JP2002217911A - Data transmission system and data transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data transmission system, which can notify invalidation of auxiliary data to for instance a transmission processing I/F for IEEE 1394 and can quickly create transmission data in a specified format to send out, dispensing with increase in the size of a circuit and signal lines. SOLUTION: An IEEE 1394 transmission processing section 13 creates transmission data of the IEEE 1394 format, by using an 1 bit audio data recorded using an SACD decoder 11a and the auxiliary data, and sends out the transmission data to a bus line for IEEE 1394. In that case, if a sub label of a specified value (≠F) showing invalid data is sent from the SACD decoder 11a, then it is replaced by the IEEE 1394 transmission processing section 13 the sub label with another sub label (e.g., D1) defined by the IEEE format.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, IEEE 1
The present invention relates to a data transmission device and a data transmission method suitable for applying audio data of various types to a 394 type bus line.

[0002]

2. Description of the Related Art It has been practically used to connect a plurality of AV devices and transmit video data, audio data, and other data between the devices by using a network using an IEEE 1394 bus line. .
In the case of the IEEE 1394 bus line, an isochronous transmission channel for transmitting large-capacity data such as video data and audio data and an asynchronous transmission channel for transmitting data such as control commands are prepared. The data can be mixed and transmitted.

For details of a format for transmitting audio data (music data) over an IEEE 1394 bus line, see [Audio and Music Data Tra
nsmission Protocol]. This [Audio
and Music Data Transmission Protocol) is http // ww
Published on w.1394TA.org.

[0004] By the way, audio data specified to be transmitted in the format described above has a sampling frequency of a fixed frequency such as 44.1 kHz, and 1 bit.
The sample is only general digital audio data such as 16 bits or 24 bits.

[0005] On the other hand, various new digital audio data formats capable of improving the reproduced sound quality have been proposed. There have been various proposals for multi-channel audio data for reproducing multi-channel audio exceeding two channels, and a large number of digital audio data formats exist.

In the above-described IEEE 1394 bus line, transmission of audio data in such a new format is not considered at present, and it is difficult to transmit in the current format.

When transmitting audio data, it may be necessary to transmit not only the audio data itself but also attached data such as copy restriction information. Such data transmission is also performed. Depending on the format of the audio data, it was not considered in some cases and needed to be dealt with.

In view of the above, the applicant of the present application has proposed a transmission method and a transmission apparatus for enabling transmission of audio data of various formats through a bus line in Japanese Patent Application No. 1999-145410. According to the transmission method and the transmission apparatus, when transmitting 1-bit audio stream data or data obtained by compressing the stream data, the label data at the beginning of each data output from the transmission method and the transmission apparatus And the sub-label data following the label data, the auxiliary data such as the compression method can be determined.

[0009]

By the way, the 1-bit audio data stream is actually converted to the IE data.
IEEE 1394 bus lines must be transmitted using the IEEE
It is necessary to input main data and auxiliary data constituting audio information data composed of digital data obtained by delta-sigma modulation to the transmission processing I / F for E1394, but when the generation of auxiliary data cannot be made in time, In some cases, there is no auxiliary data to be transmitted, and other means and signals have to be used to notify the invalidation of the auxiliary data to the IEEE 1394 transmission processing I / F.

The present invention has been made in view of the above circumstances, and transmits the invalidity of the auxiliary data to, for example, the transmission processing I / F for IEEE 1394 without using other means or signals, and It is an object of the present invention to provide a data transmission device and a data transmission method capable of quickly generating and transmitting transmission data of a predetermined format without requiring an increase in the number of signal lines.

[0011]

According to the present invention, there is provided a data transmission apparatus for transmitting information data composed of main data and auxiliary data via a bus line. Decoding means for decoding the main data and the auxiliary data from the medium and representing invalid data of the auxiliary data by using a sub-label of a specific value; and a predetermined format using the main data and the auxiliary data decoded by the decoding means. Transmission data generation and transmission means for transmitting the transmission data to the bus line, wherein the transmission data generation and transmission means transmits a sub-label of a specific value representing the invalid data from the decoding means. Then, the sub-label of the specific value is replaced with another sub-label.

In this data transmission device, when the decoding means indicates the invalidity of the auxiliary data by using a sub-label of a specific value, and when the transmission data generation / transmission means receives the sub-label of the specific value, the sub-label is replaced with another sub-label Replace with Therefore, the invalidity of the auxiliary data is determined by the IEEE1
No other means or signals are required to transmit to the 394 transmission processing I / F.

[0013] Further, upon receiving the sub-label of the specific value, the transmission data generating and transmitting means replaces the sub-label with another sub-label and replaces the invalid data with other valid data.

For this reason, the transmission data generation and transmission means stores the other valid data given in advance from the host computer in a storage means such as a register in advance,
When it is determined that the sublabel having the specific value has been sent, the sublabel is immediately replaced with the invalid data.

If the decoding means does not send a sublabel of a predetermined value that defines auxiliary data immediately after the frame signal, the transmission itself is not stopped or started.

According to a first aspect of the present invention, there is provided a data transmission method for transmitting information data including main data and auxiliary data via a bus line. And a decoding step of decoding the auxiliary data and the invalid data of the auxiliary data using a sub-label of a specific value, and transmitting the transmission data of a predetermined format using the main data and the auxiliary data decoded in the decoding step. Generating the transmission data and transmitting the transmission data to the bus line, wherein the transmission data generation and transmission step is performed when a sub-label of a specific value representing the invalid data is transmitted from the decoding step. Then, the sub-label of the specific value is replaced with another sub-label.

In this data transmission method, when the decoding step indicates the invalidity of the auxiliary data by using a sub-label of a specific value, and when the transmission data generation and transmission step receives the sub-label of the specific value, the sub-label is replaced with another sub-label. Replace with That is, the invalidity of the auxiliary data is determined by IEEE1.
No other means or signals are required to transmit to the 394 transmission processing I / F.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a data transmission apparatus and a data transmission method according to the present invention will be described below with reference to the drawings. In this embodiment, 1-bit audio data obtained by subjecting an analog audio signal to delta-sigma (ΔΣ) modulation is read from a super audio CD (SACD) 2 shown in FIG. 1 and decoded by an SACD decoder 11a. In order to transmit the data on the IEEE1394 bus line 1, the IEEE1394 transmission processing unit 13 transmits the data as a predetermined format.
It is a bit audio data transmission device.

SACD2 is referred to as a DSD (Direct Stream Digital) system, while a normal CD records digital audio data of 16 bits per channel at a sampling frequency fs of about 44.1 kHz. Data recorded as 1-bit audio stream data is recorded at a very high sampling frequency (for example, 64 times the normal CD sampling frequency fs).

When transmitting the 1-bit audio stream, it is necessary to transmit auxiliary data. For example, when the 1-bit audio data is compressed, it is necessary to send data relating to the compression method as auxiliary data. Also,
Data indicating the number of channels, copy control data, and the like are required as auxiliary data.

This auxiliary data is sent to the SACD decoder 11
“a” is read out from the SACD 2 together with the 1-bit audio data and decoded, but depending on the case, the generation of the auxiliary data may not be enough or there may be no auxiliary data to be sent.

Accordingly, the SACD decoder 11a
The 1-bit audio data and the auxiliary data are decoded from CD2, and the invalid data indicating the invalidity of the auxiliary data is represented by setting a sublabel following the label added by the IEEE1394 transmission processing unit 13 to a specific value, for example, $ FF. .

The IEEE 1394 transmission processing unit 13
Using the 1-bit audio data and auxiliary data decoded by the CD decoder 11a, transmission data in the IEEE 1394 format is generated, and the transmission data is converted to the IEEE 1394 format.
The data is transmitted to the bus line 1 for E1394. At this time, I
The IEEE 1394 transmission processing unit 13 is a SACD decoder 1
When a sub-label of a specific value ($ FF) indicating invalid data is sent from 1a, the sub-label is changed to another sub-label determined in the IEEE format (for example,
D1).

The IEEE 1394 transmission processing unit 13
When a sub-label having a specific value (FF) representing invalid data is transmitted from the SACD decoder 11a, the sub-label is replaced with another sub-label (for example, X) determined in the IEEE format, and the invalid data is replaced. Replace with other valid data.

The other valid data is transmitted from the host CPU 12 constituting the controller shown in FIG.
It is sent to the E1394 transmission processing unit 13. IEEE1
The 394 transmission processing unit 13 stores the other valid data in an internal register (not shown) or the like. And IEEE
When the E1394 transmission processing unit 13 determines that the sublabel of $ FF has been sent from the SACD decoder 11a, it immediately replaces the invalid data with another valid data.

The 1-bit audio data transmission apparatus shown in FIG. 1 is applied to a network system as shown in FIG. In this network system, I
The disk playback device 10 is connected to the EEE1394 bus line 1.
And an amplifier device 20 that performs output processing of 1-bit audio data transmitted from the disk reproducing device 10 or the like.

The disc reproducing apparatus 10 includes a disc reproducing unit 11 having the SACD decoder 11a built therein, a controller 12 for controlling the reproduction of the disc by the disc reproducing unit 11, and a controller 12 similar to the host CPU. Digital audio data played back by
The IEEE 139, which is transmitted to the IEEE 1394 bus 1,
And a transmission processing unit 13 similar to the four transmission processing units. The transmission processing in the transmission processing unit 13 is also executed under the control of the controller 12.

As a disc that can be reproduced by the digital reproducing apparatus 10, a compact disc (CD) of a normal format can be reproduced in addition to the SACD2. In addition,
In the SACD, in addition to the above-described recording layer of high-quality audio data called DSD, there is also a two-layer disc having a recording layer of audio data as a normal CD.

The amplifier device 20 includes a controller 21 for controlling the operation of the device, and a transmission processing unit 22 for receiving and processing data transmitted through the IEEE 1394 bus 1.
And an audio output processing unit 23 that performs output processing such as demodulation, analog conversion, and amplification of the audio data received by the transmission processing unit 22.
Is supplied to, for example, left and right two-channel speaker devices 24L and 24R to emit sound. In this case, the audio output processing unit 23
It is configured to be able to perform analog conversion processing of digital audio data reproduced from a normal CD, and also perform demodulation of the SACD audio data described above and analog conversion of the demodulated audio data.

Here, each of the devices 10 and 20 connected to the bus 1 is called a unit, and the AV / C Command T
AV / C Digital Interface Command Set of ransaction Set
Using a descriptor (Descriptor) defined in the General Specification (hereinafter referred to as AV / C),
Information stored in each unit can be mutually read and written, and one device can control the other device. For more information on AV / C, see http: //www.1394TA.
It is published on org.

Each unit (here, the devices 10 and 20) connected to the IEEE 1394 bus 1 is also called a node, and has a node ID set therein.
Specifies the source and destination of data on the bus. When a new device is connected to the bus 1 or when it is detected that the connected device is disconnected, the node ID is reset and the node ID is set again. Is performed. Therefore, when a bus reset occurs, the node ID of each device may change.

Next, the operation of the 1-bit audio data transmitting apparatus shown in FIG. 1 will be described. As shown in FIG. 3, the SACD decoder 11a transmits the Lch and Rch 1-bit audio data (c) and the auxiliary data (ancillary data) (b) to the IEEE 1394 transmission processing unit 13 in addition to these data. A frame signal (75 Hz) (a) indicating the beginning of a frame serving as a divided data length unit for decoding, 64 fs (fs = 44.1k)
Hz) is passed and taken in every 24 bits. Then, the IEEE 1394 transmission processing unit 13 blocks these data onto the IEEE 1394 bus line 1 and sends them out.

In data transmission according to the IEEE 1394 format, data transmission is basically performed in units of 32 bits. In AM824, the first 8 bits are a label, which is determined for each application.
CD decoder 11a to IEEE 1394 transmission processing unit 1
3 need not be transmitted. The auxiliary data also has one unit of 24 bits.

As shown in FIG. 3A, the position at which data is taken in is indicated by the frame signal. Of the 24 bits of auxiliary data, the first 8 bits are a sub-label, and define the following 16-bit data. For example, in the case of SACD, sub label (Sub LABEL) = ＄
00 defines SACD auxiliary data (Ancillary Data). Also, (Sub LABEL) = $ 01 defines SACD supplementary data.

When each data shown in FIG. 3 is received, IE
The IEEE 1394 transmission processing unit 13 is an IEEE 13
A data block of the 94 format is generated, an Iso packet for isochronous transmission is formed by the data block, and the data packet is transmitted by time division multiplexing every predetermined communication cycle (for example, 125 μsec) shown in FIG. Transmission of this signal is started when a device called a cycle master (arbitrary one device on the bus 1) sends a cycle start packet to the bus indicating that a communication cycle has started. . The cycle master is automatically determined by a procedure specified by IEEE-1394 when each device is connected to a cable constituting a bus.

The form of communication during one communication cycle is as follows:
Isochronous (Iss) that transmits real-time data such as video data and audio data
o) Transmission and asynchronous transmission (Async transmission) for reliably transmitting control commands and auxiliary data.
A type of transmission is performed. In each communication cycle, the Iso packet for isochronous transmission is transmitted before the Async packet for asynchronous transmission. Each Iso packet in one communication cycle is given an individual channel number 1, 2, 3 @ n, and a plurality of Iso packets are assigned.
o The transmission data can be distinguished. After the communication of the Iso packet is completed, a period until the next cycle start packet is used for transmitting the Async packet. Therefore, the period during which an Async packet can be transmitted is
It changes according to the number of transmission channels of the Iso packet at that time. In addition, the Iso packet is a transmission method in which a band (the number of channels) reserved for each communication cycle is secured, but no confirmation is performed from the receiving side. In the case of transmission using an Async packet, data of an acknowledgment (Ack) is returned from the receiving side, and transmission is reliably performed while checking the transmission state.

By the way, in the SACD decoder 11a,
As described above, in some cases, the generation of auxiliary data may not be in time or there may be no auxiliary data to be sent. Therefore, as shown in FIG. 5, the SACD decoder 11a sets the sublabel to $ FF, sends the sublabel to the IEEE1394 transmission processing unit 13, and notifies the IEEE1394 transmission processing unit 13 that the 24-bit data transmission including the sublabel is invalid. Notify.

Then, the IEEE 1394 transmission processing unit 13
Replaces the sublabel with D1 determined in the IEEE format, and sets the invalid auxiliary data to No-Data, as shown in FIG. At this time, IEEE
The 1394 transmission processing unit 13 sets the label not transmitted from the SACD decoder 11a to CF.

FIG. 6 shows an IEEE 1394 transmission processing unit 1
3 shows a specific example in which the label is CF, the sublabel is D1, and the invalid auxiliary data is No-Data. After the ancillary data of the sublabel 00 in the label D1, a plurality of supplementary data of the sublabel 01 in the label D1 continue, and the No-Data is
It is shown that it is provided continuously before the next frame.

FIG. 7 shows an IEEE 1394 transmission processing unit 13.
1 shows the transmission block generated by This is SAC
IEEE based on the serial input from the D decoder 11a
This is generated by the 1394 transmission processing unit 13. A header part for isochronous transmission is added to this, and IEEE
An E1394 packet is generated and transmitted to the IEEE 1394 bus line 1. The location for the auxiliary data is at the top of each block shown in FIG. The block length is 1Q
uadlet = 32 bits, 2 ch of 1-bit audio data of that length are arranged next to the auxiliary data, and the label and sublabel are CF at the bottom and the block length is even. Provide additional data. The number of stored data rows of the main data increases or decreases depending on the number of channels. Here, it is for 2 ch, and the 8-bit label = 50 is the Lch of 1-bit audio data.
A label (51 bits) is defined, and a label = 51 defines the Rch (24 bits) of the 1-bit audio data.

Each block in which the auxiliary data label = CF and the sublabel = D1 indicates that the auxiliary data is invalid data. There is no effect on the 1-bit audio data of 2 ch of the main data.

The IEEE 1394 transmission processing unit 13
Is, from the SACD decoder 11a, the sublabel = ＄ FF
Is transmitted, as shown in FIG. 8, the sub-label is replaced with another sub-label X, and the invalid data is transmitted via the host CPU 12 and stored in the register or the like. Replace with At this time, the IEEE 1394 transmission processing unit 13
The label not transmitted from the decoder 11a is also denoted by X.

FIG. 9 shows an IEEE 1394 transmission processing unit 1
3 shows a specific example in which the label is set to X, the sublabel is set to X, and other valid data is inserted. The label D1 is followed by the ancillary data of the sublabel 00, and the label D1 is followed by a plurality of supplementary data of the sublabel 01, indicating that the other valid data is provided continuously before the next frame. .

FIG. 10 shows the IEEE 1394 transmission processing unit 1.
Reference numeral 3 denotes a transmission block generated by inserting other valid data as auxiliary data. This is based on a serial input from the SACD decoder 11a and is based on IEEE139
4 is generated by the transmission processing unit 13.

Next, a modification of the 1-bit audio data transmission apparatus will be described with reference to FIG. In this modification, when the SACD decoder 11a determines that the auxiliary data is invalid from the beginning and sets the sublabel immediately after the frame signal to $ FF, the IEEE 1394 transmission processing unit 13 stops the transmission itself or starts the transmission. Decide not to. When the sublabel is not set to predetermined data, for example, $ 00 in the SACD decoder 11a, the IEEE 1394 transmission processing unit 13 may operate similarly.

As described above, the 1-bit audio data transmission apparatus according to the present embodiment has a specific value ($ F
The use of the sub-label of F) indicates that the auxiliary data cannot be generated in time or that there is no data to be transmitted.
It is possible to transmit the data to the IEEE transmission processing unit 13 and further instruct the IEEE transmission processing unit 13 to insert another data.

Further, it is possible to check the sub-label at the head of the frame and stop the transfer itself or not start the transfer if the data is not predetermined data.

In the network system, the IEEE
The case where audio data reproduced from a disk reproducing device connected to a bus line of the E1394 system is transmitted to an amplifier device has been described as an example. However, the audio data is input to another AV device serving as an audio input unit (input here). This also applies to the case where audio data that has been obtained by reproduction or the like) is transmitted to another device via a bus line of a predetermined system.

Further, regarding the format of the bus line, IE
It goes without saying that a data transmission path of a method other than the EE1394 bus line may be applied.

Although the transmitted audio data is 1-bit audio data reproduced from the SACD, the present invention can be applied to the transmission of other similarly encoded audio data.

[0051]

According to the data transmission apparatus of the present invention,
When the decoding means indicates the invalidity of the auxiliary data using the sub-label of a specific value, and the transmission data generation / transmission means receives the sub-label of the specific value, the sub-label is replaced with another sub-label. That is, the invalidation of the auxiliary data is
Since no other means or signals are used to transmit to the transmission processing I / F for EE1394, transmission data of a predetermined format is generated and transmitted promptly without increasing the circuit scale and signal lines. Can be.

Further, according to the data transmission method of the present invention, when the decoding step indicates the invalidity of the auxiliary data using the sub-label of the specific value, and the transmission data generation and transmission step receives the sub-label of the specific value, Replace a sublabel with another sublabel. That is, since other means and signals are not used to transmit the invalidity of the auxiliary data to the transmission processing I / F for IEEE 1394, the transmission data of the predetermined format can be promptly performed without increasing the circuit scale and the number of signal lines. Can be generated and sent.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a 1-bit audio data transmission device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a network system to which the 1-bit audio data transmission device is applied.

FIG. 3 is a timing chart for explaining the operation of the 1-bit audio data transmission device.

FIG. 4 is an explanatory diagram showing a specific example of a transmission state in the IEEE1394 system.

FIG. 5 is a timing chart for explaining an operation performed by the 1-bit audio data transmission device when auxiliary data is not generated in time by the SACD decoder or there is no auxiliary data to be transmitted.

FIG. 6 is a diagram showing a specific example in which a label is set to CF, a sublabel is set to D1, and invalid auxiliary data is set to No-Data by an IEEE 1394 transmission processing unit.

FIG. 7 is a diagram illustrating a transmission block generated by an IEEE 1394 transmission processing unit.

FIG. 8 is a diagram showing an example in which an IEEE1394 transmission processing unit transmits a sublabel = ＄ FF from an SACD decoder.
9 is a timing chart for explaining an operation example of inserting other valid data into invalid data.

FIG. 9 is a diagram illustrating a specific example in which a label and a sub-label are set to X and other valid data is inserted by an IEEE 1394 transmission processing unit.

FIG. 10 is a diagram illustrating a transmission block generated by inserting another valid data as auxiliary data by an IEEE 1394 transmission processing unit.

FIG. 11 is a timing chart for explaining an operation of a modification of the 1-bit audio data transmission device.

[Explanation of symbols]

1 IEEE 1394 bus line, 2 SACD, 11
a SACD decoder, 12 host CPU, 13 I
EEE1394 transmission processing unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobukazu Suzuki 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5C063 AB03 AB07 AB09 AC01 AC05 CA23 CA34 CA36 5K033 AA02 AA04 BA01 BA14 CC01 DA01 DB14

Claims (10)

[Claims] 1. A data transmission apparatus for transmitting information data composed of main data and auxiliary data via a bus line, wherein the main data and the auxiliary data are decoded from an information providing medium, and invalid data of the auxiliary data is decoded. Decoding means to be followed by a label, using a sub-label of a specific value, and generating transmission data of a predetermined format using the main data and auxiliary data decoded by the decoding means, and transmitting the transmission data to the bus line. Transmission data generation and transmission means for transmitting, the transmission data generation and transmission means, when a sub-label of a specific value representing the invalid data is transmitted from the decoding means, the sub-label of the specific value to another A data transmission device characterized by replacing with a sublabel. 2. The transmission data generating / sending means, when a sub-label of a specific value representing the invalid data is transmitted, replaces the sub-label of the specific value with another sub-label and replaces the invalid data with another sub-label. The data transmission device according to claim 1, wherein the data transmission device is replaced with valid data. 3. The transmission data generation and transmission means according to claim 1, wherein said decoding means also transmits a frame signal indicating a head of a frame which is a divided data length unit obtained by decoding said main data and auxiliary data. Data transmission equipment. 4. The transmission data generating / sending means stops the transmission itself when a sub-label of a predetermined value defining an auxiliary data from the decoding means is not transmitted immediately after the frame signal. 4. The data transmission device according to claim 3, wherein the data transmission device does not start. 5. The data transmission apparatus according to claim 1, wherein said decoding means takes out audio information data composed of digital data obtained by delta-sigma modulation from said information providing medium and inputs it. 6. A data transmission method for transmitting information data composed of main data and auxiliary data via a bus line, wherein the main data and the auxiliary data are decoded from an information providing medium, and invalid data of the auxiliary data is decoded. A transmission step of generating transmission data in a predetermined format using the main data and auxiliary data decoded in the decoding step, and transmitting the transmission data to the bus line. Generating and transmitting step, wherein the transmission data generating and transmitting step replaces the specific value sublabel with another sublabel when a specific value sublabel representing the invalid data is transmitted from the decoding step. A data transmission method characterized by the above-mentioned. 7. The transmission data generating and transmitting step includes, when a sub-label of a specific value representing the invalid data is transmitted, replacing the sub-label of the specific value with another sub-label and replacing the invalid data with another sub-label. 7. The data transmission method according to claim 6, wherein the data is replaced with valid data. 8. The data generating and transmitting step according to claim 6, wherein said decoding step also sends a frame signal indicating a head of a frame as a divided data length unit obtained by decoding said main data and auxiliary data to said data generating and transmitting step. Data transmission method. 9. The transmission data generating / sending step stops the transmission itself when a sub-label of a predetermined value defining an auxiliary data from the decoding step is not sent immediately after the frame signal. 9. The data transmission method according to claim 8, wherein the data transmission is not started. 10. The data transmission method according to claim 6, wherein in the decoding step, audio information data composed of digital data obtained by delta sigma modulation from the information providing medium is input.