JP6204684B2 - Acoustic signal reproduction device - Google Patents

Description

The present invention relates to audio signal reproducing apparatus of a multi-channel sound system having a plurality of layered sound field.

  In addition to the two-channel and 5.1-channel sound systems currently being produced, multiple sound systems such as the “three-dimensional (three-dimensional) sound system” that exceed the 5.1-channel sound systems such as 7.1 and 22.2 channels are proposed. Has been. The ITU-R, an international standardization organization related to audio, has set requirements (non-patent document 1) for a three-dimensional acoustic system (advanced multichannel audio system) beyond the 5.1 channel acoustic system as an ITU-R recommendation. It is expected that a plurality of acoustic methods will be proposed. By expressing these acoustic systems in a common format, it can be applied to a next-generation audio system and can be a flexible system that can be used in various fields.

"Performance requirements for an advanced multichannel stere ophonic sound system for use with or without accompanying picture", ITU-R recommendation BS. 1909

  As a common format capable of expressing various acoustic systems, “acoustic signals having a single acoustic space layer” are being studied. Here, a sound constructed by a plurality of spatially arranged channel signals is defined as a single acoustic space layer. In conventional program production, all the sounds required for a program are arranged in a single acoustic space layer. Dividing the acoustic space layer that has been integrated into several layers into several layers, producing an audio program, and using the format of "acoustic signal with multiple acoustic space layers", the recipient at the time of program exchange In addition, it is possible to easily transform, convert, and replace the received acoustic signal according to the home environment. Hereinafter, the “multi-channel acoustic system” will be described as intended to be an “acoustic system having a plurality of acoustic spatial layers”.

  For example, a broadcast program broadcast using a multi-channel audio system is produced by various audio systems and reproduced in various reproduction environments. There is also a need for a service that uses information before it is completed as a broadcast program, such as increasing the volume of the sound, such as in an environment where living sounds are loud or outdoors. However, if the sound that is desired to be controlled is silent for a certain period of time from a certain time, transmitting an acoustic channel signal that is silent for a long time during the program will incur a transmission cost. Also, the sound quality required in a program such as narration or music is different, and it is expensive to always transmit a sound method with a high calculation cost.

Accordingly, an object of the present invention made in view of such a point corresponds to a multi-channel acoustic system having a plurality of acoustic space layers, and the acoustic space layer is obtained by time-sharing one acoustic space layer and using a minimum amount of data. the invention is to provide a reproducible audio signal reproducing apparatus.

In order to solve the various problems described above, an acoustic signal reproducing apparatus according to the present invention is a reproduction apparatus of a multi-channel audio signal including a plurality of layered sound field, meta data included in the multichannel sound signals, sound Including the number of spatial layers, the number and content of channels in each acoustic spatial layer, the arrangement of each acoustic channel signal in each acoustic spatial layer, and a plurality of time-divided playback times for each acoustic spatial layer, based on the playback time of each layered sound field described in the metadata, among divided the layered sound to be transmitted when the decoding unit to decode only sound channel signal corresponding to the reproduction time, comprising a playback time adjustment unit for reproducing the combined sound channel signals the decoded playback time.

Also, based on the contents of each acoustic space layer included in the metadata, acoustic space layers having the same contents are defined as a group , and the decoding unit is included in the acoustic space layer selected from the group. Preferably only the acoustic channel signal is decoded.

The decoding unit preferably decodes an acoustic channel signal of another acoustic space layer included in the group in a section where the acoustic channel signal of the selected acoustic space layer is silent.

According to the audio signal reproducing apparatus according to the present invention, it supports multi-channel sound system having a plurality of layered sound field, and reproduces the sound field layer necessary minimum data time-divided single acoustic space layer It becomes possible.

It is a figure which shows the structure of the acoustic signal reproducing | regenerating apparatus which concerns on one Embodiment of this invention. It is a figure which shows an example of the acoustic space layer contained in a multichannel acoustic signal. It is a figure which shows an example of the acoustic channel signal and metadata in a multichannel acoustic signal. It is a figure which shows an example of the acoustic channel signal and metadata in a multichannel acoustic signal. It is a figure which shows an example of the acoustic channel signal and metadata in a multichannel acoustic signal. It is a figure which shows the structure of the acoustic signal production apparatus which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, the present invention corresponds to a multi-channel acoustic signal that is an “acoustic signal having a plurality of acoustic spatial layers”. The applicant has filed a Korean patent application (10-2012-0112984) for “acoustic signals having a single acoustic space layer” and a Japanese patent for “acoustic signals having multiple acoustic space layers”. An application has been filed (Japanese Patent Application 2013-010544).

  FIG. 1 is a diagram showing a configuration of an acoustic signal reproduction device according to an embodiment of the present invention. The acoustic signal reproduction device 10 includes a demultiplexer 11 (DEMUX), a decoding unit 12, a reproduction time adjustment unit 15, and a reproduction channel conversion unit 13. An output signal of the acoustic signal reproduction device 10 is sounded by a speaker 14. As played.

  The demultiplexer 11 separates the input multi-channel audio data stream into metadata and audio channel signals. The demultiplexer 11 outputs the acoustic channel signal to the decoding unit 12, and outputs the metadata to the decoding unit 12, the reproduction time adjustment unit 15, and the reproduction channel conversion unit 13.

  FIG. 2 is a diagram illustrating an example of an acoustic space layer included in a multi-channel acoustic signal (acoustic data stream) in the present embodiment. The multi-channel acoustic signal of FIG. 2 is configured to include two acoustic spatial layers. The first acoustic space layer 200 is a stereo (2ch) acoustic channel (Lch210, Rch220), and reproduces Music (background sound, environmental sound, music, etc.). The second acoustic space layer 300 is a stereo (2ch) acoustic channel (Lch310, Rch320), and reproduces Dialogue (actor dialogue, conversation, etc.).

  FIG. 3 is a diagram illustrating an example of an acoustic channel signal and metadata in the multi-channel acoustic signal illustrated in FIG. The metadata (Sound Essence 000) in FIG. 3 describes that the multi-channel acoustic signal has two acoustic space layers (Sound Field). It is described that the first acoustic space layer 200 (Sound Field 01) is configured in a 2ch stereo system, the acoustic channel signal 210 (Channel 01) is Lch, and the acoustic channel signal 220 (Channel 02) is Rch. Yes. The second acoustic space layer 300 (Sound Field 02) is configured in a 2ch stereo system, but the acoustic channel signal is time-divided into Dialogue 01 (310, 320) and Dialogue 02 (330, 340). The reproduction time of the acoustic channel signal is described in the metadata. That is, the second acoustic space layer 300 is an acoustic space layer including an acoustic channel signal that is time-divided except for a silent section (null section), and the acoustic channel signal 310 (Channel 01) is played back from Lch, sound channel signal 320 (Channel 02) is played back from Rch, and sound channel signal 330 (Channel 01) is played back from Lch and sound channel signal 340 (Channel 02) is played back from Rch from time 0:00 It is written to do so. By describing the playback time in the metadata, transmission in a silent section (null section) in each channel becomes unnecessary, and the transmission cost can be reduced.

  The decoding unit 12 decodes the acoustic channel signal of each acoustic spatial layer based on the reproduction time of the acoustic spatial layer described in the metadata included in the multi-channel acoustic signal, and converts the acoustic channel signal based on the metadata. Group by acoustic space layer. Note that the decoding unit 12 does not have to perform decoding of each audio channel signal other than the time and channel to be reproduced with reference to the metadata. Thereby, the power consumption regarding a decoding can be reduced.

  The reproduction time adjustment unit 15 adjusts the reproduction time of the decoded acoustic channel signal based on the reproduction time of the acoustic space layer described in the metadata included in the multichannel acoustic signal. The reproduction time adjustment unit 15 temporarily stores the grouped sound channel signals in a memory, and adjusts the reproduction time of the sound channel signals by delaying the time until the reproduction time written in the metadata.

  The reproduction channel conversion unit 13 adds the acoustic channel signal whose reproduction time is adjusted for each reproduction channel, and generates an acoustic channel signal to be input to each reproduction speaker.

  As described above, according to the present embodiment, the decoding unit 12 performs the time-division transmission of the acoustic space layer based on the reproduction time of the acoustic space layer described in the metadata included in the multichannel acoustic signal. The audio channel signal is decoded, and the reproduction time adjustment unit 15 adjusts the reproduction time of the decoded audio channel signal. Accordingly, in correspondence with a multi-channel acoustic system having a plurality of acoustic space layers, it is possible to reproduce one acoustic space layer by time-division and reproducing the acoustic space layer with minimum necessary data. Moreover, since the minimum necessary acoustic signal data can be transmitted and reproduced from a desired time, the transmission cost can be suppressed. Furthermore, by not transmitting an acoustic channel signal for which there is no information, transmission of a desired broadcast program and program exchange can be realized at a low transmission cost.

  FIG. 4 is a diagram illustrating another example of an acoustic channel signal and metadata in a multi-channel acoustic signal. In the metadata of FIG. 4 (Sound Essence 000), the multi-channel sound signal has two sound space layers (Sound Field), and the first sound space layer 200 (Sound Field 01) has Music (background sound, Environmental sound, music, etc.), and the second acoustic space layer 300 (Sound Field 02) and the third acoustic space layer 400 (Sound Field 03) are defined as Dialogue (actor dialogue, conversation, etc.) groups It is described that an acoustic space layer selected from the second acoustic space layer 300 and the first acoustic space layer 400 is reproduced. In this case, for example, the second acoustic space layer 300 is Japanese speech, and the third acoustic space layer 400 is commentary broadcasting, English speech, or the like. The decoding unit 12 normally decodes the second acoustic space layer 300 out of the second acoustic space layer 300 and the third acoustic space layer 400, but according to the metadata setting or the input from the user. Thus, decoding can be performed by switching to the sound of the third acoustic space layer 400. In this example, when the viewer selects the third acoustic space layer 400, the decoding unit 12 decodes the third acoustic space layer 400 only in the second section (Dialogue B2), and plays back time. The adjusting unit 15 adjusts the reproduction time of the third acoustic space layer 400. In other sections (sections in which the third acoustic space layer 400 is silent), the acoustic channel signal of the second acoustic space layer 300 which is another acoustic space layer of the group is reproduced. Since the second section, Dialogue A2 and Dialogue B2, have different lengths, different playback times are set. Thus, knowing the playback time in the program can also be applied to correcting the time lag between the video signal and the audio signal.

  As described above, the acoustic space layer group including the acoustic channel signal transmitted in a time division manner by the metadata is defined, and the decoding unit 12 decodes the selected acoustic space layer acoustic channel signal to adjust the reproduction time. When the section 15 adjusts the playback time of the acoustic channel signal of the selected acoustic space layer of the group, for example, when interviewing performers who speak different languages, the playback time is described in the metadata. It is possible to transmit only the minimum necessary data by transmitting only the time zone in which the voice is included without transmitting in the time zone in which the voice is not included.

  Further, in a section where the sound channel signal of the sound space layer for which the play time adjustment unit 15 is selected is silent, by adjusting the play time of the sound channel signal of the other sound space layer of the group, for example, a multi-language program or the like Of the switchable acoustic space layers, the program can be broadcast by automatically switching to an acoustic space layer including valid audio data.

  FIG. 5 is a diagram illustrating another example of an acoustic channel signal and metadata in a multi-channel acoustic signal. FIG. 5 shows an example of switching the sound system in one program. The sound quality required even in the same program is different in scenes that do not have to be a multi-channel sound system, such as narration, or scenes that require a high sense of realism, such as music and sports broadcasts. As shown in FIG. 5, in the case of mainly sound, a two-channel acoustic space layer (Sound field 01, Sound field 03) is used, and in a musical performance scene, a five-channel acoustic space layer (Sound field 02) is used. It is also possible to switch the acoustic space to be transmitted in one program. As described above, it is possible to efficiently transmit an acoustic signal by describing, as metadata, which sound source is reproduced at a certain time in a program.

  FIG. 6 is a diagram showing a configuration of an acoustic signal creation device according to an embodiment of the present invention. The acoustic signal generation device 20 includes a mixer 21, an encoding unit 22, and a multiplexer 23 (MUX).

  The mixer 21 mixes a plurality of acoustic signals, and outputs them to the encoding unit 22 as acoustic channel signals for each acoustic space layer.

  The encoding unit 22 encodes the acoustic channel signal of each acoustic space layer from the mixer 21 and outputs it to the multiplexer 23.

  The multiplexer 23 (multiplexer) multiplexes the time-division acoustic channel signal of the acoustic space layer and the metadata including the reproduction time of the acoustic space layer, and is inputted by a program producer or the like. The data and the encoded acoustic channel signal are multiplexed to create a multi-channel acoustic signal having a plurality of acoustic spatial layers. The multiplexer 23 multiplexes the multi-channel sound signal and transmits it to a remote place such as a home by radio wave or IP line in order to transmit the multi-channel sound signal by broadcasting or transmission. Note that the multiplexer 23 may define a group of acoustic space layers including acoustic channel signals transmitted in a time division manner in the metadata.

  Thus, according to this embodiment, the multiplexer 23 multiplexes the acoustic channel signal representing the acoustic signal of the acoustic space layer and the metadata including the reproduction time of the acoustic space layer. Thereby, on the acoustic signal reproduction apparatus side, it is possible to reproduce the acoustic space layer with the minimum necessary data by time-sharing one acoustic space layer corresponding to the multi-channel acoustic system having a plurality of acoustic space layers. It becomes possible. Moreover, since the minimum necessary acoustic signal data can be transmitted and reproduced from a desired time, the transmission cost can be suppressed. Furthermore, by not transmitting an acoustic channel signal for which there is no information, transmission of a desired broadcast program and program exchange can be realized at a low transmission cost.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each functional unit, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of functional units, steps, etc. can be combined into one or divided. It is.

DESCRIPTION OF SYMBOLS 10 Acoustic signal reproduction | regeneration apparatus 11 Demultiplexer 12 Decoding part 13 Reproduction | regeneration channel conversion part 14 Speaker 15 Reproduction | regeneration time adjustment part 20 Acoustic signal production apparatus 21 Mixer 22 Encoding part 23 Multiplexer (multiplexing part)

Claims (3)

A multi-channel acoustic signal reproducing apparatus including a plurality of acoustic spatial layers,
The metadata included in the multi-channel acoustic signal includes the number of acoustic space layers, the number and contents of channels of each acoustic space layer, the arrangement of each acoustic channel signal in each acoustic space layer, and the time of each acoustic space layer. A plurality of divided playback times, and
Based on the playback time of each layered sound field described in the metadata of the layered sound to be transmitted by time division, and a decoding unit to decode only sound channel signal corresponding to the reproduction time ,
A reproduction time adjustment unit for reproducing the decoded acoustic channel signal in accordance with the reproduction time ;
An acoustic signal reproduction apparatus comprising: Based on the content of each layered sound field included in the metadata, layered sound of the same content is defined as a group, the decoding unit, the acoustic channel included in the acoustic space layer that is selected from the group decoding a signal only, audio signal reproducing apparatus according to claim 1. 3. The acoustic according to claim 2 , wherein the decoding unit decodes an acoustic channel signal of another acoustic space layer included in the group in a section in which the acoustic channel signal of the selected acoustic space layer is silent. Signal reproduction device.

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