KR950010738B1 - Audio transmitting apparatus of catv - Google Patents

Abstract

The device consists of 14 stereo audio coding units which input the analog or digital signals of a channel and encode them, a DS3 level stereo audio multiplexing unit which outputs DS3 level stereo audio signals to an optical CATV transmitting network, a DS3 level stereo audio de-multiplexing unit which de-multiplexes the signals of 14 channels by feeding back the output of the DS3 level stereo audio multiplexing unit, an optical CATV stereo audio transmitting system which has Nth stereo audio coding units, a DS3 level stereo audio de-multiplexing unit which de-multiplexes stereo audio signals, received from the optical CATV transmitting network, and a stereo audio receiving system which has the stereo audio coding unit that encode the output of the DS3 level stereo audio de-multiplexing unit and outputs.

Description

Stereo Audio Transmitter for Optical CATV

1 is a block diagram of a stereo audio transmission device for optical CATV.

2 is a block diagram of a stereo audio encoder / decoder.

3 is a block diagram of a block in the optical CATV digital audio transmission format.

4 is a configuration diagram of a subframe in the optical CATV digital audio transmission format.

5 is a configuration diagram of sync bits in the optical CATV digital audio transmission format.

6 is a block diagram of a DS3 stereo audio multiplexing / demultiplexing apparatus.

7 is a frame diagram of a DS3 grade stereo audio multiplexing / demultiplexing apparatus.

8 is an exemplary diagram of channel coding in an AES / EBU access rule.

* Explanation of symbols for main parts of the drawings

1: Signal input device 2: Optical CATV digital audio transmission device

3: Optical CATV Stereo Audio Transmission System

4: Stereo Audio Encoder / Decoder Device

5: stereo audio encoder 6: stereo audio multiplexer / demultiplexer

7: Stereo Audio Multiplexer 8: Stereo Audio Receiving System

9: optical transmission device 10: optical CATV transmission network

11: audio demultiplexer 12: stereo audio decoder

13 subscriber terminal 14 stereo audio demultiplexer

15: stereo audio decoder

The present invention relates to a stereo audio transmission apparatus for optical CATV capable of transmitting 14 channels of stereo audio through a transmission channel.

Since a conventional audio signal is transmitted through a coaxial line in an analog form, there is a problem that the signal is easily distorted in the transmission process and difficult to recover when distorted.

Accordingly, the present invention has been made to solve the above problems, to provide a stereo audio device for optical CATV required for the transmission of analog or digital audio signals in the optical CATV consisting of a transmission device for accommodating DS3, a double rate layer. The purpose is.

In order to achieve the above object, the present invention provides a signal input device for generating an analog / digital signal of 14 channels, a stereo audio transmitter for inputting an analog / digital audio signal of 14 channels by the signal input device, and the stereo. An optical transmission device having an output of an audio transmission device, an optical CATV transmission network receiving a signal transmitted by the optical transmission device, and a subscriber station device connected to the optical CATV transmission network and connected to the audio transmission device.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a block diagram of an optical CATV transmission system including a stereo audio transmission device for an optical CATV of the present invention, in which 1 is a signal input device, 2 is a stereo audio transmission device, 3 is a transmission system, and 4 is a stereo system. Audio encoder / decoder device, 5 is stereo audio encoder, 12 is stereo audio decoder, 6 is stereo audio multiplexer / demultiplexer, 7 is stereo audio multiplexer, 8 is stereo audio receiving system, 11 is audio demultiplexer, 9 Denotes an optical transmission apparatus, 10 denotes a transmission network, 13 denotes a subscriber station, 14 denotes a stereo audio demultiplexer, and 15 denotes a stereo audio decoder.

As shown in the drawing, the optical CATV transmission system including the present invention first receives and decodes a broadcast output signal output from a broadcast source as an analog or digital audio signal of 14 channels through the signal input device 1, and then DS3. An optical CATV stereo audio transmitter (2) for multiplexing and outputting to a stereo audio signal, and demultiplexing and decoding the DS3 stereo audio signal input to the subscriber, and supplying it to the subscriber's audio playback device; An optical transmission device 9 which receives the output of 2) and outputs it as an optical signal, an optical CATV transmission network 10 receiving a signal transmitted by the optical transmission device 9, and an optical CATV transmission network 10; The optical CATV stereo audio transmitter 2 includes a subscriber station 13 connected to the audio transmitter 2.

In the optical CATV stereo audio transmission device 2 of the present invention, a function unit for encoding and transmitting is installed on the broadcasting source side, and a function unit for demultiplexing and decoding upon receiving a signal input is installed on the subscriber side.

That is, 14 stereo audio encoders 5 for receiving and encoding 14 channels of analog or digital audio signals from the signal input device 1, and 14 stereo audio encoders 5 to receive the output of the DS3 stereo Multiplexed audio signals are outputted to the optical CATV transmission network through the optical transmission device 9 through a 44.736 Mbps channel, and the DS3 level stereo audio multiplexer 7 receives the feedback from the DS3 level stereo audio multiplexer 7. Decoded DS3 stereo audio demultiplexer 11 for demultiplexing and outputting 14-channel signals, and decoded output of the DS3 grade stereo audio demultiplexer 11 for monitoring by an audio reproducing apparatus on the broadcasting side. The optical CATV stereo audio transmission system 3 having 14 stereo audio decoders 12 to be provided is installed on the broadcasting source side (such as a broadcasting station), and the optical DS3 stereo audio demultiplexer 14 for receiving and demultiplexing stereo audio signals received through CATV transmission network 10 through subscriber terminal device 13 and outputs of DS3 stereo audio demultiplexer 14 The stereo audio transmission system 8 provided with the stereo audio decoder 15 which decodes and outputs to the subscriber audio reproduction apparatus according to the output selection signal is installed in the subscriber's home.

Such an optical CATV stereo audio transmission device 2 configures an optical CATV digital audio transmission format to input and output digital audio and transmits digital audio data.

FIG. 2A is a block diagram of a stereo audio encoder for optical CATV, and FIG. 2B is a block diagram of a decoder. In FIG. 20, a digital input processor, 21 an analog input processor, 22 a digital audio transmission format component, and 23 The digital audio transmission format receiver 24 denotes a digital output processor and 25 denotes an analog output processor.

As shown in FIG. 2A, the optical CATV stereo audio encoder includes a digital input processor 20 for receiving and processing a digital audio signal, an analog input processor 21 for receiving and processing an analog audio signal, and the digital. A digital audio transmission format configuration section 22 for receiving the output of the input processing section 20 and the analog input processing section 21 to form a digital audio transmission format for optical CATV and outputting the formatted digital audio data and a data clock is provided.

In addition, as shown in FIG. 2B, the stereo audio decoder for optical CATV includes a digital audio transmission format receiving unit 23 that receives a signal configured by the digital audio transmission format forming unit 23 on the transmitting side, and the digital audio transmission. A digital output processor 24 for outputting a digital audio signal by inputting a signal received by the format receiver 23 and an analog output signal for outputting an analog audio signal as an output signal of the digital audio transmission format receiver 23 as an input. An output processor 25 is provided.

Referring to the linkage operation of the encoder and the decoder configured as described above in detail, the analog input signal is output to the optical CATV digital audio transmission format configuration unit 22 through the analog input processing unit 21, the analog input processing unit 21. ) Converts the input analog signal into 48KHz, 16-bit PCM audio signal and generates the synchronization bits, auxiliary data, V, O, C, and P bits necessary for configuring the optical CATV digital audio transmission format. The sync bit, auxiliary data, audio sample data, V, U, C, and P data output by the analog input processing unit 21 are configured and output as a transmission format by the optical CATV digital audio transmission format configuration unit 22, and output. The received signal is extracted as an original signal by the receiving side digital audio transmission format receiving unit 23 and output as an analog audio signal through the analog output processing unit 25.

In the case of the digital input signal, the digital input processing unit 20, the digital audio transmission format configuring unit 22, the digital output processing unit 24, and the digital audio transmission format receiving unit 23 are performed in the same manner as the analog input signal. Outputs a digital audio output signal.

FIG. 3 is a block diagram of a block in an optical CATV digital audio transmission format configured in the optical CATV digital audio transmission format configuration shown in FIG. 2. FIG. 4 is a block diagram of a subframe in an optical CATV digital audio transmission format. This is a block diagram of sync bits in the optical CATV digital audio transmission format.

Referring to the drawings, the optical CATV digital audio transmission format will be described.

The digital audio transmission format for optical CATV is the same except for the sync bit section in the format configuration in the AES / EBU digital audio connection standard. That is, 192 frames constitute one block 30, and one frame 31 includes two subframes 33 and 34. The subframe consists of 32 unit times (40 of FIG. 4), which is 1 / 3.072 MHz, which is equal to the length of the data clock output from the digital audio transmission format constructing unit 22 of FIG. When 32 unit times in a subframe are named as unit time 40-1, unit time 40-2, and the like, the data format of the subframe unit time interval 40-5 to 40-32 is AES / EBU. Same as format configuration of connection standard. In the subframe unit times 40-1 to 40-4, 4 bits for frame synchronization determined by the optical CATV are transmitted.

The format configuration of the unit time intervals 40-5 to 40-32 is as follows.

4 bits of auxiliary data in unit time (40-5 to 40-8), 20 bits of audio sample data in (40-9 to 40-28), and international digital audio connection standard in (40-29 to 40-32). Transmit the specified V, U, C, P bits. Here, the V bits 40-29 are bits for transmitting information on the reliability of the transmitted data, the U bits 40-30 are user bits, the C bits 40-31 are bits related to channel status, and the P bits. 40-32 are parity bits for data during the unit time (40-5 to 40-31) of the corresponding subframe. The left audio sample data is transmitted in the unit time 40-9 to 40-28 of the subframe 33, and the right audio sample data is transmitted in the unit time 40-9 to 40-28 of the subframe 34. do.

The configuration of the synchronization bits located in the subframe unit times 40-1 to 40-4 is as follows.

The frame synchronization bits located in the subframe unit time 40-1 to 40-4 are respectively set to the sync bits 50-1 and 51-1, the sync bits 50-2 and 51-2, and the sync bits 50-. 3, 51-3) and when the sync bits 50-4 and 51-4 are named, the sync bits 50-3 and 51-3 are bits that distinguish left and right sides of audio sample data and are left. &Quot; 0 " 52-1, and " 1 " 53-1 if right. Sync bits 50-4 and 51-4 are bits indicating the start of block 30, and are transmitted as "1" (54-1, 55-1) in frame 1 at which block 33 starts, and the remaining frames. 2 to 192 are transmitted as "0" (52-2, 53-2). The sync bits 50-2 and 1-2 are transmitted as "0" when they are not used as "1" while the actual audio signal is being transmitted. The sync bits 50-1 and 51-1 are always transmitted at " 1 ". Therefore, the 4-bit frame synchronization bit 38 is transmitted to 1,1,0,1 (54) through the subframes 50 and 33 of frame 1, as shown in FIG. Through 34, 1,1,1,1 (55). In the frames 2 through 192, the subframes 50 and 35 are transmitted to 1,1,0,0 (52), and the subframes 51 and 36 are 1,1,1,0 (53). Is sent to. The patterns of synchronization bits of the subframe 34 of the subframe 33 of the frame 39 are referred to as X'37 and Y'38, respectively, and the subframes 35 of the frames 2 to 192 When the sync bit patterns of the subframe 36 are X (39) and Y (40), respectively, the digital audio transmission format receiver 23 for the optical CATV of the decoder selects the X, Y patterns 39,40. First, find the subframe sections 35 and 36, and the audio sample data in the unit time (40-9 to 40-28) and the V, U of the unit time (40-29, 40-30, 40-32), The P data is obtained, and the synchronization bit patterns X'37 and Y'38 are found to obtain C data 79 of unit time 31 in which data is organized in units of blocks 30.

In case of digital input, it is channel coded because it comes to AES / EBU digital connection standard. An example of channel coding is that when data is "1", conversion occurs in the middle of the clock, and when "0", conversion does not occur, and conversion always occurs between clocks (Bi-Phase Mark Code). However, in the sync pattern section, a pattern that deviates from the above-described rule is inserted to find the start of the subframe section 33, 34, the frame section 31, and the section 30 of the block. Therefore, this AES / EBU standard signal must be decoded and replaced with a non-return to zero (NRZ) signal suitable for transmission over a DS3-class digital transmission path. The digital input processor 20 receives digital audio coming from the AES / EBU standard and generates sync bits in the optical CATV digital audio transmission format with information from the sync pattern for the unit time 40-1 to 40-4. Auxiliary data of unit time (40-5 to 40-8), audio sample data of unit time (40-9 to 40-28), V, U, C of the unit time (40-29 to 40-32) section The P data is separated and output to the optical CATV digital audio transmission format configurator 22 through a separate terminal along with a sync bit, a data clock, and an audio sample clock.

The digital audio transmission format configuration unit 22 receives each data from the digital input processing unit 20 and the analog input processing unit 21 through different terminals, selects the corresponding signal according to the input selection signal, and selects the optical CATV digital audio transmission format. And output to the DS3 grade stereo audio multiplexer (7). Audio sample data can transmit up to 20 bits per sample when transmitting for unit time (40-9 to 40-28), but can transmit up to 24 bits for transmitting during unit time (40-5 to 40-8). Can be. In any case, audio sample data is transmitted in order from least significant bit to most significant bit, and most significant bit is always transmitted in unit time (40-28). Therefore, if the digital data is output at 16 bits per sample in the analog input processor 21, the least significant bit is sent in the unit time 40-13, and the most significant bit is sent in the unit time 40-28. The unit time 40-9 to 40-12 is filled with "0".

Since the digital audio data input to the decoder 15 is received in the digital audio transmission format for optical CATV, the frame interval and subframe are detected by detecting the frame synchronization bit (FIG. 5) by the optical CATV digital audio transmission format receiver 23. Read intervals for auxiliary data during subframe unit time (40-5 to 40-8), audio sample data for unit time (40-9 to 40-28) and unit time (40-29 to 40-32) While the V, U, C, and P bits are separated, and 64 of the clock 40s at 3.072 MHz are divided by 64 at the point at which the sync bit starts. Auxiliary data for unit time (40-5 to 40-8), audio sample data for unit time (40-9 to 40-28), and unit time (40-29) by the digital audio transmission format receiver 23 To V, U, C, and P data are separated and output through different terminals.

The digital output processor 24 receives the sync bit, the auxiliary bit, the audio sample data, the V, U, C, P bits, the data clock, and the audio sample clock, and converts the data into consumer digital audio connection standard data. The consumer digital audio connection standard is a pattern indicating the start of the subframe 50 of the frame 1 when the sync bit receives the sync bit and the sync bit is 1, *, 0,1 (54). The sync bit is 1, *, 1. , 1 (55) or 1, *, 1,1 (53) is a synchronization pattern indicating the start of the subframe 51. If the sync bit is 1, *, 0,0, the frame except frame 1 Is replaced with a synchronization pattern indicating the start of the subframe 50, and the unit bits 5 to 32 are channel coded and output. Here, * transmits to "0" while not transmitting "1" while audio signal is being transmitted.

FIG. 6a is a block diagram of a DS3-class stereo audio multiplexer, and FIG. 6b is a block diagram of a demultiplexer, in which 61 is a data input device, 62 is a transmission rate regulator for transmission, 63 is a multiplexer, and 64 is a block diagram. DS3 frame configurator, 65 is DS3 line connector, 67 is adjustable clock and address generator for transmission, 70 is DS3 line connector, 71 is DS3 frame receiver, 72 is demultiplexer, 73 is transmission rate regulator, 74 is reception The adjustment clock and address generator are shown respectively.

As shown in FIG. 6A, the multiplexing device includes a transmission speed adjuster 62 for adjusting a transmission speed with respect to a signal input through the data input device 61, and an output from the transmission speed adjuster 62. A frame configured by the multiplexer 63 for multiplexing a signal, a frame configurator 64 constituting a DS3 frame using the output of the multiplexer 63 as an input, and a frame constituted by the DS3 frame configurator 64 A DS3 line connector 65 for outputting a DS3 NRZ output and a DS3 line signal to the optical transmission device 6, and receiving the DS3 clock from an external synchronizing device, wherein the transmission speed regulator 62 and the multiplexer 63 And a transmission adjustment clock and address generator 67 for supplying a transmission adjustment clock and an address signal to the DS3 frame configurator 64 and the DS3 line connector 65.

In addition, as shown in FIG. 6B, the demultiplexing apparatus receives a DS3 line connector 70 that receives a DS3 line signal from a subscriber station device 13 and an output of the DS3 line connector 70. A DS3 frame receiver 71 receiving a DS3 NRZ signal and a DS3 clock signal through the terminal device 13, a demultiplexer 72 for inputting and demultiplexing an output of the DS3 frame receiver 71, and the demultiplexer A transmission rate adjuster 73 for receiving the demultiplexed signal by 72 and generating formatted digital audio data and a data clock; and the reception rate adjuster according to channel selection information input from the outside ( 73) and a reception adjustment clock and address generator 74 for supplying a reception adjustment clock and an address signal to the demultiplexer 72, the DS3 frame receiver 71, and the DS3 line connector 70. .

Referring to FIG. 7, the operation of the multiplexer and the demultiplexer configured as described above will be described as follows.

The DS3 multiframe consists of seven subframes as shown, and each sub-multiframe consists of 680 (85x8) bits.

The sub multiframe has a frame configuration bit 79 for composing a DS3 frame by one bit for each 85 bits. 4704 (84x8x7) bits other than the frame configuration bit 79 may be transmitted during one DS3 multiframe.

Therefore, the data transfer rate is 44.2097 Mbps (44.736 Mbps X 84-85). However, since the 14-channel input and stereo audio signal speed is 43.008Mbps (14 * 3.072Mbps), the speed that can be transmitted through DS3 is faster than the speed input from stereo audio, so it is necessary to stuff bits instead of audio data at some point. There is a need. As described above, it is the transmission speed adjuster 62 that adjusts the input speed and output speed by bit stuffing or the like. The multiplexer 63 binds digital audio data coming in through 14 channels to 14 bits of audio data. The DS3 frame was composed of 14 bits multiplexed by taking one bit from each channel. This is called a multiplex unit word. The multiplex unit word becomes a unit of DS3 frame structure. The DS3 frame configurator 64 uses a large multiplexing unit word input by 14 bits for transmission in a frame conforming to the DS3 standard. A (5 bits per channel of each channel 1 to channel 14-14 × 5 × 5 per DS3 total multiframe = 350 bits), A * (4 bits per channel of channels 1 through 14, 14 x 4 = 56 bits per DS3 total multiframe), B (6 bits per channel of each channel of channels 1 through 14, DS-3 total per multiframe) 14 x 6 x 49 = 4,116 bits) and B * (6 bits per channel of V1 to V14 + channels 1 to 14-DS3 14 + 14 x 3 = 56 bits per multiframe). Here, type A is to send multiplexing unit words in five consecutive, and type A * is to send in four consecutive. Type B * is 14 bits of stuffing bits from 14 channels, sending 3 multiplexing unit words in succession. Type B sends six multiplexing unit words.

Types A, A *, and B * are for the first 85-bit string 75 of sub-multiframe 78, while Type B is for the eighth 85-bit string (77) from sub-multiframe second 85-bit string 76. Is transmitted in each defined bit period. Adjustment 1 (channel 1-1 to channel 14-1-14 bits = 14 bits per DS3 multiframe), adjustment 2 (channels 1-2 to channel 14-) in the 15-bit second in the first to third sub-multiframes 2 Bits named 2-DS3 14 bits per multiframe = 14 bits), coordination 3 (channels 1-3 to 14 bits per channel 14-3-DS3 multiframe = 14 bits) are transmitted, the first bit of each adjustment bit Is used to transmit stuffing information using 3 bits per channel, such as stuffing information about channel 1, and 2nd bit, that is, stuffing information about channel 2. If two or more of these three bits are " 1 ", it is determined that stuffing is performed. If two or more of the first bits of Adjustment 1, Adjustment 2, and Adjustment 3 are " 1 ", then stuffing has occurred on channel 1. The stuffing bits are located in positions 30 through 43 of the seventh sub-multiframe in which the B * type is located, where V1 is the stuffing bit for channel 1, V2 is the stuffing bit for channel 2,. V14 is the stuffing bit for channel 14. In the fourth sub-multiframe, the reserved bits of the eighth sub-multiframe 77 (14x6 = 84 bits per 14-DS3 multiframe).

The DS3 line connector 70 converts the data output from the DS3 frame configurator 64 to NRZ into a bit 3 zero substitution (B3ZS) line code specified in the DS3 transmission standard, and then adjusts the output level. It serves as the output. The DS3 grade stereo audio multiplexer 6 can output data in non-return to zero (NRZ).

The transmission adjustment clock and the address generator 67 receive a clock of 44.736 MHz from an external synchronizer and output an address signal for controlling the clock required for the above-described devices to operate and a position to which data input on the DS3 frame is to be transmitted. .

The DS3 line connector 70 inputs a signal received according to the DS3 transmission standard, undergoes analog processing such as an equalizer and an automatic gain adjuster, recovers a clock signal of 44.736 MHz, and decodes the B3ZS signal into an NRZ signal. The DS3 frame receiver 71 performs a function of extracting a 14-channel 3.072Mbps stereo audio signal and a clock from data transmitted by configuring a DS3 transmission frame, and the demultiplexer 72 selects a channel. The receiver outputs digital audio data and a clock of a channel selected by the information.

The channel selection information is a signal for selecting one of 14 stereo audio channels.

The receiver baud rate adjuster 73 is used to output a data rate of 3.072Mbps by subtracting the stuffed bits from the input data as in the DS3 multiplexer. The receiving adjustment clock and the address generator 74 are supplied with a clock of 44.7 36 MHz from the subscriber station 13 to generate the address where each data is located on the DS3 multiframe using the frame bits of the DS3 multiframe. It is determined whether stuffing of each channel is made from Adjustment 2 and Adjustment 3 bits, and if stuffing is done, the control signal can be output to the stereo audio decoder by subtracting the bit which is a spoof bit from the position of V bit (B *) corresponding to the channel. It outputs the clock and control signals necessary for the above-mentioned devices to operate. The stereo audio demultiplexer is configured to receive NRZ-type DS3 data and has alarm functions such as signal loss and frame synchronization loss.

8 is an exemplary diagram of channel coding in an AES / EBU access rule.

If the data is " 1 " (83) a conversion occurs in the middle 81 of the clock (85) a " 0 " (84) no conversion occurs (86) and a conversion always occurs between the clocks (82) (87). However, in the sync pattern period, the sync pattern (a) indicating the start of the subframe 50 of the frame 2 to the frame 192 has a low channel code. If the previous data is high) (89) and the synchronization pattern (c) indicating the start of the sub-frame 51 is the state of the immediately preceding data channel-coded is low, (d) is the immediately preceding data channel-coded Is high) and the synchronization pattern (e) indicating the start of the subframe 50 of the frame 1 is immediately before the channel coded, and (f) is just before the channel coded. Data is high).

Therefore, the present invention constructed and operated as described above has an effect of enabling the transmission of a stereo audio signal at a DS3 transmission rate in an optical CATV network or the like.

Claims (4)

Fourteen stereo audio encoders (5) for receiving and encoding N (N is a natural number) analog or digital audio signals from a broadcasting source, and fourteen stereo audio encoders (5) and DS3 stereo audio. Demultiplexing 14-channel signals by feeding back the output of the DS3-class stereo audio multiplexer (7) and the DS3-class stereo audio multiplexer (7) for multiplexing the signals and outputting them to the optical CATV transmission network through the optical transmitter (9). N stereo audio decoders for decoding the outputs of the DS3 grade stereo audio demultiplexing device 11 and the DS3 grade stereo audio demultiplexing device 11 and providing the audio reproducing device on the broadcasting source side for monitoring. An optical CATV stereo audio transmission system 3 including 12; And a DS3 level stereo audio demultiplexer 14 for receiving and demultiplexing a stereo audio signal received through an optical CATV transmission network through the subscriber terminal device 13 and an output of the DS3 level stereo audio demultiplexer 14. And a stereo audio receiving system (8) having a stereo audio decoder (15) for decoding the signal and outputting it to the subscriber audio reproduction apparatus according to the output selection signal. The stereo audio coder according to claim 1, wherein the optical CATV stereo audio encoder comprises: a digital input processing unit (20) for receiving and processing a digital audio signal, an analog input processing unit (21) for receiving and processing an analog audio signal, and the digital input. And a digital audio transmission format configuration unit 22 configured to receive the output of the processing unit 20 and the analog input processing unit 21 to form a digital audio transmission format for optical CATV and output a formatted digital audio data and a data clock. The stereo audio decoder for optical CATV includes a digital audio transmission format receiving unit 23 that receives a signal configured by the digital audio transmission format configuring unit 23 on the transmitting side, and a signal received by the digital audio transmission format receiving unit 23. A digital output processor 24 for outputting a digital audio signal by inputting the digital audio signal; And an analog output processor (25) for outputting an analog audio signal by inputting the output signal of the receiver (23). 3. The DS3 class stereo audio multiplexer (7) according to claim 2, further comprising: a transmission speed adjuster (62) for adjusting a transmission speed with respect to an input signal, and a signal output from the transmission speed adjuster (62). A multiplexer 63 for multiplexing, a frame configurator 64 constituting a DS3 frame with the output of the multiplexer 63 as an input, and a frame configured by the DS3 frame configurator 64 to receive a DS3 NRZ A DS3 line connector 65 for outputting the output and the DS3 line signal to the optical transmission device 6, and receiving the DS3 clock from an external synchronization device, wherein the transmission speed regulator 62, the multiplexer 63, and the And a transmission adjustment clock and address generator 67 for supplying a transmission adjustment clock and an address signal to the DS3 frame configurator 64 and the DS3 line connector 65. . The DS3 grade stereo audio demultiplexing apparatus 11 is a DS3 line connector 70 which receives a DS3 line signal from an optical CATV network side, and receives the output of the DS3 line connector 70. A DS3 frame receiver 71 for receiving the DS3 NRZ signal and the DS3 clock signal through the subscriber station device 13, a demultiplexer 72 for inputting and demultiplexing the output of the DS3 frame receiver 71, and the inverse A reception rate adjuster 73 for receiving the demultiplexed signal by the neutralizer 72 and generating formatted digital audio data and a data clock; and the reception rate adjuster according to channel selection information input from the outside. A receiving adjustment clock and address generator 74 for supplying a receiving adjustment clock and an address signal to the demultiplexer 72, the DS3 frame receiver 71, and the DS3 line connector 70; Compared optical CATV stereo audio transmission apparatus, characterized in that the.