support H.239 content so in theory if you built a room using the content channel for a second stream of video you should have relatively good interoperability with newer systems. I think your biggest question will be who are you going to connect to? If it’s the general population (i.e. you don’t control both ends of the call) then you should probably stick to a single stream of video for the time being.
However if you control both ends of the call then I know of two options: One is the old way in which you use two pairs of codecs and run two parallel calls. This works very well until you get into a multipoint situation. The other is to look into the dual video options offered by the Sony G70 codecs. I have not used this codec personally, but I have also heard some very good things from other users. The only complaints I’ve heard about this unit are audio quality and management issues. Also I doubt that the Sony dual video stream solution is interoperable with a non Sony codec so you need to check this out when testing the unit.
Good Luck

[Glen Sykes]

Hi Cedi,

If you wanted to do that with a VSX, you would require the visual concert device and a camera capable of VGA output.

This would allow you to send images from 2 cameras to the far end simultaneously, either using the People and Content standard, or H.239.

The problem with this implementation is that the XGA stream is geared for clarity, and not motion, so whilst you will get an image from the XGA camera, it will be poor quality as the frame rate will be low.

Tandberg (with the NPP option) have a more open way of sending 2 streams at the same time, in that you can send 2 x video images from any of its sources at the same time (including the VGA/DVI input). The Tandberg will apply 'motion' rules to its video inputs, so assuming you have decent bandwidth, you should get good quality video from both cameras at the same time. In other words, you can acheive exactly what you want to do with the Tandberg, but with the VSX it's a bit of a compromise.

[tom9933]

Glen,
So when the Tandberg sends this is it a Tandberg only thing or does it interoperate with the Sony endpoints? In theory there shouldn’t be any reason that an endpoint can’t support multiple video streams, but I don’t know if there is a standard way to do it.
Thanks

[qxm]

hi,

I think if we connecting with the same vendor, there is no problem... tandberg to tandberg , polycom to polycom , sony to sony etc... and I think cedi should be tell us , he wants to connect with the same vendor or different vendor????.....about interoperability, I have connected duo video on tandberg 880 classic s/w: E4.1 with polycom vsx7000 and activated their both H.239, it worked...so as polycom activated their people + content with t880 it worked too.. but I have a problem when I connect T880 with MGC 100 then activated duo video(correct me if I'm wrong:) )

[Sean Lessman]

Glen,
So when the Tandberg sends this is it a Tandberg only thing or does it interoperate with the Sony endpoints? In theory there shouldn’t be any reason that an endpoint can’t support multiple video streams, but I don’t know if there is a standard way to do it.
Thanks
TANDBERG does this using H.239 or DuoVideo. The other manufacturers (today) have chosen only to allow PC on the second stream. Within H.239 you need to signal whether or not the second stream is live or content, but it is certainly possible.

Sean

[Glen Sykes]

I can't understand why a manufacturer would want to be so restrictive with their implementation of H.239!

I mean it's not only PC content that users show in meetings, document cameras, DVD / VCR playback, auxiliary cameras, these are all things used in well managed videoconferences. Why restrict them!

I have to applaud Tandberg on this, they implemented dual streams in a proper way years ago and it would seem that the only reason other manufacturers don't support dual streams on any source is because Tandberg do!

[tom9933]

Sean,
So when the H.239 stream is a second camera is it sent as CIF or 4CIF? Also was is the frame rate of the second stream?
Thanks

[James Flockton]

Is the FPS based apon the connection speed of the call? Or is it down to Processor load on th codec?

[glennder]

Is the FPS based apon the connection speed of the call? Or is it down to Processor load on th codec?

FPS is primarily associated with the processor load on the codec but obviously it matters what the speed is as well. The Codec will always connect as a at best options so if it can send 30FPS it will try, but when you move in front of it, it will drop a little.

[Sean Lessman]

Sean,
So when the H.239 stream is a second camera is it sent as CIF or 4CIF? Also was is the frame rate of the second stream?
Thanks
Hi Tom,

The resolution is determined by the source and the 'sharpness' or 'motion' bias of that source. As a general rule, motion will be lower resolution (i.e. CIF) and reserved for face cameras. You can change the bias to 'sharpness' and the face camera will be 4CIF.

For content, the default is biased towards 'sharpness' which is typically 4CIF for document cameras and XGA for PCs. Other motion sources such as VCRs and DVDs are typically default biased for 'motion'.

The biases are selectable in the menu system.

Short answer is out of the box, a second camera would be CIF as it is connected to the 'Aux' input. You can change the bias to 'sharpness' and the second camera will be 4CIF.

Sean

[tom9933]

Sean,
That sounds good, so in theory if both inputs were set to motion you could send two CIF streams at 30fps. I can see this being very useful in a classroom environment. So is there any talk of adding FECC to the content stream? IE does FECC exist in the H.239 spec? I can see a real advantage in being able to both control and select a second camera from the far site.
Thanks

[pzielie]

Aethra supports any two sources on the video stream. They will also do Duo Video or H.239. I will have to play with FECC to see how it works on both sources. It should work in theory, you have local control over both.

[trapehzoid]

I can't understand why a manufacturer would want to be so restrictive with their implementation of H.239!

I mean it's not only PC content that users show in meetings, document cameras, DVD / VCR playback, auxiliary cameras, these are all things used in well managed videoconferences. Why restrict them!

Because the systems couldn't do it. In the viewstations you had to use the visual concert for the encoder (remember it has a equator dsp in it). Ipower could send other sources as content. Image share on the Ipower was just a VGA DA and cabling.

I've heard the vsx will do this in the future, but I haven't had that confirmed.

I'm not familar with vcon or aethera's capabilities.

[trapehzoid]

FPS is primarily associated with the processor load on the codec but obviously it matters what the speed is as well. The Codec will always connect as a at best options so if it can send 30FPS it will try, but when you move in front of it, it will drop a little.

dropping frame rate isn't a function of load on the CPU typically.. its a function of efficency and ability to encode enough of the picture at that bandwidth.

If you exceed the amount of info the system can send at that bandwidth.. you'll either drop framerate or loose clarity (depending on how the encoder is programmed). Its not always a function of 'load'.. its simply an issue of exceeding the system's capabilities typically.

If you only have 128kbs.. you can only send a fixed amount of info.. the magic is sending 'enough' of the picture to make it look good and being able to mask the stuff you are tossing out.

Doing things like waving your hand in front of the camera or moving the camera cause the entire picture to update.. asking the codec to encode the entire picture.. not just the parts moving.. which is what they normally do.

Having said all that tho.. yes.. in some systems who are doing alot more sharing of resources between tasks.. performance can drop based on activities (like if one stream is XGA.. or doing things in menus.. web interfaces.. etc)

[qxm]

I have tested connecting VSX7000 ver.7 with TANDBERG 880 ver.E4.2... the first problem came when both codecs successful connected, on TANDBERG call status shown that codec recieving 2 stream from polycom(H239 enable on polycom) so when polycom want to use people+content, TANDBERG can recieve smoothly but when tandberg want to use duo video, tandberg have problem to transmit their 2 stream because polycom had use their 2 stream from the first time both codec connecting, any suggestion ?


Regards

[Glen Sykes]

Because the systems couldn't do it. In the viewstations you had to use the visual concert for the encoder (remember it has a equator dsp in it). Ipower could send other sources as content. Image share on the Ipower was just a VGA DA and cabling.

I've heard the vsx will do this in the future, but I haven't had that confirmed.

I'm not familar with vcon or aethera's capabilities.

I was thinking IPower when I wrote that. Did they expand the IPower capability to be able to send video sources down the content channel? I thought it could only send PC sources or desktop. I don't know the IPower that well.

[Sean Lessman]

I have tested connecting VSX7000 ver.7 with TANDBERG 880 ver.E4.2... the first problem came when both codecs successful connected, on TANDBERG call status shown that codec recieving 2 stream from polycom(H239 enable on polycom) so when polycom want to use people+content, TANDBERG can recieve smoothly but when tandberg want to use duo video, tandberg have problem to transmit their 2 stream because polycom had use their 2 stream from the first time both codec connecting, any suggestion ?


Regards
This is being worked on collaboratively as we speak between TANDBERG and Polycom. Stay tuned.

Sean

[trapehzoid]

I was thinking IPower when I wrote that. Did they expand the IPower capability to be able to send video sources down the content channel? I thought it could only send PC sources or desktop. I don't know the IPower that well.

Yes, they later added the ability to define each input as 'content' or 'people', but the definition was static. You couldn't just on the fly decide to send the VCR as people.. and then later as content. A flexibility I think only the tandberg units have.