JP2007027928A - Transmitter and transmission method of audio signal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a transmitter and a transmission method of audio signal which are applied to transmission of a multichannel audio signal by infrared ray, for example, such that an audio signal is transmitted by multichannel while utilizing a conventional format for two-channel audio signal effectively. <P>SOLUTION: When a two-channel audio signal is transmitted, assignment of extra information to a subframe for assigning sampling data by the audio signal of each channel is omitted. The subframe is divided and sampling data by the audio signal of a plurality of channels is assigned sequentially and the extra information is assigned to the region of management information. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an audio signal transmission apparatus and an audio signal transmission method, and can be applied to, for example, transmission of multi-channel audio signals by infrared rays. In the present invention, when transmitting a two-channel audio signal, the assignment of additional information to subframes to which sampling data based on the audio signal of each channel is assigned is omitted, and the subframe is divided into a plurality of audio signals. By sequentially allocating sampling data according to, and by assigning additional information to the management information area, it is possible to transmit a multi-channel audio signal by effectively using the conventional format for a two-channel audio signal.

  Conventionally, in the transmission of an audio signal by infrared rays, a stereo audio signal is transmitted based on DIAT (Digital Infrared Audio Transmission) which is an international standard by IEC (International Electrotechnical Commission) -61603-8-1. Yes.

  FIG. 3 is a chart showing the format by this DIAT. The DIAT transmits a stereo audio signal through a series of chapters, and the chapters are created by the structure shown in FIG. That is, a chapter is formed by arranging 384 subframes SF in 12 rows × 32 columns to form a block of subframes, and one column (48 [bytes]) at the end in the column direction of the blocks of the subframes. A management information recording area AR is provided. Also, a parity code in the Reed-Solomon format for one row (33 × 10 [bytes]) is provided at the end in the row direction of the block by the block by this subframe and the management information recording area AR. As indicated by arrows, the DIAT sequentially transmits data according to this chapter structure in the order of raster scanning.

  In addition, as shown in FIG. 3B, the subframes SF that form chapters in this way are sequentially assigned to the right channel and the left channel, respectively. As a result, the two consecutive subframes SF become one frame F.

  Each subframe is formed of 32 bits as shown in FIG. 3A, and the top 4 bits are assigned to a free field to which data can be freely assigned. Here, each manufacturer assigns unique information to the free field, such as the volume of each channel and the total volume of all channels. Subsequently, 24 bits and one sample of audio data are allocated, and the valid flag V, user bit U, channel status C, and parity bit P are sequentially allocated to the remaining 4 bits.

  For such audio signal transmission using infrared rays, various devices have been proposed in, for example, Japanese Patent Laid-Open No. 10-41888.

  By the way, the conventional DIAT format has a drawback that it is difficult to transmit only two-channel audio signals. As a result, there is a problem that multi-channel audio signals of three or more channels cannot be transmitted.

However, if multi-channel audio signals can be transmitted by effectively using such a conventional format for 2-channel audio signals, it can be used, for example, for surround playback of home theater systems using DVD (Digital Versatile Disk) optical disks. Can be considered convenient.
Japanese Patent Laid-Open No. 10-41888

  The present invention has been made in consideration of the above points. An audio signal transmission apparatus and an audio signal transmission apparatus capable of transmitting an audio signal by multi-channel by effectively using a conventional format for a two-channel audio signal. It is intended to propose a transmission method.

  In order to solve such a problem, the invention of claim 1 is applied to an audio signal transmission apparatus for transmitting a multi-channel audio signal, and outputs a format circuit for outputting the audio signal in a predetermined format, and output data of the format circuit. The predetermined format is a format based on a series of chapters in which management information and parity are assigned to a predetermined number of subframes. When transmitting a 2-channel audio signal, the predetermined format is continuous. The sub-frames are alternately assigned to the right channel and the left channel, and audio data sampling data and additional information are assigned to the sub-frames by the audio signal, respectively. When transmitting an audio signal, additional information to be allocated to the subframe is allocated to the recording area of the management information, the allocation of the additional information to the subframe is stopped, the subframe is divided and the multi-frame is divided. The sampling data based on the audio signal of the channel is assigned sequentially.

  Further, the invention of claim 2 is applied to an audio signal transmission method for transmitting a multi-channel audio signal in a predetermined format, wherein the predetermined format is a chapter of a chapter in which management information and parity are assigned to a predetermined number of subframes. When a two-channel audio signal is transmitted in a continuous format, the consecutive subframes are alternately assigned to the right channel and the left channel, and audio data sampling data and additional information are respectively transmitted to the subframes by the audio signal. In the audio signal transmission method, when transmitting the two-channel audio signal, additional information to be assigned to the subframe is assigned to the management information recording area, and is transmitted to the subframe. It stops allocation of the additional information, successively allocated for transmitting the sampling data by the audio signal of the multi-channel by dividing the sub-frame.

  The structure of claim 1 is applied to an audio signal transmission device for transmitting a multi-channel audio signal, and outputs a format circuit for outputting the audio signal in a predetermined format, and modulates and outputs the output data of the format circuit. The predetermined format is a format based on a series of chapters in which management information and parity are assigned to a predetermined number of subframes. When transmitting a two-channel audio signal, the continuous subframes are alternately arranged. Are assigned to the right channel and the left channel, and audio data sampling data and additional information are assigned to the subframes by the audio signal, respectively, and the format circuit transmits the two-channel audio signal. If the additional information to be allocated to the subframe is allocated to the recording area of the management information and the allocation of the additional information to the subframe is stopped, data that can be allocated to one subframe accordingly. The amount will increase. Accordingly, by dividing the subframe and sequentially assigning sampling data based on the multi-channel audio signal, the multi-channel audio signal can be transmitted by effectively using the format for the 2-channel audio signal.

  Thus, according to the configuration of claim 2, it is possible to provide an audio signal transmission method capable of transmitting an audio signal by multi-channel by effectively using the format for 2-channel audio signal.

  According to the present invention, it is possible to transmit a multi-channel audio signal by effectively using a format for a two-channel audio signal.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

(1) Configuration of Embodiment FIG. 2 is a block diagram showing an audio signal transmission apparatus according to an embodiment of the present invention. The audio signal transmission device 1 is applied to a home theater system using, for example, a DVD (Digital Versatile Disk) optical disk, and among 5.1-channel audio signals reproduced by a source source 2 such as an optical disk player or the like, left and right front and left and right The rear four-channel audio signals SA (CH1 to CH4) are transmitted to the amplifier 3 that drives the left and right front and left and right speakers. Therefore, in this audio signal transmission device 1, the transmission device 4 transmits the 4-channel audio signals SA (CH1 to CH4) obtained from the source source 2 by infrared rays, and the reception device 5 receives the audio signals SA (CH1 to CH1). CH4) is received and output to the amplifier 3. Note that the transmission device 4 and the reception device 5 are switched in operation according to a switch setting by the user and transmit a 2-channel audio signal instead of the 4-channel audio signal SA (CH1 to CH4), thereby configuring the home theater system. The number of channels of audio signals used for transmission can be switched corresponding to the above. In this case, the two-channel audio signal is, for example, an audio signal related to driving left and right front speakers, an audio signal related to driving left and right rear speakers, or the like.

  In the transmission device 4, the format circuit 6 divides the audio signal output from the source source 2 in predetermined block units, adds parity and the like, and outputs the audio signal in a predetermined format. Here, when the audio signal to be transmitted is an audio signal with two channels, the format circuit 6 outputs the audio signal in the conventional DIAT format described above with reference to FIG. At this time, valid data is assigned to the free field only for the first 10 subframes, and dummy data is assigned to the remaining subfields. As a result, 4 × 10-bit data is provided as additional information. Assign.

  On the other hand, when the audio signal to be transmitted is an audio signal SA (CH1 to CH4) having four channels, the audio signal is output in a format using the DIAT format similar to the conventional DIAT format.

  Here, as shown in FIGS. 1A to 1D, the format related to the transmission of the audio signal of 4 channels is the same as the format of DIAT, and the audio signal is transmitted by continuous chapters. Further, as shown in FIG. 1C, the chapter is formed by arranging 384 subframes SF by 12 rows × 32 columns in the same manner as the DIAT format, and a block by the subframe SF is formed. A management information recording area AR corresponding to one column (48 [bytes]) is provided at the end of the block in the column direction, and at the end of the block in the row direction of the block by the subframe and the management information recording area AR. A parity code in the Reed-Solomon format for one row (33 × 10 [bytes]) is provided. As with the DIAT format, the format circuit 6 sequentially transmits data of this chapter structure in the raster scan order.

  Further, as shown in FIG. 1B, the subframe SF that forms chapters in this way forms one frame by two consecutive subframes SF. As shown in FIG. 1A, the 32-bit sub-frames constituting one frame are divided by the center, and the 16-bit audio data of each of the channels CH1 to CH4 are sequentially and cyclically allocated. . Accordingly, in this embodiment, a 4-channel audio signal, which is a multi-channel, is transmitted by effectively using the conventional format for a 2-channel audio signal.

  In this case, by assigning the audio signal by dividing the entire subframe SF into two, information assigned to the free field in the DIAT format (hereinafter referred to as additional information) cannot be transmitted. For this reason, as shown in FIG. 1D, the format circuit 6 transmits the additional information assigned to the free field when transmitting the 2-channel audio signal when the 4-channel audio signal is transmitted. Assigned to the recording area AR.

  That is, the management information recording area AR can use 40 [bytes] out of 48 [bytes], and the additional information is allocated to the free area of the 40 [bytes] usable area.

  The format circuit 6 sequentially sets and outputs a synchronization signal, a header, and the like when outputting data according to the chapter set in this way.

  The error correction circuit 9 adds an error correction code based on the Reed-Solomon code to the output data of the format circuit 6 and outputs the result after interleaving. The modulation circuit 10 outputs the output data of the error correction circuit 9 to DQPSK ( (Differential Quadrature Phase Shift Keying) Modulate and output. The light emitting element 11 is formed of, for example, a light emitting diode, and transmits infrared rays according to the output signal of the modulation circuit 10. As a result, the transmission device 4 transmits 2-channel or 4-channel audio signals by infrared rays.

  In the receiving device 5, the light receiving element 12 is formed of, for example, a photodiode, receives the infrared rays transmitted from the transmitting device 4, and outputs a light reception result, and an AGC (Automatic Gain Control) circuit 13 performs this gain control by automatic gain control. The signal level of the light reception result by the light receiving element 12 is corrected and output. The demodulation circuit 14 demodulates and outputs the output data of the error correction circuit 9 of the transmission device 4 by inputting and processing the output signal of the AGC circuit 13. The error correction circuit 15 deinterleaves the output data of the demodulation circuit 14, and then performs error correction processing using an error correction code based on the Reed-Solomon code added at the time of transmission and outputs the result. As a result, the receiving device 5 decodes the output data of the format circuit 6.

  The deformat circuit 16 processes the output data of the error correction circuit 15 in reverse to the format circuit 6 of the transmitter 4, thereby decoding the 4-channel or 2-channel audio signal from the output data, and the amplifier 3. Output to. Further, additional information based on the volume of each channel, total volume, etc. is reproduced, and this additional information is output to the amplifier 3 to control the volume of each channel.

(2) Operation of Embodiment In the above configuration (FIG. 1), the audio signal output from the source source 2 is input to the error correction circuit 9 via the format circuit 6, where an error correction code is added. After the interleaving process, the light is modulated by the modulation circuit 10 and used to drive the light emitting element 11. As a result, in the audio signal transmission device 1, the audio signal from the source source 2 is transmitted from the transmission device 4 by infrared rays.

  The infrared rays transmitted in this way are received by the light receiving element 12 of the receiving device 5, and the light reception results are sequentially processed by the AGC circuit 13, the demodulation circuit 14, and the error correction circuit 15. The audio signal is decoded and output to the amplifier 3.

  When the audio signal transmitted from the transmission device 4 to the reception device 5 in this way is a two-channel audio signal in a stereo system, successive subframes are sequentially assigned to the right channel and the left channel in the format circuit 6. Along with the additional information, the user flag, etc., corresponding sampling data is assigned to each subframe. Also, management information, parity, and the like are assigned to the block of this subframe to form a chunk, and the chunk is transmitted in succession. As a result, in the audio signal transmission apparatus 1, an audio signal with two channels is sent to a transmission target in the DIAT format.

  On the other hand, when this audio signal is an audio signal with four channels, assignment of additional information, user flags, etc. to each subframe is omitted, and a sufficient free area is secured in each subfield. Further, each of the subfields is divided into two parts, which are sequentially and cyclically assigned to 4-channel audio signals, and sampling data based on audio data is assigned. Further, management information, parity, and the like are assigned to blocks by subfields to which audio signals are sequentially assigned in this way, so that a chunk is formed and transmitted by continuation of this chunk. As a result, in this audio signal transmission apparatus 1, the audio signal of 4 channels is sent to the transmission target in a format using the DIAT format.

  Thus, in this embodiment, when transmitting a 2-channel audio signal, the allocation of additional information to subframes to which sampling data based on the audio signals of each channel is allocated is omitted, and the subframe is divided into a plurality of channels. The sampling data based on the audio signals can be sequentially allocated, and the multi-channel audio signal can be transmitted by effectively using the conventional format for the 2-channel audio signal.

  Further, the additional information whose assignment to the sub-frame is stopped in this way is assigned to the management information recording area, so that information such as volume necessary for reproduction of the multi-channel transmitted to the transmission target is also 2 channels. The audio signal can be transmitted by effectively using a conventional format.

(3) Advantages of the Embodiment According to the above configuration, when transmitting a 2-channel audio signal, assignment of additional information to subframes to which sampling data based on the audio signal of each channel is assigned is omitted. By dividing the frame and sequentially assigning sampling data based on the audio signal of a plurality of channels and assigning additional information to the management information area, the multi-channel audio signal can be used effectively by using the conventional format for the 2-channel audio signal. Can be transmitted.

  In the above-described embodiments, the case where the audio signal is transmitted by infrared rays has been described. However, the present invention is not limited to this, and is widely applied to the case where the audio signal is transmitted by various methods such as wireless communication and wired communication. can do.

  In the above-described embodiment, the case where the 4-channel audio signal SA is transmitted by applying to the 5.1 channel home theater system is described. However, the present invention is not limited to this, and the 7.1 channel, 9. The present invention can be widely applied to a surround system having various channels such as one channel.

  The present invention relates to an audio signal transmission apparatus and an audio signal transmission method, and can be applied to, for example, transmission of multi-channel audio signals by infrared rays.

It is a figure represented to description of the format in the audio signal transmission apparatus which concerns on the Example of this invention. It is a block diagram which shows the audio signal transmission apparatus which concerns on the Example of this invention. It is a table | surface used for description of the format of DIAT.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Audio signal transmission apparatus, 4 ... Transmission apparatus, 5 ... Reception apparatus, 6 ... Format circuit, 10 ... Modulation circuit, 16 ... Deformat circuit, 14 ... Demodulation circuit

Claims (2)

An audio signal transmission device for transmitting a multi-channel audio signal,
A format circuit for outputting the audio signal in a predetermined format;
A modulation circuit for modulating and outputting the output data of the format circuit,
The predetermined format is:
It is a format with a series of chapters in which management information and parity are assigned to a predetermined number of subframes,
In the case of transmitting a two-channel audio signal, it is a format in which consecutive subframes are alternately assigned to the right channel and the left channel, and audio data sampling data by the audio signal and additional information are assigned to the subframes, respectively. ,
The format circuit includes:
When transmitting the two-channel audio signal, the additional information allocated to the subframe is allocated to the recording area of the management information, and the allocation of the additional information to the subframe is stopped,
An audio signal transmission apparatus, wherein the subframe is divided and sampling data based on the multi-channel audio signal is sequentially allocated. An audio signal transmission method for transmitting a multi-channel audio signal in a predetermined format,
The predetermined format is
It is a format with a series of chapters in which management information and parity are assigned to a predetermined number of subframes,
In the case of transmitting a two-channel audio signal, it is a format in which consecutive subframes are alternately assigned to the right channel and the left channel, and audio data sampling data by the audio signal and additional information are assigned to the subframes, respectively. ,
The audio signal transmission method includes:
When transmitting the two-channel audio signal, the additional information allocated to the subframe is allocated to the recording area of the management information, and the allocation of the additional information to the subframe is stopped,
A method of transmitting audio signal data, comprising dividing the sub-frame and sequentially assigning and transmitting sampling data based on the multi-channel audio signal.

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