JP6228387B2 - 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. In recent years, audio systems with more channels than 5.1ch surround sound systems have been proposed. In order to prevent quality degradation due to channel conversion, it is conceivable to transmit sound channel signals produced by a plurality of multi-channel sound systems so that a multi-channel sound system suitable for the reproduction environment can be selected. However, in order to reduce the calculation cost due to decoding up to unnecessary acoustic channel signals, it is desirable to decode only the acoustic channel signals related to the multi-channel acoustic system that matches the reproduction environment.

Accordingly, an object of the present invention made in view of such a point is to support a multi-channel sound system having a plurality of sound space layers, and to select and decode sound channel signals in the sound space layer suitable for the reproduction environment. It is to provide a signal reproducing apparatus.

In order to solve the above-described problems, an audio signal reproduction device according to the present invention is a multi-channel audio signal reproduction device including a plurality of acoustic space layers completed alone as a broadcast program. and data of the acoustic space layers described in metadata included, have row decoding of the audio channel signals of one of the acoustic space layer that is selected based on the reproduction environment data, acoustic space other than the layered sound field in which the selected A decoding unit that does not decode the acoustic channel signal of the layer .

  The data of the acoustic space layer is related to the number of channels of the acoustic space layer, and the decoding unit is configured to use the one acoustic space layer based on the number of channels of the reproduction environment that is data of the reproduction environment. It is preferable to select

  Further, the data of the acoustic space layer relates to a correspondence between a video and the acoustic space layer, and the decoding unit is configured to select the one acoustic space layer based on a video switching signal that is data of the reproduction environment. It is preferable to select

In addition, when the acoustic space layer is switched to another acoustic space layer, the decoding unit decodes the acoustic channel signals of the acoustic space layer and the other acoustic space layer only for a predetermined period required for switching. Is preferable.

According to the acoustic signal reproducing device of the present invention, it is possible to select and decode an acoustic channel signal of an acoustic space layer suitable for a reproduction environment, corresponding to a multi-channel acoustic system having a plurality of acoustic space layers. .

It is a figure which shows the structure of the acoustic signal reproducing | regenerating apparatus which concerns on the 1st 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 metadata in a multichannel acoustic signal. It is a figure which shows the structure of the acoustic signal reproducing | regenerating apparatus which concerns on the 2nd 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 metadata in a multichannel acoustic signal. It is a figure which shows an example of the noise reduction method at the time of acoustic space layer switching. 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).

(First embodiment)
FIG. 1 is a diagram showing a configuration of an acoustic signal reproduction device according to the first embodiment of the present invention. The acoustic signal reproduction device 10 includes a demultiplexer 11 (DEMUX), a decoding unit 12, and a reproduction channel conversion unit 13. The output signal of the acoustic signal reproduction device 10 is reproduced as sound by the speaker 14.

  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 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 in the present embodiment includes three acoustic spatial layers with the user 100 as the center. In the first acoustic space layer 200, five channels (210 to 250) are arranged around the user 100. In the second acoustic space layer 300, two channels (310, 320) are arranged around the user 100. In the third acoustic space layer 400, one channel (410) is arranged around the user 100. In the present embodiment, these three acoustic space layers are each a complete professional program (complete mix), and are acoustic space layers that have been completed independently as a broadcast program. In other words, even for music of the same program, audio signals produced with different numbers of channels are sent to the viewer as independent acoustic space layers, and the viewer selects and plays the acoustic space layer that matches the playback environment. can do.

  FIG. 3 is a diagram illustrating an example of an acoustic channel signal and metadata in a multi-channel acoustic signal. The metadata (Sound Essence 000) in FIG. 3 describes that the multi-channel sound signal has three sound field layers (Sound Fields) having a role of music. The first acoustic space layer (Sound Field 01) is a complete professional program of 5 channels. For each acoustic channel signal 210-250, the number of the acoustic channel signal (Channel 01-05), the channel label (LRC BL) BR) is described. The second acoustic space layer (Sound Field 02) is a two-channel complete program, and for each acoustic channel signal 310, 320, the number of the acoustic channel signal (Channel 06-07), the channel label (LR) Is described. The third acoustic space layer (Sound Field 03) is a one-channel complete program, and the acoustic channel signal number (Channel 08) and channel label (Mono) are described for the acoustic channel signal 410. .

  The decoding unit 12 decodes the sound channel signal of one sound space layer selected based on the sound space layer data described in the metadata included in the multi-channel sound signal and the reproduction environment data. Note that the reproduction environment data indicates the speaker arrangement (number of channels, channel positions, etc.) of the reproduction environment, the video switching signal described later, etc., and holds data predetermined for each device. It is input from a user through a remote controller or the like.

  In the case of the multi-channel acoustic signals shown in FIGS. 2 and 3, when receiving information indicating that the speaker configuration is 5 channels as the reproduction environment data, the decoding unit 12 selects the first acoustic spatial layer and selects each acoustic channel. Decode the signals 210-250. In addition, when receiving information indicating that the speaker configuration is stereo as the reproduction environment data, the decoding unit 12 selects the second acoustic space layer and decodes the acoustic channel signals 310 and 320. Further, when receiving information indicating that the speaker configuration is monaural as reproduction environment data, the decoding unit 12 selects the third acoustic space layer (Sound Field 03) and decodes the acoustic channel signal 410. Note that the decoding unit 12 refers to the metadata and the reproduction environment data, and for the acoustic space layer that is not to be reproduced, it is not necessary to decode each acoustic channel signal of the acoustic space layer. Thereby, the power consumption regarding a decoding can be reduced.

  The reproduction channel conversion unit 13 appropriately converts and adjusts the decoded acoustic channel signal and outputs it as a signal to each reproduction speaker.

  Thus, according to this embodiment, the decoding unit 12 selects one acoustic space based on the acoustic space layer data described in the metadata included in the multi-channel acoustic signal and the reproduction environment data. Decode the acoustic channel signal of the layer. Accordingly, it is possible to select and decode an acoustic channel signal of an acoustic space layer suitable for a reproduction environment, corresponding to a multi-channel acoustic system having a plurality of acoustic space layers. In addition, since only the decoding related to the acoustic space layer that matches the reproduction environment is performed, the calculation cost related to decoding can be reduced.

  The data of the acoustic space layer relates to the number of channels of the acoustic space layer, and the decoding unit 12 selects one acoustic space layer based on the number of channels of the reproduction environment that is data of the reproduction environment. As a result, the acoustic space layer having the number of channels suitable for the reproduction environment can be selected, and acoustic reproduction with higher presence can be achieved.

(Second Embodiment)
FIG. 4 is a diagram showing a configuration of an acoustic signal reproduction device according to the second embodiment of the present invention. The acoustic signal reproduction device according to the second embodiment includes an acoustic signal switching unit 15 for switching the acoustic space layer in response to the video switching signal from the user in the acoustic signal reproduction device according to the first embodiment. This is an added configuration. For the functional blocks common to the first embodiment, the description overlapping with the first embodiment is omitted.

  FIG. 5 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 in the present embodiment includes two acoustic spatial layers with the user 100 as the center. In the first acoustic space layer 200, two channels (210, 220) are arranged around the user 100. In the second acoustic space layer 300, two channels (310, 320) are arranged around the user 100. In the present embodiment, these two acoustic space layers are each a complete professional program (complete mix), and are acoustic space layers that have been completed independently as a broadcast program. The present embodiment relates to so-called multi-angle content, and switches an acoustic space layer in accordance with switching of video signals in a broadcast program adopting multi-angle.

  FIG. 6 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. 6 describes that the multi-channel acoustic signal has two acoustic space layers (Sound Field) having the role of music. The first acoustic space layer (Sound Field 01) is a complete professional program associated with the video V1, and for each of the acoustic channel signals 210 and 220, an acoustic channel signal number (Channel 01-02), a channel label (LR) is described. The second acoustic space layer (Sound Field 02) is a complete professional program associated with the video V2, and for each acoustic channel signal 310, 320, the number of the acoustic channel signal (Channel 03-04), The channel label (LR) is described.

  When the audio signal switching unit 15 receives a video switching signal from the user to the multi-angle content as reproduction environment data, the audio signal switching unit 15 notifies the decoding unit 12 of the information. For example, when receiving a video switching signal indicating that switching to the video V1 from the user, the acoustic signal switching unit 15 notifies the decoding unit 12 to that effect, and the decoding unit 12 receives the first video signal associated with the video V1. The acoustic channel signal of one acoustic space layer is decoded. Also, when receiving a video switching signal indicating that switching to the video V2 from the user, the acoustic signal switching unit 15 notifies the decoding unit 12 to that effect, and the decoding unit 12 receives the first video signal associated with the video V2. Decode the acoustic channel signals of the two acoustic spatial layers. The decoding unit 12 outputs the decoded acoustic channel signal to the reproduction channel conversion unit 13.

  When the acoustic space layer is switched to another acoustic space layer, the decoding unit 12 decodes the acoustic channel signal of the acoustic space layer before and after the switching for a predetermined period in order to reduce noise at the time of switching the acoustic space layer. Can do. FIG. 7 is a diagram illustrating an example of a noise reduction method at the time of acoustic space layer switching. When the acoustic space layer is switched in synchronization with the video switching, the decoding unit 12 decodes the acoustic channel signal of the acoustic space layer before and after the switching for a predetermined period and outputs the decoded signal to the reproduction channel conversion unit 13. The reproduction channel conversion unit 13 appropriately adjusts the acoustic channel signal of the acoustic space layer before and after switching and outputs it to the speaker 14, so that noise during acoustic space layer switching can be reduced. For example, as shown in FIG. 7, the reproduction channel conversion unit 13 gradually changes the ratio of the acoustic space layer before switching and the ratio of the acoustic space layer after switching, thereby reducing the noise at the time of switching the acoustic space layer. Can be reduced.

  As described above, according to the present embodiment, the data of the acoustic space layer relates to the correspondence between the video and the acoustic space layer, and the decoding unit 12 is based on the switching signal of the video that is the data of the reproduction environment. One acoustic space layer is selected. Accordingly, in multi-angle content, it is possible to switch to a corresponding acoustic space layer in synchronization with video switching, and to provide an acoustic service corresponding to the multi-angle content.

  Moreover, the decoding part 12 decodes the acoustic channel signal of an acoustic space layer and another acoustic space layer for a predetermined period, when switching an acoustic space layer to another acoustic space layer. This makes it possible to reproduce by combining the acoustic channel signals of the acoustic space layer before and after switching for a predetermined period, so that noise during acoustic space layer switching can be reduced.

  FIG. 8 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. Here, each acoustic space layer is an acoustic space layer completed as a broadcast program independently.

  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 (multiplexing unit) multiplexes the acoustic channel signal of the acoustic space layer completed as a broadcast program alone and the metadata including the data related to the selection of the acoustic space layer. The multi-channel acoustic signal having a plurality of acoustic spatial layers is created by multiplexing the metadata inputted by the above and the encoded acoustic channel signal. Here, the data relating to the selection of the acoustic space layer relates to, for example, the number of channels in the acoustic space layer and the correspondence between the video and the acoustic space layer. 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.

  Thus, according to the present embodiment, the multiplexer 23 multiplexes the acoustic channel signal of the acoustic space layer completed as a broadcast program alone and the metadata including data related to the selection of the acoustic space layer. Thereby, on the acoustic signal reproduction apparatus side, it is possible to select and decode the acoustic channel signal of the acoustic space layer suitable for the reproduction environment, corresponding to the multi-channel acoustic system having a plurality of acoustic space layers.

  The acoustic space layer data relates to the number of channels in the acoustic space layer. As a result, the acoustic signal reproduction apparatus can select the acoustic space layer having the number of channels suitable for the reproduction environment, and can reproduce sound with a higher sense of presence.

  The acoustic space layer data relates to the correspondence between the video and the acoustic space layer. As a result, on the audio signal reproduction device side, in the multi-angle content, it is possible to switch to the corresponding acoustic space layer in synchronization with the video switching, and to provide an audio service corresponding to the multi-angle content.

  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, functions included in each member, each means, each step, etc. can be rearranged so as not to be logically contradictory, and a plurality of means, steps, etc. can be combined or divided into one. Is possible.

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

Claims (4)

A multi-channel audio signal reproducing device including a plurality of acoustic space layers completed independently as a broadcast program,
Acoustic wherein the data of the acoustic space layers described in meta data included in the multichannel audio signal, have row decoding of the audio channel signals of one of the acoustic space layer that is selected based on the reproduction environment data, said selected An acoustic signal reproducing apparatus comprising: a decoding unit that does not decode an acoustic channel signal in an acoustic space layer other than the spatial layer . The data of the acoustic space layer relates to the number of channels of the acoustic space layer, and the decoding unit selects the one acoustic space layer based on the number of channels of the reproduction environment that is data of the reproduction environment. The sound signal reproducing apparatus according to claim 1 . The data of the acoustic space layer relates to correspondence between video and the acoustic space layer, and the decoding unit selects the one acoustic space layer based on a video switching signal that is data of the reproduction environment. The sound signal reproducing apparatus according to claim 1 . The decoding unit, when switching the acoustic space layer to another acoustic space layer, decodes the acoustic channel signals of the acoustic space layer and the other acoustic space layer only for a predetermined period required for switching. Item 4. The acoustic signal reproduction device according to any one of Items 1 to 3 .

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