Patent Grant
8098977
This application is a national stage filing under 35 U.S.C. § 371 of international application PCT/JP02/06114, filed Jun. 19, 2002, which claims the benefit of Japanese Application Nos. JP2001-185252, filed Jun. 19, 2001, and JP2002-171797, filed Jun. 12, 2002, the disclosures of all of which are incorporated by reference herein in their entirety.
This invention relates to a signal reproduction device and signal reproduction method for signal format recognition in, for example, a multi disc player and audio-video (AV) amplifier.
Conventionally, in interfaces conforming to the IEEE 1394 standard, for example between signal recording and reproduction devices, music data is transmitted and received, and music data which had been recorded in one signal recording and reproduction device is reproduced in another signal recording and reproduction device.
However, there is the problem that, because there is no means for recognizing the data format for AM824E standard data used by the above-described conventional signal recording and reproduction device to send and receive music data through an interface conforming to the IEEE 1394 standard, if the contents of the data are not examined, the data format cannot be determined.
However, actual examination of data contents requires time, so that there is the problem that audio interruptions and absence of track beginnings occur.
As a method other than that described above, it is possible for equipment which sends and receives music data to perform negotiation in order to conduct communications, and to set a communication protocol for transmission and reception; however, the method for setting a communication protocol for this purpose is not stipulated in the standards, and so when setting the communication protocol, there is the problem that the format must be recognized based on the data contents.
This invention was devised in light of the above problems, and has as an object the provision of a signal reproduction device and signal reproduction method enabling the automatic discrimination of the data format of, and reproduction of, input data.
A signal reproduction device of this invention comprises reception means to receive transmitted transmission signals resulting from the conversion of data in a plurality of prescribed signal formats into a prescribed packet type; reproduction means to reproduce signals in a prescribed signal format from transmission signals received by the reception means and converted into packets; packet extraction means to extract a prescribed packet of transmission signals received by the reception means; modification data detection means to detect, in an extracted packet, data indicating that modification has been performed from the currently received prescribed signal format to another prescribed signal format; and, control means to send, to the reproduction means, parameters necessary for reproduction by the reproduction means, from signals received and converted into packets to signals in another prescribed signal format, based on detected signal format modification data.
Further, a signal reproduction method of this invention comprises a reception step, in which transmission signals, obtained by converting data in a plurality of prescribed signal formats into a prescribed packet format and transmitting, are received; a reproduction step, in which signals in a prescribed signal format are reproduced from transmission signals converted into packet form, received in the reception step; a packet extraction step, in which a prescribed packet of transmission signals received in the reception step is extracted; a modification data detection step, in which data is detected, in an extracted packet, indicating that modification has been performed from the currently received prescribed signal format to another prescribed signal format; and, a control step, in which, based on the detected signal format modification data, parameters necessary for reproduction of signals in another prescribed signal format from received signals converted into packets in the reproduction step are sent to the reproduction step.
Hence the action according to this invention is as follows.
The reception means acts to receive transmission signals, which are data in a plurality of prescribed signal formats converted into a prescribed packet format and transmitted. The reproduction means acts to reproduce signals in a prescribed signal format from transmission signals, converted into packets, which have been received by the reception means. The packet extraction means acts to extract a prescribed packet of the transmission signals received by the reception means. The modification data detection means acts to detect data, from an extracted packet, indicating that modification has been performed from a prescribed signal format of the currently received signals to another prescribed signal format. The control means acts, based on the detected signal format modification data, to send to the reproduction means parameters necessary to reproduce signals in other prescribed signal formats from signals converted into packets and received by the reception means.
Below, an aspect of this invention is explained.
A signal reproduction device of this aspect examines received data packets and automatically recognizes data formats, and can be applied to, for example, data in an IEC 60958-conformant format among formats conforming to Audio and Music Data Transmission Protocol 1.0 and AMDTR 2.0, as well as data in DSD (Digital Stream Direct) format, and data in DVD (Digital Versatile Disc) Audio format.
In
The multiformat-compatible transmitter 1 is configured to have a disc 2 as recording media on which is recorded the data 10; a CD/SACD/DVD DSP (Digital Signal Processor) 3 which performs reproduction signal processing of data in various formats, recorded on the disc 2; an IEEE 1394 link chip 4, which makes settings for transmission of the data 10 over a network conforming to the IEEE 1394 standard; an IEEE 1394 microcontroller 5, which controls the IEEE 1394 link chip 4; a system microcontroller 6, which controls the multiformat-compatible transmitter 1; an operation portion 7 capable of various input in order to operate the multiformat-compatible transmitter 1; and a display portion 8 which displays the status of operation of the multiformat-compatible transmitter 1.
The multiformat-compatible receiver 11 is configured to have an IEEE 1394 link chip 12, which makes settings for reception of the data 10 over a network conforming to the IEEE 1394 standard; an IEEE 1394 microcontroller 13, which controls the IEEE 1394 link chip 12; a system microcontroller 14, which controls the multiformat-compatible receiver 11; an operation portion 15 capable of various input in order to operate the multiformat-compatible receiver 11; a display portion 16 which displays the status of operation of the multiformat-compatible receiver 11; a D/A converter 17 which converts 6-channel digital data received by the IEEE 1394 link chip 12 into analog signals; and a speaker 18 which reproduces and acoustically outputs the converted analog signals.
The IEEE 1394 microcontroller 13 is a host controller, and has a function for performing reception format settings 20 of the IEEE 1394 link chip 12 by performing CFR (configuration register) reading from the IEEE 1394 link chip 12.
In
The data 10 on the IEEE 1394-standard network 9 is received and processed in the IEEE 1394 link chip 12, and in the above-described CFR register 26, is allocated to RxLABEL 26-1, which makes reception settings; INT 26-2, which performs interrupt processing for the system microcontroller 14 depending on the combination of received signals; and SubLABEL 26-3.
The AM824 data 24 of the above-described IEEE 1394 packet 21 is data 24-1 having data regions for various formats; this data 24-1 is configured to have, for example, data 25 having beginning-portion ancillary data 25-1 and actual data 25-2. Here, ancillary data 25-1 is additional data for the actual data 25-2, and indicates data such as the number of channels and the speaker placement.
In this IEEE 1394 link chip 12, AM824 data 24 in an IEEE 1394 packet 21 is such that the data format cannot be determined if the data contents are not observed. Hence in the IEEE 1394 link chip 12, reception signal data is allocated to the register 26, and by having the register 26 set flags according to the data format of the reception signals, the system microcontroller 14 can detect flags and automatically discriminate the format of the data 24.
For example, 8000 items of the AM824 data 24 of an IEEE 1394 packet 21 are input in one second, and by detecting values indicated by INT26-2 performing the allocation processing of the system microcontroller 14 by combining signals received in the register 26, as well as detecting ancillary no-data for detection of stream changes, the system microcontroller 14 detects stream changes occurring over an interval of 10 msec or longer. Here the ancillary no-data 28 indicates that the data of this one sample is invalid, and that the data is not audio processed and output. In this aspect, when such data is detected, stream change detection can be performed.
When the system microcontroller 14 detects a stream change, on recognizing that there has been a change in the signal data format, the data is supplied to a later-stage audio processing circuit.
The data 24-5 are configured to have an unspecified region 31, comprising a detection data region 31-1 in the leading portion, a specified region 32, and a specified region 33. The specified region 32 is configured to have common/application specifier ancillary data, having a common data region in a variety of formats. The specified region 33 is configured to have common/AS ancillary data, having a common data region in a variety of formats. While standards permit the intermixing and sending of data in various formats in the specified regions 32 and 33, for practical reasons data is sent separately for each of the different formats. Also, a data CRC 34 is provided at the end.
In
Further, 42 shows the structure of multi-bit linear audio format DVD audio and other data; 45 shows the structure of DVD audio and other data in the ancillary no-data for multi-bit linear audio format. The multi-bit linear audio format (DVD audio) data 42 is discriminated by either “D0” (hexadecimal) in the upper 8 bits of the value of the register indicated by 48 and “01” (second quadlet “02”) (hexadecimal) in the lower 8 bits, or by “CF” (hexadecimal) in the upper 8 bits of the value of the register indicated by 48-1, and “D0” (hexadecimal) in the lower 8 bits.
Further, 43 indicates the structure of SACD and other data in a one-bit audio data format; 46 indicates the structure of SACD and other data in an ancillary no-data for one-bit audio data format. The one-bit audio data format (SACD) data 43 and the ancillary no-data for one-bit audio data format (SACD) data 46 are discriminated by either “D1” (second quadlet “50”) (hexadecimal) in the upper 8 bits of the value of the register indicated by 49 and “00” (hexadecimal) in the lower 8 bits, or by “CF” (hexadecimal) in the upper 8 bits of the value of the register indicated by 49-1, and “D1” (second quadlet “50”) (hexadecimal) in the lower 8 bits.
In
In
In
In
In
In
Here, by detecting, in the second and subsequent packets, that the first quadlet consists of “CFD0” and ancillary data, the following second quadlet consists of “CFD0” and ancillary data, and that the third quadlet consists of “CF48” and no data, stream changes can be detected.
In
In each of the following drawings, changing the value set for a flag in each register from “0” to “1” is simply called turning on the flag for each register.
In
Next, the CF50 detection means detects whether the leading two bytes of the first quadlet of the AM824 packet data are CFD1, and moreover the leading two bytes of the second quadlet are CF50. For example, the CF50 detection means comprises a logic circuit or software module. At this time, the CF50 detection means turns on the CF50 flag 51, and by detecting the on state of the CF50 flag 51, the system microcontroller 14 can detect the occurrence of a stream change of AM824 packet data to SACD data 52. Here the CF50 detection means detects, as a simple detection method, only whether the leading two bytes of the second quadlet are CF50, and turns on the CF50 flag 51.
Next, the CFD0 detection means detects whether the leading two bytes of the first quadlet of the AM824 packet data are CFD0, and moreover the leading two bytes of the second quadlet are CFD0. The CFD0 detection means comprises, for example, a logic circuit or a software module. At this time, the CFD0 detection means turns on the CFD0 flag 53, and by detecting the on state of the CFD0 flag 53, the system microcontroller 14 can detect the occurrence of stream changes in the AM824 packet data to DVD-audio data 54. Here the CFD0 detection means may detect, as a simple detection method, only whether the leading two bytes of the second quadlet are CFD0, and turn on the CFD0 flag 53.
Next, the Rx label detection means detects whether the upper four bits of the first quadlet of the AM824 packet data are 0000. The Rx label detection means comprises, for example, a logic circuit or software module. At this time, the Rx label detection means turns on RxLABEL 055, and by detecting the on state of the RxLABEL 055, the system microcontroller 14 can detect a stream change in AM824 packet data to CD/MD data (IEC 60958) 56. Detection that the upper four bits of the first quadlet are 0000 can be performed by, for example, taking the output of an AND circuit employing four data bits 0000 as negative-logic input as input to turn on RxLABEL 055, and performing detection and preferential processing through interrupt processing of the system microcontroller 14.
Of the AM824 packet data, the audio label 59-1 and audio sub-label 59-2 of the first quadlet and second quadlet are stored in the IBO register 59. At this time, the system microcontroller 14 detects the audio label 59-1 and audio sub-label 59-2 of the IBO register 59, and by this means can confirm the data format of the AM824 packet data.
In
In
By this means, ancillary no-data in formats before and after conversion by the device on the data reception side can be discriminated and reception settings made, so that format conversion discrimination is possible. Also, stream changes can be detected using data with few combinations, and, at this time, by turning on various flags in the above-described registers to enable easy detection by the system microcontroller 14, the load on the host controller can be alleviated.
Next, judgment of the format of packet data being received through operation of the microcontroller using the registers is explained. The following processing and judgment are performed by, for example, a microcontroller, but the present invention is not thus limited, and other judgment means may be used, so long as judgments of the formats of packet data allocated to registers can be made from the states of the registers.
In
In step S1, if RxLABEL CF=1 or RxLABEL0=0, processing proceeds to step S2, and in step S2, a judgment is made as to whether RxLABEL CF50=1 and moreover RxLABEL CFD0=0 and moreover RxLABEL0=0.
In step S2, when RxLABEL CF50=1 and moreover RxLABEL CFD0=0 and moreover RxLABEL0=0, processing proceeds to step S3, and in step S3, a judgment is made as to whether the packet data is in a 1-bit audio (SACD) format.
When in step S1 it is not the case that RxLABEL CF=1 or that RxLABEL0=0, processing proceeds to step S13, and in step S13, a judgment is made as to whether the packet data is in an IEC 60958 format.
In step S2, when it is not the case that RxLABEL CF50=1 and moreover RxLABEL CFD0=0 and moreover RxLABEL0=0, processing proceeds to step S4, and in step S4, a judgment is made as to whether RxLABEL CF50=0 and moreover RxLABEL CFD0=1 and moreover RxLABEL0=0.
In step S4, when RxLABEL CF50=0 and moreover RxLABEL CDD0=1 and moreover RxLABEL0=0, processing proceeds to step S5, and in step S5 the packet data is judged to be in a multi-bit audio (DVD audio) format.
In step S4, when it is not the case that RxLABEL CF50=0 and moreover RxLABEL CFD0=1 and moreover RxLABEL0=0, processing proceeds to step S6, and in step S6 a judgment is made as to whether RxLABEL CF50=0 and moreover RxLABEL CFD0=0 and moreover RxLABEL0=0.
In step S6, when RxLABEL CF50=0 and moreover RxLABEL CFD0=0 and moreover RxLABEL0=0, processing proceeds to step S7, and in step S7 a judgment is made as to whether the packet being received is IEC 60958-conformant or is an empty packet.
In step S7, when the packet being received is IEC 60958-conformant or is an empty packet, processing proceeds to step S8, and in step S8, the packet data is judged to be in the IEC 60958 format.
In step S7, if it is not the case that the packet being received is IEC 60958-conformant or is an empty packet, processing proceeds to step S9, and in step S9, a judgment is made as to whether the packet being received is in a 1-bit audio (SACD) format.
In step S9, when the packet being received is in a 1-bit audio (SACD) format, processing proceeds to step S10, and in step S10, the packet data is judged to be in a 1-bit audio (SACD) format.
In step S9, when the packet being received is not in a 1-bit audio (SACD) format, processing proceeds to step S11, and in step S11, a judgment is made as to whether the packet being received is in a multi-bit audio (DVD audio) format.
In step S11, when the packet being received is in a multi-bit audio (DVD audio) format, processing proceeds to step S12, and in step S12, the packet data is judged to be in a multi-bit audio (DVD audio) format.
After the judgment of a 1-bit audio (SACD) format in step S3, the judgement of a multi-bit audio (DVD audio) format in step S5, the judgment of an IEC 60958 format in step S8, the judgment of a 1-bit audio (SACD) format in step S10, the judgment of a multi-bit audio (DVD audio) format in step S12, and the judgment of an IEC 60958 format in step S13, processing proceeds to step S14, and in step S14, each of the flags is cleared.
Next, examples of stream changes among various formats of packet data being received are explained.
In the following drawings, detection, judgment, and other operations may be performed by, for example, a microcontroller; however, this invention is not thereby limited, and other judgment means may be used, so long as judgments of the formats of packet data allocated to registers can be made from the states of the registers.
In
At time T1, as indicated by 85, the value of RxLABEL0 changes from 1 (on) to 0 (off), so that a stream change ending IEC60958 Conformant data is detected.
At this time, as shown in
In the interval from time T1 to time T2, RxLABEL CF50=0, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=indefinite, so that the received packet data is in the state of an empty packet 82. This state is the state in which empty packet data is judged in step S7 as a result of a “YES” branch in step S6 of the flowchart of the above-described
In the interval from time T2 to time T3, RxLABEL CF50=1, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=1, so that the received packet data is in the state of SACD ancillary no-data 83.
At this time, as shown in
Next, the CF50 detection means detects that the leading 2 bytes of the first quadlet among the packet data are CFD1 and the leading 2 bytes of the second quadlet are CF50, and the CF50 detection means turns on the CF50 flag; the system microcontroller 14, by detecting the on state of the CF50 flag 51, detects the occurrence of a stream change in the AM82 packet data to SACD data 52.
As indicated by 86, the RxLABEL on state is one CF50 only, so that the packet data is judged to be the SACD format of the on state of this RxLABEL CF50. At this time, the received packet is confirmed, the data length is confirmed, and the IEEE 1394 microcontroller 13 shown in
At time T3, RxLABEL CF50=0, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=0, so that the received packet data is in the state of the SACD format. This state is the state in which the packet data is judged to be in 1-bit audio (SACD) format in step S3, as a result of a “YES” branch in step S2 of the flowchart in the above-described
As indicated by 87, the value of RxLABEL CF has changed from 1 (on) to 0 (off), and so it is judged that a stream change from IEC 60958-conformant to SACD has ended.
In
At time T1, as indicated by 95, the value of RxLABEL CF50 changes from 0 (off) to 1 (on), so that a stream change ending SACD 91 data is detected.
At this time, as shown in
Next, the CF50 detection means detects that the leading two bytes of the first quadlet of the packet data are CFD1 and that the leading two bytes of the second quadlet are CF50, and the CF50 detection means turns on the CF50 flag 51; the system microcontroller 14, by detecting the on state of the CF50 flag 51, detects the occurrence of a stream change in the AM824 packet data to SACD data 52.
In the interval from time T11 to time T12, RxLABEL CF50=1, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=1, so that the received packet data is in the state of SACD ancillary no-data 92.
In the interval from time T12 to time T13, RxLABEL CF50=0, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=indefinite, so that the received packet data is in the state of the empty packet 93. This state is the state in which a packet is judged in step S7 to be an empty packet as a result of a “YES” branch in step S6 of the flowchart of the above-described
As indicated by 96, all RxLABEL flags are in the off state, so that data being received is judged to be IEC 60958-conformant data. Further, because RxLABEL0=0, a stream change is judged to occur. In order to reliably identify the data, the audio label and sub-label of the data being received are investigated, and the IEEE 1394 microcontroller 13 shown in
At this time, the Rx label detection means detects that the upper four bits of the first quadlet of the packet data are 0000, and the Rx label detection means turns on RxLABEL 055; as the judgment means, the system microcontroller 14 detects the on state of RxLABEL 055, and in this way detects a stream change to CD/MD data (IEC 60958) 56.
Further, the audio label 59-1 and audio sub-label 59-2 of the first quadlet and second quadlet of the packet data are stored in the IBO register 59, and by examining the audio label 59-1 and audio sub-label 59-2 in the IBO register 59, the system microcontroller 14 confirms the data format of the packet data.
At time T13, RxLABEL CF50=0, RxLABEL CFD0=0, RxLABEL0=1, and RxLABEL CF=0, so that received packet data is in the IEC 60958-conformat 94 state. This state is the state in which packet data is judged in step S13 to be in IEC 60958 format as a result of a “NO” branch in step S1 of the flowchart of the above-described
As indicated by 97, the value of RxLABEL 0 changes from 0 (off) to 1 (on), so that it is judged that a stream change from SACD to IEC 60958-conformant format has ended.
In
At time T21, as indicated by 105, the value of RxLABEL CF50 has changed from 0 (off) to 1 (on), so that a stream change ending SACD 101 data is detected.
At this time, as shown in
Next, the CF50 detection means detects the face that the leading two bytes of the first quadlet of the packet data are CFD1 and that the leading two bytes of the second quadlet are CF50, and the CF50 detection means turns on the CF50 flag 51; the system microcontroller 14, by detecting the on state of the CF50 flag 51, detects a stream change ending the SACD data 52.
In the interval from time T21 to time T22, RxLABEL CF50=1, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=1, so that the received packet data is in the SACD ancillary no-data 102 state.
In the interval from time T22 to time T23, RxLABEL CF50=0, RxLABEL CFD0=1, RxLABEL0=0, and RxLABEL CF=1, so that the received packet data is in the DVD ancillary no-data 103 state.
At this time, as shown in
Next, the CFD0 detection means detects that the two leading bytes of the first quadlet of the packet data are CFD0 and that the two leading bytes of the second quadlet are CFD0. At this time, the CFD0 detection means turns on the CFD0 flag 53, and the system microcontroller 14, by detecting the on state of the CFD0 flag 53, detects that a stream change has occurred in the packet data to the DVD audio data format 54.
As indicated by 106, there is only one RxLABEL on state, for CFD0, so that the packet data is judged to be in the DVD format with the RxLABEL CFD0 in the on state. At this time, the received packet is confirmed, the data length is confirmed, and the IEEE 1394 microcontroller 13 shown in
At time T23, RxLABEL CF50=0, RxLABEL CFD0=1, RxLABEL0=0, and RxLABEL CF=0, so that the received packet data is in the DVD 104 state. This state is the state in which packet data is judged in step S5 to be in the multi-bit audio (DVD audio) format as a result of a “YES” branch in step S4 of the flowchart of the above-described
As indicated by 107, the value of RxLABEL CF has changed from 1 (on) to 0 (off), so that it is judged that a stream change from SACD 101 to DVD 104 has ended.
In
At time T31, as indicated by 115, the value of RxLABEL CF50 changes from 0 (off) to 1 (on), so that a stream change ending the SACD 111 data is detected.
At this time, as shown in
Next, the CF50 detection means detects that the leading two bytes of the first quadlet of the packet data are CFD1 and that the leading two bytes of the second quadlet are CF50, and the CF50 detection means turns on the CF50 flag 51; the system microcontroller 14, by detecting the on state of the CF50 flag 51, detects a stream change ending the SACD data 52.
In the interval from time T31 to time T32, RxLABEL CF50=1, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=1, so that the received packet data is in the SACD ancillary no-data 112 state.
As indicated by 116, the only RxLABEL on state is CF50, and so the format is set to the SACD format of this RxLABEL CF50 on state. At this time, the received packet is confirmed, the data length is confirmed, and the IEEE 1394 microcontroller 13 shown in
During the interval from time T32 to time T33, RxLABEL CF50=1, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=1, so that received packet data is in the SACD ancillary no-data 113 state.
At this time, as shown in
Next, the CF50 detection means detects that the leading two bytes of the first quadlet of the packet data are CFD1 and that the leading two bytes of the second quadlet are CF50, and the CF50 detection means turns on the CF50 flag 51; the system microcontroller 14, by detecting the on state of the CF50 flag 51, detects a stream change to SACD data 52.
Here, as indicated by 117, the IEEE 1394 microcontroller 13 repeats the operation of setting the IEEE 1394 link chip 12 into the SACD format reception state, but the data length changes, and so a change in the number of channels is detected.
At time T33, RxLABEL CF50=0, RxLABEL CFD0=0, RxLABEL0=0, and RxLABEL CF=0, so that the received packet data is in the SACD state. This state is the state in which packet data is judged in step S3 to be in the 1-bit audio (SACD) format as a result of a “YES” branch in step S2 of the flowchart of the above-described
As indicated by 118, the value of RxLABEL CF changes from 1 (on) to 0 (off), so that a stream change from SACD 5-channel (111) format to SACD 6-channel (114) format is judged to have ended.
In
Below, reception states 126 in each of the stream changes 121 to 123 are explained.
In
In a stream change (from the IEC 60958 format to the SACD format) in the packet data indicated by 121 in
During the interval from time T2 to time T3, when the trigger detection register 125 detects that RxLABEL CF50 (51)=on, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=on, as indicated by 126, prior notice is given that the received packet is in SACD format.
During the interval following time T3, when the trigger detection register 125 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=off, as indicated by 126, a state is entered in which an SACD format reception packet is being received.
In
In a stream change (from SACD format to IEC 60958 format) in the packet data indicated by 122 in
During the interval from time T12 to time T13, when the trigger detection register 125 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=off, and RxLABEL0 (54)=off, as indicated by 126, the received packet is judged to be an empty packet, and the receiving side enters a state of preparation for reception of packet data in the IEC 60958 format.
During the interval following time T13, when the trigger detection register 125 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=on, and RxLABEL CF (57)=off, as indicated by 126, an IEC 60958 format reception packet is being received.
In
Below, reception states 136 in each of the stream changes 131 to 133 are explained.
In
In a stream change (from the SACD format to the DVD-audio format) in the packet data indicated by 132 in
During the interval from time T21 to time T22, when the trigger detection register 135 detects that RxLABEL CF50 (51)=on, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=on, as indicated by 136, the received packet is judged to be in the SACD ancillary no-data state, and on the receiving side a mute state is entered in which audio is not output.
During the interval from time T22 to time T23, when the trigger detection register 135 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=on, RxLABEL0 (54)=off, and RxLABEL CF (57)=on, as indicated by 136, the received packet is judged to be a packet in DVD-audio format, and the receiving side enters the mute state in which audio is not output.
During the interval following time T23, when the trigger detection register 135 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=off, a DVD-audio format reception packet is being received.
In
In the stream change (change in the number of SACD channels) in the packet data indicated by 133 in
During the interval from time T31 to time T32, when the trigger detection register 135 detects that RxLABEL CF50 (51)=on, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=on, as indicated by 136, the received packet is judged to be in the SACD ancillary no-data state, and the receiving side enters the mute state in which audio is not output.
During the interval from time T32 to time T33, when the trigger detection register 135 detects that RxLABEL CF50 (51)=on, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=on, as indicated by 136, the received packet is in the SACD ancillary no-data state, but the receiving side is in the mute state in which audio is not output, and the received packet is judged to be in SACD 6-channel format.
During the interval following time T33, when the trigger detection register 135 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=off, as indicated by 136, an SACD 6-channel format reception packet is being received.
In
In a stream change (from IEC 60958 format to DVD-audio format) in packet data indicated by 123 in
During the interval from T02 to T03, when the trigger detection register 135 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=on, RxLABEL0 (54)=off, and RxLABEL CF (57)=on, as indicated by 136, prior notice is given that the received packet is in DVD-audio format.
During the interval following time T03, when the trigger detection register 135 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=off, as indicated by 136, a DVD-audio format reception packet is being received.
Though not shown here, other stream changes (from IEC 60958 format to CD/MD format) result in similar states. The DVD-audio format is called the multibit linear audio (MBLA) format.
In
In a stream change (from DVD-audio format to SACD format) in the packet data indicated by 131 in
During the interval from time T011 to time T012, when the trigger detection register 135 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=on, RxLABEL0 (54)=off, and RxLABEL CF (57)=on, as indicated by 136, the received packet is judged to be in the DVD-audio ancillary no-data state, and the receiving side enters the mute state in which audio is not output.
During the interval from time T012 to time T013, when the trigger detection register 135 detects that RxLABEL CF50 (51)=on, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=on, as indicated by 136, the received packet is judged to be in SACD format, and the receiving side enters the mute state in which audio is not output.
During the interval following time T013, when the trigger detection register 135 detects that RxLABEL CF50 (51)=off, RxLABEL CFD0 (53)=off, RxLABEL0 (54)=off, and RxLABEL CF (57)=off, as indicated by 136, an SACD format reception packet is being received.
As stated above, by means of operation of a microcontroller or other judgment means using the registers in the IEEE 1394 link chip 12 within the multiformat-compatible receiver 11 shown in
When RxLABEL CF (57)=on, CF is contained in the audio label of the AM824 data.
Then, when RxLABEL CF50 (51)=on, an SACD format packet is being received. At this time, the audio label and sub-label of the second quadlet of the AM824 data are CF50. Here the second quadlet is examined because, in 1-bit audio and multi-bit audio, the positions of ancillary data are different, so that if the second quadlet is checked it is possible to discriminate the type of data content in the case of 1-bit audio and the data format through the type of ancillary data in the case of multi-bit audio. In this case, ancillary no-data for SACD or other 1-bit audio data is included. That is, a stream change related to SACD or other 1-bit audio is occurring.
Next, when RxLABEL CFD0 (53)=on, a DVD-audio format packet is being received. At this time, the audio label and sub-label of the second quadlet of the AM824 data are CFD0. Here the second quadlet is examined for the same reason as the above-mentioned RxLABEL CF50 (51). In this case, ancillary no-data is included in the DVD-audio or other multi-bit linear audio data. That is, a stream change related to the DVD-audio or other multibit linear audio is occurring.
Next, when RxLABEL0 (54)=on, a CD/MD format packet is being received. At this time, when the leading four bits of the AM824 data are 0, the data being received is IEC 60958-conformant data.
The contents of the IBO register are the audio label and sub-label for two received quadlets. Here received data is normally stored. By confirming this audio label and sub-label, the format of the data currently being received can be confirmed.
Here, if data allocated to each register is detected, the format of the data in the stream change can be judged and confirmed.
Further, in cases other than a stream change in the packet data, that is, when AM824 data is constantly being input, the current AM824E format can be judged from the audio label and sub-label of the IBO register.
As explained above, when IEC 60958-conformant (CD/MD or similar) data is being received, and SACD or other 1-bit audio data is then received, the following procedure is used to judge that the packet data is in SACD format.
First, when IEC 60958-conformant data is being input constantly, PxLABEL0 (54)=on. Next, when a stream change occurs so that the packet data changes to a different format, in order to indicate this change, the receiver receives ancillary no-data or empty packet data. At this time, RxLABEL0 (54)=off, and the beginning of the stream change can be detected. Here, as an example, when SACD 1-bit audio data is received, RxLABEL CF (57)=on results, indicating this SCAD anceillary no-data. At this time, if a state obtains in which only one RxLABEL is on, the data format can be confirmed to be SACD, so that the IEEE 1394 microcontroller 13 within the multiformat-compatible receiver 11 shown in
Also, when SACD or other 1-bit audio data is being received, and IEC 60958-conformant (CD/MD or similar) data is then received, when judging that the data is IEC 60958-conformant, the following procedure is used.
When a stream change occurs because SACD or other 1-bit audio data had been input constantly and the data format of the packet data is changed, the receiver receives ancillary no-data, RxLABEL CF50 (51) is turned on, and the beginning of a stream change can be detected. Next, if as an example IEC 60958-conformant data arrives, all the RxLABEL flags are turned off, and it can be predicted that a stream change is occurring to IEC 60958-conformant data. Because there exists equipment which, due to past standards, does not use IEC 60958-conformant ancillary no-data, a judgment cannot be made solely on the basis of ancillary no-data. However, in this case it is certain that the packet data is not in a 1-bit audio or multi-bit audio format, and so the IEC 60958-conformant format is predicted, and by examining the audio label and sub-label of actually received data, the format can be determined reliably, so that the IEEE 1394 microcontroller 13 within the multiformat-compatible receiver 11 shown in
In cases where SACD or other 1-bit audio data is being received, and then DVD-audio or other multi-bit linear audio data is received, the following procedure is used to judge that the data is DVD-audio.
First, when 1-bit audio data is arriving, and then the format of the packet data changes so that a stream change occurs, RxLABEL CF (57) is turned on. At this time, if only one RxLABEL is turned on, it can be confirmed that the next data format is the multi-bit audio data format, and so the IEEE 1394 microcontroller 13 within the multiformat-compatible receiver 11 shown in
Next, when a stream change is detected when the data format does not change but the number of channels of audio data changes, the following procedure is used. As an example, the case in which there is a change in SACD data, which is 1-bit audio data, from 5 channels to 6 channels is explained.
When there are a plurality of channels, the data size changes depending on the number of channels. This data size is stated as the data length in the 1394 header. It is sufficient to be able to judge differences in this data length.
In this example, 1-bit audio data is received in a continuous state; when a stream change occurs in order to change the number of channels of the packet data, RxLABEL CF50 (51) is turned on. At this time, the beginning of the stream change can be detected. When the stream change is detected, the ancillary no-data data length is confirmed, and the number of channels is judged from the data size. RxLABEL CF50 (51)=on even when the next ancillary no-data arrives, and so detection at the instant of the change is not possible; but according to AM824E standards, the interval for output of ancillary no-data is 10 msec or longer, and so if this check is repeated at fixed intervals, a change in the data length can be detected. By means of this detection, the number of channels of new data can be judged, and the IEEE 1394 microcontroller 13 within the multiformat-compatible receiver 11 shown in
The Direct Stream Digital (DSD) method adopted by SACD is a method which represents the magnitude of audio signals using the density (concentration) of 1-bit digital pulses, and is completely different from the conventional Pulse Code Modulation (PCM) method.
In the above-described aspect, an example was described which uses an IEEE 1394-standard interface; however, the present invention is not thereby limited, and other interfaces such as a USB (Universal Serial Bus) interface or wireless IEEE 1394-standard interface may be used.
The signal reproduction device of this invention comprises reception means to receive transmitted transmission signals resulting from the conversion of data in a plurality of prescribed signal formats into a prescribed packet type; reproduction means to reproduce signals in a prescribed signal format from transmission signals received by the reception means and converted into packets; packet extraction means to extract a prescribed packet of transmission signals received by the reception means; modification data detection means to detect, in an extracted packet, data indicating that modification has been performed from the currently received prescribed signal format to another prescribed signal format; and, control means to send, to the reproduction means, parameters necessary for reproduction by the reproduction means, from signals received and converted into packets to signals in another prescribed signal format, based on detected signal format modification data. Hence there is the advantageous result that the data format can be automatically judged from the input data, and data can be reproduced.
Further, a signal reproduction device of this invention further comprises output means to output signals reproduced by the reproduction means of the above-described signal reproduction device; when signal type modification data is detected, the control means can suppress the output of signals from the output means during the period until completion of the signal format conversion, so that there is the advantageous result that degradation of the quality of reproduced signals accompanying modification of the signal format can be prevented.
Also, a signal reproduction device of this invention has the further advantageous result that, in the above description, data indicating modification of the signal format is such that, after transmission of a signal indicating that transmitted data in the signal format currently being received is invalid data, data indicating the signal format of the data to be transmitted next is transmitted, so that the next data format can be predicted and reception settings for this data can be set in advance.
Also, a signal reproduction device of this invention has the further advantageous result that, in the above description, the signal reproduction device detects other signal formats through the packet size of received data, so that when the data size changes due to a change in the number of channels, because the data size is described as the data length in the header, by judging differences in the data length it is possible to judge changes in the number of channels.
Also, a signal reproduction method of this invention comprises a reception step, in which transmission signals, obtained by converting data in a plurality of prescribed signal formats into a prescribed packet format and transmitting, are received; a reproduction step, in which signals in a prescribed signal format are reproduced from transmission signals converted into packet form, received in the reception step; a packet extraction step, in which a prescribed packet of transmission signals received in the reception step is extracted; a modification data detection step, in which data is detected, in an extracted packet, indicating that modification has been performed from the currently received prescribed signal format to another prescribed signal format; and, a control step, in which, based on the detected signal format modification data, parameters necessary for reproduction of signals in another prescribed signal format from received signals converted into packets in the reproduction step are sent to the reproduction step. Hence there is the advantageous result that the data format can be automatically judged from the input data, and reproduction processing can be performed.
This signal reproduction device examines received data packets and automatically recognizes the data format, and through the operation of a microcontroller or other judgment means utilizing the registers of an IEEE 1394 link chip within a multiformat-compatible receiver which has received AM824 data, detects stream changes according to data combinations and can judge the next data format. The signal reproduction device can be applied to, for example, IEC 60958-conformant format data among the formats conforming to the audio and music data transmission protocol 1.0 and AMDTR 2.0, to DSD (Digital Stream Direct) format data, and to DVD (Digital Versatile Disc) audio format data.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2001-185252 | Jun 2001 | JP | national |
| 2002-171797 | Jun 2002 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP02/06114 | 6/19/2002 | WO | 00 | 6/6/2003 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO02/103698 | 12/27/2002 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6618549 | Kato et al. | Sep 2003 | B1 |
| 6741795 | Takehiko et al. | May 2004 | B1 |
| 6788653 | Sakamoto et al. | Sep 2004 | B1 |
| 6850696 | Van Gestel | Feb 2005 | B1 |
| 6904403 | Muraki et al. | Jun 2005 | B1 |
| 6947422 | Ichimura et al. | Sep 2005 | B1 |
| Number | Date | Country |
|---|---|---|
| 1085724 | Mar 2001 | EP |
| 2001-94448 | Apr 2001 | JP |
| 2001-144785 | May 2001 | JP |
| 2001-160266 | Jun 2001 | JP |
| 2001-250318 | Sep 2001 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20040033057 A1 | Feb 2004 | US |
