Measurement device, measurement method, and program

Abstract

To provide a measurement device, a method, and a program for measuring a transmission delay difference between contents transmitted through two different lines with a high accuracy at an arbitrary timing.SOLUTION: In a measurement system, a measurement device 8 includes: an input part that inputs a first audio data transmitted through a first transmission path 5A and a second audio data transmitted through a second transmission path 5B; a detection part that detects the maximum audio level in a predetermined section of the first audio data and detects the maximum audio level in a predetermined section of the second audio data; and a measurement part that measures a time difference between a first point in time and a second point in time as a transmission delay difference in the first transmission path and the second transmission path when a difference between the maximum audio levels of the first audio data and the second audio data is within a predetermined range, a difference between the audio levels of the first audio data and the second audio data at a point in time before the maximum audio level is within the predetermined range, and a difference between the audio levels at a point in time after the first point in time and the second point in time is within the predetermined range.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a measurement device, a measurement method, and a program. [Background technology]

[0002] When broadcasting sports programs and other events, a backup line is almost always set up in case of a malfunction. In such cases, content passing through the two lines (main and backup) will arrive at the destination with a time lag due to differences in the transmission route. To eliminate this lag, a person performs a check action in advance, such as clapping their hands, in front of the on-site camera at the broadcast destination, and the receiver at the destination can visually check the lag between the two contents and adjust the delay value (delay difference).

[0003] Patent Document 1 describes a synchronization system for eliminating the difference in delay between video and audio that occurs when video and audio are processed separately. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Application No. 2023-139681 Summary of the Invention [Problem to be solved by the invention]

[0005] When measuring the time difference between the main line and the backup line by having a person on-site clap their hands and then having a person at the destination visually check the time difference between the clapping movements, the time difference is measured by human sense. In this case, it is difficult to measure the time difference between the main line and the backup line precisely, and there is also variation due to human sense.

[0006] Furthermore, conducting the measurement requires the installation of equipment and the task of clapping hands on-site, and because the measurement is triggered by the on-site clapping, the measurement on the receiving side must be carried out according to the convenience of the site.

[0007] The present disclosure has been made in consideration of the above circumstances, and an object of the present disclosure is to provide a technology that can measure the difference in transmission delay between content transmitted over two different lines with high accuracy and at any timing. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, one aspect of the present disclosure is a measurement device comprising: an input unit that inputs first audio data of a content transmitted via a first transmission path and second audio data of the content transmitted via a second transmission path; a detection unit that detects a maximum audio level in a predetermined section input at a certain time from a predetermined timing of the first audio data, and detects a maximum audio level in a predetermined section input at a predetermined time from the predetermined timing of the second audio data; and a measurement unit that, when a difference between the maximum audio level of the first audio data and the maximum audio level of the second audio data is within a predetermined range, a difference between the audio level of the first audio data at a time point before a first time point and the audio level of the second audio data at a time point before a second time point of the maximum audio level is within the predetermined range, and a difference between the audio level at a time point after the first time point and the audio level at a time point after the second time point is within the predetermined range, measures the time difference between the first time point and the second time point as a transmission delay difference of the content on the first transmission path and the second transmission path.

[0009] One aspect of the present disclosure is a measurement method performed by a measurement device, which inputs first audio data of content transmitted via a first transmission path and second audio data of the content transmitted via a second transmission path, detects a maximum audio level in a predetermined section input at a certain time from a predetermined timing of the first audio data, and detects a maximum audio level in a predetermined section input at a certain time from the predetermined timing of the second audio data, and if the difference between the maximum audio level of the first audio data and the maximum audio level of the second audio data is within a predetermined range, the difference between the audio level at a point before the first point in time at which the maximum audio level of the first audio data is and the audio level at a point before the second point in time at which the maximum audio level of the second audio data is within the predetermined range, and the difference between the audio level at a point after the first point in time and the audio level at a point after the second point in time is within the predetermined range, the time difference between the first point in time and the second point in time is measured as the transmission delay difference of the content on the first transmission path and the second transmission path.

[0010] One aspect of the present disclosure is a program that causes a computer to function as the measurement device. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to provide a technology that can measure the difference in transmission delay between content transmitted over two different lines with high accuracy and at any timing. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the overall configuration of the measurement system of this embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of the measurement device of this embodiment. [Figure 3] FIG. 3 is a flowchart showing the processing of the measurement device of this embodiment. [Figure 4] FIG. 4 is a diagram showing an example of an audio waveform of the first audio data and an example of an audio waveform of the second audio data. [Figure 5] FIG. 5 is a diagram illustrating an example of a message output by the measurement device. [Figure 6] FIG. 6 shows an example of the hardware configuration. DETAILED DESCRIPTION OF THE INVENTION

[0013] Embodiments of the present disclosure will be described with reference to the accompanying drawings. In this specification and drawings, the same reference numerals indicate the same or corresponding parts.

[0014] 1 is a diagram showing the overall configuration of the measurement system of this embodiment. In this embodiment, content (video) captured at a relay destination or other location is transmitted to a destination (e.g., a broadcast station) via two transmission paths (a main line and a backup line).

[0015] The illustrated measurement system includes a camera 2, a microphone 3, and two multiplexing / encoding devices 4A and 4B located at the site. The measurement system also includes two demultiplexing / decoding devices 6A and 6B located at the transmission destination, an audio interface 7, and a measurement device 8.

[0016] At the scene, camera 2 captures an event such as a sports match or concert held at stadium 1, and outputs the captured video to multiplexing / encoding devices 4A and 4B. Microphone 3 converts ambient sound into an electrical signal and outputs the converted electrical signal to multiplexing / encoding devices 4A and 4B.

[0017] The multiplexing and encoding device 4A is the main device, and the multiplexing and encoding device 4B is a backup sub-device. The multiplexing and encoding device 4A multiplexes and encodes the video and audio input from the camera 2 and microphone 3 to generate content (transmission data) and transmits it to the demultiplexing and decoding device 6A via the transmission path 5A. The multiplexing and encoding device 4B similarly multiplexes and encodes the video and audio input from the camera 2 and microphone 3 to generate content and transmits it to the demultiplexing and decoding device 6B via the transmission path 5B.

[0018] The transmission path 5A (first transmission path) is a main line, and the transmission path 5B (second transmission path) is a sub-backup line. The transmission path 5A and the transmission path 5B are different transmission paths. For example, the transmission path 5A may be a transmission path using optical fiber, and the transmission path 5B may be a transmission path via a satellite. Furthermore, the transmission path 5A and the transmission path 5B may be the same type of transmission path but different routes.

[0019] The demultiplexing / decoding device 6A is a main device, and the demultiplexing / decoding device 6B is a backup sub-device. The demultiplexing / decoding device 6A decodes the content transmitted via the transmission path 5A, separates it into video and audio, and outputs the separated first audio data to the audio interface 7. Similarly, the demultiplexing / decoding device 6B decodes the content transmitted via the transmission path 5B, separates it into video and audio, and outputs the separated second audio data to the audio interface 7.

[0020] The audio interface 7 inputs the first audio data output from the separation / decoding device 6A and the second audio data output from the separation / decoding device 6B to the measurement device 8 via a USB (Universal Serial Bus). The audio interface 7 is an external general-purpose device for inputting audio data to the measurement device 8. For example, an RCA terminal (RCA cable) or the like can be used as the audio interface 7.

[0021] The measuring device 8 measures and outputs the transmission delay difference (delay value) of the audio transmitted via the two different transmission paths 5A and 5B. The transmission delay difference output by the measuring device 8 is input to an adjustment device (not shown) that adjusts the transmission delay difference of the content transmitted via the two transmission paths 5A and 5B. A general-purpose computer such as a PC can be used as the measuring device 8.

[0022] 2 is a block diagram showing an example of the configuration of the measurement device 8 of this embodiment. The measurement device 8 shown in the figure includes an input unit 81, a detection unit 82, a measurement unit 83, and a storage unit 84.

[0023] The input unit 81 receives the first audio data of the content transmitted via the transmission path 5A and the second audio data of the content transmitted via the transmission path 5B, and stores them in the storage unit .

[0024] The input unit 81 receives, via the audio interface 7, the first audio data output from the demultiplexing / decoding device 6A and the second audio data output from the demultiplexing / decoding device 6B as they are.

[0025] The detection unit 82 detects the maximum audio level in a predetermined section input at a certain time from a predetermined timing of the first audio data, and also detects the maximum audio level in a predetermined section input at a certain time from the predetermined timing of the second audio data.

[0026] The detection unit 82 may detect a maximum audio level for each of a plurality of predetermined sections input at a fixed time from a plurality of timings of the first audio data, and may also detect a maximum audio level for each of a plurality of predetermined sections input at a fixed time from the plurality of timings of the second audio data.

[0027] If the difference between the maximum audio level of the first audio data and the maximum audio level of the second audio data is within a predetermined range, the difference between the audio level of the first audio data at a point in time before the first point in time and the audio level of the second audio data at a point in time before the second point in time is within the predetermined range, and the difference between the audio level at a point in time after the first point in time and the audio level at a point in time after the second point in time is within the predetermined range, the measurement unit 83 measures the time difference between the first point in time and the second point in time as the transmission delay difference of the content on the transmission path 5A and the transmission path 5B.

[0028] The measurement unit 83 may output the transmission delay difference when the transmission delay difference measured in a plurality of predetermined sections is the same a predetermined number of times in succession.

[0029] The measurement unit 83 may measure the time difference between the first point in time and the second point in time as a transmission delay difference when the difference between the maximum audio level of the first audio data and each audio level at a point in time before and after the first point in time of the maximum audio level exceeds a threshold, and when the difference between the maximum audio level of the second audio data and each audio level at a point in time before and after the second point in time of the maximum audio level exceeds a threshold.

[0030] The storage unit 84 stores the first voice data and the second voice data.

[0031] Next, the measurement process of the measurement device 8 of this embodiment will be described with reference to FIGS.

[0032] 3 is a flowchart showing an example of the measurement process of the measurement device 8 of this embodiment. The measurement process shown in the figure is performed as a preparation before the start of transmission of content to be broadcast or distributed. For example, it can be performed at any time after the lines of the two transmission paths 5A and 5B are connected.

[0033] The measuring device 8 receives the first audio data and the second audio data output from the separation / decoding devices 6A and 6B, respectively, via the audio interface 7 (S11). The first audio data is audio data of the content transmitted via the transmission path 5A, and the second audio data is audio data of the content transmitted via the transmission path 5B.

[0034] The measurement device 8 measures the transmission delay difference of the content using the input first audio data and second audio data. For example, the user may input a measurement start instruction to the measurement device 8, causing the measurement device 8 to start the processing from S12 onwards.

[0035] First, the measurement device 8 detects the maximum audio level in a predetermined section input at a fixed time from a predetermined timing of the first audio data, and also detects the maximum audio level in a predetermined section input at a fixed time from the predetermined timing of the second audio data (S12). Specifically, the measurement device 8 extracts section data of a predetermined section from the first audio data that arrived at the separation / decoding device 6A at an arbitrary time (a fixed time width from the predetermined time) and input to the measurement device 8, and detects the maximum audio level of the section data. Similarly, the measurement device 8 extracts section data of a predetermined section from the second audio data that arrived at the separation / decoding device 6B at the arbitrary time and input to the measurement device 8, and detects the maximum audio level of the section data.

[0036] For example, the measurement device 8 may extract a predetermined section of the first voice data and a predetermined section of the second voice data that are input for a certain period of time from the timing when a predetermined time has elapsed since the measurement start instruction was input.

[0037] Then, the measuring device 8 detects the audio levels of the first audio data at points before and after the first point in time when the audio level is maximum, and the audio levels of the second audio data at points before and after the second point in time when the audio level is maximum (S13).

[0038] 4 illustrates an audio waveform 41 of a predetermined section of the first audio data and an audio waveform 42 of a predetermined section of the second audio data. The vertical axis of the graph shown represents the normalized audio level, and the horizontal axis represents time. The horizontal axis shows the time of the predetermined section (e.g., 2 seconds) with a resolution of 88,200 points.

[0039] The measurement device 8 detects a maximum audio level m1 in an audio waveform 41 of the first audio data and a maximum audio level m2 in an audio waveform 42 of the second audio data. The measurement device 8 detects audio levels a1, b1 at points before and after a first point in time of the maximum audio level m1 of the first audio data, and audio levels a2, b2 at points before and after a second point in time of the maximum audio level m2 of the second audio data.

[0040] The previous and next audio levels are audio levels at points in time that are a predetermined time ahead and behind the first or second time point. Here, the points in time are 1000 points before and 1000 points after the first or second time point, but are not limited to this. Here, the previous and next points in time are points that are the same distance apart from the first or second time point, but may be different.

[0041] Then, the measuring device 8 compares the maximum audio level of the first audio data with the audio levels at the time points before and after that, and the maximum audio level of the second audio data with the audio levels at the time points before and after that, and determines whether the differences in audio levels at all time points are within a predetermined range (S14).

[0042] In the example shown in Figure 4, the measurement device 8 compares the maximum audio level m1 of the first audio data with the audio levels a1 and b1 before and after it, and the maximum audio level m2 of the second audio data with the audio levels a2 and b2 before and after it.

[0043] Specifically, the measurement device 8 compares the maximum audio levels (m1, m2) and determines whether the difference between them is within a predetermined range. In other words, it determines whether similar maximum audio levels exist. Furthermore, the measurement device 8 compares the audio levels (a1, a2) and (b1, b2) before and after the maximum audio level and determines whether the difference between them is within a predetermined range.

[0044] If the difference in audio level at at least one point in time exceeds the predetermined range (S14: NO), the measurement device 8 returns to S12 and repeats the subsequent processes. In this case, the measurement device 8 detects the maximum audio level in another predetermined section of the first audio data input at a fixed time from a different timing than the previous time, and also detects the maximum audio level in another predetermined section of the second audio data input at a fixed time from the different timing (S12).

[0045] If the difference in audio level at all points in time is within a predetermined range (S14: YES), the measuring device 8 determines whether the difference between the maximum audio level of the first audio data and each audio level at points in time before and after the first point in time of the maximum audio level exceeds a threshold, and may also determine whether the difference between the maximum audio level of the second audio data and each audio level at points in time before and after the second point in time of the maximum audio level exceeds a threshold (S15).

[0046] In the example shown in Figure 4, the measurement device 8 calculates the difference between the maximum audio level m1 and audio level a1 of the first audio data, the difference between the maximum audio level m1 and audio level b1, the difference between the maximum audio level m2 and audio level a2 of the second audio data, and the difference between the maximum audio level m2 and audio level b2, and determines whether all of the differences exceed a predetermined threshold.

[0047] This is a mechanism to avoid incorrect measurements when the audio data contains data that sustains the maximum audio level, such as a 1 kHz reference signal.

[0048] If all the differences exceed the threshold (S16: YES), the measurement device 8 measures the time difference between the first point in time of the first audio data and the second point in time of the second audio data as the transmission delay difference of the content on the transmission paths 5A and 5B (S17).On the other hand, if at least one difference is equal to or smaller than the threshold (S16: NO), the measurement device 8 returns to S12 and repeats the subsequent processes.

[0049] If the transmission delay difference measured in S17 is the same a predetermined number of times in succession (S18: YES), the measurement device 8 may output (display) the transmission delay difference measured in S17 (S19). In this embodiment, the measurement can be performed repeatedly until the same transmission delay difference is measured a predetermined number of times in succession (for example, three times), thereby enabling measurement of a transmission delay difference with higher accuracy. If the transmission delay difference measured in S17 is not the same a predetermined number of times in succession (S18: NO), the measurement device 8 returns to S12 and repeats the subsequent processes. For example, the measurement device 8 may extract the next predetermined section of the first voice data and the second voice data when returning to S12, or may extract the next predetermined section of the first voice data and the second voice data when a predetermined time has elapsed since the previous extraction of the predetermined section.

[0050] Note that the same value may include a certain error. For example, when the transmission delay difference is expressed in frame units, if the values ​​are the same down to the first decimal place, they may be considered the same value. In this case, a frame refers to a video frame that changes 30 times per second, and the duration of one frame is 1 second / 30 times = 33 ms. If expressed down to the first decimal place, this is 1 / 10 of 33 ms, so the measuring device 8 may determine that the values ​​are the same if there is an error of less than 3.3 ms, but may determine that the values ​​are not the same if there is a time difference of 3.3 ms or more.

[0051] FIG. 5 shows an example of a message about the transmission delay difference output by the measuring device 8. Here, the transmission delay difference is expressed in units of frames and time (ms). The example shown shows that the first audio data (ch1) is 27.0 frames (891.0 ms) earlier than the second audio data (ch2). The measuring device 8 calculates the number of frames by dividing the measured time (ms) of the transmission delay difference by 33 ms. The measuring device 8 may also output or display the audio waveform graph shown in FIG. 4 along with the message shown in FIG. 5.

[0052] The measurement device 8 of this embodiment described above comprises an input unit 81 that inputs first audio data of a content transmitted via a first transmission path and second audio data of the content transmitted via a second transmission path; a detection unit 82 that detects a maximum audio level in a predetermined section input for a certain time from a predetermined timing of the first audio data, and detects a maximum audio level in a predetermined section input for a certain time from the predetermined timing of the second audio data; and a measurement unit 83 that, when the difference between the maximum audio level of the first audio data and the maximum audio level of the second audio data is within a predetermined range, the difference between the audio level of the first audio data at a time point before the first point in time and the audio level of the second audio data at a time point before the second point in time is within the predetermined range, and the difference between the audio level at a time point after the first point in time and the audio level at a time point after the second point in time is within the predetermined range, measures the time difference between the first point in time and the second point in time as the transmission delay difference of the content on the first transmission path and the second transmission path.

[0053] In this embodiment, it is possible to provide a technique that can measure the difference in transmission delay between content transmitted over two different lines with high accuracy and at any timing.

[0054] Specifically, by measuring the difference in transmission delay using the audio data of the content, it is possible to measure the difference in transmission delay of the content with an accuracy of milliseconds (ms), which is finer than the video frame unit.

[0055] Furthermore, in this embodiment, the transmission delay difference can be measured without any action such as clapping by a person on-site, by simply inputting each piece of audio data of content transmitted from the site over two different lines into the measurement device 8. As a result, in this embodiment, the receiving side of the transmission destination does not need to measure the transmission delay difference in cooperation with the site, and can measure the transmission delay difference at any timing.

[0056] Furthermore, in this embodiment, the transmission delay difference between content transmitted over two different lines can be measured simply by providing a measurement device 8 using a general-purpose computer and an audio input interface 7. That is, the measurement device 8 of this embodiment can be realized by installing an application program having the above-mentioned measurement function on a general-purpose computer. Therefore, in this embodiment, the transmission delay difference between content can be measured at low cost.

[0057] The measuring device 8 of the present embodiment described above can use, for example, a general-purpose computer system as shown in Fig. 6. The computer system shown in the figure includes a CPU (Central Processing Unit, processor) 901, a memory 902, a storage 903 (HDD: Hard Disk Drive, SSD: Solid State Drive), a communication device 904, an input device 905, and an output device 906. The memory 902 and the storage 903 are storage devices. In this computer system, the CPU 901 executes a predetermined program (application program) loaded onto the memory 902, thereby realizing each function of the measuring device 8. The program may be written in a general-purpose programming language such as Python.

[0058] Furthermore, the measurement device 8 may be implemented in one computer or in multiple computers. Furthermore, the measurement device 8 may be a virtual machine implemented in a computer. The program for the measurement device 8 may be stored in a computer-readable recording medium such as a HDD, SSD, USB (Universal Serial Bus) memory, CD (Compact Disc), or DVD (Digital Versatile Disc), or may be distributed via a network. The computer-readable recording medium is, for example, a non-transitory recording medium.

[0059] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present disclosure. [Explanation of symbols]

[0060] 2: Camera 3: Microphone 4A, 4B: Multiplexing / encoding device 5A, 5B: Transmission path 6A, 6B: Separation and decoding device 7: Voice interface 8: Measuring equipment 81: Input section 82:Detection unit 83: Measuring part 84: Storage section

Claims

1. an input unit that inputs first audio data of the content transmitted via a first transmission path and second audio data of the content transmitted via a second transmission path; a detection unit that detects a maximum sound level in a predetermined section input for a certain period from a predetermined timing of the first sound data, and detects a maximum sound level in a predetermined section input for a certain period from the predetermined timing of the second sound data; a measurement unit that measures a time difference between the first point in time and the second point in time as a transmission delay difference of the content on the first transmission path and the second transmission path when a difference between the maximum audio level of the first audio data and the maximum audio level of the second audio data is within a predetermined range, a difference between an audio level of the first audio data at a time point before a first point in time and an audio level of the second audio data at a time point before a second point in time is within the predetermined range, and a difference between an audio level at a time point after the first point in time and an audio level at a time point after the second point in time is within the predetermined range. Measuring equipment.

2. the detection unit detects a maximum audio level for each of a plurality of predetermined sections input at a fixed time from each of a plurality of timings of the first audio data, and detects a maximum audio level for each of a plurality of predetermined sections input at a fixed time from each of the plurality of timings of the second audio data, The measurement unit outputs the transmission delay difference when the transmission delay difference measured in a plurality of predetermined sections is the same a predetermined number of times in succession. The measuring device according to claim 1 .

3. When a difference between the maximum audio level of the first audio data and each audio level at a time point before and after the first time point of the maximum audio level exceeds a threshold, and when a difference between the maximum audio level of the second audio data and each audio level at a time point before and after the second time point of the maximum audio level exceeds a threshold, the measurement unit measures a time difference between the first time point and the second time point as the transmission delay difference. The measuring device according to claim 1 .

4. A measurement method performed by a measurement device, inputting first audio data of the content transmitted via a first transmission path and second audio data of the content transmitted via a second transmission path; detecting a maximum sound level in a predetermined section input for a fixed time from a predetermined timing of the first sound data, and detecting a maximum sound level in a predetermined section input for a fixed time from the predetermined timing of the second sound data; When a difference between the maximum audio level of the first audio data and the maximum audio level of the second audio data is within a predetermined range, a difference between an audio level at a time point before the first time point at which the maximum audio level of the first audio data is reached and an audio level at a time point before the second time point at which the maximum audio level of the second audio data is reached is within the predetermined range, and a difference between an audio level at a time point after the first time point and an audio level at a time point after the second time point is within the predetermined range, a time difference between the first time point and the second time point is measured as a transmission delay difference of the content on the first transmission path and the second transmission path. Measurement method.

5. A program that causes a computer to function as the measurement device according to any one of claims 1 to 3.

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