JP2002351826A - Data transfer device, data transfer method, and data transfer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize previous sample word data hold transfer for DVD audio on a IEEE1394 bus. SOLUTION: A TxDVD circuit 21 generates a 2LRCK signal by dividing inputted LRCK into two and supplies the channel data designated by a channel signal at 2LRCK=low to FIFO22 as it is (data through). Then, the channel data are fixed at 2LRCK=high. Consequently, the sampling frequency of the data on the channel becomes 1/2 fs. When sending the above data to IEEE1394 serial bus, TxDVD circuit automatically changes ASI1 and ASI2 of the above channel to be attached to the data in accordance with data conversion operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to multi-channel audio data such as DVD audio,
The present invention relates to a data transfer device, a data transfer method, and a data transfer program for transferring a previous sample word data hold via a 394 serial bus.

[0002]

2. Description of the Related Art Conventionally, as an interface suitable for portable and desktop computer environments and consumer devices such as audio devices and video devices, IEEE (Institute of Electronics) which is one of the serial bus standards has been used.
Electrical and Electronics Engineers) A 1394 serial bus is known. Communication according to the IEEE 1394 standard includes isochronous data transfer, asynchronous (asynchronous) data transfer, and high-speed data transfer (100
３3200 Mbps), and can be connected to a plurality of devices (nodes).

[0003]

In recent years, DVD audio has attracted attention as a format of the next generation music CD. For DVD audio, sampling frequencies: 44.1 kHz, 88.2 kHz, 179.
48kHz, 96kHz, 192kHz in addition to 4kHz
Supports z, number of coding bits: 16 bits, 20 bi
t, 24 bits, maximum transfer rate: 9.6 Mbps, multi-channel support: maximum 6 channels.

To transfer the DVD audio data to another device (such as a playback device), it is conceivable to transfer the data via the above-mentioned IEEE 1394 serial bus. However, in the prior art, D
DVD data is transferred by the previous sample word data hold transfer, which is one of the VD audio data transfer methods.
There is no technology for transferring audio data over an IEEE 1394 serial bus. In the previous sample word data hold transfer, data of a specific channel is individually converted into 1/2 fs data and transferred.

Accordingly, the present invention provides a method for transferring multi-channel audio data via a serial bus by using a previous sample word data hold transfer in which data of a specific channel is individually converted into 1/2 fs data and transferred. It is an object of the present invention to provide a data transfer device, a data transfer method, and a data transfer program which can perform the following.

[0006]

In order to achieve the above object, a data transfer apparatus according to the first aspect of the present invention is a data transfer apparatus for performing a prior sample word data hold transfer of multi-channel audio data via a serial bus. Data conversion means for converting audio data of a designated channel among the multi-channel audio data into data having a sampling frequency of し て and transmitting the data to the serial bus; And an additional data changing means for changing a value of the additional data relating to the previous sample word data hold transfer added to the data of each channel to be transmitted, based on a conversion operation by the data conversion means. And

In a preferred embodiment, in the data transfer device according to the first aspect, the data conversion means outputs a channel switching signal added to the multi-channel audio data. A frequency-divided signal is generated, and based on the frequency-divided signal, audio data of a designated channel is passed through or held to a subsequent circuit to convert the audio data into data having a sampling frequency of 、. The additional data changing means includes first additional data indicating that the channel has been converted by the data converting means, and second data indicating whether the data has been passed through or held by the converting means. May be changed based on the conversion operation by the data conversion means.

In a preferred aspect, in the data transfer device according to the first aspect of the present invention, the data conversion means includes a timing for switching from a mute mode to a reproduction mode; May be added to the timing when the data is held.

In a preferred embodiment, the serial bus may be an IEEE 1394 serial bus in the data transfer device according to the first aspect.

In order to achieve the above object, a data transfer method according to a fifth aspect of the present invention is a data transfer method for performing a prior sample word data hold transfer of multi-channel audio data via a serial bus. A previ- ous sample, which converts audio data of a specified channel from among the multi-channel audio data into data whose sampling frequency is halved and is added to data of each channel transmitted to the serial bus. The value of the additional data relating to the word data hold transfer is changed based on the conversion operation.

In a preferred embodiment, a frequency-divided signal obtained by dividing the channel switching signal added to the multi-channel audio data by two is generated based on the frequency-divided signal. By passing or holding the audio data of the designated channel to the subsequent circuit, the sampling frequency can be reduced by half.
The first additional data indicating that the channel is the data converted channel, and the second additional data indicating whether the data is passed data or held data, It may be changed based on the conversion operation.

According to a preferred aspect, in the data transfer method according to the fifth aspect, the timing for switching from the mute mode to the reproduction mode and the timing for holding data by the data conversion means are provided. May match, zero data may be added.

In order to achieve the above object, a data transfer program according to the invention of claim 8 is a data transfer program for transferring previous sample word data hold transfer of multi-channel audio data via a serial bus, Converting the audio data of the designated channel out of the multi-channel audio data into data whose sampling frequency is halved; and adding a previous data to the data of each channel transmitted to the serial bus. Changing the value of the additional data according to the sample word data hold transfer based on the conversion operation.

According to a preferred aspect, in the data transfer program according to the ninth aspect, a frequency-divided signal obtained by dividing the channel switching signal added to the multi-channel audio data by two. Generating an audio data of a specified channel based on the frequency-divided signal, and converting the audio data to a data having a sampling frequency of ２ by passing or holding the audio data to a subsequent circuit; and Changing, based on the conversion operation, first additional data indicating that the channel is a passed channel, and second additional data indicating whether the data is through data or held data. The program may be executed by a computer.

According to a preferred aspect, in the data transfer program of the present invention, the timing for switching from the mute mode to the reproduction mode and the timing for holding data by the data conversion means are provided. May match, the step of adding zero data may be executed by a computer.

According to the present invention, the audio data of the designated channel among the multi-channel audio data is converted by the data conversion means into a sampling frequency of 1 unit.
/ 2, and transmits the data to the serial bus. The additional data changing means adds the additional data associated with the previous sample word data hold transfer, which is added to the data of each channel transmitted to the serial bus. The value is changed based on the conversion operation by the data conversion unit. Therefore, multi-channel audio data can be transferred via a serial bus by the previous sample word data hold transfer in which data of a specific channel is individually converted into 1/2 fs data and transferred.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a DVD audio reproduction system according to an embodiment of the present invention. The DVD audio data transmission device 1
The data recorded in accordance with the DVD audio standard is read out from the medium 3 by the EE1394 processing unit 2, and the data of the channel for the precedent sample word data hold transfer is converted into 1/2 fs (fs = sampling frequency), and the data is converted to the IEEE1394 bus Send out.

The DVD audio reproducing device 5 is an IEEE standard.
The DVD audio data transferred via the previous sample word data hold transfer via the 1394 bus is
D received by the IEEE 1394 processing unit 6 and D (not shown)
The audio data of each channel is converted into an analog signal by the / A converter, the gain is adjusted by the amplifier 7, and then output from the speakers 8-1 to 8-6 of each channel.

FIG. 2 is a block diagram showing a schematic configuration of the DVD audio data transmitting apparatus. Register 20
Holds ancillary data and channel signals from a host (microcomputer: control unit) not shown. The ancillary data includes data ASI1 and ASI2, a sampling frequency fs at the time of transfer, channel data information, correspondence information between data and channel, copyright information, and indicates whether the ancillary data is valid or invalid. Includes information, data modes, etc.
In addition, the channel signal indicates which channel data is 1
/ 2fs.

The TxDVD circuit 21 is a DVD (not shown)
The LRCK signal from the audio data reading unit is divided by 2 to generate a 2LRCK signal, and the LRCK signal and the 2LR
According to the CK signal, the data of the channel specified by the channel signal is reduced to 1/2 fs. Also, Tx
According to the DVD circuit 21 having been set to 、 fs,
ASI1, A of ancillary data added to data
SI2 is automatically changed. The data DATA1 to DATA3 have the same sampling frequency (fs) at the time when they are input to the TxDVD circuit 21.
In each channel, ASI1 is
“10”, ASI2 is “00” when the effective data length is 24 bits, and “0” when the effective data length is 20 bits.
1 "and" 10 "when the effective data length is 16 bits. The TxDVD circuit 21 changes the data ASI1 (2 bits) to a value “11” indicating that the channel is a data-converted channel, and changes the data ASI2 (2 bits).
Indicates the value set by the host (not shown) when the data is passed through, and changes to “11” when the data is held.

The FIFO 22 is a buffer that holds data (isochronous packets) from the TxDVD circuit 21 and sequentially sends the data to the Phy circuit 23 at a predetermined transmission timing. Phy circuit (Phy: physical layer) 2
Reference numeral 3 converts an isochronous packet from the FIFO 22 into an electric signal flowing on an actual IEEE 1394 bus, and performs arbitration for acquiring the bus.

B. Next, an operation of the above-described embodiment will be described. Here, FIG. 3 is a timing chart for explaining the operation when creating 1/2 fs data. FIG.
Are ASI2 for data through and ASI for fixed data
FIG. 2 is a conceptual diagram for explaining No. 2; FIG. 5 is a timing chart for explaining the operation when the mode is switched from the mute mode to the reproduction mode.

First, ancillary data and a channel signal from a host (microcomputer: control unit) not shown are held in the register 20. In the TxDVD circuit 21, as shown in FIG.
A 2LRCK signal is generated by dividing the frequency, and 2LRCK = 2LRCK =
The data A is supplied to the FIFO 22 as it is at a low level (through). Next, with 2LRCK = High, the data A is fixed (hold). As a result, the sampling frequency of the data A becomes 1/2 fs.

When transmitting data on the IEEE 1394 bus, quadlet data is packetized and transmitted. First, the channel (ch3, ch) to be changed to ｆ fs from the host (microcomputer control unit).
The data ASI1 of 4) is set from “10” to “11”. In the TxDVD circuit 21, as shown in FIG.
In the data fixing period, the data ASI2 of the channel (ch3, ch4) to which the data is fixed is changed from “00” to “11”. Further, during the next data through period, the data ASI of the channel (ch3, ch4)
2 is changed from “11” to “00”.

Also, as shown in FIG.
te) When the moment when the mode is switched from the mode to the reproduction mode overlaps with the fixed timing of the data,
When switching from mute mode to playback mode,
If the data ASI1 and data ASI2 of the ancillary data set from outside or from the host indicate data hold, zero data is added. This allows
No unnecessary data is output.

According to the above-described embodiment, among data input at the same sampling frequency (fs), 3 to 6
The previous sample word data hold transfer, in which arbitrary data of the channel is converted into 1/2 fs and transferred,
It can be realized via an IEEE 1394 bus.
Also, the AS added to the data accompanying the above data conversion
Since I2 is automatically changed, it is not necessary to change the ASI of ancillary data input from the host for each sample. Further, when an arbitrary channel of DVD audio data is already 1/2 fs, A
Even if the timing of adding SI2 = 2'b11 is not taken into consideration, the host automatically sets ASI = 2'b11, so that the ASI2 added to the 1/2 fs channel and its data are automatically timed. be able to.

[0027]

According to the first aspect of the present invention, of the multi-channel audio data, the audio data of the designated channel is converted into data whose sampling frequency is halved by the data conversion means. The value of the additional data relating to the previous sample word data hold transfer, which is transmitted to the serial bus and added to the data of each channel transmitted to the serial bus by the additional data changing means, is converted by the data converting means. Since the data is changed based on the operation, the previous sample word data hold transfer, in which the data of a specific channel is individually converted into 1/2 fs data and transferred, is used to transfer multi-channel audio data via a serial bus. The advantage of being able to transfer is obtained.

According to the second aspect of the present invention, the data conversion means generates a frequency-divided signal obtained by dividing the channel switching signal added to the multi-channel audio data by two, and generates the frequency-divided signal. By passing through or holding audio data of a designated channel to a subsequent circuit based on the signal, the sampling frequency becomes 1
/ 2, and the first additional data indicating that the channel has been converted by the data converting means by the additional data changing means, and whether the data has been passed through by the converting means. The second additional data indicating whether the data is the converted data is changed on the basis of the conversion operation by the data conversion means.
The previous sample word data hold transfer, which converts and transfers the data to multiple data, allows multi-channel audio data to be transferred via a serial bus, and the first and second additional data input from the host are sampled by one sample. The advantage is obtained that it is not necessary to change each time.

Further, according to the third aspect of the present invention, the timing for switching from the mute mode to the reproduction mode;
When the timing at which data is held by the data conversion means matches, the data conversion means
Since zero data is added, multi-channel audio data is transferred via a serial bus by the previous sample word data hold transfer, in which data of a specific channel is individually converted to 1/2 fs data and transferred. The advantage is that it can be

According to the fourth aspect of the present invention, the serial bus is an IEEE 1394 serial bus, so that the data of a specific channel is individually converted into 1/2 fs data and transferred. The advantage of the hold transfer is that multi-channel audio data can be transferred via the IEEE 1394 serial bus.

According to the fifth aspect of the present invention, the audio data of the designated channel among the multi-channel audio data is converted to a sampling frequency of 1 /.
2 and the value of the additional data related to the previous sample word data hold transfer, which is added to the data of each channel transmitted to the serial bus, is changed based on the conversion operation. So
The previous sample word data hold transfer, in which data of a specific channel is individually converted to data of 1/2 fs and transferred, has an advantage that multi-channel audio data can be transferred via a serial bus.

According to the sixth aspect of the present invention, a frequency-divided signal obtained by dividing the channel switching signal added to the multi-channel audio data by two is generated, and designated based on the frequency-divided signal. The audio data of the converted channel is passed through or held to a subsequent circuit, thereby converting the audio data into data having a sampling frequency of 、. The first additional data indicating the data-converted channel is then passed through. And the second additional data indicating whether the data is the held data or the held data, based on the conversion operation,
Multi-channel audio data can be transferred via a serial bus by a previous sample word data hold transfer in which data of a specific channel is individually converted to 1/2 fs data and transferred, and is input from the host. An advantage is obtained that the first and second additional data need not be changed for each sample.

According to the seventh aspect of the present invention, the timing for switching from the mute mode to the reproduction mode,
When the data conversion timing coincides with the data hold timing, zero data is added.
The previous sample word data hold transfer in which the data is transferred after converting to s data has an advantage that multi-channel audio data can be transferred via a serial bus.

According to the eighth aspect of the present invention, the audio data of the designated channel among the multi-channel audio data is converted to a sampling frequency of 1 /.
2; and changing the value of the additional data associated with the previous sample word data hold transfer, which is added to the data of each channel transmitted to the serial bus, based on the conversion operation. Is executed by a computer, so that the multi-channel audio data can be converted via a serial bus by a priori sample word data hold transfer in which data of a specific channel is individually converted into 1/2 fs data and transferred. The advantage of being able to transfer is obtained.

According to the ninth aspect of the present invention, a step of generating a frequency-divided signal obtained by dividing the channel switching signal added to the multi-channel audio data by two, and based on the frequency-divided signal, Converting the audio data of the specified channel to data having a sampling frequency of ス ル ー by passing through or holding the audio data to a subsequent circuit; and first additional data indicating that the channel has been converted. And changing the second additional data indicating whether the data is passed-through data or held data based on the conversion operation. Previous sample word data hold transfer for individually converting and transferring data to 1 / 2fs data Thus, it is possible to transfer multi-channel audio data via the serial bus, and it is possible to eliminate the need to change the first and second additional data input from the host for each sample. .

According to the tenth aspect of the present invention, when the timing for switching from the mute mode to the reproduction mode coincides with the timing for holding data by the data conversion means, the step of adding zero data is performed. Transfer of multi-channel audio data via a serial bus by a previous sample word data hold transfer in which data of a specific channel is individually converted to 1/2 fs data and transferred. Is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a DVD audio playback system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a DVD audio data transmission device.

FIG. 3 is a timing chart for explaining an operation when creating 1/2 fs data.

FIG. 4 shows ASI2 at data through and A at data fixed
It is a conceptual diagram for explaining SI2.

FIG. 5 is a timing chart for explaining an operation when switching from a mute mode to a reproduction mode;

[Explanation of symbols]

1 ... DVD audio data transmission device, 2 ... IEEE
E1394 processing unit, 3 ... Media, 5 ... DVD audio playback device, 6 ... IEEE1394 processing unit, 7 ...
... Amplifier, 8-1 to 8-6 ... Speaker, 20 ... Register, 21 ... TxDVD circuit (data conversion means, additional data change means), 22 ... FIFO, 23 ... Phy
circuit

Claims (10)

[Claims] 1. A data transfer device for transferring a multi-channel audio data via a priori sample word data hold via a serial bus, wherein the multi-channel audio data includes a specified channel audio data. Data conversion means for converting the data into data having a sampling frequency of し て and transmitting the data to the serial bus; and adding a previous sample word data hold transfer to data of each channel transmitted to the serial bus. A data transfer device, comprising: additional data changing means for changing a value of data based on a conversion operation by the data conversion means. 2. The data conversion means generates a frequency-divided signal obtained by dividing a channel switching signal added to the multi-channel audio data by two, and generates a frequency-divided signal of a designated channel based on the frequency-divided signal. By passing through or holding the audio data to a subsequent circuit, the audio data is converted into data having a sampling frequency of 、, and the additional data changing means is a first signal indicating that the data is converted by the data converting means. And the second additional data indicating whether the data is data passed through or held by the conversion means, based on a conversion operation by the data conversion means. The data transfer device according to claim 1. 3. The data conversion means adds zero data when a timing of switching from a mute mode to a reproduction mode coincides with a timing at which data is held by the data conversion means. 2. The data transfer device according to 1. 4. The method according to claim 1, wherein the serial bus is an IEEE1394.
2. The data transfer device according to claim 1, wherein the data transfer device is a serial bus. 5. A data transfer method for pre-hold sample word data hold transfer of multi-channel audio data via a serial bus, wherein the multi-channel audio data includes audio data of a designated channel, The value of the additional data related to the previous sample word data hold transfer, which is converted to data having a sampling frequency of が and is added to the data of each channel transmitted to the serial bus, based on the conversion operation A data transfer method characterized by changing. 6. A frequency-divided signal generated by dividing a channel switching signal added to the multi-channel audio data by two, and based on the frequency-divided signal, audio data of a designated channel is sent to a subsequent circuit. By passing through or holding, the data is converted into data whose sampling frequency is halved, and a first signal indicating the data-converted channel
7. A data transfer method according to claim 6, wherein said additional data and second additional data indicating whether the data is passed data or held data are changed based on said conversion operation. . 7. The data transfer method according to claim 5, wherein zero data is added when the timing of switching from the mute mode to the reproduction mode coincides with the timing at which data is held by the data conversion means. . 8. A data transfer program for transferring a multi-channel audio data through a priori sample word data hold via a serial bus, wherein the multi-channel audio data is a sampled audio data of a designated channel. Converting the frequency to 1/2 data; and adding the value of the additional data related to the previous sample word data hold transfer, which is added to the data of each channel transmitted to the serial bus, based on the conversion operation. A data transfer program causing a computer to execute the steps of: 9. A step of generating a frequency-divided signal obtained by dividing the channel switching signal added to the multi-channel audio data by two, and converting the audio data of the designated channel into a subsequent stage based on the frequency-divided signal. Converting the data into data whose sampling frequency is halved by passing through or holding the data to a circuit;
And causing the computer to execute a step of changing, based on the conversion operation, the additional data of (i) and the second additional data indicating whether the data is passed data or held data. Item 9. The data transfer program according to Item 8. 10. When a timing of switching from a mute mode to a reproduction mode coincides with a timing at which data is held by the data conversion means, the computer is caused to execute a step of adding zero data. 8. The data transfer program according to item 8.