CN105791986B

CN105791986B - The detection method and device of video time delay

Info

Publication number: CN105791986B
Application number: CN201410812122.0A
Authority: CN
Inventors: 黄薇
Original assignee: China Mobile Communications Group Co Ltd
Current assignee: China Mobile Communications Group Co Ltd
Priority date: 2014-12-23
Filing date: 2014-12-23
Publication date: 2019-06-25
Anticipated expiration: 2034-12-23
Also published as: CN105791986A

Abstract

The invention discloses a kind of detection methods of video time delay, comprising: while obtaining the first current real-time time information of local terminal image collecting device and the first image that local terminal video display devices are shown；The first image is the image comprising the second real-time time information corresponding to the local terminal image acquisition device the first image；According to the first real-time time information and the second real-time time information, Delay is determined.The present invention also discloses a kind of detection devices of video time delay.

Description

Video time delay detection method and device

Technical Field

The present invention relates to the field of data services, and in particular, to a method and an apparatus for detecting video delay.

Background

The set-top box has definite requirements for realizing video call, but at present, a plurality of technical problems are not solved, including that the set-top box needs to realize the acquisition of local-end video through an external camera, but the cost of the external special camera is relatively high, and the multiplexing mobile phone camera is used as a remote camera of the set-top box, so that the problem is solved to a certain extent, but a certain time delay is introduced.

The video time delay is an important evaluation index of a video conference or a video call system, and the test of the video time delay comprises an intervention type and a non-intervention type. The non-intrusive testing method mainly comprises the steps of manually recording the absolute time values of the videos reaching the two modules by using a stopwatch, and subtracting the absolute time values to obtain the time difference as time delay. The intrusive test method has certain requirements on a tested system or needs to modify the tested system, adds a timestamp into a video data packet, and adds a data packet analysis module on each module to calculate the relative time delay. The method has higher requirements on a tested system and requires absolute synchronization of time systems of all modules so as to ensure accurate and objective time difference among calculation modules; but is not suitable for a system with an acquisition module, a coding and decoding module and a display module which are relatively independent.

At present, no scheme for acquiring time delay tests among local display modules exists.

Disclosure of Invention

In order to solve the existing technical problem, embodiments of the present invention provide a method and an apparatus for detecting video latency.

The embodiment of the invention provides a method for detecting video time delay, which comprises the following steps:

simultaneously acquiring current first real-time information of a local terminal image acquisition device and a first image displayed by a local terminal video display device; the first image is an image containing second real-time information corresponding to the first image acquired by the local image acquisition device;

and determining time delay information according to the first real-time information and the second real-time information.

In the above solution, the acquiring current first real-time information of the home terminal image acquisition device and the first image displayed by the home terminal video display device at the same time includes:

simultaneously acquiring the first real-time information and the first image displayed by the local image acquisition device to obtain a second image;

and extracting the first real-time information and the first image from the second image.

In the foregoing solution, the determining the delay information according to the first real-time information and the second real-time information includes:

and subtracting the second real-time information from the first real-time information to obtain the time delay information.

In the above scheme, the method further comprises:

continuously and simultaneously acquiring the current real-time information displayed by the local image acquisition device and the image displayed by the local video display device within a set time period to obtain an image group; extracting the displayed current real-time information and the time information in the displayed image from each image in the image group respectively;

determining time delay information of the corresponding moment of each image according to the current real-time information in each image and the time information in the displayed image;

and averaging the obtained time delay information of the time corresponding to each image to obtain the average time delay in the set time period.

The embodiment of the invention also provides a method for detecting the video time delay, which comprises the following steps:

collecting each image displayed by the local video display device within a set time period; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device;

and determining the average time delay in the set time period according to the real-time information in each image.

In the foregoing solution, the determining the average time delay within the set time period according to the real-time information in each image includes:

determining time delay information of each moment in the set time period according to real-time information in adjacent images; averaging the obtained time delay information at each moment to obtain the average time delay in the set time period; or,

determining the total time delay information of each moment in the set time period according to the real-time information in the last image and the real-time information in the first image in each image; and averaging the obtained total time delay information to obtain the average time delay in the set time period.

In the above scheme, the determining, according to the real-time information in the adjacent images, the time delay information at each time in the set time period is as follows:

subtracting the real-time information in the adjacent images to obtain the time delay information of each moment in the set time period; or,

determining total time delay information in the set time period according to the real-time information in the last image and the real-time information in the first image in each image, wherein the total time delay information in the set time period is as follows:

and subtracting the real-time information in the last image from the real-time information in the first image to obtain the total time delay information at each moment in the set time period.

The embodiment of the invention also provides a method for detecting video time delay, which comprises the following steps:

collecting each image displayed by the local video display device in each set time period to obtain each image group; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device;

determining time delay information of a time period corresponding to each image group according to real-time information in each image of each image group;

and determining the average time delay of each time period according to the time delay information of the time period corresponding to each image group.

In the foregoing solution, the determining, according to the real-time information in each image of each image group, the time delay information of the time period corresponding to each image group includes:

determining time delay information of each moment in a time period corresponding to each image group according to real-time information in adjacent images of each image group; averaging the obtained time delay information of each moment to obtain time delay information of a time period corresponding to each image group; or,

determining the total time delay information of each time in each time period according to the real-time information in the last image and the real-time information in the first image of each image group; and averaging the obtained total time delay information to obtain the time delay information of the time period corresponding to each image group.

In the above scheme, the determining, according to the real-time information in the adjacent images of each image group, the time delay information at each time in the time period corresponding to each image group is as follows:

subtracting real-time information in adjacent images of each image group to obtain time delay information of each moment in a time period corresponding to each image group; or,

the total time delay information at each moment in each time period is determined according to the real-time information in the last image and the real-time information in the first image of each image group, and the total time delay information is as follows:

and subtracting the real-time information in the last image of each image group from the real-time information in the first image, and obtaining the total time delay information at each moment in each time period.

In the foregoing solution, the determining the average time delay of each time segment according to the time delay information of the time segment corresponding to each image group includes:

and averaging the time delay information of the time periods corresponding to the image groups to obtain the average time delay of each time period.

The embodiment of the invention also provides a device for detecting video time delay, which comprises: an acquisition unit and a first determination unit; wherein,

the acquisition unit is used for simultaneously acquiring the current first real-time information of the local image acquisition device and a first image displayed by the local video display device; the first image is an image containing second real-time information corresponding to the first image acquired by the local image acquisition device;

the first determining unit is configured to determine delay information according to the first real-time information and the second real-time information.

In the foregoing solution, the obtaining unit is specifically configured to: simultaneously acquiring the first real-time information and the first image displayed by the local image acquisition device to obtain a second image; and extracting the first real-time information and the first image from the second image.

In the foregoing scheme, the first determining unit is specifically configured to subtract the second real-time information from the first real-time information to obtain the time delay information.

In the above scheme, the acquiring unit is further configured to continuously and simultaneously acquire the current real-time information displayed by the home terminal image acquisition device and the image displayed by the home terminal video display device within a set time period to obtain an image group; respectively extracting the displayed current real-time information and the time information in the displayed images from each image in the image group;

the first determining unit is further configured to determine time delay information of a moment corresponding to each image according to current real-time information in each image and time information in the displayed image; and averaging the obtained time delay information of the time corresponding to each image to obtain the average time delay in the set time period.

An embodiment of the present invention further provides a device for detecting video latency, including: a first acquisition unit and a second determination unit; wherein,

the first acquisition unit is used for acquiring each image displayed by the local video display device within a set time period; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device;

and the second determining unit is used for determining the average time delay in the set time period according to the real-time information in each image.

In the foregoing solution, the second determining unit includes: a first determining module and a second determining module; wherein,

the first determining module is used for determining the time delay information of each moment in the set time period according to the real-time information in the adjacent images;

the second determining module is configured to average the obtained delay information at each time to obtain an average delay within the set time period; or,

the first determining module is configured to determine total delay information at each time within the set time period according to the real-time information in the last image and the real-time information in the first image in each image;

the second determining module is configured to average the obtained total delay information to obtain an average delay in the set time period.

In the above scheme, the image effective display area in the home terminal video display device is located within the acquisition range of the home terminal image acquisition device.

The embodiment of the invention also provides a device for detecting video time delay, which comprises: the device comprises a second acquisition unit, a third determination unit and a fourth determination unit; wherein,

the second acquisition unit is used for acquiring each image displayed by the local video display device in each set time period to obtain each image group; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device;

the third determining unit is used for determining the time delay information of the time period corresponding to each image group according to the real-time information in each image of each image group;

and the fourth determining unit is used for determining the average time delay of each time period according to the time delay information of the time period corresponding to each image group.

In the foregoing solution, the third determining unit includes: a third determining module and a fourth determining module; wherein,

the third determining module is used for determining the time delay information of each moment in the time period corresponding to each image group according to the real-time information in the adjacent images of each image group;

the fourth determining module is configured to average the obtained time delay information at each time to obtain time delay information of a time period corresponding to each image group; or,

the third determining module is used for determining the total time delay information of each time in each time period according to the real-time information in the last image and the real-time information in the first image of each image group;

and the fourth determining module is used for averaging the obtained total time delay information to obtain the time delay information of the time period corresponding to each image group.

In the foregoing solution, the fourth determining unit is specifically configured to: and averaging the time delay information of the time periods corresponding to the image groups to obtain the average time delay of each time period.

According to the method and the device for detecting the video time delay, provided by the embodiment of the invention, the current first real-time information of the local terminal image acquisition device and a first image displayed by the local terminal video display device are obtained simultaneously; the first image is an image containing second real-time information corresponding to the first image acquired by the local image acquisition device; and determining time delay information according to the first real-time information and the second real-time information, so that the time delay of the video can be simply, quickly and accurately measured.

Collecting each image displayed by the local video display device within a set time period; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device; and determining the average time delay in the set time period according to the real-time information in each image, so that the time delay of the video can be measured more objectively and accurately.

Drawings

In the drawings, which are not necessarily drawn to scale, like reference numerals may describe similar components in different views. Like reference numerals having different letter suffixes may represent different examples of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed herein.

Fig. 1 is a schematic flow chart of a first method for detecting video latency according to an embodiment of the present invention;

fig. 2 is a flowchart illustrating a second method for detecting video latency according to an embodiment of the present invention;

fig. 3 is a flowchart illustrating a third method for detecting video latency according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a second video latency detection apparatus according to a second embodiment of the present invention;

fig. 5 is a schematic structural diagram of another video delay detection apparatus according to another embodiment of the present invention;

fig. 6 is a schematic structural diagram of a second third apparatus for detecting video latency according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a remote camera system using a mobile phone as a home terminal image acquisition device as a set top box according to a third embodiment of the present invention;

FIG. 8 is a schematic diagram of a three-delay test system according to an embodiment of the present invention;

fig. 9 is a schematic flow chart of a three-way delay detection method according to an embodiment of the present invention;

fig. 10 is a schematic diagram of a multi-layer nested video image displayed on a display screen of a third set-top box according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

The system time delay of the video call is divided into one-way end-to-end time delay and two-way end-to-end time delay; the one-way end-to-end time delay comprises the sum of the time delays of all modules, such as video acquisition time delay, coding time delay, network transmission time delay, decoding display time delay and the like, and the two-way end-to-end time delay comprises the sum of the time delay from the local terminal to the opposite terminal and the time delay from the opposite terminal to the local terminal. Existing delay tests are generally mainly directed to one-way or two-way end-to-end system delay or network transmission delay.

The scheme of the embodiment of the invention mainly aims at the measurement of the one-way time delay from the video acquisition module to the local video display module, for example, a mobile phone camera is used as a remote camera of the set-top box to realize the video call system, the time delay acquired by the mobile phone camera and displayed by the local set-top box in decoding needs to be accurately measured, the absolute value of the time delay is small, but the time delay of the whole system is influenced to a certain extent, and the existing test method cannot simply, objectively and accurately measure the time delay.

Based on this, in various embodiments of the present invention, the current first real-time information of the home terminal image acquisition device and the first image displayed by the home terminal video display device are simultaneously obtained; the first image is an image containing second real-time information corresponding to the first image acquired by the local image acquisition device; the first image is displayed on the local video display device after being subjected to local screen projection application; and determining time delay information according to the first real-time information and the second real-time information.

Example one

The method for detecting video delay in this embodiment may be applied to a video conference or a video call system, as shown in fig. 1, and includes the following steps:

step 101: simultaneously acquiring current first real-time information of a local terminal image acquisition device and a first image displayed by a local terminal video display device; the first image is an image containing second real-time information corresponding to the first image acquired by the local image acquisition device; the first image is an image displayed on the local video display device after being subjected to local screen projection application;

here, in practical application, the local image capturing device may be a terminal having a camera function, such as: cell phones or cameras, etc.; the local screen projection application can be a terminal with video encoding and decoding functions, such as a set-top box and the like. The local image acquisition device is used for acquiring local images. The local terminal image acquisition device encodes the acquired local image and sends the processed image to the local terminal screen projection application, and the local terminal screen projection application decodes the local image acquired by the local terminal image acquisition device and displays the decoded local image on the local terminal video display device.

The method for simultaneously acquiring the current first real-time information of the local terminal image acquisition device and the first image displayed by the local terminal video display device specifically comprises the following steps:

A timer or a stopwatch can be operated on the local image acquisition device to display real-time information; accordingly, the second real-time information may be generated by a timer or stopwatch; the accuracy of the timer or stopwatch may be in the order of milliseconds or more. Here, when the real-time information is generated by a timer, since the counter has a corresponding time for each counting, the time delay information can be obtained by performing the calculation according to the correspondence.

In practical application, in a video conference or a video call system, the local image acquisition device serves as a remote acquisition device for the local screen projection application, and due to processing time delay of the local image acquisition device and the local screen projection application and network time delay existing in transmission between the local image acquisition device and the local screen projection application, a certain difference exists between the first real-time information and the second real-time information. The absolute value of the time delay is small, but has a certain influence on the time delay of the whole system, so objective and accurate measurement is needed.

Step 102: and determining time delay information according to the first real-time information and the second real-time information.

Specifically, the second real-time information is subtracted from the first real-time information to obtain the delay information.

In practical application, in order to further obtain relatively objective time delay data, the method may further include:

The determining, according to the current real-time information in each image and the time information in the displayed image, the time delay information of the time corresponding to each image is specifically:

and subtracting the time information in the displayed image from the current real-time information in each image to obtain the time delay information of the corresponding moment of each image.

The length of the time period may be set as desired.

In practical application, in order to further obtain relatively objective time delay data, the method shown in fig. 1 can be transformed into the method shown in fig. 2, and the method includes:

step 201: collecting each image displayed by the local video display device within a set time period; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device;

step 202: and determining the average time delay in the set time period according to the real-time information in each image.

The determining, by the real-time information in each image, the average time delay within the set time period specifically includes:

Here, the determining, according to the real-time information in the adjacent images, the time delay information at each time in the set time period specifically includes:

and subtracting the real-time information in the adjacent images to obtain the time delay information of each moment in the set time period.

Determining total time delay information in the set time period according to the real-time information in the last image and the real-time information in the first image in each image, specifically:

The length of the time period may be set as desired.

In practical application, in order to obtain more objective average delay data, the method shown in fig. 2 can be transformed into the method shown in fig. 3, where the method includes:

step 301: collecting each image displayed by the local video display device in each set time period to obtain each image group; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device;

and during the actual application, the length of each time period is set according to the requirement.

Step 302: determining time delay information of a time period corresponding to each image group according to real-time information in each image of each image group;

specifically, time delay information of each moment in a time period corresponding to each image group is determined according to real-time information in adjacent images of each image group; averaging the obtained time delay information of each moment to obtain time delay information of a time period corresponding to each image group; or,

Here, the determining, according to the real-time information in the adjacent images of each image group, the time delay information at each time in the corresponding time period of each image group specifically includes:

and subtracting the real-time information in the adjacent images of each image group to obtain the time delay information of each moment in the corresponding time period of each image group.

The method for determining the total time delay information of each time in each time period according to the real-time information in the last image and the real-time information in the first image of each image group specifically comprises the following steps:

Step 303: and determining the average time delay of each time period according to the time delay information of the time period corresponding to each image group.

Specifically, the time delay information of the time period corresponding to each image group is averaged to obtain the average time delay of each time period.

It should be noted that: the method shown in fig. 2 and 3 is a testing method based on the principle of video multiple mirroring; and the effective image display area in the local video display device is positioned in the acquisition range of the local image acquisition device.

In other words, during testing, the effective image display area in the local video display device is placed in the acquisition range of the local image acquisition device.

Here, at present, in order to obtain relatively objective experimental data, a test can be generally performed by a method of averaging experiments through a plurality of measurements. The method needs to repeat measurement from the beginning for many times, then records and calculates time delay successively, and calculates the average value of each time delay; therefore, the test process is complicated, and errors caused by the change factors of the test environment are easily introduced into multiple times of measurement. The scheme provided by the embodiment can obtain objective and accurate experimental data.

The method for detecting video time delay provided by this embodiment obtains current first real-time information of a home terminal image acquisition device and a first image displayed by a home terminal video display device at the same time; the first image is an image containing second real-time information corresponding to the first image acquired by the local image acquisition device; and determining time delay information according to the first real-time information and the second real-time information, so that the time delay of the video can be simply, quickly and accurately measured.

In addition, current real-time information displayed by the local image acquisition device and images displayed by the local video display device are continuously and simultaneously acquired within a set time period to obtain image groups; extracting the displayed current real-time information and the time information in the displayed image from each image in the image group respectively; determining time delay information of the corresponding moment of each image according to the current real-time information in each image and the time information in the displayed image; and averaging the obtained time delay information of the time corresponding to each image to obtain the average time delay in the set time period, so that the time delay of the video can be measured more objectively and accurately.

In addition, each image displayed by the local video display device is collected in each set time period to obtain each image group; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device; determining time delay information of a time period corresponding to each image group according to real-time information in each image of each image group; and determining the average time delay of each time period according to the time delay information of the time period corresponding to each image group, so that more objective video time delay can be obtained.

Example two

To implement the method of the first embodiment, the apparatus for detecting video latency provided in this embodiment may be applied to a video conference or a video call system, as shown in fig. 4, and includes: an acquisition unit 41 and a first determination unit 42; wherein,

the acquiring unit 41 is configured to acquire current first real-time information of the home terminal image acquisition device and a first image displayed by the home terminal video display device at the same time; the first image is an image containing second real-time information corresponding to the first image acquired by the local image acquisition device; the first image is an image displayed on the local video display device after being subjected to local screen projection application;

the first determining unit 42 is configured to determine delay information according to the first real-time information and the second real-time information.

Wherein, during practical application, the local image acquisition device can be a terminal with a camera shooting function, such as: cell phones or cameras, etc.; the local screen projection application can be a terminal with video encoding and decoding functions, such as a set-top box and the like. The local image acquisition device is used for acquiring local images. The local terminal image acquisition device encodes the acquired local image and sends the processed image to the local terminal screen projection application, and the local terminal screen projection application decodes the local image acquired by the local terminal image acquisition device and displays the decoded local image on the local terminal video display device.

The obtaining unit 41 is specifically configured to: simultaneously acquiring the first real-time information and the first image displayed by the local image acquisition device to obtain a second image; and extracting the first real-time information and the first image from the second image.

The first determining unit 42 is specifically configured to subtract the second real-time information from the first real-time information to obtain the delay information.

In practical application, in order to further obtain relatively objective time delay data, the obtaining unit 41 is further configured to continuously and simultaneously collect current real-time information displayed by the home terminal image collecting device and an image displayed by the home terminal video display device within a set time period, so as to obtain an image group; respectively extracting the displayed current real-time information and the time information in the displayed images from each image in the image group;

the first determining unit 42 is further configured to determine, according to the current real-time information in each image and the time information in the displayed image, time delay information of a time corresponding to each image; and averaging the obtained time delay information of the time corresponding to each image to obtain the average time delay in the set time period.

The length of the time period may be set as desired.

In practical application, the obtaining Unit 41 may be implemented by a Central Processing Unit (CPU), a Micro Control Unit (MCU), a Digital Signal Processor (DSP), or a Programmable logic array (FPGA) in the video delay detection apparatus, in combination with an image acquisition device; the first determining unit 42 may be implemented by a CPU, an MCU, a DSP, or an FPGA in the video delay detection apparatus.

In practical application, in order to further obtain relatively objective time delay data, so as to implement the method shown in fig. 2, the apparatus shown in fig. 4 may be modified into an apparatus shown in fig. 5, where the apparatus includes: a first acquisition unit 51 and a second determination unit 52; wherein,

the first acquisition unit 51 is configured to acquire each image displayed by the home terminal video display device within a set time period; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device;

the second determining unit 52 is configured to determine the average time delay within the set time period according to the real-time information in each image.

The second determining unit 52 may include a first determining module and a second determining module; wherein,

Here, the first determining module is specifically configured to subtract real-time information in adjacent images to obtain time delay information of each time within the set time period.

The length of the time period may be set as desired.

In practical application, the first collecting unit 51 may be implemented by an image collecting device in a video delay detection apparatus; the second determining unit 52, the first determining module and the second determining module may be implemented by a CPU, an MCU, a DSP or an FPGA in the video delay detecting apparatus.

In practical applications, in order to obtain more objective average delay data and thereby implement the method shown in fig. 3, the apparatus shown in fig. 5 may be modified into the apparatus shown in fig. 6, and the apparatus includes: a second acquisition unit 61, a third determination unit 62, and a fourth determination unit 63; wherein,

the second acquisition unit 61 is configured to acquire each image displayed by the home terminal video display device in each set time period to obtain each image group; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device;

the third determining unit 62 is configured to determine, according to the real-time information in each image of each image group, time delay information of a time period corresponding to each image group;

the fourth determining unit 63 is configured to determine an average time delay of each time period according to the time delay information of the time period corresponding to each image group.

The third determination unit 62 may further include: a third determining module and a fourth determining module; wherein,

The third determining module is specifically configured to subtract real-time information in adjacent images of each image group to obtain time delay information of each time in a time period corresponding to each image group; or,

the third determining module is specifically configured to subtract the real-time information in the last image of each image group from the real-time information in the first image, and obtain total delay information at each time in each time period.

The fourth determining unit 63 is specifically configured to average the time delay information of the time period corresponding to each image group to obtain an average time delay of each time period.

In practical application, the second capturing unit 61 may be implemented by an image capturing device in a video delay detection apparatus; the third determining unit 62, the fourth determining unit 63, the third determining module and the fourth determining module may be implemented by a CPU, an MCU, a DSP or an FPGA in the video delay detection apparatus.

It should be noted that: the implementation scheme of the apparatus shown in fig. 4 and 5 is a testing method based on the principle of multiple video images; and the effective image display area in the local video display device is positioned in the acquisition range of the local image acquisition device.

Here, at present, in order to obtain relatively objective experimental data, a test can be generally performed by a method of averaging experiments through a plurality of measurements. The method needs to repeat measurement from the beginning for many times, then records and calculates time delay successively, and calculates the average value of each time delay; therefore, the test process is complicated, and errors caused by the change factors of the test environment are easily introduced into the process of measuring for many times; the scheme provided by the embodiment can obtain objective and accurate experimental data.

In the detection apparatus for video time delay provided by this embodiment, the obtaining unit obtains the current first real-time information of the home terminal image acquisition device and the first image displayed by the home terminal video display device at the same time; the first image is an image containing second real-time information corresponding to the first image acquired by the local image acquisition device; the first determining unit determines the time delay information according to the first real-time information and the second real-time information, so that the time delay of the video can be simply, quickly and accurately measured.

In addition, the acquisition unit continuously and simultaneously acquires the current real-time information displayed by the local image acquisition device and the image displayed by the local video display device within a set time period to obtain an image group; extracting the displayed current real-time information and the time information in the displayed image from each image in the image group respectively; the first determining unit determines time delay information of the corresponding moment of each image according to the current real-time information in each image and the time information in the displayed image; and averaging the obtained time delay information of the time corresponding to each image to obtain the average time delay in the set time period, so that the time delay of the video can be measured more objectively and accurately.

The first acquisition unit acquires each image displayed by the local video display device within a set time period; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device; the second determining unit determines the average time delay in the set time period according to the real-time information in each image, so that the time delay of the video can be measured more objectively and accurately.

In addition, the second acquisition unit acquires each image displayed by the local video display device in each set time period to obtain each image group; each image displayed by the local video display device is an image containing an image displayed by the local display device at the last moment and corresponding real-time information displayed by the local image acquisition device; the third determining unit determines time delay information of a time period corresponding to each image group according to real-time information in each image of each image group; the fourth determining unit determines the average time delay of each time period according to the time information of the time period corresponding to each image group, so that more objective video time delay can be obtained.

EXAMPLE III

In this embodiment, on the basis of the first embodiment, a detection process of a one-way time delay between a home terminal video capture module (home terminal image capture device) and a home terminal video display module (home terminal video display device) in a video call system is described in detail.

In this embodiment, the home terminal image acquisition device may be a mobile phone or a common camera with a camera function; the object collected by the local image collecting device comprises a mobile phone or a stopwatch with a timing function, and the timing precision is more than millisecond; the local screen projection application can be an application on a mobile phone and a set top box.

Fig. 7 is a schematic structural diagram of a remote camera system in which a mobile phone is used as a home-end image capturing device, that is, a mobile phone a is used as a set-top box in this embodiment. FIG. 8 is a diagram illustrating a test system according to the present embodiment.

With reference to fig. 7 and 8, the detection process of the one-way delay in this embodiment, as shown in fig. 9, includes the following steps:

step 900: starting a remote peripheral system, aligning a camera of a mobile phone A to a screen of another mobile phone B, and then executing a step 901;

step 901: the mobile phone B starts a stopwatch timing application, and then executes a step 902;

here, the stopwatch value changes to the precision of milliseconds, i.e., the precision of the time displayed by the handset B is in the order of milliseconds.

Step 902: the camera of the mobile phone A encodes the collected image containing the real-time information displayed by the screen of the mobile phone B and then sends the encoded image to the local set-top box;

step 903: after receiving the image, the local set-top box performs decoding processing and displays the image on a display screen connected with the local set-top box;

here, the video received by the local set-top box side will display the stopwatch value on the screen of the mobile B after a certain time delay, in other words, the image displayed on the display screen connected to the local set-top box contains the stopwatch value on the screen of the mobile B.

Step 904: extracting a stopwatch value on a screen of the mobile phone B in an image displayed by the local set top box, and calculating a difference value between the stopwatch value and the stopwatch value on the mobile phone A during display to obtain single-measurement time delay information;

here, since the time difference is in the millisecond level, it is difficult for a human to simultaneously and accurately read and record two values at the same time, so that the mobile phone C can be used to start the camera application of the mobile phone C, and simultaneously align the mobile phone a (or the screen of the mobile phone B) and the display screen of the set-top box to take a picture.

The picture is shot, so that the acquired stopwatch value on the mobile phone A and the image display time of the local set top box are the same time; at the moment, the photo shot by the mobile phone C is opened, two time values displayed by the mobile phone and the set top box on the photo are read and subtracted, and the accurate and objective time delay value at the moment is obtained.

After the steps are executed, only single time delay information is obtained. In practical application, as shown in fig. 8, the camera of the mobile phone a can be directed to the display screens of the mobile phone B and the local set-top box (with or without interrupting the last test), that is: the effective image display area in the local video display device is placed in the acquisition range of the local image acquisition device, after a period of time, due to the principle of multiple mirror images of videos, as shown in fig. 10, a plurality of layers of nested video images are displayed on the display screen of the set-top box, that is: each layer of video image comprises an image displayed on a display screen at the previous moment and corresponding stopwatch numerical values, each layer of image comprises different stopwatch numerical values, and the difference between the two stopwatch numerical values in the adjacent images is the time delay corresponding to different moments in the past time period so as to test average time delay information.

Because the stopwatch values in the multilayer nested images are difficult to read at the same time manually, different stopwatch values in the multilayer nested images can be acquired at one time by a method of aligning the mobile phone C to the display screens of the mobile phone A (or the screen of the mobile phone B) and the set top box and shooting photos.

Then, reading a plurality of numerical values on the photo, subtracting two stopwatch numerical values in adjacent images in each layer of nested images to obtain time delay numerical values at a plurality of moments at one time, and calculating an average value of the obtained time delay numerical values at the plurality of moments to quickly obtain the average time delay of the time period; or, with time as an axis, subtracting the stopwatch value in the first image from the stopwatch value in the last image to obtain the total time delay value of the time period at multiple moments, and calculating the average value of the obtained total time delay values to quickly obtain the average time delay of the time period.

In practical application, as shown in fig. 8, on the basis of one-time averaging, multiple sets of multilayer nested images can be obtained in different time periods by using a method of taking a picture by using a mobile phone C, each set corresponds to one time period, and the average time delay of the corresponding time period is obtained by using the images of each set according to the above scheme; and then, the average time delay of each time period is calculated again to obtain more objective average time delay.

As can be seen from the above description, the detection scheme provided by the present embodiment is a method and system for testing one-way delay with the aid of the mobile phone B (stopwatch) and the mobile phone C (camera). Of course, the stopwatch may also be a counter, and the time delay can be obtained by the relationship between each count and the corresponding time.

The data reading method comprises the following steps: the mobile phone C is used for taking a picture/shooting a video at a specific angle and simultaneously reading two data (stopwatch values), so that the objectivity of the test values is ensured.

The method for obtaining a plurality of data samples in one test comprises the following steps: the camera of the tested mobile phone A is placed at a special shooting angle, and the effect of obtaining a plurality of test data by one-time testing is achieved by utilizing the principle of multiple video mirror images; therefore, the time delay difference values of a plurality of moments are obtained in a short time, and the average time delay can be calculated according to the time delay difference values. Here, it should be noted that: the position of the mobile phone B cannot shield the display screen of the set top box, so that the mobile phone C can completely acquire the video image on the display screen.

The average time delay calculation method comprises the following steps: the primary average of the data of the same group of images obtained at the same time can be obtained through calculation, multiple groups of data (each group of data has data at multiple times) can be obtained through video shooting, and accordingly the secondary high-order average value of different groups of data can be calculated, and more objective average time delay can be obtained.

Accordingly, the scheme provided by the embodiment can solve the following problems:

the problem of subjective errors introduced by the timing of an artificial stopwatch;

the intrusive test method has the problems that the system is required to be modified, the clocks of the mobile phone and the set top box are required to be absolutely synchronous, the video data packet is required to be analyzed, and the test method is complex;

the method comprises the following steps that mobile phone video is collected, coded and transmitted, a set top box end receives, decodes and displays, and the set top box cannot transmit video back to the mobile phone end, so that the problem of one-way time delay cannot be measured by a method for testing two-way time delay/2;

the method for taking the average value through multiple tests, records and calculations is relatively complicated, and the problem of errors caused by the change of the test environment is easily introduced.

The scheme provided by the embodiment can bring the following technical effects:

firstly, the scheme provided by the embodiment is simple, fast and easy to implement, and is specifically represented by:

a) the method can be realized by only needing another two mobile phones (or a stopwatch and a camera) without special testing equipment;

b) the test system is independent of the tested system, and the tested system does not need to be modified or intervened;

c) by using a multiple-time mirror image principle, enough test data samples are obtained in a short time, and more accurate and objective average time delay is calculated.

Secondly, the measurement result is accurate and objective, which is shown in the following concrete points:

a) by means of an accurate clock second table and an accurate reading method, a plurality of data can be accurately read at one time, and subjective test errors and environment change errors caused by multiple measurements do not exist.

b) And on the basis of multiple groups of data, a high-order average value is calculated, and the average time delay obtained by calculation is more accurate and objective.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims

1. A method for detecting video latency, the method comprising:

simultaneously acquiring current first real-time information of a local terminal image acquisition device and a first image displayed by a local terminal video display device;

determining time delay information according to the first real-time information and the second real-time information; the time delay information represents the time delay of image transmission between the local terminal image acquisition device and the local terminal video display device;

the method for simultaneously acquiring the current first real-time information of the local terminal image acquisition device and the first image displayed by the local terminal video display device comprises the following steps:

acquiring an image of first real-time information from a first video display device by using a local image acquisition device;

displaying a first image through a local video display device; the first image is an image of second real-time information which is acquired by the local terminal image acquisition device from the first video display device and transmitted to the local terminal video display device for display;

a second image including an image of the first real-time information and an image of the second real-time information is acquired using the first image acquisition device.

2. The method of claim 1, wherein the determining delay information according to the first real-time information and the second real-time information comprises:

3. The method of claim 1, further comprising:

4. A method for detecting video latency, the method comprising:

collecting each image displayed by the local video display device within a set time period; each image displayed by the local video display device is an image containing an image displayed by the local video display device at the last moment and real-time information displayed by the corresponding local image acquisition device;

determining the average time delay in the set time period according to the real-time information in each image;

the method is characterized in that each image displayed by the local video display device is collected in the set time period, and the method comprises the following steps:

placing a first video display device and an image effective display area in the local video display device in an acquisition range of the local image acquisition device;

acquiring each image containing real-time information from a first video display device within a set time period by using a local-end image acquisition device, and transmitting the image to the local-end video display device;

displaying the images on the local video display device by a video mirror principle;

and acquiring each image displayed by the first video display device and the local video display device by using the first image acquisition device.

5. The method of claim 4, wherein determining the average time delay within the set time period according to the real-time information in each image comprises:

6. The method according to claim 5, wherein the determining the time delay information of each time in the set time period according to the real-time information in the adjacent images is:

7. A method for detecting video latency, the method comprising:

collecting each image displayed by the local video display device in each set time period to obtain each image group; each image displayed by the local video display device is an image containing an image displayed by the local video display device at the last moment and real-time information displayed by the corresponding local image acquisition device;

determining the average time delay of each time period according to the time delay information of the time period corresponding to each image group;

the method for acquiring each image displayed by the local video display device in the set time period comprises the following steps:

8. The method according to claim 7, wherein the determining the time delay information of the time period corresponding to each image group according to the real-time information in each image of each image group comprises:

9. The method according to claim 8, wherein the determining the time delay information of each time within the corresponding time period of each image group according to the real-time information in the adjacent images of each image group comprises:

10. The method of claim 7, wherein determining the average delay of each time segment according to the delay information of the time segment corresponding to each image group comprises:

11. An apparatus for detecting video latency, the apparatus comprising: an acquisition unit and a first determination unit; wherein,

the first determining unit is configured to determine delay information according to the first real-time information and the second real-time information; the time delay information represents the time delay of image transmission between the local terminal image acquisition device and the local terminal video display device;

the method for simultaneously acquiring the current first real-time information of the local image acquisition device and the first image displayed by the local video display device comprises the following steps: acquiring an image of first real-time information from a first video display device by using a local image acquisition device; displaying a first image through a local video display device; the first image is an image of second real-time information which is acquired by the local terminal image acquisition device from the first video display device and transmitted to the local terminal video display device for display; a second image including an image of the first real-time information and an image of the second real-time information is acquired using the first image acquisition device.

12. The apparatus of claim 11, wherein the first determining unit is specifically configured to subtract the second real-time information from the first real-time information to obtain the delay information.

13. The device according to claim 11, wherein the acquiring unit is further configured to acquire the current real-time information displayed by the local image acquisition device and the image displayed by the local video display device continuously and simultaneously within a set time period to obtain an image group; respectively extracting the displayed current real-time information and the time information in the displayed images from each image in the image group;

14. An apparatus for detecting video latency, the apparatus comprising: a first acquisition unit and a second determination unit; wherein,

the first acquisition unit is used for acquiring each image displayed by the local video display device within a set time period; each image displayed by the local video display device is an image containing an image displayed by the local video display device at the last moment and real-time information displayed by the corresponding local image acquisition device;

the second determining unit is configured to determine an average time delay within the set time period according to real-time information in each image;

15. The apparatus according to claim 14, wherein the second determining unit comprises: a first determining module and a second determining module; wherein,

16. The apparatus according to claim 14, wherein the image effective display area of the local video display apparatus is located within the capture range of the local image capture apparatus.

17. An apparatus for detecting video latency, the apparatus comprising: the device comprises a second acquisition unit, a third determination unit and a fourth determination unit; wherein,

the second acquisition unit is used for acquiring each image displayed by the local video display device in each set time period to obtain each image group; each image displayed by the local video display device is an image containing an image displayed by the local video display device at the last moment and real-time information displayed by the corresponding local image acquisition device;

the fourth determining unit is configured to determine an average time delay of each time period according to the time delay information of the time period corresponding to each image group;

the method is characterized in that each image displayed by the local video display device is collected in the set time period, and the method comprises the following steps: placing a first video display device and an image effective display area in the local video display device in an acquisition range of the local image acquisition device; acquiring each image containing real-time information from a first video display device within a set time period by using a local-end image acquisition device, and transmitting the image to the local-end video display device; displaying the images on the local video display device by a video mirror principle; and acquiring each image displayed by the first video display device and the local video display device by using the first image acquisition device.

18. The apparatus of claim 17, wherein the third determining unit comprises: a third determining module and a fourth determining module; wherein,

19. The apparatus according to claim 17, wherein the fourth determining unit is specifically configured to: and averaging the time delay information of the time periods corresponding to the image groups to obtain the average time delay of each time period.

20. The apparatus according to claim 17, wherein the image effective display area of the local video display apparatus is located within the capture range of the local image capture apparatus.