Troubleshoot network monitoring jam visual experience 400ms delay

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My eyes can easily determine the 400ms delay error, can you? Many users reflect mobile phone monitoring, PC remote monitoring video will be Kaka, throw away equipment operation failure, in fact, this phenomenon is the network transmission delay caused. And in our visual sense, when we clearly determine that there is a "lag" phenomenon, how long this delay, we have to test today.

Everyone and everyone have different criteria for judging the video lag, rather than a test, rather an instinctive response. Even the analog monitoring system will be delayed, but this delay phenomenon you are difficult to explore with the naked eye, you must pass more accurate stopwatch test; network monitoring delay in the industry household name, especially for home surveillance cameras, manufacturers are difficult to balance performance and price, so network delay will be more serious than the industry products.

Troubleshoot network monitoring jam visual experience 400ms delay

　　Gimbal Rotation video is incoherent

Most home surveillance cameras have multi-angle viewing capabilities, and the gimbal is the best choice for remote control. Due to the gimbal rotation, real-time video changes in motion, so the video will appear in the phenomenon, in the premise of ensuring that the gimbal is not fault, let us look at video image coherence.

In order to ensure the accuracy of the test, I chose to let the gimbal automatically run. From the video 19 seconds onwards, the home monitoring camera gimbal was moved horizontally and vertically, respectively. As you can see from this video, there is still some lag in this home surveillance camera. Its coherence needs to be improved.

Mechanical operation will cause image instability, in order to make this test more representative. The author will monitor the camera to a running fan, see the fan's motion trajectory to determine the delay effect of this surveillance camera.

Target object Fast running video appears in Camden

The author chooses a normal operation of the electric fan, in the state of the open to let the fan swing, so as to ensure that the target is in multiple operation state. It is not difficult to see from this video, when the fan "pendulum head", the naked eye to observe the effect of each direction of rotation will appear a little pause, this stay time is not long, but with our naked eye enough to distinguish out.

It is believed that many users are encountering the same problem before they can react to monitor the camera lag phenomenon. The above all uses the PC side to record, then the mobile end will appear what kind of situation?

Home surveillance cameras mobile surveillance recorders are in cloud storage mode and cannot be copied to local storage. But we can imagine, mobile phone remote monitoring itself is an unstable factor, in addition to distance and network environment differences, it is easy to cause the video has a slight delay.

As a user, should understand this delay, as the enterprise, should be reduced to the minimum delay, as the author, we should tell you, what causes the video transmission delay problem.

Mobile Mobile Monitoring Test

　WiFi transmission is good 3G video effect is poor

Public WiFi network environment is everyone's favorite, neither need to spend their mobile phone package traffic, the Internet faster, more stable, why not? The use of WiFi remote monitoring is the main push of many monitoring vendors, but also the future development of mobile surveillance is an important trend. As the current public WiFi coverage is too small, many people want to use 3G network to achieve mobile monitoring, the results of course, but the effect is really difficult for users to meet. Obviously the network environment is not good, is causes the video to appear the lag and the delay one factor.

The effect of video codec on video transmission

Many people will think that video codec affects video quality and video size, in fact, this is only one of them. More importantly, the video data is compressed and uploaded to the network, which is displayed at the back end of the decompression. Not only the codec determines the bandwidth of the video, but also feel a transmission speed.

High-efficient compression mode allows the video to be transferred smoothly under the narrow bandwidth, and if the general compression method is used, not only the overall picture quality effect, its transmission speed and occupation space will increase, the data may appear "queued" phenomenon. This is also the queuing phenomenon, causing the delay effect we see.

Delay test Results

For the above surveillance camera, this can be seen by the naked eye how long is the delay? The author through more accurate software testing found that its network delay of about 400ms. That is to say, when we can distinguish a video has a more obvious lag phenomenon, that the things we see is already past, and real-time events, we need to wait for 400ms.

For home cameras, theoretically within 1 seconds of delay is understandable, because the user needs are different (for non-professional users), they are concerned about the overall situation in the home, and will not be too entangled in the delay is 400ms or 1 seconds. But the delayed fact will cause people's visual effect "uncomfortable", will let the user think that this is not yet optimized complete equipment, value for money feeling disappeared.

All in all, as the home security market continues to expand, home surveillance cameras are gaining in popularity. In the face of uneven products in the store, consumers may wish to choose a large brand of products, technology development and product design will not appear too big flaws, and will not appear a large delay effect.

Troubleshoot network monitoring jam visual experience 400ms delay