JP3727736B2 - Video / audio signal generator for time difference detection between video and audio - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video signal / audio signal generator used to detect a time lag (time difference) between video and audio caused by television program production or a relay line. When a time difference between video and audio is detected using the apparatus of the present invention, it is possible to adjust the time difference to be zero by a delay circuit inserted in the video or audio system.
[0002]
[Prior art]
Conventionally, in order to detect the time difference between the generated video and audio, a person stands in front of the television camera and makes a voice or claps his hands, subjectively, the time difference between the video and audio is zero. Both time positions (hereinafter referred to as reproduction times) were matched.
[0003]
In addition, as a measure to measure the time difference quantitatively, Mizoguchi et al., “Development of Video / Audio Delay Difference Measuring Device”, 1992 Institute of Electrical Engineers of Tokai Branch, 527, or related to the applicant's application. There exists a thing of Unexamined-Japanese-Patent No. 5-219459.
[0004]
[Problems to be solved by the invention]
However, the first method described above as the prior art, that is, the method of subjectively matching is the method of Kurosumi et al., “Study on the relative time difference between TV video and audio”, Acoustical Society of Japan, Spring 2008 presentation paper, 3- As can be seen from 3-6, the range in which the playback time of video and audio is judged to be subjectively matched is 170 ms, and it is difficult to accurately match the playback time of video and audio with the above method. It is. In other words, it is difficult to accurately determine the difference between video and audio playback times using different human senses (visual and auditory) simultaneously.
[0005]
In addition, in the “development of video / audio delay difference measuring device” announced by Mizoguchi et al., Video and audio are presented only once at the same time. It is difficult to accurately judge the difference between them subjectively.
[0006]
Furthermore, the device described in Japanese Patent Laid-Open No. 5-219459 transmits a video from a relay site and an audio signal temporally synchronized therewith, and the receiving side detects and controls the video and audio by a detection device. By visually observing the difference between video and audio on a video monitor and adjusting the amount of audio and / or video delay on the receiving side quantitatively in a short time, the two are synchronized. The method also includes the above-described problem that it is necessary to determine the difference between the reproduction time of the video and the sound by using simultaneously different human senses that the video is finally an eye and the sound is an ear.
[0007]
[Means for Solving the Problems]
As described above, since it is difficult to accurately determine the difference between the playback time of video and audio using different human senses simultaneously, the present invention uses a light source that emits light at equal time intervals. A method in which a human once memorizes the time interval (timing or tempo) in the brain is adopted. According to this, the generation time of the sound source generated at the time interval stored using the light source that emits light at equal time intervals can be determined using only auditory sense.
[0008]
Similarly, when a sound source that generates sound at equal time intervals is used to temporarily store the time interval (timing or tempo), the light emission time of the light source that emits light at the stored time interval is used only for vision. Judgment can be made. In this way, the time difference between video and audio can be determined using only one of auditory and visual senses, so it is more accurate than the conventional case of determining using visual and auditory simultaneously. Judgment can be made.
[0009]
For example, according to Tanaka et al., “Time Error in Perception of Empty Time”, Proceedings of the Acoustical Society of Japan 1992 Spring Research Presentation, March 1992, 1-6-8, When the time sensation (timing or tempo) is 800 ms, it can be determined with an accuracy of an error of about 10 ms or less.
[0010]
That is, the video signal / audio signal generator according to the present invention emits sound from a sound source at the next light emission timing after the light source emits light a plurality of times at equal time intervals, and the light emission status and the sound generation status are indicated. The television camera and the microphone are respectively picked up and picked up to generate a video signal and an audio signal for detecting a time difference between the video and the audio, respectively.
[0011]
The video signal / audio signal generator according to the present invention is characterized in that the light emission is stopped when the sound is generated.
[0012]
Also, the video signal / audio signal generating apparatus according to the present invention generates a sound a plurality of times at equal time intervals from a sound source, and then causes the light source to emit light at the next sound generation timing, and the sound generation status and the light emission status Are picked up and picked up by a microphone and a television camera, respectively, to generate an audio signal and a video signal for detecting a time difference between the video and audio, respectively.
[0013]
The video signal / audio signal generator according to the present invention is characterized in that the generation of the audio is stopped when the light source emits light.
[0014]
The video signal / audio signal generator according to the present invention is such that at least one of the video signal and the audio signal obtained by imaging by a television camera and sound collection by a microphone is a signal obtained directly by an artificial method. It is characterized by.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on an embodiment of the invention with reference to the accompanying drawings.
FIG. 1 shows a first embodiment of the device of the present invention, and (a) and (b) are Examples 1 and 2, respectively.
[0016]
1A and 1B, 1 is a timing pulse generator, 2 is a light source, 3 is a final pulse passage circuit, 4 is a sound source, and 5 is a final pulse cutoff circuit.
As for the operation, first, in the case of FIG. 1A (Example 1), for example, four pulses are generated at intervals of one second in the timing pulse generator. The light source 2 emits light in synchronization with the four pulses. On the other hand, the final pulse passing circuit 3 passes only the final fourth pulse that has arrived, and generates a sound signal from the sound source 4 in synchronization with the last pulse. For example, a light emitting diode (LED) can be used as the light source 2, and a pure sound of 1 kHz can be used as the audio signal.
[0017]
In FIG. 1B (Example 2), the last pulse (between the timing pulse generator 1 and the light source 2 is stopped so as to stop the light emission of the light source 2 when the sound signal is generated from the sound source 4. A final pulse cut-off circuit 5 for cutting off the fourth pulse) is inserted.
[0018]
FIG. 2 shows a second embodiment of the device of the present invention, in which (a) and (b) are Examples 3 and 4, respectively.
[0019]
2A and 2B, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG.
In the case of FIG. 2A (Embodiment 3), the operation is first generated, for example, by generating four pulses at intervals of 1 second in the timing pulse generator 1, and continuing for, for example, 20 ms. A sound signal of 500 Hz is generated from the sound source 4. On the other hand, the last pulse passing circuit 3 passes only the last fourth pulse that has arrived, and the light source 2 emits light in synchronization with the last pulse.
[0020]
In FIG. 2B (Example 4), when the light source 2 emits light, the generation of a 500 Hz audio signal from the sound source 4 is stopped between the timing pulse generator 1 and the sound source 2. The final pulse cut-off circuit 5 for cutting off the pulse (the fourth pulse) is inserted.
[0021]
As shown in FIG. 3, the light emission generated and the sound generated as described above are shown in FIG. 3 taking the case of FIG. The sound generation state from the sound source 4 such as a speaker is converted into a video signal and an audio signal by the John camera 6 and the microphone 7 respectively, and a reference signal for time difference detection is transmitted to a transmission system such as a relay circuit where a time difference between the video and the audio occurs. Send out as
[0022]
Thus, since the reference signal for time difference detection is eventually a video signal and an audio signal, for example, by using a computer graphic (CG) or an audio frequency oscillator to obtain these signals, the above example is used. As described above, the video signal / audio signal for time difference detection may be generated by an artificial and more direct method, not through a television camera or a microphone.
[0023]
In addition, what is important for the video signal / audio signal obtained by the device of the present invention is not, for example, that a light emitting diode emitting light is imaged, but information indicating a situation where the light emitting diode simply emits light and becomes bright. In that sense, in the case of the latter artificial method, a black level image signal may be constantly transmitted, and a white level image signal may be transmitted at equal time intervals. . The same concept can be applied to audio signals.
[0024]
The video signal and the audio signal generated by the apparatus of the present invention cause a time difference between them in the transmission system (in fact, the video signal and the audio signal are transmitted through different routes). Now, in order to detect the arrival time difference based on the video signal / audio signal generated by the apparatus of FIG.
[0025]
That is, first, a television image monitor and an audio monitor are prepared on the receiving side. The timings can be perceived by each of the above-mentioned monitors prepared for video signals and audio signals representing the generation of light emission and sound from the apparatus of FIG. In the case of this example, the person (person in charge) who detects the time difference memorizes the equal time interval (timing or tempo) of the light emission projected on the video monitor in his own brain. That is, a tempo of a certain time interval is formed in the human brain. If audio is generated from the audio monitor at a timing that matches this tempo, there will be no time difference between the video signal and the audio signal.
[0026]
However, if audio is generated outside the tempo, there will be a time difference between the video and audio signals, and a delay circuit for compensating for the time difference inserted into either the video or audio transmission system. Adjust the delay amount to zero time difference. According to this method, the time difference can be detected with extremely high accuracy as described in the literature introduced in the above section (Means for Solving the Problems), and accordingly, the time difference is adjusted to zero. be able to.
[0027]
The video / audio signal generating device for detecting the time difference between video and audio according to the present invention is the same as that of the first and second embodiments described above (Example 1; Example 2 and Example 3; Example 4 respectively). It is not limited. For example, in each of the above examples (Examples 1 to 4), in the case of Examples 1 and 2 (see FIGS. 1 (a) and 1 (b), respectively), another light source is arranged in parallel with the sound source 4. This light source may emit light simultaneously with the generation of sound from the sound source 4.
[0028]
In the case of Examples 3 and 4 (see FIGS. 2 (a) and 2 (b), respectively), another sound source is provided in parallel with the light source 2, and this sound source generates sound simultaneously with the light emission of the light source 2. You may make it do. In this case, in order to distinguish the sound generated from another sound source from the sound generated from the sound source 4 (necessary when multiplexed transmission is performed on the sound transmission path), for example, the frequency is 1 kHz and the duration is 500 ms (sound source 4 ) Is assumed to have a frequency of 500 Hz and a duration of 20 ms.
[0029]
In addition, the video signal and audio signal generated by the device of the present invention are not only terminated once as a set, but are generated more and more conveniently by repeatedly generating the same set of signals. Can be. Furthermore, it is practical to generate the video signal and the audio signal in synchronization with the synchronization signal of the television video signal.
[0030]
Finally, in the device of the present invention, it is not absolutely necessary that the light emission (or sound generation) that occurs a plurality of times at equal time intervals and the sound generation (or light emission) that occurs at the next timing occur simultaneously. This is because the present invention does not perceive a time difference by simultaneously using different human senses (sight and hearing) of perceiving light emission and sound generation.
[0031]
【The invention's effect】
If the time difference between the video signal and the audio signal is measured using the device of the present invention, not only a physical time difference measuring device is not required on the receiving side, but also human beings of vision and hearing as in the past. Instead of detecting the time difference based on different sensations, only one sensation, for example, only visual sense or auditory sense (comparison is based on an equal time interval signal sent from the device of the present invention. The time difference is subjectively detected on the basis of the timing (which is stored in the brain as a timing), so that highly accurate detection is possible.
[0032]
Moreover, if the apparatus of the present invention is used, it is possible to detect a time difference with high accuracy, and therefore it is possible to time-align video and audio with high accuracy.
[0033]
Furthermore, as can be seen from FIGS. 1 (a) and 1 (b) and FIGS. 2 (a) and 2 (b), the device of the present invention can be configured very simply.
[Brief description of the drawings]
FIG. 1 shows a first embodiment of an apparatus according to the present invention.
FIG. 2 shows a second embodiment of the apparatus of the present invention.
FIG. 3 shows a process of converting a light emission state and a sound generation state generated according to FIG. 1 or FIG. 2 into a video signal and a sound signal, respectively.
[Explanation of symbols]
1 Timing pulse generator 2 Light source (light emitting diode)
3 Final pulse passage circuit 4 Sound source (speaker)
5 Final pulse cut-off circuit 6 Television camera 7 Microphone

Claims (5)

  After causing the light source to emit light a plurality of times at equal time intervals, sound is generated from the sound source at the next light emission timing, and the light emission state and the sound generation state are respectively imaged and collected by a television camera and a microphone, A video signal / audio signal generator for detecting a time difference between video and audio, wherein the video signal and the audio signal are generated for detecting the time difference between video and audio, respectively. 2. The video signal / audio signal generator according to claim 1, wherein the light emission is stopped when the sound is generated, and the time difference detection between video and audio is detected.   After generating sound several times at regular time intervals from the sound source, the light source is caused to emit light at the next sound generation timing, and the sound generation state and the light emission state are collected and imaged by a microphone and a television camera, respectively. A video signal / audio signal generator for detecting a time difference between video and audio, wherein the audio signal and video signal for detecting the time difference between video and audio are generated. 4. The video signal / audio signal generator according to claim 3, wherein the generation of the audio is stopped when the light source emits light, and the time difference detection between video and audio is detected. . 5. At least one of a video signal and an audio signal obtained by imaging with a television camera according to any one of claims 1 to 4 and sound collection with a microphone is a signal directly obtained by an artificial method. A video / audio signal generator for detecting the time difference between video and audio.

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