GeoVision Audio Bandwidth Requirements

[CCTVDude 0]

What is the min bandwidth to get a stable audio & quad multi-view display? We have a customer w/ dsl 1.5/256 (actually getting 1.2M down / 212K up) and the audio has gaps. I don't think it's a mic problem (although could be), but I was just wondering how much b/w the audio uses.

[scottj 0]

32K is all it uses from what we tested since it is 8-bit mono. ADPCM.

Something you can do which will help the latency on the audio side, is go into the WebCam setup menu and set a maximum limit (RPB tab) of bandwidth allowed to 125kb. This will reduce the video frame rate during remote viewing, and help ease the network congestion on the upload side of the server. The network congestion is what causes the audio to clip if in fact it is bandwidth related. We also use a Crown PZM-11LL (line Level) with phantom/24VAC powered Mic. here is a link to the PDF from Crown.

 

http://www.crownaudio.com/pdf/mics/136455.pdf

 

Works great, crisp clear sound over IP and can be mounted in drywall or a drop ceiling with a single gang box.

 

Scottj

[iwatchlive 0]

Is it for multiple users? FOr example, it will limit how much people can download, butdoes it have any affect on the webcam live viewing/listening?

[scottj 0]

No, This particular setting is labeled RPB (not to be confused with Remote Playback Server) and will limit the amount of bandwidth usage to stream video for live viewing. There is also a setting for this under the Remote Playback Server (bandwidth control) that will limit the amount of bandwidth used for downloading from the recorded video database. It really is a poor labeling issue that Geo should address, as it causes confusion to many people. Setting a upper bandwidth limit just keeps the DVR from congesting the network. By default (unchecked), the WebCam Server will attempt to use ALL of your upload bandwidth, regardless if it even needs it or not. The remote connection then becomes very burstable and if you have a low cost router in place it has been known to lockup the routers (such as D-Link,Netgear). The request for maximum bandwidth is just not needed, as many cameras with average movement compresses using GeoMPEG or MPEG4 only require 25-35KB/sec to achieve 15 FPS or better remotely per channel.

 

Limiting the number of people can be done by setting the maximum channels in the Webcam or the Remote Playback Servers. For example if you set the max channels to 5, then only 5 users will be allowed to perform that function at any given time simultaneously.

 

Does this explain it better?

 

Scottj

[CCTVDude 0]

32K is all it uses from what we tested since it is 8-bit mono. ADPCM.

Something you can do which will help the latency on the audio side, is go into the WebCam setup menu and set a maximum limit (RPB tab) of bandwidth allowed to 125kb. This will reduce the video frame rate during remote viewing, and help ease the network congestion on the upload side of the server. The network congestion is what causes the audio to clip if in fact it is bandwidth related. We also use a Crown PZM-11LL (line Level) with phantom/24VAC powered Mic. here is a link to the PDF from Crown.

 

http://www.crownaudio.com/pdf/mics/136455.pdf

 

Works great, crisp clear sound over IP and can be mounted in drywall or a drop ceiling with a single gang box.

 

Scottj

32K is not much at all, but I think it's maxing out his DSL. We talked him into upgrading to a higher DSL package (3M/756K ?). Hopefully it will help.

 

I'm not one to go for inferior hardware, but we've had good luck using the cheap-o powered mics.

[Yeasin 0]

I have recently installed a GV800 system for a company in Paris. The remote view works fine except for the audio (although it works fine when downloading audio from Remote playback). When the audio is enabled in multiview, I only get a load tapping/rapping sound. The system is connected to the internet with an 8mb connection. Surely I have more than enough bandwitdth? Is there anything I need to change in settings to be able to get clear audio. The system is a GV800 4 Cam System. I'm using all 4 audio channels. Thanks in advance for any help or assistance anyone can offer.

[CCTVDude 0]

I have recently installed a GV800 system for a company in Paris. The remote view works fine except for the audio (although it works fine when downloading audio from Remote playback). When the audio is enabled in multiview, I only get a load tapping/rapping sound. The system is connected to the internet with an 8mb connection. Surely I have more than enough bandwitdth? Is there anything I need to change in settings to be able to get clear audio. The system is a GV800 4 Cam System. I'm using all 4 audio channels. Thanks in advance for any help or assistance anyone can offer.

Sounds like the problem I have. Audio that is recorded is perfect but over the net it's choppy... I was hoping it was BW related. Anyone w/ ideas?

[rory 0]

What type of mics are you using?

[scottj 0]

Have you guys tried limiting the bandwidth through the Geo software yet?

Also, check your gain settings in the audio setup menu, if it is maxed at 10, knock it down to about 6 and adjust at the Mic level if it is amplified.

I'm betting it is the bandwidth management portion more so than the gain, but that gain adjustment if flaky and we found anything over 6 degraded the quality.

 

Scottj

[Yeasin 0]

Thanks for your help. Have taken your advise and adjusted the bandwidth. The tapping sound appears to have gone, however can't check till monday whether it works as the office is closed for the weekend.

 

Will let you know if it works.

 

Yeasin.