CN102325059B - Audio frequency end-to-end time delay measurement method of non-intrusive single end acquisition and apparatus thereof - Google Patents
Audio frequency end-to-end time delay measurement method of non-intrusive single end acquisition and apparatus thereof Download PDFInfo
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- CN102325059B CN102325059B CN2011102681507A CN201110268150A CN102325059B CN 102325059 B CN102325059 B CN 102325059B CN 2011102681507 A CN2011102681507 A CN 2011102681507A CN 201110268150 A CN201110268150 A CN 201110268150A CN 102325059 B CN102325059 B CN 102325059B
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Abstract
The invention provides an audio frequency end-to-end time delay measurement method of non-intrusive single end acquisition and an apparatus thereof. The audio frequency end-to-end time delay measurement method comprises the following steps: placing a measurement signal generator locally, closing an echo elimination function of a far-end terminal, taking a microphone close to a loudspeaker at a far end to form an audio frequency loop. One audio frequency measuring signal emitted by the signal generator directly enters into a measurement apparatus, and the other audio frequency measuring signal enters into a local terminal of a detected system, and both of them returns through a remote terminal audio frequency loop respectively. Delay inequalities of the two signals are divided by 2, and a result is taken as a measured value of audio frequency end-to-end time delay. The measurement apparatus provided in the invention comprises an audio frequency measuring signal generator, an audio frequency multipath acquisition module, an audio frequency time delay measurement unit and a data storage and display unit. The method is a non-intrusive type. Compared with the prior art, the method is not influenced by internal realization of the detected system, time delay of all link are included comprehensively, and the method has the characteristics of accuracy and convenience.
Description
Technical field
The present invention relates to computer media Information Communication, QoS qos measurement, particularly relate to audio frequency end-to-end time delay method of measurement and the device of the single-ended collection of non-intervention type.
Background technology
Along with based on network multimedia service application is fast-developing and universal, the systems such as network audio-video program request, network audio-video meeting are popular rapidly.The user has proposed more and more higher requirement to the QoS service quality of network multimedia business.How can be fast, convenient, accurately the key qos parameter of candidate products is made assessment, be the key of successfully selecting best product.
Simultaneously, research and development and produce the network multimedia business and the manufacturer of system, also need a kind of device to measure the key parameter of the own network multimedia product of producing quickly and easily, in order to measure key parameter in product development process, and improvement at any time.
End-to-end time delay is one of critical performance parameters of multimedia service, and it directly affects the assessment of QoS and user's experience.End-to-end time delay generally includes and gathers time delay, coding time delay, network transfer delay, decoding time delay, Playout delay etc.
The method of existing detection end-to-end time delay roughly can be divided into two large classes: a class belongs to insertion type, namely by an end of the signal transmission path at system under test (SUT), inject the measuring-signal of feature, perhaps additional measurement data on the original signal data of system under test (SUT), then extract measurement data and record the time that receives at the other end, relatively the difference of two times is obtained the time delay size.
The main feature of this class insertion type method is need to get involved in the signal transmission path of system under test (SUT), adds wherein data or therefrom extracts measurement data, has being connected of physical circuit between measurement mechanism and equipment under test.
The Major Difficulties of this class invasive measurement method is:
At first, the Frame or the packet that usually depend on system under test (SUT) due to measurement data are transmitted, and middle inevitable through links such as compression coding, encapsulation, decapsulation, decodings, measurement data may lose or damage in compression coding and decompression procedure;
Secondly, because data format, encapsulation format, compression coding and the decoding algorithm of system under test (SUT) may not disclose, the tester will design the metering system and the measuring-signal that match can be more difficult.
The 3rd, the invasive measurement method usually requires serial connection tap or tandem head on the signal data path of system under test (SUT), and is for the system under test (SUT) that has installed, usually cumbersome or be not allowed to.
In addition, the tool software that some invasive measurement methods need to operating measurement be used on the terminal of system under test (SUT), carry out timing by tool software.This mode may affect the normal operation of system under test (SUT) terminal itself, can only use in exploitation and debug phase at most, and be difficult to be used on the system of commercialization.
Another kind of method of testing is non-intervention type, does not have physical contact between system under test (SUT) and measurement mechanism, and system under test (SUT) is considered as flight data recorder, and test signal is mainly to enter system under test (SUT) by the sound and optic signal mode, and with sound, light mode, exports.Measurement mechanism by contrast and analysis input, output signal obtains the time delay size.The advantage of these class methods is the actual motions that stay out of system under test (SUT), and is irrelevant with the system under test (SUT) specific implementation, so have applicability the most widely.Such as subjective sensation and the sense of hearing by human eye, people's ear, assessing end-to-end time delay is exactly these class methods.
Although utilize human eye, people's ear to come subjective evaluation and test very directly perceived, exists in the relatively more approaching situation of the end-to-end time delay parameter of very large error, especially two kinds of systems under test (SUT), be difficult to make science and judge accurately, cause measurement result to lack persuasion.
Summary of the invention
The object of the invention is to overcome the shortcoming and defect of above-mentioned prior art, audio frequency end-to-end time delay method of measurement and the device of the single-ended collection of non-intervention type is provided.
The present invention adopts non-intervention strategy, and system under test (SUT) is used as flight data recorder, for system under test (SUT) end to end the audio frequency time delay designed the measuring technology scheme.
The technical scheme that audio frequency end-to-end time delay of the present invention is measured, comprise the steps:
(1) with the far-end echo elimination/inhibit feature temporary close of system under test (SUT), the far-end microphone, near far-end loudspeaker, is formed the transmission loop of audio signal between local side and far-end;
(2) utilize measuring signal generator to produce the audio-frequency test signal of characteristic frequency, AD HOC at local side, this test signal is gathered by the microphone of measurement mechanism and system under test (SUT) simultaneously;
(3), from the audio-frequency test signal of measuring signal generator, after the microphone collection by measurement mechanism, directly submit to signal processing module and detect, and record the T time of advent of this audio-frequency test signal
A1
(4) the audio-frequency test signal that is gathered by the microphone of system under test (SUT),, through links such as compression coding, Internet Transmission, decodings, play back in the far-end loudspeaker of system under test (SUT);
(5) the audio-frequency test signal of system under test (SUT) far-end loudspeaker broadcast, after the far-end microphone collection by system under test (SUT), the links such as encoded compression, Internet Transmission, decoding, again sent back to local side, and at the local side loud speaker, played back;
(6) the audio-frequency test signal play of local side loud speaker, again gathered by the microphone of measurement mechanism, and submit to signal processing module and detect, and record the T time of advent of this audio-frequency test signal
A2
(7) signal processing module of measurement mechanism, according to test record, calculates the time delay (T between the twice audio-frequency test signal that comes respectively automatic signal generator and the local loud speaker of system under test (SUT)
A2-T
A1), this time delay has represented the audio loop time delay between local side and far-end, namely comprises forward-propagating time delay and backpropagation time delay.The signal processing module of measurement mechanism this loop time delay divided by 2 test results as the audio frequency end-to-end time delay, i.e. Δ T
A=(T
A2-T
A1)/2.
The audio frequency end-to-end time delay measurement mechanism of the single-ended collection of non-intervention type of the present invention number comprises following assembly:
Assembly 1, audio-frequency test signal generator 100, be responsible for producing the audio-frequency test signal.This signal can be analyzed and be identified by audio frequency latency measurement unit.
Assembly 2, voice-frequency-multichannel acquisition module 200, be responsible for the multichannel voice frequency test signal that input separates or mixes, and the audio signal that will collect input audio frequency time-delay measuring unit.
Assembly 3, audio frequency time-delay measuring unit 300, be responsible for the audio signal of input is analyzed, identifies, compared and measures, and determines the audio frequency end-to-end time delay.
Assembly 4, data storage and display unit 400, be used for the audio frequency end-to-end time delay that storage shows that described audio frequency time-delay measuring unit 300 is determined.
Audio frequency end-to-end time delay method of measurement and the device of the single-ended collection of non-intervention type of the present invention have the following advantages:
(1) the inventive method is non-intervention type, and system under test (SUT) is considered as flight data recorder.Therefore, method of testing of the present invention is not subjected to the impact of the factor such as internal structure, network type, data format, code decode algorithm, function implementation of system under test (SUT).
(2) the audio frequency end-to-end time delay measured of the inventive method, comprised from audio collection until audio frequency is play the time delay summation in interior all links, and the audio frequency time delay that while with the user, doing subjective evaluation and test, institute experiences and assesses is in full accord on type and content.
(3) propagation path of the test signal of the inventive method in system under test (SUT) forms a loop, both comprised the propagation path from this locality to the far-end, also comprised the propagation path from the far-end to this locality.Even there is the whereabouts path in transmission network and returns asymmetric to the performance in path, also can postpone by counter circuit, then obtain a comprehensive mean value divided by 2, eliminate the impact that the performance asymmetry of this network path causes, the result after average can reflect the actual performance of system under test (SUT) audio frequency end-to-end time delay more accurately.
(4) the inventive method at the appointed time makes measuring signal generator produce constantly test signal in section, utilize measurement mechanism to carry out continuance test, obtain a series of delay data, and therefrom analyze the statistical natures such as maximum delay, minimal time delay and average delay, can more fully reflect the performance change under the heterogeneous networks load condition of end-to-end time delay.
Description of drawings
Fig. 1 is the audio frequency end-to-end time delay test philosophy schematic diagram of the present invention's one example;
Fig. 2 is the measurement mechanism internal structure schematic diagram of the present invention's one example.
Embodiment
, below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention are not limited to this.
Embodiment 1, and Fig. 1 has provided the principle schematic of audio frequency end-to-end time delay test.
As Fig. 1, audio frequency end-to-end time delay method of measurement of the present invention comprises:
Step 1, the audio-frequency test signal generator sends the audio-frequency test signal, the microphone of the microphone of this signal while input measurement device and the local terminal of system under test (SUT).
(1) the audio-frequency test signal generator in this step 1 need to be placed in the effective pickup distance of the microphone of measurement mechanism, guarantee audio-frequency test signal that this generator produces effectively measured device receive.
(2) the audio-frequency test signal generator in this step 1 need to be placed in the effective pickup distance of local microphone of system under test (SUT), guarantees that the audio-frequency test signal that this generator produces can enter equipment under test effectively.
(3) the audio-frequency test signal in this step 1 can be the tonepulse of particular frequency range, and the frequency of this tonepulse and pattern must be able to be identified by measured device, and records its initial time and the peak value moment.Such as: but the audio-frequency test signal can be very brief sound in people's ear identification frequency range, that some strength is arranged.
Step 2, enter the signal of local terminal microphone through processing and Internet Transmission, arrives the loud speaker of distance terminal.The signal that enters the local audio collecting device direct measured device reads.
(1) the audio-frequency test signal in this step 2 enters system under test (SUT) from local microphone, and through a series of links, finally the loud speaker at the system under test (SUT) distance terminal broadcasts.Such as, this audio-frequency test signal in system under test (SUT) the link of process include but not limited to: audio collection, compression coding, encapsulation, network transmission, Internet Transmission, network receive, connect encapsulation, decoding, broadcast etc.
(2) while of the audio-frequency test signal in this step 2 is by the microphone collection of measurement mechanism.The local microphone model of the model of the microphone of measurement mechanism and system under test (SUT) is irrelevant.
(3) the audio-frequency test signal that collects of the microphone of the measurement mechanism in this step 2, finally be submitted to signal processing unit analysis, and record its time of advent.
Step 3, system under test (SUT) distance terminal microphone, near far-end loudspeaker, receive the testing audio of far-end loudspeaker, after encoding and decoding, by Internet Transmission, pass local terminal back.
(1) microphone of the system under test (SUT) distance terminal in this step 3 needs to guarantee that near far-end loudspeaker the test audio signal that far-end loudspeaker is sent can effectively He reliably be received by the microphone of distance terminal.
(2) the system under test (SUT) distance terminal in this step 3 needs temporary close echo elimination/inhibit feature, can be received by the far-end microphone smoothly to guarantee the audio-frequency test signal that far-end loudspeaker is sent, and be transmitted back to local side.
(3) test audio signal received of the system under test (SUT) distance terminal microphone in this step 3 enters system under test (SUT) again, along passing local terminal back in the other direction, the link of passage in transit includes but not limited to: audio collection, compression coding, encapsulation, network transmission, Internet Transmission, network receive, connect encapsulation, decoding, broadcast etc.
Step 4, local terminal receive the testing audio that distance terminal is passed back, play-over after decoding, and the local audio signal collecting device of measured device receive, and then measured device reads.
(1) test audio signal in this step 4 is passed local terminal back, plays at the local terminal loud speaker after decoding.
(2) the local loud speaker of the system under test (SUT) in this step 4 need to be positioned in effective pickup distance of measurement mechanism microphone, guarantees the audio-frequency test signal measured device microphone collection effectively reliably that local loud speaker is play.
(3) microphone of the microphone of the measurement mechanism in this step 4 and the measurement mechanism in step 2 is same equipment.
(4) microphone of the measurement mechanism in this step 4 collects after the audio-frequency test signal that postpones, and submits to signal processing unit analysis.
Step 5, measurement mechanism is identified the test audio signal of successively receiving, calculates time difference between the two, and divided by 2, as the audio frequency end-to-end time delay of system under test (SUT).
(1) measurement mechanism in this step 5 is identified the audio-frequency test signal of successively receiving.Audio-frequency test signal through the system under test (SUT) transmission, compare with the audio-frequency test signal that directly from signal generator, receives, may have distortion to a certain degree, measurement mechanism need to correctly identify with the audio-frequency test signal that postpones from the signal that receives, and records its time of advent.
(2) measurement mechanism in this step 5, according to the time of advent of the audio-frequency test signal of successively twice arrival, calculates time difference between the two.This time difference comprises from this locality to the far-end and returns to the time delay of this locality from far-end, is equivalent to the end-to-end time delay of twice, therefore need to, divided by 2, obtain the mean value of end-to-end time delay.
In above-mentioned steps 1～step 5, measuring signal generator can be as required, periodically generate the audio-frequency test signal, testing apparatus is repeating step 1～step 5 periodically, obtain a series of time delay records, therefrom carry out statistical analysis, obtain the series of parameters such as maximum delay, minimal time delay, average delay and time delay variance, and data set is submitted to respectively memory device and demonstration is preserved and printed to display device.
Embodiment 2, and Fig. 2 has provided the organigram of audio frequency end-to-end time delay measurement mechanism
As Fig. 2, audio frequency end-to-end time delay measurement mechanism of the present invention comprises:
Assembly 1, audio-frequency test signal generator 100, be responsible for producing the audio-frequency test signal.This signal can be analyzed and be identified by audio frequency latency measurement unit.
Assembly 2, voice-frequency-multichannel acquisition module 200, be responsible for the multichannel voice frequency test signal that input separates or mixes, and the audio signal that will collect input audio frequency time-delay measuring unit.
Assembly 3, audio frequency time-delay measuring unit 300, be responsible for the audio signal of input is analyzed, identifies, compared and measures, and concrete steps comprise:
(1) step 1, mixed multiplex audio-frequency test signal to the input of voice-frequency-multichannel acquisition module is analyzed, due to the audio-frequency test signal after postponing unavoidably with noise jamming, need to recognize exactly the corresponding time point of starting point, peak value of audio-frequency test signal from mixed signal, and record.
(2) step 2, compare putting the time of advent of the audio-frequency test signal after the delay of recording with the some time of advent of the audio-frequency test signal that directly is received from signal generator, calculates both differences, divided by 2, as the audio frequency end-to-end delay of reality.
(3) step 3,, from the audio frequency end-to-end delay that step 2 obtains, be submitted to respectively data storage and display unit, and audio/video synchronization delayed time measuring unit.
Assembly 4, data storage and display unit 400, be used for the audio frequency end-to-end time delay that storage shows that described audio frequency time-delay measuring unit (300) is determined.
Above-described embodiment is the better execution mode of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not deviate from change, the modification done under Spirit Essence of the present invention and principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, within being included in protection scope of the present invention.
Claims (1)
1. the audio frequency end-to-end time delay method of measurement of the single-ended collection of non-intervention type, is characterized in that, comprises following steps:
(1) with the far-end echo elimination/inhibit feature temporary close of system under test (SUT), the far-end microphone, near far-end loudspeaker, is formed the transmission loop of audio signal between local side and far-end;
(2) utilize measuring signal generator to produce the audio-frequency test signal at local side, this test signal is gathered by the microphone of measurement mechanism and system under test (SUT) simultaneously;
(3), from the audio-frequency test signal of measuring signal generator, after the microphone collection by measurement mechanism, directly submit to signal processing module and detect, and record the time of advent of this audio-frequency test signal;
(4) the audio-frequency test signal that is gathered by the microphone of system under test (SUT), after treatment, play back in the far-end loudspeaker of system under test (SUT);
(5) the audio-frequency test signal of system under test (SUT) far-end loudspeaker broadcast, after the far-end microphone collection by system under test (SUT), again sent after treatment back to local side, and at the local side loud speaker, played back;
(6) the audio-frequency test signal play of local side loud speaker, again gathered by the microphone of measurement mechanism, and submit to signal processing module and detect, and record the time of advent of this audio-frequency test signal;
(7) signal processing module of measurement mechanism is determined audio frequency time delay end to end according to the time of step (3), step (6) record.
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|---|---|---|---|---|
| CN103532821B (en) * | 2012-07-02 | 2018-02-13 | 腾讯科技（深圳）有限公司 | A kind of MSN audio transmission delay contrast test method and apparatus |
| CN103219029A (en) * | 2013-03-25 | 2013-07-24 | 广东欧珀移动通信有限公司 | Method and system for automatically adjusting synchronization of audio and video |
| CN104125022B (en) * | 2013-11-27 | 2016-03-23 | 腾讯科技(成都)有限公司 | The method of measurement of audio transmission time delay and system |
| CN105450882B (en) * | 2015-11-13 | 2018-07-20 | 公安部第三研究所 | A kind of audio conversion characteristic test method |
| WO2018120545A1 (en) * | 2016-12-30 | 2018-07-05 | 华为技术有限公司 | Method and device for testing latency of audio loop |
| CN107331406B (en) * | 2017-07-03 | 2020-06-16 | 福建星网智慧软件有限公司 | Method for dynamically adjusting echo delay |
| CN108566316B (en) * | 2018-04-18 | 2019-10-22 | 百度在线网络技术（北京）有限公司 | Unmanned vehicle delay statistics method, apparatus, equipment and computer-readable medium |
| CN109362099A (en) * | 2018-12-05 | 2019-02-19 | 南昌黑鲨科技有限公司 | Wirelessly communicate delay testing method, device, computer equipment and storage medium |
| CN109587542B (en) * | 2018-12-27 | 2020-11-27 | 北京奇艺世纪科技有限公司 | Audio and video data synchronization device, method, data processing device and medium |
| CN110691301A (en) * | 2019-09-25 | 2020-01-14 | 晶晨半导体（深圳）有限公司 | Method for testing delay time between far-field voice equipment and external loudspeaker |
| CN111526455A (en) * | 2020-05-21 | 2020-08-11 | 菁音电子科技（上海）有限公司 | Correction enhancement method and system for vehicle-mounted sound |
| CN112489686A (en) * | 2020-12-02 | 2021-03-12 | 公安部第三研究所 | End-to-end audio signal delay testing method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050219366A1 (en) * | 2004-03-31 | 2005-10-06 | Hollowbush Richard R | Digital audio-video differential delay and channel analyzer |
| CN1747502A (en) * | 2004-09-09 | 2006-03-15 | 华为技术有限公司 | Tester and test for end to end speech time delay |
-
2011
- 2011-09-09 CN CN2011102681507A patent/CN102325059B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050219366A1 (en) * | 2004-03-31 | 2005-10-06 | Hollowbush Richard R | Digital audio-video differential delay and channel analyzer |
| CN1747502A (en) * | 2004-09-09 | 2006-03-15 | 华为技术有限公司 | Tester and test for end to end speech time delay |
Non-Patent Citations (2)
| Title |
|---|
| METHODS FOR NONE INTRUSIVE DELAY MEASURMENT FOR AUDIO COMMUNICATION OVER PACKET NETWORKS;Mohammad R Zad-Issa et al;《2006 IEEE International Conference on Multimedia and Expo》;20060712;第1页右栏倒数第1段、第2页左栏第1-2段、图1 * |
| Mohammad R Zad-Issa et al.METHODS FOR NONE INTRUSIVE DELAY MEASURMENT FOR AUDIO COMMUNICATION OVER PACKET NETWORKS.《2006 IEEE International Conference on Multimedia and Expo》.2006, |
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