Training: Frame Rates for IP Cameras

Author: John Honovich, Published on Apr 18, 2010

This is the industry's most in depth guide to frame rates in video surveillance.

As a precursor, you need to know the speed of objects, most typically people.

Speed of People

The faster a person moves, the more likely you are to miss an action. You know the 'speed' of frame rate - 1 frame per second, 10 frames per second, 30, etc., but how many frames do you need for reliable capture? 

Here's how fast people move. 

For a person walking, a leisurely, ordinary pace is ~4 feet per second, covering this 20 foot wide FoV in ~5 seconds:

For a person running, our subject goes through the 20' FOV in ~1.25 seconds, meaning he covers ~16' in one second:

For example, if you only have 1 frame per second, a person can easily move 4 to 16 feet in that time frame. We need to keep this in mind when evaluating frame rate selection.

Get Video Surveillance News In Your Inbox
Get Video Surveillance News In Your Inbox

In this guide, we cover:

  • What speed do people move at and how does that compare to frame rates.
  • Walking: What risks do you have capturing a person walking at 1, 10 and 30fps.
  • Running: What do you have capturing a person running at 1, 10 and 30fps.
  • Head Turning: How many more clear head shots do you get of a person at 1, 10 and 30fps.
  • Playing Cards: What do you miss capturing card dealing at 1, 10 and 30fps.
  • Shutter speed vs Frame Rate: How are these two related?
  • Bandwidth vs Frame Rate: How much does bandwidth rise with increases in frame rate?
  • Average Frame Rates used: What is the industry average?

Walking Examples

As our subject walks through the FOV, we view how far he moves from one frame to the next. In 30 and 10 fps streams, he does not complete a full stride. However, in the 1fps example, he has progressed ~4' between frames, which falls in line with our measured walking speed of ~4' a second.

Running Examples

With our subject sprinting through the FOV, the 30 fps stream still catches him mid stride, while in the 10 fps stream, he has traveled ~1' between frames. In the 1 fps example, only one frame of the subject is captured, with him clearing the rest of the FOV between frames, with only his back foot visible in the second frame.

Capturing Faces

Trying to get a clear face shot can be difficult when people move because they naturally shift their head frequently. In this demonstration, we had the subject shake their head back and forth walking down a hallway to show the difference frame rate plays.

Take a look:

Notice, at 1fps, only a single clear head shot is captured, but at 10fps, you get many more. Finally, at 30fps, you may get one or two more, but it is not much of an improvement.

Playing Cards

In this test, our subject dealt a series of playing cards from ace to five with the camera set to default shutter speed (1/30). 

In the 30 and 10 fps examples, we can see each card as it is removed from the top of the deck and placed on the table. However, in the 1 fps example, we see only the cards appearing on the table, not the motions of the dealer, as frame rate is too low.

Shutter Speed vs Frame Rate

Frame rate does not cause blurring. This is a misconception. The camera's automatic shutter speed control does.

Dealing cards ace through 5 again, we raised the camera's minimum shutter speed to 1/4000 of a second. The image below compares the motion blur in the dealers hand and card, with the 2 card much more easily legible in the fast shutter speed example.

1/4000s shutter speed completely eliminated all traces of motion blur. 1/1000 and 1/2000 of a second shutter speeds significantly reduces blur, but it was still noticeable around the dealers fingers and edges of the cards when looking at the recordings frame-by-frame.

If you have blurring, you have shutter speed configuration problem, not a frame rate one.

Slow Shutter and Frame Rate

On the other side, sometimes users want or camera manufacturers default their maximum shutter to a rate slower than the frame rate (e.g., a 1/4s shutter for a 1/30s camera). Not only does this cause blurring of moving objects, you lose frames.

Key lesson: The frame rate per second can never be higher than the number of exposures per second. If you have a 1/4s shutter, the shutter / exposure only open and closes 4 times per second (i.e., 1/4s + 1/4s + 14/s + 1/4s = 1s). Since this only happens 4 times, you can only have 4 frames in that second.

Some manufacturers fake frames with slow shutter, simply copying the same frame over and over again. For example, if you have 1/15s shutter, you can only have 15 exposures and, therefore, 15 frames. To make it seem like you have 30 frames, each frame can be sent twice in a row.

Be careful with slow shutter. Beyond blur, you can either lose frames or waste storage.

Bandwidth vs Frame Rate

Frame rate impacts bandwidth, but for modern codecs, like H.264, it is less than linear. So if you increase frame rate by 10x, the increase in bandwidth is likely to be far less, often only 3 to 5 times more bandwidth. This is something we see mistaken regularly in the industry.

The reason for this is inter-frame compression, that reduces bandwidth needs for parts of scenes that remain the same across frames (for more on inter and intra frame compression, see our CODEC tutorial).

Illustrating this point further, we took 30, 10 and 1 fps measurements to demonstrate the change in bit rate in a controlled setting in our conference room. The average bitrates were as follows:

  • 1 fps was 0.179 Mb/s
  • 10 fps, with 10x more frames, consumed 4x more bandwidth than 1 fps (0.693 Mb/s)
  • 30 fps, with 3x more frames, consumed double the bandwidth of 10fps and, with 30x the frames, 7x the bandwidth of 1fps (1.299 Mb/s)

These measurements were done with 1 I frame per second, the most common setting in professional video surveillance (for more on this, see: Test: H.264 I vs P Frame Impact).

For more on this, see our reports testing bandwidth vs frame rate and 30 vs 60 fps.

Average Frame Rates Used

Average industry frame rate is ~8-10fps, reflecting that this level provides enough frames to capture most actions granularly while minimizing storage costs.

As show above, going from 10fps to 30fps can double storage costs but only marginally improve details captured.

From our Average Frame Rate Used for Recording survey results, see this table:

For more commentary on why integrators choose the frame rates hey do, see the Average Frame Rate Used for Recording report.

Methodology

For this test we used an Axis Q1604 (firmware version 5.50.3) with three streams (30/10/1) recorded by ExacqVision 6.2.7.63216.

 

To see for yourself, download the 6 video samples.

Related Reports

Automatic Door Operators For Access Tutorial on Sep 20, 2017
Opening and closing doors might sound simple, but it takes a high-tech piece of door hardware to pull it off. Integrating automatic door operators...
Avigilon 'Blue' Cloud Entry Examined on Sep 19, 2017
Avigilon is moving to the cloud. The company announced their Avigilon Blue platform, designed to be a web-managed surveillance system, utilizing...
September IP Networking Course on Sep 14, 2017
LAST Chance - Registration is ending. Register now. This is the only networking course designed specifically for video surveillance professionals...
Master Keying Tutorial on Sep 14, 2017
Mechanical keys are the most fundamental, albeit unsophisticated, form of access control. Like access control, Master Keying allows large scale use...
Fail Safe vs. Fail Secure Tutorial on Sep 13, 2017
Few terms carry greater importance in access control than 'fail safe' and 'fail secure'. Access control professionals must know how these concepts...
Dedicated Vs Converged IP Video Networks Statistics on Sep 12, 2017
'Convergence' has been a major industry theme for many years. All organizations have IP networks today with laptops, tablets, phones and more...
October Camera Course on Sep 07, 2017
Learn video surveillance and get certified. IPVM provides live online classes, recorded videos, personal help, cutting edge education and...
FLIR Lorex Wire Free System Tested on Aug 29, 2017
Wire free video surveillance is a major trend amongst consumers. But wire free systems tend to be designed for few cameras, lower resolution and...
Camera Application Selection Guide 2017 on Aug 23, 2017
Entrances, hallways, rooms and parking lots are perhaps the 4 most common areas where surveillance is deployed. But what is the best type of camera...
Dahua 4K IR PTZ Tested on Aug 21, 2017
4K has made its way to IR PTZs. In this report, we examine the Dahua 6AE830VNI, a 4K PTZ with 30x optical zoom, 200m (~650') integrated IR, and...

Most Recent Industry Reports

Reseting IP Cameras - 30 Manufacturer Directory on Sep 22, 2017
Every camera has a reset button (well, almost) but it is not always clear what these buttons do, how long they need to be held, what settings they...
Genetec Launches Cloud Access Control (Synergis SaaS) on Sep 21, 2017
Genetec's cloud everything expansion continues, with their announcement of Synergis SaaS edition, joining their cloud video offering Stratocast,...
Genetec CEO Warns Against Insider Threats on Sep 21, 2017
With Dahua and Hikvision cybersecurity issues becoming indisputable, a new counter has emerged. Just put them behind a firewall, buy cheap...
New IPVM Calculator V3 Released on Sep 20, 2017
The New IPVM Calculator V3 is released. An entirely new architecture delivers the following benefits: Turbo The calculator is now ~50% faster in...
Automatic Door Operators For Access Tutorial on Sep 20, 2017
Opening and closing doors might sound simple, but it takes a high-tech piece of door hardware to pull it off. Integrating automatic door operators...
'Clowns' Allege Ubiquiti 'Completely Fraudulent' on Sep 20, 2017
A short seller has alleged Ubiquiti is 'completely fraudulent'. Ubiquiti's CEO has responded calling them 'clowns'. Here is the short...
Avigilon 'Blue' Cloud Entry Examined on Sep 19, 2017
Avigilon is moving to the cloud. The company announced their Avigilon Blue platform, designed to be a web-managed surveillance system, utilizing...
HID Buys Mercury Security on Sep 19, 2017
One of the biggest access control deals in years. Mercury Security, the most widely used access hardware OEM, and partner to 20+ manufacturers,...
Hikvision Backdoor Exploit on Sep 18, 2017
Full disclosure to the Hikvision backdoor has been released, allowing easy exploit of vulnerable Hikvision IP cameras. As the researcher, Monte...

The world's leading video surveillance information source, IPVM provides the best reporting, testing and training for 10,000+ members globally. Dedicated to independent and objective information, we uniquely refuse any and all advertisements, sponsorship and consulting from manufacturers.

About | FAQ | Contact