Subscriber Discussion

What IP Cameras Support Embeded Timecodes, And How Do You Find Out?

TP
Thomas Purchas
Sep 14, 2016

Does anyone know which IP cameras support embedding timecodes in their video streams? I hoping to use the timecode data to sync up other data streams (e.g. Point-of-Sale), but I can't seem to find any information on this.

Also if anyone has experience syncing CCTV data to other data streams it would be great to hear your experiences.

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Vincent Tong
Sep 14, 2016

Most IP cameras have time overlays, but sometimes you have to enable and set them in the camera's web interface first. There you can set the position, color and format.

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Jon Dillabaugh
Sep 15, 2016
Pro Focus LLC

I haven't seen an IP camera that DOESN'T have this feature. A list of models NOT supporting this feature would be a much shorter list to make.

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Brian Karas
Sep 15, 2016
IPVM

I might be wrong, but I think Thomas is asking about embedding the date/time stamp as a form of meta-data in the RTSP stream so that it can be easily read by another software to match video frames to other time-stamped events.

Many (most?) cameras support time-stamp overlays, but I do not recall seeing one that had the date/time meta data in the RTSP stream (other than the VideoIQ cameras, which are all EOL now, and most likely would not have been a good fit anyway). However this is also not the kind of info that would be listed out on a spec sheet, as it is too low-level.

TP
Thomas Purchas
Sep 15, 2016

Yeah, I should have been clearer. I'm for cameras that support embedding a timecode into the actual video stream as metadata, so that software can pull out the exact moment a frame was captured (within reason).

Currently I'm using machine vision techniques to read the OSD timestamp, but I'm now discovering how poor many cameras are at keeping track of time (FPS is inconsistent, the timestamp jumps entire seconds without reason etc).

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Brian Karas
Sep 15, 2016
IPVM

Of course, you're assuming the camera itself has a fairly accurate time-stamp, and I don't know that I would make that bet myself.

Are you relying solely on using video recorded elsewhere, or can you capture video in real-time and add your own time data?

TP
Thomas Purchas
Sep 15, 2016

Well the evidence so far is that most cameras don't have a particularly accurate time-stamp, but the real issue for us is dealing with the variability. When extracting from the OSD we discovered that most seconds have 8-9 frames (the camera is set to 10FPS), and then you get occasional craziness with a second containing 20 frames or less than 5.

If the camera wrote the time it thought a frame was captured into the stream, it would remove a lot of guesswork, and reduce the computation load (computer vision is expensive) of dealing with the video.

Ideally we would like to rely solely on using video captured elsewhere, without installing new kit or software. But based on this we might not have a choice.

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Brian Karas
Sep 15, 2016
IPVM

Honest question: You think the camera would be more accurate writing what it thinks the current time is to a meta-data track instead of OSD text?

I get the ease of extraction part, but I think you will still have a time accuracy problem.

TP
Thomas Purchas
Sep 15, 2016

I'm hopeful.... Really the biggest improvement will be getting sub-second accuracy out (even if it's wrong). Reading the OSD and interpolating the time for frames that have the same time displayed is proving difficult and error prone.

Also if it had turned out that most camera could/did encode digital timecodes, then it makes it easier to be compatible with multiple cameras, eliminating the need for a different algorithm for each OSD.

In short, I doubt the camera would be more accurate writing a meta-data track. But it would make extraction considerably easier. It would also make it easier to debug if we can see what the camera thinks is happening on a frame-by-frame basis.

U
Undisclosed #1
Sep 15, 2016
IPVMU Certified

So Thomas, are talking about video and cameras that you have no control over until an incident?

Meaning that you are maybe really asking what is the likelihood of a stream from an IP camera having timestamp meta-data embedded in it by default?

That might be low.

Also, I understand the difficulties involved in OSD OCR, but when this metadata does exist, it could be in a different propreitery format for each manufacturer. And unlike the OSD kind, it might not be readily decipherable.

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TP
Thomas Purchas
Sep 15, 2016

Very limited control over (I could ask them to turn change some settings, but couldn't get them replaced).

OSD OCR is a pain, we have even seen some OSD where the white text of the timestamp is placed over a white background, extremely unhelpful.

The advantage of the meta-data is that once we reverse engineering for one camera, we can be confident that environmental conditions won't break it. If no cameras out there support this kind of feature, then we have no choice but to work around it.

UM
Undisclosed Manufacturer #2
Sep 16, 2016

I have not tested extensively or looked through the API for this, but I have noticed that Samsung (now Hanwha) cameras, when recording AVI files to an SD card/NAS includes an SMI (subtitle) file. This file includes the timestamp, which VLC player automatically overlays. This timestamp is down to the second, and you see each second tick by. Not sure if this is helpful...

Not sure if this timestamp is included in metadata or headers when streaming live.

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