Slow Refresh of Dynamic images
Costas Theoharis
Posts: 30
Dear all,
I have a technical question. In a project we have 10 NXD-700Vi installed. We have 13 cameras shown through dynamic images (4 per page). The problem is that the refresh is too slow meaning that it takes more than 5 minutes for a frame! (we have set refresh value 1 in the dynamic image setup). Even if we just show one camera per screen the refresh is still the same. If I simulate the Touch panel design (through TPDesign4) with my PC the refresh is simultaneous. The network is ?clean? with no traffic and with an AMX ENET24 network switch. The panels firmware version is 2.81.6 and the controller has the latest.
Is there a possibility we have memory issues? If the format isn't mjpeg should we still be able to see the images? The camera system is an AVER Media PC based.
Any ideas what to try?
I have a technical question. In a project we have 10 NXD-700Vi installed. We have 13 cameras shown through dynamic images (4 per page). The problem is that the refresh is too slow meaning that it takes more than 5 minutes for a frame! (we have set refresh value 1 in the dynamic image setup). Even if we just show one camera per screen the refresh is still the same. If I simulate the Touch panel design (through TPDesign4) with my PC the refresh is simultaneous. The network is ?clean? with no traffic and with an AMX ENET24 network switch. The panels firmware version is 2.81.6 and the controller has the latest.
Is there a possibility we have memory issues? If the format isn't mjpeg should we still be able to see the images? The camera system is an AVER Media PC based.
Any ideas what to try?
0
Comments
I wonder if the issue is more to do with having so many touch panels hitting one camera. You could try an experiment and shut down all but one of the touch panels power and see if the single touch panel has a better refresh rate.
Streaming 10 clients from one camera is a lot of work for the little server.
When I worked at a university, we used a lot of cameras in the computer labs and classrooms. Several people could be looking at the cameras at one time. They eventually had to get a streaming server to act as an intermediary so the cameras themselves wouldn't get bogged down. The server also served as a DVR for all the cameras and would monitor them and report problems to the admin whenthe camera went down for some reason.
Thank you for your reply. I'll go and check tommorow and see. If a panel is not on the cameras page it's still asking for the images? The problem appears even if only one is on the cameras page and the others are on different pages.
Regards,
Costas
I don't think the touch panel is technically 'connected' to the server if you're not actively looking at the image. I wasn't sure from your post just how many panels were viewing at one time or not.
It would be unusual for all the panels to be flaky. Are the cameras you speak of able to be seen outside the network? If so, perhaps one of us could try the image on one of our panels and see what we get.
HTTP Request Format for Continuous MJPEG Video Streaming
Continuous sequence of JPEG images (MJPEG) separated by the boundary separator can be requested from AV cameras by using the following GET method request format:
GET/mjpeg?res=resolution_value&x0=X0&y0=Y0&x1=X1&y1=Y1&quality=quality_value&doublescan=doublescan_value&fps=value&id=value
HTTP/1.1\r\n
Host: ip_address\r\n
\r\n
where
?
Res can have value of either full or half and specifies whether camera should decimate the image by a factor of 2 in each direction;
?
X0, Y0, X1, Y1 are the left, top, right and bottom coordinates of the requested image window, respectively. These values cannot exceed the size of the image sensor array for the specific camera;
?
Quality is the compression quality of the jpeg image with the range from 1 to 20;
?
Doublescan is the parameter that allows the user to specify whether the camera should delay the image output until the new image is available (doublescan = 0) or the image request should be serviced by outputting the content of the image buffer that was already once output (useful for picture-in-picture display).
?
FPS specifies the requested frame rate; values 1 to 15 result in the specified frame rate, while omitting fps parameter as well as fps values of 0 and all values above 16 result in maximum frame rate that is model dependent.
The following example illustrates the request to camera with IP address 192.168.0.36 for the new full resolution 1600x1200 video stream with compression quality 12 at a maximum frame rate:
GET /mjpeg?res=half&x0=0&y0=0&x1=1600&y1=1200&quality=12&doublescan=0 HTTP/1.1\r\n
Host: 192.168.1.11\r\n\r\n
In response to the above request the camera sends continuous stream of images separated by the boundary separator ?fbdr? in accordance with MIME multipart/x-mixed-replace format. Please note that MIME multipart/x-mixed-replace format is not directly supported by Internet Explorer and requires user application to correctly process the image stream. For video viewing based on IE only the users should use on-camera script that can be accessed via [url]HTTP://ip_address/index.html[/url] request.
UPD: Telnet log from the panel would be worth to look at as well during the test.
Careful, I just got caught on this: the new 430, 435, 5100, and 5150 panels do not support motion jpeg streams. See this for more info:
http://amx.com/assets/comparisonCharts/Chart-TouchPanels.pdf
Areconts are terrible cameras. They probably can't handle all the TPs all hitting them at once.
That information is now out of date. The 430 and 435 do dynamic images now (we use it!); the chart says NO, as was the case with the original release. I believe that motion/streams (but maybe not "Dynamo") are also included now with dynamic on these panels. The 5100 and 5150 I think remain disabled on images.