JP6228389B2 - 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 program production, the video on the screen may match the sound image, but the viewing angle assumed for the video format proposed as the next-generation broadcast format is as large as 30 to 100 degrees, for example. Even if the speakers are installed at the same spatial position, the role of the speakers may differ depending on the video format.

Accordingly, an object of the present invention made in view of the above point is to support a multi-channel audio system having a plurality of acoustic space layers, and to appropriately select and reproduce an audio channel signal having a role corresponding to a video format. An object is to provide an acoustic signal reproducing device.

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 respectively corresponding to different video formats, and the multi-channel audio signal is an audio signal. includes a video format corresponding to the space layer in the metadata, the video format corresponding to the acoustic space layer, have row decoding of the audio channel signals of a single layered sound field selected on the basis of the video format of the playback environment, A decoding unit that does not decode an acoustic channel signal of an acoustic space layer other than the selected acoustic space layer .

  In addition, when the screen layout of the playback environment is different from the standard layout for the video format, among the acoustic channel signals, an acoustic channel signal that is linked to the screen is played from the acoustic channel position in the screen layout of the playback environment. It is preferable that a reproduction channel conversion unit for converting the acoustic channel signal is provided.

  In addition, when the speaker arrangement of the reproduction environment is different from the standard arrangement for the video format, the audio channel signal that is not linked to the screen among the audio channel signals is reproduced from the standard arrangement for the video format. It is preferable to include a reproduction channel conversion unit that converts channel signals.

According to the audio signal reproducing device of the present invention, it is possible to appropriately select and reproduce an audio channel signal having a role corresponding to a video format, corresponding to a multi-channel audio system having a plurality of acoustic space layers. Become.

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 screen arrangement | positioning of the sound space layer and video format which are contained in a multichannel sound signal. It is a figure which shows an example of the metadata in a multichannel acoustic signal. It is a figure which shows the difference in the role of the channel by a video format. It is a figure which shows conversion of an acoustic channel signal when the screen arrangement | positioning of a reproduction environment differs from the standard arrangement | positioning with respect to a video format. It is a figure which shows conversion of an audio channel signal when the speaker arrangement | positioning of a reproduction environment differs from the standard arrangement | positioning with respect to a video format. It is a figure which shows the relationship between the acoustic channel position in the screen arrangement | positioning of reproduction | regeneration environment, and the standard arrangement | positioning with respect to a video format. It is a figure which shows the outline | summary of an amplitude panning method. 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, 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 a screen arrangement of an acoustic space layer and a video format included in a multichannel audio signal (acoustic data stream) in the present embodiment. The acoustic space layer 100 shown in FIG. 2 has 10 channels (110 to 200) arranged around the user. In addition, as shown in the drawing, the screen layout 320 corresponding to UHDTV-1 (4K) which is a video format of UHDTV (Ultra High Definition Television) and the screen layout 310 corresponding to UHDTV-2 (Super Hi-Vision) have a viewing angle. Are different.

  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 includes a single sound field layer (Sound Field) in which the multi-channel sound signal plays a role of voice (Talk), and each of the video formats UHDTV-2 and UHDTV-1 On the other hand, it is described that the first acoustic space layer (Sound Field 01) and the second acoustic space layer (Sound Field 02) correspond.

  The first acoustic space layer (Sound Field 01) corresponds to UHDTV-2 and is a 10-channel complete program (complete mix, a program that contains all the sounds necessary for playback). Is 60 degrees. Also, for each acoustic channel signal 110-200, whether the acoustic channel signal number (Channel 01-10), channel label (FL FR FLc FRc FC SiL SiR BL BR BC), and the position of each channel are linked to the screen (Linked / Unlinked) is described.

  The second acoustic space layer (Sound Field 02) corresponds to UHDTV-1 and is a 10 channel complete professional program (complete mix, a program that contains all the sounds necessary for playback). Is 30 degrees. Also, for each acoustic channel signal 110-200, whether the acoustic channel signal number (Channel 01-10), channel label (FLw FRw FL FR FC SiL SiR BL BR BC), and the position of each channel are linked to the screen (Linked / Unlinked) is described. As described above, in the first acoustic space layer and the second acoustic space layer, the arrangement of the channels is the same spatial position, but the roles of the left and right channels (channel labels) are different.

  FIG. 4 is a diagram illustrating the difference in channel roles depending on the video format. FIG. 4A shows a screen layout 320 corresponding to UHDTV-1 and the role of each channel. In the case of UHDTV-1, the channel 130 corresponding to both ends of the screen arrangement 320 is Lch, and the channel 140 is Rch. Further, the channel 110 outside (wide side) from the channel 130 is the Lw channel, and the channel 120 outside the channel 140 is the Rw channel.

  FIG. 4B is a diagram showing a screen layout 310 corresponding to UHDTV-2 and the role of each channel. In the case of UHDTV-2, the channel 110 corresponding to both ends of the screen arrangement 310 is Lch and the channel 120 is Rch. Further, the channel 130 on the inner side (center side) from the channel 110 is the Lc channel, and the channel 140 on the inner side from the channel 120 is the Rc channel.

  In FIG. 4, Lch and Rch, which are channels on both sides of the screen, are taken as an example, but the roles of other channels including LEF (effect channel for low frequency band) also change depending on the video format. There is.

  The decoding unit 12 selects an acoustic space layer corresponding to the reproduction environment based on the metadata and the reproduction environment data included in the multi-channel audio signal, and decodes the acoustic channel signal included in the selected acoustic space layer. The reproduction environment data is a video format, a screen size, a speaker arrangement, a user position, and the like, and is data set in advance for each device or data input from the user through a remote controller or the like.

  In the case of the multi-channel audio signal shown in FIGS. 2 and 3, when the decoding unit 12 receives information indicating that the video format is UHDTV-2 as the reproduction environment data, the decoding unit 12 displays the first acoustic space layer (Sound Field 01). Select and decode each acoustic channel signal 110-200. In addition, when receiving information indicating that the video format is UHDTV-1 as the reproduction environment data, the decoding unit 12 selects the second acoustic space layer (Sound Field 02), and stores each of the acoustic channel signals 110 to 200. Decrypt. 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 generates an acoustic channel signal to be input to each reproduction speaker based on the metadata and the reproduction environment data. When the screen layout and the speaker layout of the playback environment are the same as the standard layout (standard layout) for the video format or within a predetermined allowable range, the playback channel conversion unit 13 receives the sound channel from the corresponding speaker as it is. Play the signal. As a result, it is possible to prevent deterioration of sound quality due to unnecessary signal processing. The standard layout for the video format related to the screen layout and the speaker layout is an ideal playback environment in each acoustic space layer. For example, the standard layout is determined based on the standard, or the playback environment assumed by the program producer is appropriately set. It can be. The reproduction channel conversion unit 13 converts an audio channel signal when the screen arrangement and the speaker arrangement of the reproduction environment are different from the standard arrangement for the video format (over an allowable range).

  FIG. 5 shows the conversion of sound channel signals when the screen layout of the playback environment is different from the standard layout for the video format. Here, it is assumed that the standard layout of the UHDTV-2 screen layout and speaker layout is the screen layout 310 and the channels 110 to 200 shown in FIG. In FIG. 5, the screen layout 310 is different from the standard layout of UHDTV-2 shown in FIG. For this reason, the acoustic channel positions in the screen layout of the reproduction environment are different from the standard channels 110, 130, 140, and 120 as illustrated as the L channel 410, the Lc channel 430, the Rc channel 440, and the R channel 420. It becomes. In the metadata of FIG. 3, among the first acoustic space layers corresponding to UHDTV-2, the acoustic channel signals 110 to 150 describe that the position of each channel is linked to the screen (Linked). When the screen layout is different from the standard layout, it is necessary to convert the playback position of the acoustic channel signal linked with the screen. Therefore, the reproduction channel conversion unit 13 converts the acoustic channel signals 110 to 140 so that a virtual sound image is generated at the positions of the channels 410 to 440 shown in FIG. Note that the conversion of the acoustic channel signal can be omitted for the acoustic channel signal 150 in which the channel position is not changed by the change in the screen layout. Moreover, since the position of each channel of the acoustic channel signals 160 to 200 is not linked to the screen (UnLinked), the reproduction channel conversion unit 13 reproduces the acoustic channel signal from the corresponding speaker as it is.

  FIG. 6 shows the conversion of the acoustic channel signal when the speaker arrangement in the reproduction environment is different from the standard arrangement for the video format. In FIG. 6, the screen layout 310 is different from the standard screen layout of UHDTV-2 shown in FIG. 4B, and the channels 110 to 140 are respectively set corresponding to the acoustic channel positions in the screen layout of the playback environment. The L channel 210, the Lc channel 230, the Rc channel 240, and the R channel 220 are arranged at positions. In the metadata of FIG. 3, among the first acoustic space layers corresponding to UHDTV-2, the acoustic channel signals 110 to 150 describe that the position of each channel is linked to the screen (Linked). In the case of FIG. 6, since the speaker arrangement is the acoustic channel position in the screen arrangement of the reproduction environment, the reproduction channel conversion unit 13 reproduces the acoustic channel signals from the corresponding speakers as they are as the acoustic channel signals 110 to 150. In addition, since the position of each channel is not linked to the screen (UnLinked) in the acoustic channel signals 160 to 200, the reproduction channel conversion unit 13 generates a sound image so that a virtual sound image is generated at the position of the standard arrangement of the corresponding speaker. Performs channel signal conversion.

  FIG. 7 is a diagram showing the relationship between the speakers arranged in accordance with the reproduction environment and the standard arrangement for the video format. Channels 210 and 220 are speakers arranged in accordance with the screen layout of the reproduction environment, and channels 110 to 200 indicate a standard layout of speakers in the video format. In FIG. 7, when the metadata of the Lch acoustic channel signal describes that the channel position is linked to the screen (Linked), the reproduction channel conversion unit 13 reproduces the Lch acoustic channel signal as it is from the channel 210. Let Further, when the metadata of the Lch acoustic channel signal describes that the channel position is not linked to the screen (Unlinked), the reproduction channel conversion unit 13 generates a virtual sound image at the channel 110 position. , Conversion of acoustic channel signals.

  Any suitable method can be used to generate the virtual sound image by the reproduction channel conversion unit 13. For example, as a method of converting an acoustic channel signal, there is a method of converting so that VBAP (Vector Base Amplitude Panning) and acoustic intensity match. In addition, the acoustic channel signal may be rendered by a method such as WFS (Wave Field Synthesis).

FIG. 8 is a diagram showing an outline of an amplitude panning method which is an example of a method for converting an acoustic channel signal. In the amplitude panning method, in order to generate a virtual sound image at the position of the speaker SP13, speakers SP22 and SP23 which are adjacent speakers across the direction of the virtual sound image are used. Sound channel signals S (t) is considered the case where it is distributed to left and right speakers SP23 and SP22 by the weight coefficient _{W L} and _{W R.} When the angle between the speakers SP23 and SP22 is 2θ and the angle from the center of the speakers SP23 and SP22 to the virtual sound image (speaker SP13) is φ, the tangent law in the amplitude panning method is used to localize the sound to the angle φ. weight coefficient _{W L} and _{W R} is represented by the formula (1).

Here, when 1 the sum of the weighting factors _{W L} and _{W R,} the denominator of the right side becomes 1 of the formula (1), the weight coefficient _{W L} and _{W R} formula (2) is derived.

As described above, the reproduction channel conversion unit 13 has the acoustic signals S _L (t) and S to be reproduced from the speakers SP22 and SP23 shown in Expression (3) for the acoustic channel signal S (t) assigned to the speaker SP13. By converting to _R (t), it is possible to correct the speaker position by the virtual sound image.

  Thus, according to the present embodiment, the decoding unit 12 selects based on the video format corresponding to the acoustic space layer described in the metadata included in the multi-channel audio signal and the video format of the playback environment. The acoustic channel signal of one acoustic space layer is decoded. Accordingly, it is possible to appropriately select and reproduce an acoustic channel signal having a role corresponding to a video format, corresponding to a multi-channel acoustic system having a plurality of acoustic space layers.

  In addition, when the screen layout of the playback environment is different from the standard layout with respect to the video format, the playback channel conversion unit 13 determines that the acoustic channel signal that is linked to the screen out of the acoustic channel signals from the acoustic channel position in the screen layout of the playback environment. The sound channel signal is converted so as to be reproduced. As a result, even when the screen layout of the playback environment is different from the standard layout for the video format, it is possible to convert an appropriate sound channel signal, and sound playback with higher presence can be realized.

  In addition, when the speaker arrangement in the reproduction environment is different from the standard arrangement for the video format, the reproduction channel conversion unit 13 causes the audio channel signal that is not linked to the screen among the audio channel signals to be reproduced from the standard arrangement for the video format. The sound channel signal is converted. As a result, even when the speaker arrangement in the reproduction environment is different from the standard arrangement for the video format, it is possible to convert an appropriate sound channel signal, and it is possible to reproduce sound with a higher sense of reality.

  FIG. 9 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 sound channel signal of the sound space layer and the metadata including the corresponding video format of the sound 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 the acoustic space layer and the metadata including the video format corresponding to the acoustic space layer. As a result, on the acoustic signal reproduction device side, it is possible to appropriately select and reproduce an acoustic channel signal corresponding to a multi-channel acoustic system having a plurality of acoustic space layers and having a role corresponding to a video format.

  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 20 Acoustic signal production apparatus 21 Mixer 22 Encoding part 23 Multiplexer (multiplexing part)

Claims (3)

A multi-channel audio signal reproducing apparatus including a plurality of sound space layers corresponding to different video formats ,
The multi-channel audio signal includes a video format corresponding to the audio space layer in the metadata, and an audio channel signal of one audio space layer selected based on the video format corresponding to the audio space layer and the video format of the reproduction environment decoding gastric row, audio signal reproducing apparatus including a decoding unit, which does not perform the decoding of the audio channel signals of the acoustic space layer other than the layered sound field in which the selected. When the screen layout of the playback environment is different from the standard layout for the video format, among the acoustic channel signals, an acoustic channel signal that is linked to the screen is played back from the acoustic channel position in the screen layout of the playback environment. The acoustic signal reproduction device according to claim 1 , further comprising a reproduction channel conversion unit that performs conversion of the acoustic channel signal. When the speaker arrangement of the playback environment is different from the standard arrangement for the video format, the audio channel signal is reproduced from the standard arrangement for the video format among the audio channel signals. The audio signal reproduction device according to claim 1 , further comprising: a reproduction channel conversion unit that performs the conversion.

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