JP6204681B2 - 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, standardization organizations such as ITU and ARIB have proposed volume adjustment methods based on loudness in order to eliminate non-uniformity in sound volume between programs due to differences in production and playback environments. However, the optimum volume adjustment value differs depending on the reproduction environment and the program genre, and the reproduction apparatus side is required to adjust the volume according to the reproduction environment and the viewer's preference.

  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 adjust sound while maintaining the recommended loudness defined for each sound space layer. An object of the present invention is to provide a signal reproduction device and an acoustic signal creation device that creates the acoustic signal.

In order to solve the above-described problems, an audio signal reproduction device according to the present invention reproduces a component constituting a program as an acoustic space layer made up of multi-channel audio signals by overlapping a plurality of acoustic space layers. A multi-channel sound signal reproducing apparatus including a plurality of sound space layers , in which one program is realized, wherein the number of sound space layers included in the multi-channel sound signal and constituting the program, Metadata describing the recommended loudness, program genre, number and arrangement of sound channel signals constituting each sound space layer, recommended loudness of each sound space layer, and contents of each sound space layer the basis, the a volume adjusting unit for adjusting the volume of the entire program by adjusting the volume of each sound field layer, and volume input of the entire multi-channel audio signal from the user A volume input unit that receives a volume input of a specific acoustic space layer, and the volume adjustment unit is a volume input that adjusts the volume of the entire multi-channel acoustic signal based on the recommended loudness of each acoustic space layer. Based on the function of adjusting the volume of each acoustic space layer in conjunction with each other at the same ratio and the volume input for adjusting the volume of the specific acoustic space layer, the volume of the specific acoustic space layer is adjusted. And having a function .

In addition, a microphone and an environment measurement unit that measures environmental sound by the microphone, the volume adjustment unit, the recommended loudness of each acoustic space layer described in the metadata , the volume input, and the environment It is preferable to adjust the volume of each acoustic space layer based on the sound measurement result .

According to the audio signal reproducing apparatus according to the present invention, supports multi-channel sound system having a plurality of layered sound field, it is possible to adjust the volume while maintaining the recommended loudness defined for each sound field layer .

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 volume input part of the acoustic signal reproducing | regenerating apparatus which concerns on 2nd Embodiment. It is a figure which shows the structure of the acoustic signal reproducing | regenerating apparatus which concerns on the 3rd Embodiment of this invention. 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, a volume adjustment unit 15, and a reproduction channel conversion unit 13. An output signal of the acoustic signal reproduction device 10 is output as sound by a speaker 14. 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 volume 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 five-channel acoustic channel (210 to 250), and reproduces Music (background sound, environmental sound, music, etc.). The second acoustic space layer 300 is a stereo (2ch) acoustic channel (310, 320) and reproduces Dialogue (actor dialogue, conversation, etc.).

  FIG. 3 is a diagram illustrating an example of metadata of the multi-channel acoustic signal illustrated in FIG. The metadata (Sound Essence 000) in FIG. 3 describes that the multi-channel sound signal has two sound fields, and the recommended loudness (−24LKFS) and program of the entire multi-channel sound signal. A genre (Talk) is described. The first acoustic space layer 200 (Sound Field 01) is composed of 5 channels, the recommended loudness is −18 LKFS, the acoustic channel signal 210 (Channel 01) is Lch, the acoustic channel signal 220 (Channel 02) is Rch, and the acoustic channel. It is described that the signal 230 (Channel 03) is reproduced from Cch, the acoustic channel signal 240 (Channel 04) is reproduced from BLch, and the acoustic channel signal 250 (Channel 05) is reproduced from BRch. The second acoustic space layer 300 (Sound Field 02) is a 2ch stereo system with a recommended loudness of -25LKFS, the acoustic channel signal 310 (Channel 06) is reproduced from the Lch, and the acoustic channel signal 320 (Channel 07) is reproduced from the Rch. It is described that it is done.

  The decoding unit 12 decodes the acoustic channel signal from the demultiplexer 11 for each channel, and groups the acoustic channel signal for each acoustic spatial layer based on the metadata.

  The volume adjusting unit 15 adjusts the volume of each acoustic space layer based on the recommended loudness of each acoustic space layer described in the metadata. The volume adjusting unit 15 adjusts the volume of each acoustic space layer based on the recommended loudness of each acoustic space layer described in the metadata. For example, in the case of FIG. The volume of each acoustic space layer is adjusted while maintaining the recommended loudness ratio (−18: −25) between the acoustic space layer 200 and the second acoustic space layer 300. Further, when adjusting the volume of the entire multi-channel acoustic signal, the volume adjusting unit 15 changes the loudness change range for each acoustic space layer while using the recommended loudness of each acoustic space layer described in the metadata as a reference. Can be adjusted. For example, in the case of FIG. 3, when the volume adjustment unit 15 lowers the overall volume from −24 LKFS to −28 LKFS, the first acoustic space layer 200 (music) is relatively lowered from −18 LKFS to −24 LKFS. Then, the volume of each acoustic space layer is adjusted according to the role of the acoustic space layer, for example, the second acoustic space layer 300 (sound) is relatively lowered from -25LKFS to -26LKFS. As a result, it is possible to adjust the volume more easily heard according to the content.

  The reproduction channel conversion unit 13 combines a plurality of acoustic space layers into one acoustic space, and generates an acoustic channel signal to be input to each reproduction speaker in accordance with the reproduction environment.

  As described above, according to the present embodiment, the volume adjusting unit 15 adjusts the volume of each acoustic space layer based on the recommended loudness of each acoustic space layer described in the metadata included in the multi-channel acoustic signal. Accordingly, it is possible to adjust the volume while maintaining the recommended loudness defined for each acoustic space layer, corresponding to a multi-channel acoustic system having a plurality of acoustic space layers. It is also possible to adjust the volume of the sound space layer at a desired ratio, such as when the elderly people are difficult to hear the sound, with the recommended sound volume loudness of the sound space layer being reduced and only the background sound loudness being reduced. is there.

(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 has a configuration in which a volume input unit 16 that receives a volume input from a user is added to the acoustic signal reproduction device according to the first embodiment. 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 the volume input unit 16. In FIG. 5A, a key 161 is a broadcast channel selection key, and the keys 162 and 163 receive a volume input from the user as a volume input unit. The key 162 adjusts the volume of the entire multi-channel acoustic signal. When the volume adjusting unit 15 receives the volume input from the key 162, each volume is adjusted based on the recommended loudness of each acoustic space layer described in the metadata. Adjust the volume of the acoustic space layer. For example, in the case of FIG. 3, the volume adjusting unit 15 maintains the recommended loudness ratio (−18: −25) between the first acoustic space layer 200 and the second acoustic space layer 300, and Adjust the volume. The key 163 adjusts the volume of a specific acoustic space layer called voice (Dialogue), and when the volume adjustment unit 15 receives a volume input from the key 163, the volume of the acoustic space layer described in the metadata as Dialogue Adjust. For example, in the case of FIG. 3, the volume adjustment unit 15 adjusts the volume of the second acoustic space layer 300 that is Dialogue. In FIG. 5B, a key 161 is a broadcast channel selection key, and the key 164 and the key 165 accept a volume input from the user as a volume input unit. The key 164 switches the acoustic space layer that is the target of volume adjustment. For example, in the case of FIG. 3, the volume adjustment target is switched between the first acoustic space layer 200 and the second acoustic space layer 300 by the key 164. The key 165 adjusts the volume of the acoustic space layer selected by the key 164. Upon receiving the volume input from the key 165, the volume adjustment unit 15 adjusts the volume of the acoustic space layer selected by the key 164. . For example, in the case of FIG. 3, the volume adjustment unit 15 adjusts the volume of the first acoustic space layer 200 or the second acoustic space layer 300 by selecting the key 164.

  As described above, according to the present embodiment, the acoustic signal reproduction device 10 includes the volume input unit 16 that receives volume input from the user, and the volume adjustment unit 15 sets the recommended loudness of each acoustic space layer described in the metadata. Based on the volume input, the volume of each acoustic space layer is adjusted. As a result, the volume can be adjusted while maintaining the recommended loudness defined for each acoustic space layer. In addition, when a user wants to listen to a specific sound space layer such as a voice, the sound volume can be adjusted for each sound space layer according to the user's preference. As a result, it is possible to make it easy to hear the sound covered with the background sound. Furthermore, it is also possible to select the target acoustic space layer and adjust the volume. Thereby, the volume adjustment part 15 can adjust the volume of each acoustic space layer based on volume input by the ratio of the loudness according to a user preference. Note that the interface of the volume input unit 16 is not limited to FIG.

(Third embodiment)
FIG. 6 is a diagram showing a configuration of an acoustic signal reproduction device according to the third embodiment of the present invention. The acoustic signal reproduction device according to the third embodiment has a configuration in which a microphone 17 and an environment measurement unit 18 that measures environmental sound using the microphone 17 are added to the acoustic signal reproduction device according to the first embodiment. For the functional blocks common to the first embodiment, the description overlapping with the first embodiment is omitted.

  The microphone 17 collects ambient environmental sounds, and the environmental measurement unit 18 estimates the background sound level of the reproduction environment based on the difference between the environmental sound and the reproduction sound, and sets the volume adjustment value of the entire program as a volume adjustment unit. 15 is output. When receiving the volume adjustment value from the environment measurement unit 18, the volume adjustment unit 15 adjusts the volume of each acoustic space layer based on the recommended loudness of each acoustic space layer described in the metadata. It is also possible to increase only the loudness of the sound space layer of the sound, such as when the volume of the entire program becomes too high. For example, in the case of FIG. 3, the volume adjusting unit 15 maintains the recommended loudness ratio (−18: −25) between the first acoustic space layer 200 and the second acoustic space layer 300, and Adjust the volume. However, when the environmental sound is loud, the loudness of the first acoustic space layer 200 (music) and the second acoustic space layer 300 (sound) is increased by the sound (−18: −20). At this time, if the actual environmental sound is followed as it is, the volume adjustment value constantly changes. Therefore, the environmental measurement unit 18 smoothes the environmental sound in the time direction, and a change that needs to be adjusted for a certain time or longer is generated. The configuration may be such that the volume adjustment value is output only when it continues. In a talk program, it is also possible to adjust the volume according to the program genre, such as increasing only the volume of the sound space layer related to audio.

  As described above, according to the present embodiment, the acoustic signal reproduction device 10 includes the microphone 17 and the environment measurement unit 18, and the volume adjustment unit 15 includes the recommended loudness ratio of each acoustic space layer described in the metadata. Or the volume of each acoustic space layer is adjusted according to user preferences or based on environmental sounds. As a result, the volume can be adjusted while maintaining the recommended loudness defined for each acoustic space layer. In addition, by constantly monitoring the reproduction environment with the microphone 17 and the environment measuring unit 18, it is possible to automatically adjust the volume according to the living sound.

  FIG. 7 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 acoustic channel signal of each acoustic space layer and the metadata including the recommended loudness of each acoustic space layer, and includes metadata input by a program producer or the like. The encoded acoustic channel signal is 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.

  Thus, according to this embodiment, the multiplexer 23 multiplexes the acoustic channel signal of each acoustic space layer and the metadata including the recommended loudness of each acoustic space layer. Thereby, on the acoustic signal reproduction device side, it is possible to adjust the volume while maintaining the recommended loudness defined for each acoustic space layer, corresponding to a multi-channel acoustic system having a plurality of acoustic space layers.

  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 Playback channel conversion part 14 Speaker 15 Volume adjustment part 16 Volume input part 17 Microphone 18 Environment measurement part 20 Acoustic signal production apparatus 21 Mixer 22 Encoding part 23 Multiplexer (multiplexing part) )

Claims (2)

Multi-channel sound including multiple sound space layers , in which a single program is realized by using a plurality of sound space layers superimposed on each other as a sound space layer composed of multi-channel sound signals. A signal reproducing device,
Included in the multi-channel audio signal, the number of sound space layers constituting the program, the recommended loudness of the entire program, the program genre, the number and arrangement of the sound channel signals constituting each sound space layer, A volume adjusting unit that adjusts the volume of the entire program by adjusting the volume of each acoustic space layer based on the metadata that describes the recommended loudness of the acoustic space layer and the content of each acoustic space layer ;
A volume input unit for receiving a volume input of the entire multi-channel audio signal and a volume input of a specific acoustic space layer from a user;
With
The sound volume adjustment unit adjusts the sound volume of each acoustic space layer at the same rate based on the volume input for adjusting the sound volume of the entire multi-channel sound signal based on the recommended loudness of each sound space layer. And a function for adjusting the volume of the specific acoustic space layer based on a volume input for adjusting the volume of the specific acoustic space layer . A microphone,
An environmental measurement unit that measures environmental sound with the microphone;
The volume adjustment unit adjusts the volume of each acoustic space layer based on the recommended loudness of each acoustic space layer described in the metadata , the volume input, and the measurement result of the environmental sound. The acoustic signal reproducing device described in 1.

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