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Pelco API RTSP Playback with Digital Sentry

Pelco API RTSP Playback with Digital Sentry


I cannot get RTSP playback to work with Digital Sentry. I have followed the url format stated here

Please see the attached picture where DS ControlPoint shows there is recording. What is the correct RTSP URL for the attached timestamp in the picture? (Note I'm at UTC-5) (I've tried rtsp://ip/?deviceid=2&starttime=2018-11-22T19:10:00&endtime=2018-11-22T19:30:00 and a few variation on that but without any luck).

Thank you.


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Hello there, thank you for your post.

We haven't actively done work with or on the DS Pelco API service, or integrations involving Digital Sentry in over 2 years. Based on the link outlining the DS RTSP URL forum... the format looks correct though the values may be different. Are you sure that the Device ID is "2"? Usually the device IDs that I've seen when the DS Pelco API is being used are in the 100's. If you check the device XML (information about how to do that is on this forum post: System.runtime.interopServices.SEHExeption - DS Pelco API Troubleshooting, you should be able to find the camera's logical assigned camera numbers.

Also another curious question would be if Live video is working or not using the camera values but without the time. If that's working... then you should have the correct device ID.

If you're continuing to have problems with this, I will advise you to reach out to Pelco Product Support. Our integration and development teams do no work with Digital Sentry any longer... so it's best to ask the Support teams to investigate the setup to see if there are issues with the DS Pelco API services running correctly (or not). Perhaps it's a problem with the 3rd party camera combination with DS Pelco API combined with trying to get the RTSP stream. I really couldn't tell you if that is supposed to work or not.

The deviceid=2 is fine as live rtsp video works with that id (I believe the 100's range is for cameras that are labeled IP or Analog in DS, in DSAdmin).

Anyhow, this morning I managed to figure out what is going on: I believe the DS NVR is applying UTC offset twice. So if I'm at UTC-5, I'd have to request time that's UTC-10 to get correct hour of playback. Furthermore, the requested second is off by 1 minute and 45 seconds. I'd consider these bugs in the DS Pelco API as I am specifying the correct UTC time format as per API here

Ahh, gotcha. I'm really happy that you were able to figure it out. Your comment about the 100's range for cameras also demonstrates how you already probably know more about working with this than I've forgotten in the time since we were supporting it (which admittedly was a pretty narrow window of time).

I'm not sure if the Digital Sentry team is doing any further development on the DS Pelco API service. It was created by a member of that team several years ago so that Digital Sentry had the same API services as Endura and therefore could be used with Pelco SDK (our team originally designed Pelco SDK -- though all of those engineers have moved on since). If you want to pursue having this potentially fixed, please reach out to Pelco Product Support to let them know also, reports from the field always carry more weight. I'll send the DS team lead an email to inform them of this post and your findings, too.

If you're satisfied with the workaround, I wouldn't worry about it.

I did open a ticket with our Digital Sentry teams so that they are aware of this problem. Typically these issues should be reported from Product Support, but I wanted to at least make the team aware.

They are now asking me for complete versions of Digital Sentry, DS Pelco API, which camera(s) and firmware this is seen with, and what kind of system setup where this problem is occurring -- so that they have that information to test and replicate the issue.

I can see from the screenshot that you are using DS Control Point version 7.18.72, and an Axis Q5915 camera is highlighted. If you can further complete the picture on all of the details of this DS system and the cameras where you see this problem, I'm willing to pass the details along to the Digital Sentry lead for their team to possibly investigate.

Yep, here are the steps to reproduce the issue:
1. Install DS-NVS-Installer v7.18.72.11464 on a clean machine (I'm using Windows Server 2012 R2 in a VM)
2. Add a camera for continuous recording using DS Quick Setup (I don't think it matters what the camera is, but I'm using Axis V5915)
3. Let recording happen for a while (I had to set recording quality to Low using DSAdmin so that I can get a long period of days saved to my 20GB recording disk)
4. Use VLC to request playback of a period starting at an hour you want. Then check the time overlay on playback video (from Axis camera) or if you have a clock in the scene (that the camera can see).

For example, I'm at UTC-5 so both my DS NVR machine and my VLC machine are at the same time zone. If I want to start video playback for 8am local time then my RTSP URL using UTC would be something like rtsp://ip/?deviceid=2&starttime=2018-11-26T13:00:00&endtime=2018-11-26T13:05:00. This gave me the wrong playback hour. If I apply UTC timezone offset twice it gives me the correct playback hour so the correct working RTSP URL for this case is rtsp://ip/?deviceid=2&starttime=2018-11-26T18:00:00&endtime=2018-11-26T18:05:00.

I plan to test different time zone once I have some time to prove the timezone offset issue I'm seeing.

Thanks. I've sent this information to the Digital Sentry team as well.

While on the playback subject, does the Pelco RTSP server support playback at faster speeds? (Perhaps through RTSP "Speed: " parameter). Thanks!

Hello there, I've been looking and looking all morning. From the best that I can tell, it looks like the answer may be "No". At the very least it doesn't clearly indicate that it does, and/or isn't documented clearly that it does.

I've found several articles, though admittedly many appear to relate to the Pelco API Viewer ... which is very old Pelco SDK toolbox code.

pelcoapiviewer-sample-12-usage (there is a link for Trick Play there) -- again it isn't clear that it does support this and how, and this tool is very very very old.

The Digital Sentry RTSP URL format link (from earlier in this post) obviously didn't have anything about it, either.

I did find an internal article about the parameters - but it was a 9-year old article and hadn't been updated since then. The links to it went to dead pages and code that no longer existed in our repositories. The one piece that I captured to show you is this:

RTSP Formal Definition.PNG

RTSP Formal Definition.PNG

... which doesn't appear to have any inclusion for that functionality. I must put a big DISCLAIMER that this is very old and may not even be relevant any longer -- it may have changed or updated since. What it doesn't include is any parameter for playing at different speeds for playback.

My answer is that it doesn't look like it does. If it does, it isn't documented in anything that I could find (so if you do find it working -- that's great!!).