JP2008131341A - Video / audio playback system and video playback device - Google Patents

Abstract

Synchronizing video playback and audio playback between a video playback device and an audio playback device connected to a network.
A projector and an audio device that receive input of digital stream data via a network perform video playback and audio playback individually. The audio device receives an audio signal as a synchronization signal included in the digital stream data. And the sound is reproduced from the speaker 402 after being modulated into an analog sound signal. The projector 300 acquires the synchronization signal synthesized and generated on the acoustic device 400 side through the sound collection microphone 316, the sound demodulator 318, and the signal separator 320 after collecting the speaker reproduction sound and demodulating / separating the sound. Then, the projector 300 synchronizes with the sound reproduction of the acoustic device 400 based on the synchronization signal, and then performs image reproduction at the image forming projection unit 302.
[Selection] Figure 1

Description

  The present invention relates to a video / audio playback system including a video playback device having a video playback device, an audio playback device having an audio playback device, and a content transmission device for video / audio content connected to a network, and the network connected to the network. The present invention relates to a video playback apparatus that plays back video based on a video signal input via the network.

  In recent years, digital-compatible AV (Audio Visual) devices such as large televisions and projectors, DVD (Digital Versatile Disk) players, CD (Compact Disc) players, 5.1ch surround sound playback devices, and the like are becoming widespread. Among these devices, large televisions and projectors that reproduce video and audio handle video and audio content that includes the synchronized video and audio signals as video and audio playback signals. As this audio-video content, for example, there is MPEG2 (Moving Picture Experts Group phase 2). In this MPEG2, the video signal and the audio signal are compressed by the MPEG standard, and both signals are synchronized. Large TVs and projectors receive this MPEG2 data from a DVD player built in these devices or a DVD player connected via an external terminal attached to the device, and receive the video signal and audio signal included in the video / audio content (MPEG2). Video processing and audio playback are performed in the signal processing for each playback. This relationship also applies to transmission / reception reproduction in so-called digital television broadcasting.

  By the way, when the video signal and the audio signal are subjected to signal processing for reproduction in this way, there is a difference between the video reproduction and the audio reproduction due to the difference in processing speed between the video signal processing and the audio signal processing. Therefore, a coping technique for synchronizing video reproduction and audio reproduction has been proposed (for example, Patent Document 1), and such synchronization countermeasures have reduced the viewer's uncomfortable feeling. In this patent document, synchronization of video playback and audio playback in an AV device (video / audio playback device) capable of video / audio playback, such as a large television or a projector, video playback in the video / audio playback device, and the device There has been proposed a countermeasure for synchronization with audio reproduction in an audio reproduction apparatus directly connected to the audio transmission cable (optical digital cable). As this synchronization countermeasure, an audio signal output delay to a speaker included in the video / audio reproduction device and an audio signal output delay to an audio transmission cable output terminal included in the video / audio reproduction device are performed.

JP 2005-184563 A

  On the other hand, a plurality of AV devices are connected via a network, video playback is performed on a large TV or projector, and an audio playback device that is a separate device from the large TV or projector, such as a 5.1ch surround sound playback device. Then, it is desired to perform audio reproduction. In other words, there is an increasing demand for users who listen to sound from a 5.1ch surround sound playback device while wearing a home living room as if it were a mini-theater and watching the video on a large TV or projector.

  However, when the video playback device and the audio playback device are connected via a network in this way, the problem that the synchronization countermeasure proposed in the above patent document cannot be applied as it is will be pointed out as described below. It was.

  The video playback device and the audio playback device each receive the same video / audio content (MPEG2) via the network, and the video playback device independently processes the video signal included in the content to perform the video playback, and the audio playback. Even in the device, the audio signal is independently processed to reproduce the sound. In other words, although the video playback device and the audio playback device are both connected to the network, the video playback device and the audio playback device are separate devices. (Output delay) cannot be applied as it is.

  In addition, since the transmission of video / audio content (MPEG2) to the video playback device and the audio playback device is via a network, depending on the data transmission status in the network, the transmission of the video / audio content to the video playback device via the network. It is expected that the time is different from the transmission time of the video / audio content to the audio reproduction device via the network, and the difference between the two transmission times is not steady. In other words, the synchronization countermeasure (audio signal output delay) as proposed in the above-mentioned patent document cannot be applied as it is because of network-specific circumstances in which data is transmitted to the video reproduction device and the audio reproduction device via the network.

  The object of the present invention is to solve the above-mentioned problems of the prior art and to ensure the reliability of synchronization between video playback and audio playback when video playback / audio playback is performed between a video playback device and an audio playback device connected to a network. The purpose is to increase

  In order to achieve at least a part of the above-described object, in the video / audio reproduction system of the present invention, video / audio content including a video signal and an audio signal synchronized with each other is transmitted from the content transmission apparatus via the network. Transmit to the playback device and the audio playback device. In this way, in the audio reproduction device that has received the input of the video / audio content, the audio signal included in the video / audio content and the synchronization signal included in the video / audio content are synchronized with each other by the synchronization signal synthesis unit. Generating a synthesized voice reproduction signal obtained by synthesizing the voice signal and the synchronization signal in the signal form of the voice reproduction signal while converting into a signal form of the voice reproduction signal suitable for voice reproduction in The reproduction signal is output to the audio reproduction device of the audio reproduction apparatus by the audio reproduction unit, and the audio reproduction is performed by the audio reproduction device.

  In the video playback device that has received the input of the video / audio content, the video signal included in the video / audio content is subjected to processing for video playback in the video playback device of the video playback device in the video playback unit, A video playback signal suitable for video playback on the video playback device is generated, and the generated video playback signal is output to the video playback device to perform video playback on the video playback device.

  As described above, the audio reproduction and the video reproduction are performed by the audio reproduction apparatus and the latter by the video reproduction apparatus. When the video reproduction apparatus performs the video reproduction by the video reproduction device, the video reproduction apparatus Based on the sync signal included in the synthesized audio playback signal obtained by synthesizing the audio signal and the synchronization signal included in the video / audio content in the signal format of the audio playback signal on the audio playback device side, the playback synchronization unit performs video playback. By delaying, the audio playback from the audio playback device and the video playback from the video playback device are synchronized. Therefore, although audio playback and video playback are individually performed by the audio playback device and the video playback device connected to the network, the reliability of synchronization between video playback and audio playback can be improved. In addition, since the synchronization signal included in the synthesized audio reproduction signal synthesized and generated every time the audio reproduction is performed on the audio reproduction device side, the deviation between the audio reproduction and the video reproduction can be suppressed and the deviation can be made steady. Therefore, it is possible to reduce a sense of incongruity based on the difference between audio reproduction and video reproduction for a viewer who listens to audio while watching the video. Such synchronization of audio reproduction and video reproduction is achieved by connecting the audio reproduction apparatus, the video reproduction apparatus, and the content transmission apparatus, which are independent as separate devices, to the network separately from the content transmission apparatus. This can be achieved simply by transmitting video / audio content over a network.

  In the video / audio reproduction system of the present invention described above, the video reproduction apparatus is configured to delay the video reproduction on the video reproduction apparatus side based on the synchronization signal included in the synthesized audio reproduction signal synthesized on the audio reproduction apparatus side. The reproduction synchronization unit includes a sound collection unit that collects audio reproduced by the audio reproduction device of the audio reproduction device, and generates a reproduction audio signal by demodulating the collected audio, and the reproduction audio signal Is subjected to processing corresponding to synthesis of the synchronization signal when the synchronization signal synthesis unit of the audio reproduction device generates the synthesized audio reproduction signal, and the synchronization signal separation is performed to separate the synchronization signal from the reproduction audio signal. A video reproduction by the video reproduction unit based on the separated synchronization signal. In this way, it is only necessary to provide the above-described sound collection unit and synchronization signal separation unit in a video reproduction apparatus that can be connected to a network, which is convenient.

  Further, when generating a synthesized audio reproduction signal obtained by synthesizing the audio signal and the synchronization signal included in the video / audio content in the signal form of the audio reproduction signal on the audio reproduction device side, the synchronization signal of the audio reproduction device is generated. A synthesizing unit that generates the synthesized audio reproduction signal by modulating the synchronization signal into a signal in a frequency range outside a human audible range, and the synchronization signal separating unit in the reproduction synchronizing unit of the video reproduction device includes: The reproduced audio signal can be subjected to a demodulation process corresponding to the modulation to separate the synchronization signal. In this way, when audio is played back from the audio playback device using the synthesized audio playback signal, the signal component corresponding to the synchronization signal can be prevented from being heard by the viewer as noise, thus suppressing degradation of the audible quality of the playback audio. it can.

  In addition, in a video playback device that performs synchronization based on a synchronization signal included in a synthesized audio playback signal synthesized on the audio playback device side, an audio playback device associated with the video playback device and the input received. In addition, the audio signal included in the video / audio content is converted into a signal form of an audio reproduction signal suitable for audio reproduction by the apparatus-associated audio reproduction device, and the apparatus-associated audio by the converted audio reproduction signal is converted. An in-video reproduction apparatus synchronization unit that synchronizes audio reproduction on the reproduction device and video reproduction on the video reproduction device using the video reproduction signal based on the synchronization signal for synchronization included in the video / audio content; The priority order of the audio playback on the audio playback device and the audio playback on the device-associated audio playback device of the audio playback device is determined according to a predetermined order. A video playback device synchronization stop unit that stops the operation of the video playback device synchronization unit when determining based on conditions and prioritizing audio playback on the audio playback device of the audio playback device; It can also be done.

  In this way, as described above, video playback can be performed while synchronizing on the video playback device side based on the synchronization signal included in the synthesized audio playback signal synthesized on the audio playback device side, and only the video playback device It is possible to execute video playback and audio playback in synchronization with each other.

  In this case, when the same video / audio content from the content transmission apparatus is transmitted to both the video reproduction apparatus and the audio reproduction apparatus and the audio reproduction is executed by the audio reproduction apparatus, and the apparatus When there is a user operation to stop the audio playback on the accompanying audio playback device, the audio playback on the audio playback device is actually performed, or the user plays the audio playback on the audio playback device. It can be said that it wants. Therefore, in such a case, it is assumed that the order defining condition for giving priority to the audio reproduction by the audio reproduction device is satisfied, and the audio reproduction by the audio reproduction device of the audio reproduction device is performed.

  The video / audio reproduction according to the present invention described above is not only a video / audio reproduction system that is already provided by individually connecting an audio reproduction device, a video reproduction device, and a content transmission device to a network, but also connected to a network and connected via the network. The present invention can also be applied as a video playback apparatus that can receive signals. That is, by connecting such a video playback device to a network to which the audio playback device and the content transmission device are already connected, the audio playback on the audio playback device and the video playback on the video playback device are synchronized. Can be executed.

  Hereinafter, embodiments of the present invention will be described based on examples. FIG. 1 is a block diagram schematically showing the configuration of a video / audio reproduction system 100 as an embodiment of the present invention. As illustrated, the video / audio reproduction system 100 includes a content transmission device 200, a projector 300, and an audio device 400 connected to a network 110, and the content transmission device 200 connects the projector 300 and the audio device 400 via the network 110. Send digital stream data. This digital stream data is a video / audio content (MPEG-TS (Motion Picture Expert Group-Transport Stream)) including a digital video signal and an audio signal that are synchronized with the MPEG2 standard and synchronized. Then, the image forming / projecting unit 302 included therein reproduces a video composed of video data of MPEG2 data and projects it onto the screen S, and the acoustic device 400 is composed of audio data of MPEG2 data using the speaker 402 included therein. Play audio. In addition, the video / audio reproduction system 100 includes a digital broadcast receiver 450, a DVD player 460, and a CD player 470 connected to the network 110.

  The content transmission device 200 includes an internal hard disk 202, an external hard disk 204, a content transmission control unit 206, and a network driver 208. The content transmitting apparatus 200 stores the digital stream data provided by the digital broadcast receiving apparatus 450 and the DVD player 460 in the hard disk 202, the hard disk 204, etc., and the stored digital stream data is networked by the content transmission control unit 206. The data is transmitted to the network 110 via the driver 208. Digital stream data transmission at this time is executed in response to an operation instruction of a user operation device (not shown) (for example, a mouse or a keyboard), and the content transmission control unit 206 performs the projector 300 and the audio device 400 based on the instruction. Send digital stream data to both devices. The content transmission device 200 is configured by a computer, and cooperates with a CPU that executes logical operations, a ROM that stores programs and data, a RAM that performs good temporary data processing, and a program that performs the following. A function, that is, a data transmission function based on a user instruction is achieved. In this case, the data transmission from the content transmission device 200 is performed to both the projector 300 and the acoustic device 400, but the input destination of the digital stream data, for example, the content transmission device on the projector 300 and the acoustic device 400 side. 200, the digital broadcast receiving device 450, or one of the DVD players 460 may be designated.

  The projector 300 includes a network driver 310, a data decoder 312, a video player 314, a sound collecting microphone 316, an audio demodulator 318, and a signal separator 320 in addition to the image forming / projecting unit 302 described above. The data decoder 312 decodes a video signal included in digital stream data (MPEG2 data) received from the network 110 via the network driver 310. The video player 314 includes a buffer area capable of storing a plurality of video images composed of decoded video data in units of frames, and based on a synchronization signal received from a signal separator 320 described later, The frame image is transmitted to the image forming projection unit 302. That is, the video signal data included in the digital content data input via the network 110 is subjected to video playback processing suitable for video playback in the image forming projection unit 302 by the cooperation of the data decoder 312 and the video playback device 314. The image is then converted into a video reproduction signal and transmitted to the image forming projection unit 302. The image forming and projecting unit 302 includes a liquid crystal display unit 303, displays an image based on a video reproduction signal on the display unit, projects the image with light from a light source device (not shown), and magnifies the image with a lens 304. The image is displayed on the screen S. In this case, at the time of decoding by the data decoder 312, the decoded video reproduction signal and the decoded synchronization signal are associated with each other so that a correspondence with a synchronization signal generated by a signal separator 320 described later can be obtained. That is, the order of reproducing images (frame images) in the image forming projection unit 302 after the transmission of the decoded video reproduction signal is determined by the decoded synchronization signal, and the decoding synchronization signal and the signal separator 320 in the data decoder 312 are generated. If the sync signal corresponds, the image forming / projecting unit 302 reproduces an image (frame image) corresponding to the sync signal generated by the signal separator 320.

  A sound collecting microphone 316 of the projector 300 collects sound emitted from the speaker 402 by an acoustic device 400 described later, and a sound demodulator 318 demodulates the collected sound into an analog signal. The signal separator 320 separates the sync signal component included in the analog signal by filtering, and outputs the sync signal obtained by the separation to the video player 314. Then, as described above, the video player 314 transmits the image signal to the image forming projection unit 302 on a frame basis based on the synchronization signal from the signal separator 320. At this time, the synchronization signal from the signal separator 320 and the decoded synchronization signal in the data decoder 312 are collated, and the video reproduction signal transmission and the video reproduction are performed based on the collated synchronization signal of the signal separator 320. Is called. Since the synchronization signal separated by the signal separator 320 is nothing but a video / audio synchronization signal included in the same digital stream data transmitted to the projector 300 and the audio device 400, video reproduction at the projector 300 is audio reproduction. Will be done in sync with. This will be described in detail together with the description of the configuration and processing of the acoustic device 400.

  In addition to the speaker 402, the acoustic device 400 includes a network driver 410, a data decoder 412, a signal synthesizer 414, and an amplifier 416. The data decoder 412 decodes an audio signal included in digital stream data (MPEG2 data) received from the network 110 via the network driver 410. At the time of decoding, the synchronization signal included in the received digital stream data is also converted into the same type of data as the decoded audio signal data (decoded audio signal data), and the signal synthesizer 414 receives the decoded audio signal data. And the synchronization signal of the same kind of data are converted to analog for audio reproduction by the speaker 402, and the decoded audio signal data and the synchronization signal are synthesized as an analog audio signal. In the data conversion / synthesis of the synchronization signal, the synchronization signal is modulated into a signal in a frequency range (for example, a low frequency region of 20 Hz or less, or a high frequency region of 20 KHz or more) that is out of the human audible range. The modulated signal is synthesized with the audio reproduction signal obtained by converting the decoded audio signal data. Then, the audio signal synthesized and generated by the signal synthesizer 414 as described above is amplified by the amplifier 416, output to the speaker 402, and reproduced as audio by the speaker 402. In other words, the playback sound from the speaker 402 is in a frequency range outside the audible frequency corresponding to the audio in the audible frequency range formed by the audio signal included in the received digital stream data and the synchronization signal synchronized with the playback of the audio. Audio will be included.

  Since the sound reproduced by the speaker 402 of the acoustic device 400 is collected by the sound collecting microphone 316 of the projector 300 in this manner, the projector 300 undergoes demodulation by the sound demodulator 318 and signal separation by the signal separator 320. Thus, a synchronization signal synchronized with the audio signal included in the digital stream data can be acquired. Therefore, the projector 300 performs video playback from the video playback device 314 based on the synchronization signal on the projector 300 side, so that the audio device 400 synchronizes with the audio played back from the speaker 402 to display the video. Reproduce. Specifically, based on the synchronization signal separated by the signal separator 320, the video data output from the video player 314 (video data output from the buffer) is delayed to delay the video reproduction, and thereby the projector 300 The image reproduction from the image forming projection unit 302 is synchronized with the sound reproduction from the speaker 402 of the audio device 400.

  As described above, the video / audio reproduction system 100 according to the present embodiment includes the projector 300 and the audio device 400 individually connected to the network 110, and separately performs video reproduction in the former and audio reproduction in the latter. . Then, when performing video playback / audio playback on both devices, the audio device 400 side modulates and synthesizes an audio signal and a synchronization signal included in the digital stream data so as to be suitable for audio playback on the speaker 402. A sound signal is generated, and sound is reproduced by the speaker 402 based on the analog sound signal. On the projector 300 side, the sound reproduced by the speaker 402 is demodulated and included in the analog sound signal that is the source of the sound. The synchronization signal is acquired separately, and the video reproduction on the speaker 402 is delayed based on the synchronization signal, so that the audio reproduction from the speaker 402 and the video reproduction from the image forming projection unit 302 are synchronized. Therefore, although the video reproduction and the audio reproduction are individually performed by the projector 300 and the audio apparatus 400 individually connected to the network 110, the video reproduction and the audio reproduction by the individual apparatus can be executed while being highly reliable and synchronized. In addition, since the synchronization signal included in the analog audio reproduction signal synthesized and generated every time audio is reproduced on the acoustic device 400 side, the deviation between the audio reproduction and the video reproduction can be suppressed and the deviation can be made steady. Therefore, a viewer who listens to the sound from the speaker 402 at a location away from the screen S or the projector 300 while watching the image of the screen S projected by the image forming projection unit 302 feels uncomfortable based on the difference between the sound reproduction and the image reproduction. Can not be given. Such synchronization of audio reproduction and video reproduction is performed by connecting the projector 300, the audio device 400, and the content transmission device 200, which are independent as separate devices, to the network 110 individually, and then connecting the both from the content transmission device 200. This can be achieved simply by transmitting digital stream data to the apparatus via the network 110, which is convenient.

  In the audio / video reproduction system 100 according to the present embodiment, when the projector 300 acquires the synchronization signal generated by synthesizing the audio signal included in the digital stream data on the acoustic device 400 side, the speaker 402 of the acoustic device 400 is used. It collects the sound actually emitted, demodulates it, and separates the sync signal. Accordingly, it is possible to further improve the reliability of the video reproduction delay based on the synchronization signal acquired from the acoustic device 400 and the synchronization of the video reproduction with the audio reproduction. In addition, when performing video reproduction in synchronization with the audio reproduction of the acoustic device 400, the projector 300 that can be connected to the network 110 may be equipped with the sound collection microphone 316, the audio demodulator 318, and the signal separator 320. It is.

  In addition, when the audio device 400 generates an audio signal included in the digital stream data by synthesizing and synthesizing the audio / video synchronization signal after converting it into a low frequency, the audio signal included in the digital stream data is out of the human audible range. The signal is generated by modulating the signal to a signal in a high frequency range. Therefore, when reproducing the sound from the speaker 402 using the generated analog sound reproduction signal, the signal component corresponding to the synchronization signal can be prevented from being heard by the viewer as noise. Reduces audible quality.

  Synchronous reproduction of video and audio by the projector 300 and the audio device 400 individually connected to the network 110 is not limited to the case of the same digital stream data transmission from the content transmission device 200 to both devices, but the DVD player 460 or digital In addition to the case where the broadcast receiving device 450 is a transmission source of digital stream data in place of the content transmission device 200, in addition to the case where both the projector 300 and the audio device 400 have selected the content transmission device 200 as the transmission source of digital stream data, When the content transmission device 200 is selected with the player 460 as the transmission source, the same processing is executed when the content transmission device 200 is selected with the digital broadcast reception device 450 as the transmission source. In each of the above cases, it is assumed that the same digital stream data is transmitted to both the projector 300 and the audio device 400 that are individually connected to the network 110. However, the projector 300 and the audio device 400 are connected to each other. The case of receiving input of different digital stream data will be described later. When the digital broadcast receiving device 450 is the transmission source of the digital stream data, the projector 300 and the acoustic device 400 each have a data decoder included in the digital stream data transmitted by the digital broadcast receiving device 450. What is necessary is just to comprise so that the decoder of the digital audio | voice signal and video signal according to an encoding standard can be performed.

  Next, a modified example will be described. This modification is characterized in that the projector 300 has a video / audio playback function capable of executing audio playback in addition to video playback. FIG. 2 is a block diagram schematically showing a configuration of a video / audio reproduction system 100 of a modified example. As shown in the drawing, in the video / audio reproduction system 100 of the modified example, the projector 300 includes a built-in speaker 330, and an audio modulator 332, an audio delay unit 334, and an audio reproduction selection device so that audio can be reproduced by the speaker. 336. In this modification, the network driver 310 decodes the audio signal included in the digital stream data in addition to the decoding of the video signal included in the digital stream data (MPEG2 data) received from the network 110 via the network driver 310. Also decode. The data decoder 312 transmits the decoded audio signal data to the audio delay unit 334 together with the synchronization signal included in the digital stream data.

  The audio delay unit 334 determines a delay time that matches the synchronization signal, delays by the delay time, and outputs decoded audio signal data to the audio modulator 332, and the audio modulator 332 converts the decoded audio signal data to analog The sound is reproduced from the built-in speaker 330 after modulation. The sound reproduction selector 336 determines the priority order between sound reproduction by the built-in speaker 330 of the projector 300 and sound reproduction by the speaker 402 of the acoustic device 400, and is operated by the user. For example, when the sound erasure of the projector is selected by a remote controller (not shown) attached to the projector 300, the user desires to reproduce the sound with the speaker 402 included in the acoustic device 400. Audio playback has priority. Therefore, in such a case, the audio reproduction selection device 336 outputs a signal to that effect to the data decoder 312, the video reproduction device 314, and the audio demodulation device 318.

  In the following, explanation will be given in accordance with the determination of the priority order of sound reproduction by the sound reproduction selector 336. When the audio playback selection device 336 gives priority to audio playback on the speaker 402 of the acoustic device 400 as described above, the data decoder 312, the video playback device 314, and the audio demodulator 318 that have received a signal to that effect are the same. It operates in the same manner as the embodiment described above. That is, the data decoder 312 transmits the decoded video signal data to the video player 314, and the video player 314 receives the synchronization signal included in the signal demodulated by the audio demodulator 318 via the signal separator 320, The image forming projection unit 302 reproduces the video while synchronizing based on the synchronizing signal (that is, the synchronizing signal included in the sound reproduced by the speaker 402). In this case, the data decoder 312 may not decode the audio signal included in the digital stream data and transmit the decoded audio signal to the audio delay unit 334, or may decode the audio signal itself. Alternatively, the data transmission to the audio delay unit 334 may not be performed.

  On the other hand, when the audio reproduction selector 336 gives priority to audio reproduction using the built-in speaker 330 included in the projector 300, the data decoder 312 that receives the signal to that effect receives each of the audio signal and video signal included in the digital stream data. The decoded audio signal and the synchronization signal are transmitted to the audio delay unit 334, and the decoded video signal is transmitted to the video player 314 to the video player 314. Also, the audio demodulator 318 stops demodulating the sound collected by the sound collection microphone 316 and stops data delivery to the signal separator 320. Then, since there is no synchronization signal input from the signal separator 320, the video player 314 sequentially transmits the decoded video signal received from the data decoder 312 to the liquid crystal display unit 303 of the image forming projection unit 302. The audio modulator 332 reproduces the video by synchronizing with the video reproduction of the image forming projection unit 302 by the signal output having the delay time determined by the audio delay unit 334 by the audio modulator 332. .

  Therefore, according to the modification described with reference to FIG. 2, in addition to being able to achieve synchronization when the projector 300 and the audio device 400 are separately performing video playback / audio playback, an image can be obtained using only the projector 300. Since the video reproduction by the forming projection unit 302 and the audio reproduction by the built-in speaker 330 can be executed in synchronization with each other, the product value as a single projector 300 is increased.

  Moreover, this modification can also be realized in the following manner. When the sound reproduction priority by the sound reproduction selector 336 is set to the sound from the speaker 402 of the sound device 400, the sound device 400 is obtained from the demodulation result of the sound demodulated by the sound collection microphone 316 in the sound demodulator 318. It is possible to determine that there is no audio reproduction on the other side, or that the audio apparatus 400 is performing audio reproduction based on data different from the digital stream data that is the source of the video in the projector 300. For example, when the sound device 400 is not replayed due to power-off or when sound reproduction is poor due to equipment failure, there is no sound collection by the sound collection microphone 316. In such a case, the speaker 402 of the sound device 400 is used. Even if the audio reproduction priority is given, the projector 300 cannot obtain the synchronization signal from the acoustic device 400 side. Therefore, in this case, the decoded audio signal output from the data decoder 312 to the audio delay unit 334 and the decoded video signal from the data decoder 312 to the video player 314 regardless of the reproduction priority result by the audio reproduction selection unit 336. By performing the signal output, it is possible to synchronize and execute the video reproduction by the image forming projection unit 302 and the audio reproduction by the built-in speaker 330 using only the projector 300.

  In addition, the audio signal demodulated by the audio demodulator 318 and the audio signal decoded by the data decoder 312 are compared with the audio collected by the audio collecting microphone 316, and the audio reproduced by the acoustic device 400 is obtained based on the comparison result. A match / mismatch between the corresponding decoded audio signal and the audio signal decoded by the data decoder 312 of the projector 300 is known. If these two signals match, it can be said that the projector 300 and the audio device 400 are performing video reproduction and audio reproduction based on the same digital stream data. It is possible to give priority to the sound reproduction by the speaker 402 of the other. If the two audio signals do not match, for example, the user listens to audio unrelated to the video from the speaker 402 of the audio device 400 while the projector 300 performs synchronized video playback and audio playback. It can be said that it wants. In this case, since sound reproduction based on different digital stream data is executed by the projector 300 and the sound device 400, the sound device 400 side performs sound reproduction based on the received digital stream data. On the other hand, on the projector 300 side, video playback and audio playback based on the received digital stream data can be executed in synchronization. In this way, while listening to audio unrelated to the video from the speaker 402 of the audio device 400, the projector 300 can cope with the user's request to enjoy synchronized video playback and audio playback, increasing the product value.

  The present invention is not limited to the above-described embodiments and modifications, and can be implemented in various modes without departing from the scope of the invention. For example, the sound collecting microphone 316 and the sound demodulator 318 are used in the above embodiment to acquire the synchronization signal synthesized with the sound signal on the acoustic device 400 side on the projector 300 side. You can also. In other words, the audio device 400 outputs a sound reproduction signal obtained by synthesizing and modulating the synchronization signal to the speaker 402, and modulates and transmits the signal according to a short-range data transmission standard using infrared rays, for example. In place of the sound collecting microphone 316, the above-mentioned audio reproduction signal is received and demodulated by a receiver of the short-range data transmission standard, and the synchronization signal synthesized by the acoustic device 400 is obtained from the signal. You can also.

  Further, although a projector is used as an example of a video playback device, various video playback devices such as a liquid crystal display and a plasma display can be applied. The network 110 can be applied regardless of wired or wireless.

1 is a block diagram schematically showing a configuration of a video / audio reproduction system 100 as an embodiment of the present invention. FIG. It is a block diagram which shows roughly the structure of the video / audio reproduction system 100 of the modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Video / audio reproduction system 110 ... Network 200 ... Content transmission apparatus 202 ... Hard disk (built-in)
204: Hard disk (external)
DESCRIPTION OF SYMBOLS 206 ... Content transmission control part 208 ... Network driver 300 ... Projector 302 ... Image formation projection part 303 ... Liquid crystal display part 304 ... Lens 310 ... Network driver 312 ... Data decoder 314 ... Video player 316 ... Sound collection microphone 318 ... Audio demodulator 320 ... Signal separator 330 ... Built-in speaker 332 ... Audio modulator 334 ... Audio delay device 336 ... Audio reproduction selector 400 ... Sound device 402 ... Speaker 410 ... Network driver 412 ... Data decoder 414 ... Signal synthesizer 416 ... Amplifier 450 ... Digital broadcast receiver S ... Screen

Claims (8)

A video playback device having a video playback device, an audio playback device having an audio playback device, and a content transmission device that is a transmission source of video and audio content including a synchronized video signal and audio signal are connected to a network. And a video / audio reproduction system for transmitting the video / audio content from the content transmission device to the video reproduction device and the audio reproduction device via the network,
The audio playback device
When the input of the video / audio content is received from the content transmission apparatus via the network, the audio signal included in the input video / audio content and the synchronization signal for synchronization included in the video / audio content Is converted into a signal form of a sound reproduction signal suitable for sound reproduction by the sound reproduction device, and a synthesized sound reproduction signal obtained by synthesizing the sound signal and the synchronization signal in the signal form of the sound reproduction signal. A synchronization signal synthesizer to generate,
An audio reproduction unit that outputs the synthesized audio reproduction signal to the audio reproduction device and reproduces the audio by the audio reproduction device;
The video playback device
When receiving the input of the video / audio content from the content transmission device via the network, the video signal included in the received video / audio content is processed for video playback on the video playback device. And generating a video playback signal suitable for video playback on the video playback device, outputting the generated video playback signal to the video playback device, and playing back the video on the video playback device. And
Based on the synchronization signal included in the synthesized audio reproduction signal synthesized by the synchronization signal synthesizing unit of the audio reproduction device, video reproduction by the video reproduction unit is delayed, and audio reproduction from the audio reproduction device and the video A video / audio playback system including a playback synchronization unit that synchronizes with video playback from a playback device. The video / audio reproduction system according to claim 1,
The playback synchronization unit of the video playback device includes:
A sound collection unit that collects sound reproduced by the sound reproduction device of the sound reproduction device;
The sound collected is demodulated to generate a playback audio signal, and the playback audio signal is combined with the synchronization signal when the synchronization signal synthesis unit of the audio playback device generates the synthesized audio playback signal. And a synchronization signal separation unit that separates the synchronization signal from the reproduced audio signal.
A video / audio reproduction system that delays video reproduction by the video reproduction unit based on the separated synchronization signal. The video / audio reproduction system according to claim 2,
The synchronization signal synthesizing unit of the audio reproducing device is
Modulating the synchronization signal into a signal in a frequency range outside the human audible range, and generating the synthesized sound reproduction signal,
The synchronization signal separation unit in the playback synchronization unit of the video playback device is
A video / audio reproduction system in which the reproduction audio signal is subjected to a demodulation process corresponding to the modulation to separate the synchronization signal. The video / audio reproduction system according to any one of claims 1 to 3,
The video playback device
An audio playback device associated with the video playback device;
While converting the audio signal included in the received video / audio content into a signal format of an audio reproduction signal suitable for audio reproduction by the apparatus-associated audio reproduction device, the converted audio reproduction signal A video playback device that synchronizes audio playback on the audio playback device associated with the device and video playback on the video playback device using the video playback signal based on the synchronization signal for synchronization included in the video and audio content An internal synchronization unit,
The audio reproduction device included in the audio reproduction device is configured to determine a priority order of audio reproduction in the audio reproduction device included in the audio reproduction device and audio reproduction in the audio reproduction device associated with the device based on a predetermined order defining condition. A video / audio reproduction system comprising: an in-video reproduction apparatus synchronization stop unit that stops the operation of the in-video reproduction apparatus synchronization unit when priority is given to audio reproduction in the video reproduction apparatus. The video / audio reproduction system according to claim 4,
The video playback device synchronization stop unit is
When the same video / audio content from the content transmission device is transmitted to both the video reproduction device and the audio reproduction device and the audio reproduction is being performed by the audio reproduction device, and the audio reproduction accompanying the device A video / audio playback system that prioritizes audio playback on the audio playback device of the audio playback device, assuming that the ranking regulation condition is satisfied, at least when a user operation to stop audio playback on the device is performed . A video playback device that is connected to a network and is capable of receiving a signal via the network and that plays back a video composed of an input video signal based on the video signal,
When a video / audio content including a video signal and an audio signal that are synchronized is input from the content transmission device that is a transmission source of the video / audio content via the network, the input is included in the received video / audio content The video signal is processed for video playback on a video playback device to generate a video playback signal suitable for video playback on the video playback device, and the generated video playback signal is used as the video playback signal. A video playback unit that outputs to a playback device and plays back the video on the video playback device;
When an audio playback device connected to the network plays back audio composed of the audio signal included in the video / audio content received from the content transmission device via the network based on the audio signal A playback synchronization unit that performs video playback by the video playback unit in synchronization with audio playback in the audio playback device, the playback synchronization unit,
The audio reproduction device that has received the input of the video / audio content converts the audio signal and the synchronization signal included in the video / audio content into audio that is suitable for audio reproduction by the audio reproduction device of the audio reproduction device. Based on the synchronization signal included in the synthesized audio reproduction signal obtained by synthesizing the audio signal and the synchronization signal in the signal form of the audio reproduction signal while converting to the signal form of the reproduction signal, the video by the video reproduction unit A video playback device that delays playback and synchronizes audio playback from the audio playback device of the audio playback device and video playback from the video playback device. The video playback device according to claim 6,
The reproduction synchronization unit
A sound collection unit that collects sound reproduced by the sound reproduction device of the sound reproduction device;
Demodulating the collected audio to generate a reproduced audio signal, and subjecting the reproduced audio signal to a process corresponding to the synthesis of the synchronization signal when the audio reproducing device generates the synthesized audio reproduced signal; A synchronization signal separation unit that separates the synchronization signal from the reproduced audio signal;
A video playback device that delays video playback by the video playback unit based on the separated synchronization signal. The video reproduction device according to claim 6 or 7, wherein
An audio playback device associated with the video playback device;
While converting the audio signal included in the received video / audio content into a signal format of an audio reproduction signal suitable for audio reproduction by the apparatus-associated audio reproduction device, the converted audio reproduction signal A video playback device that synchronizes audio playback on the audio playback device associated with the device and video playback on the video playback device using the video playback signal based on the synchronization signal for synchronization included in the video and audio content An internal synchronization unit,
The audio reproduction device included in the audio reproduction device is configured to determine a priority order of audio reproduction in the audio reproduction device included in the audio reproduction device and audio reproduction in the audio reproduction device associated with the device based on a predetermined order defining condition. A video playback device comprising: an internal video playback device synchronization stop unit that stops the operation of the internal video playback device synchronization unit when giving priority to audio playback in the video playback device.

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