JP2000307647A - Data reception device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically decide the transfer mode and timing mode of a transmit packet. SOLUTION: A mode detection part 65 detects data indicating the transfer mode of a transmit packet inserted into a payload part included in the transmit packet of SDTI(Serial Data Transport Interface) and data indicating the timing mode to automatically decide those modes. the decision result is outputted to a timing generating circuit 62 to generate a timing signal for data extraction. The reading and writing of memories 101 and 102 provided to a data extracting circuit 100 are controlled according to the timing signal, and then data of a video signal, etc., are extracted from the transmit packet. The extraction can securely be performed whatever mode the transmission mode of the transmit packet is, so the data can securely be extracted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a data receiving apparatus. More specifically, the received data can be correctly extracted by determining data indicating a transfer mode different from the asynchronous transfer mode and data indicating the timing of data transmission.

[0002]

2. Description of the Related Art As a transmission format for transmitting digital data, SMPTE-standardized by SMPTE is used.
259M "10-bit 4: 2: 2 Component
ntand 4fsc Composite Digit
al Signals-Serial Digita
l Interface ”(hereinafter“ SDI (Serial Digi
tal Interface) format) is known. This transmission standard is a standard for transmitting a digital component video signal (D1 signal), a digital composite signal (D2 signal), and the like.

As is well known in this transmission format,
Although it is a standard that allows audio data and other data to be inserted into the ancillary data area and transmitted, it is not in a format that allows compressed data (video data) to be inserted into the active video area and transmitted. .

[0004] The transmission format is standardized so that even such compressed data can be transmitted.
05M "Serial Data Transport"
Interface "(hereinafter referred to as" SDTI format "). That is, this is the SDT corresponding to the active video area ACV in the SDI format.
In addition to fixed-length data, variable-length data such as compressed video data and audio data is inserted into a payload (Payload) section in the I format so that the data can be transmitted.

[0005]

By the way, this SDT
When transmitting video data, audio data, and the like using the I format, it is conceivable to transmit the video data simultaneously on the receiving side. Judgment is made as to whether to transfer in synchronization with the receiving side or to transmit in consideration of isochronism. Therefore, it may be better to change the transfer mode according to the purpose of data transmission.

[0006] In the same transfer mode, whether data to be transmitted is inserted into the first field and transmitted.
There is a difference in the delay in the transmission system depending on whether the data is inserted in the second field and transmitted. That is, several types of timing modes of data to be transmitted can be selected.

[0007] When the transfer mode or the timing mode is selected according to the purpose of transmission as described above, if the data receiving side cannot identify the type of the transmission packet transmitted, the data receiving side cannot determine the type of the transmission packet. Data cannot be extracted correctly. In that case, it is preferable that the mode can be automatically determined.

Therefore, the present invention has solved such a conventional problem, and it is possible to automatically determine the transfer mode and the timing mode of a transmission packet and to reliably extract data based on the determined output. It is like that.

[0009]

According to a first aspect of the present invention, there is provided a data receiving apparatus comprising: a section of one line of a video frame having an end synchronization code area in which an end synchronization code is inserted; And an auxiliary data area in which auxiliary data is inserted, a start synchronization code area in which a start synchronization code is inserted, and a payload area in which data including a video signal is inserted. In a data receiving apparatus for receiving a transmission packet, the data receiving apparatus includes a data extracting unit for extracting data including the video signal, data indicating a transfer mode of the transmission packet inserted in the payload area, and / or Mode detection means for determining timing mode data indicating a packet transmission timing; A timing generator for generating a timing signal to be supplied to the data extractor, wherein a timing signal corresponding to the transfer mode and / or the timing mode is generated by the timing generator at the output of the mode detecting means. It is characterized by having been made.

According to the present invention, data indicating a transfer mode of a transmission packet inserted into a payload portion included in a transmission packet of a serial digital transfer interface (SDTI) and / or data indicating a timing mode of the transmission packet are detected. .

The transfer modes include a synchronous transfer mode and an isochronous transfer mode in addition to the asynchronous transfer mode. When transmitting compressed video data or the like from a video camera in real time, it is necessary to transmit data while synchronizing the transmitting side and the receiving side.
This is because when multiplexing transmission of video data of a channel, it is necessary to transmit data while synchronizing the transmission side and the reception side.

The timing mode when transmitting a transmission packet is determined based on whether data is transmitted in the first field or not.
It indicates whether data is transmitted in the second field or whether data is transmitted using the first and second fields. The timing mode is set in both the synchronous transfer mode and the isochronous transfer mode. Depending on how the timing mode is set, the system delay between transmission and reception can be minimized.

Data indicating a transfer mode and a timing mode are detected from the payload portion of the received transmission packet, and a timing signal for extracting original data such as video data is generated. No matter what mode data is transferred by this timing signal, the data can be reliably extracted.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, data such as video and audio materials are packaged and each item (for example, picture item (Pictu
reItem) and audio items (AudioItem), and package information and metadata about each item into one item (system item (Sys
tem Item)) and package these items. This package is called a content package. Further, a transmission packet is generated from the content package, and the SMPTE 305M (So
ciety of Motion Picture and Television Engineers 3
The transmission is carried out using SDTI (Serial Digital Transfer Interface) standardized in 2005M).

The SDTI is obtained by inserting various types of header information into an ancillary area with respect to a transmission packet in the SDI format standardized by SMP 259M.

Next, the SDI format will be described.

When the SDI format is arranged in one frame of video, a digital video signal of the NTSC 525 system is 1716 (4+
268 + 4 + 1440) words and 525 lines in the vertical direction. Also, a digital video signal of the PAL625 system is 172 lines per line in the horizontal direction.
8 (4 + 280 + 4 + 1440) words, vertical is 6
It consists of 25 lines. However, it is 10 bits / word.

For each line, four words from the first word to the fourth word are used as a video signal area 144.
Indicates the end of the 0-word active video area, and is used as an area for storing a code EAV (End of Active Video) for separating the active video area and an ancillary data area described later.

For each line, 268 words from the fifth word to the 272th word are used as an ancillary data area, and header information and the like are stored. Four words from the 273rd word to the 276th word indicate the start of the active video area, and a code SA for separating the active video area from the ancillary data area.
It is used as an area for storing V (Start of Active Video), and the 277th word and subsequent words are used as an active video area.

In the active video area, the D1 signal or D
Two digital video signals are inserted. SDTI
In the format, a payload area is provided in the same area as the active video area so that not only the D1 signal and the D2 signal but also various data such as compressed video data and computer data can be inserted into the active video area of the SDI format. .

Further, in the SDTI format, a header data area into which various header data is inserted is provided in the ancillary data area. Details of the header data area will be described later.

In the SDTI-CP format according to the present invention, the above-mentioned various items are inserted into the payload area of the SDTI format.

FIG. 1 shows an example in which the SDTI-CP format is arranged in a video frame. As shown in FIG. 1, system items, picture items, audio items, and auxiliary items (auxiliary items) are arranged in this order in the payload area. In FIG. 1, the numbers in parentheses indicate the numerical values of the PAL625 video signal, and the numbers without the parentheses indicate the numerical values of the NTSC 525 video signal. Hereinafter, only the NTSC system will be described.

The structure of the end synchronization code EAV will be described with reference to FIG. This code EAV is 3FFh, 000h, 0
00h, XYZh (h indicates hexadecimal notation, and the same applies to the following description).

In "XYZh", the bit b9 is set to "1" and the bits b0 and b1 are set to "0". Bit b8 is a flag indicating whether the field is the first field or the second field.
Is a flag indicating a vertical blanking period. Bit b6 is a flag indicating whether the 4-word data is EAV or SAV. The flag of the bit b6 is set to "1" for EAV and "0" for SAV. Bits b5 to b2 are data for performing error detection and correction.

Next, FIG. 2 also shows the configuration of header data (Header Data) included in the ancillary data area. At the beginning of the header data, fixed patterns 000h, 3FFh, and 3FFh are arranged as data "ADF (Ancillary data flag)" for header data recognition. Following this fixed pattern, “DID (Data ID)” and “SDID (Secondary data ID)” are provided.
The DID and SDID indicate attributes of the ancillary data part. DID and SDID are fixed patterns 140 indicating that this attribute is a user application.
h, 101h are arranged.

"Data Count" is replaced with "Line
Number-0 ”to“ Header CRC1 ”
This indicates the number of words up to 46 words, and the number of words is 46 words (22Eh).

"Line Number-0, Line
"Number-1" indicates the line number of the video frame. In the NTSC 525 system, these two words indicate the line numbers from 1 to 525. In the PAL system 625 system, line numbers from 1 to 625 are indicated.

"Line Number-0, Line
Number-1 followed by Line Number
er CRC0, Line Number CRC1 "
Are arranged, and this “Line Number CR”
C0, Line Number CRC1 ”is“ DI
D ”to“ Line Number-1 ”, CRC (cyclic redundancy check) for 5-word data
codes), which are used for checking transmission errors.

"Code & AAI (Authorized addr
ess identifier) indicates information such as what the word length of the payload area from the SAV to the EAV is set and what data format is used for the addresses of the sending side and the receiving side. .

[Destination Addresses]
"s" is the address of the data receiving side (transmission destination), and "S
"source Address" is the address of the data transmission side (transmission source).

The "Block Type" following the "Source Address" indicates the format of the payload area, for example, whether the payload area has a fixed length or a variable length. Compressed data is inserted. Here, SDTI-C
In the P format, each item is a variable-length block (Var
iable Block). Therefore, SDTI-C
“Block Type” in the P format is fixed data 1C1h.

"CRC Flag" indicates whether a CRC is placed in the last two words of the payload area.

In addition, "Da" following "CRC Flag"
“ta extension flag” indicates whether or not the user data packet is extended.

"Data extension fla
Following "g", a 4-word "Reserved" area is provided. Next "Header CRC 0, Head
erCRC 1 ”is a CRC for data from“ Code & AAI ”to“ Reserved 4 ”.
(Cyclic redundancy check codes), which are used for checking transmission errors. The next "Check Su
“m” is a Check Sum code for all header data, and is used for checking transmission errors.

In the payload area shown in FIG. 1, data of items such as video and audio is packaged as a variable-length block in SDTI format. FIG. 3 shows the format of a variable-length block. "Separator" and "End Cod"
"e" indicates the start and end of the variable-length block,
The value of “Separator” is “309h”, and “End”
The value of “Code” is set to “30 Ah”.

In addition, in the SDTI format,
Fixed-length blocks are defined. SDTI-CP
In the format, each item is inserted in a variable-length block format of the SDTI format.

"Data Type" indicates the type of data to be inserted into the data block area.
The -CP format indicates the type of each item inserted in the data block area.

For example, “04h” is set for a system item, “05h” is set for a picture item, and “0” is set for an audio item.
6h ”, AUX item (Auxiliary It
em) is “07h”. As described above, one word is 10 bits. For example, when the word is 8 bits as shown in "04h", 8 bits are bits b7 to b7.
It corresponds to 0. Further, by adding even parity of bits b7 to b0 as bit b8 and adding logically inverted data of bit b8 as bit b9, 10 bits are obtained.
Bit data. The 8-bit data in the following description is similarly converted into 10 bits.

In "Word Count", "Data
The “Dat” indicates the number of words of “Block”.
"a Block" is the data of each item. Here, the data of each item is packaged in picture units, for example, frame units, and in the NTSC system, the program switching position is set to the position of 10 lines. Therefore, in the NTSC system, as shown in FIG. 1 in
From the third line, system items, picture items,
Audio items and AUX items are transmitted in this order.

FIG. 4 shows the structure of a system item. This system item is inserted into the payload area of the SDTI format. “Separatar” and “Item Type” at the beginning of the payload area
e) and “Word Count” followed by “Syst
em Item Bitmap "," Content
Package Rate "," Content Pa "
package Type "," Channel Hand "
le "," Continuity Count ", SM
PTE Universal Label "," Ref
erence Data / Time Stamp ",
“Current Data / Time Stam
p "," Package Metadata Se
t "," Audio Metadata Set ",
The whole is composed of “Auxiliary Metadata Set” and “Control Element”, and further inserted with an end code defined in the SDTI format.

One-word “System Item B”
The bit b7 of "itmap" is a flag indicating whether or not an error detection and correction code such as a Reed-Solomon code is added, and when "1" is set, the error detection and correction code is added. Is shown. Bit b6 is a flag indicating whether or not there is SMPTE Label information. Here, when “1” is set, it indicates that the information of the SMPTE Label is included in the system item. Bits b5 and b
4 is Reference Date / Time status
mp, Current Date / Time stamp
This is a flag indicating whether or not p is in the system item. This Reference Date / Times
In the “tamp”, for example, the time or date when the content package was first created is indicated. Also Curren
In t Date / Time stamp, the time or date when data of the content package was last corrected is indicated.

Bit b3 is a picture item, bit b
2 is an audio item, and bit b1 is a flag indicating whether or not the AUX item is after the system item. When "1" is set, it indicates that the item exists after the system item.

The bit b0 is the control element (C
ontrol Element).
When "1" is set, it indicates that the control element exists. In addition, although not shown, the bit b
8, b9 are added as described above and transmitted as 10-bit data.

One word "Content Packa"
bits b7 to b6 of "ge Rate" are undefined areas (Res
erved), and the bits b5 to b1 indicate the package rate which is the number of packages per second in the 1 × speed operation.
(Package Rate) is displayed. Bit b0 is a 1.001 flag, and when the flag is set to "1", it indicates, for example, a 59.94 (= 60 / 1.001) field per second.

One-word "Content Packa"
Bits b7 to b5 of “ge Type” are “Stream States” flags for identifying the position of the picture unit in the stream. This 3
The following eight types of states are indicated by the bit flags.

0: The picture unit is a pre-roll (pr
e-roll) section, editing section, post-roll
It does not belong to any of the sections. 1: This picture unit is a picture included in the pre-roll section, and is followed by an editing section. 2: This picture unit is the first picture unit of the editing section.

3: This picture unit is a picture unit included in the middle of the editing section. 4: This picture unit is the last picture unit of the editing section. 5: This picture unit is a picture unit included in the post-roll section. 6: This picture unit is the first and last picture unit of the editing section (the state where the editing section has only one picture unit). 7: Not defined

Bit b4 is an undefined area (Reserved), and bits b3 and b2 of "Transfer Mod"
"e" indicates the transmission mode of the transmission packet. Also, the transmission timing mode when transmitting the transmission packet is indicated by “Timing Mode” of bits b1 and b0. Here, when the value indicated by the bits b3 and b2 is “0”, the synchronous mode (Synchronous mode)
When "1", isochronous mode,
When it is "2", it is set to an asynchronous mode (Asynchronous mode). When the value indicated by the bits b1 and b0 is “0”, the transmission of the content package for one frame is started at a timing of a predetermined line of the first field (Normal timing mode).
Advanced timing mode in which transmission is started at the timing of a predetermined line in the second field when "1"
(Advanced timing mode), when "2", a dual timing mode in which transmission is started at a timing of a predetermined line in each of the first and second fields (Dual timing mode)
mode).

[Content Package Ty]
"Channel" followed by two words "Channel Handl"
"e" is used to determine the content package of each program when the content packages of a plurality of programs are multiplexed and transmitted, and are identified by identifying the values of bits H15 to H0. Content packages can be separated for each program.

The two-word "Continuity Co"
"unt" is a 16-bit modulo counter. This counter is counted up for each picture unit, and is independently counted for each stream. Therefore, when a stream is switched by a stream switcher or the like, the value of this counter becomes discontinuous, and a switching point (editing point) can be detected. Since this counter is a 16-bit modulo counter as described above and has a very large value of 65536, the probability that the value of the counter coincidentally coincides at the switching point between the two switched streams is extremely low. In addition, practically sufficient accuracy can be provided for detecting the switching point.

After “Continuity Count”, the above-mentioned SMPTE Label or Refer
ence Date / Time and Current
"SMPTE Universal" indicating Date / Time
sal Label "," Reference Dat "
e / Time stamp "," Current Da
A "te / Time stamp" area is provided.

After that, "Package Meta"
data Set ”or“ Picture Metada ”
ta Set "," Audio Metadata Se "
t "" Auxiliary Metadata Se
A "t" region is provided. In addition, "Picture Me
tadata Set "," Audio Metadat "
a Set "," Auxiliary Metadata "
Set ”indicates that the corresponding item is“ System I
It is provided when it is indicated that the content is included in the content package by the flag of “tem Bitmap”.

17 bytes are allocated to the above-mentioned “Time stamp”, and “Time” is used in the first byte.
e stamp ", and the remaining 16 bytes are used as a data area. here,
The first 8 bytes of the data area are, for example, SMPTE12
Time code (Timecode) standardized as M is shown, and the subsequent 8 bytes are invalid data.

As shown in FIG. 5, the 8-byte time code includes "Frame", "Seconds", and "Minute".
s "," Hours "and 4-byte" Binary "
Group Data ”.

The bits b5 and b4 of "Frame" indicate the tens place of the frame number, and the bits b3 to b0 indicate the place of the first place. Similarly, “Secons” and “Minute”
s ”,“ Hours ”, each bit b6 to b0 indicates seconds,
Minutes and hours are shown.

The bit b7 of "Frame" is a color frame flag (Color Frame Flag), and indicates whether the frame is the first color frame or the second color frame. Bit b6 is a drop frame flag (Drop Frame flag).
Flag), which is a flag indicating whether or not the video frame inserted in the picture item is a drop frame. Bit b7 of “Seconds” is, for example, NTSC
In the case of the system, a field phase (Field Phase), that is, whether the field is the first field or the second field is indicated. In the case of the PAL method, the field phase is indicated by the bit b6 of “Hours”.

3 bits B0 of bit b7 of "Minutes" and bits b7 and b6 of "Hours"
B3 (In the PAL system, “Seconds” and “Mini
tes ”and“ Hours ”, each bit b7) indicates whether or not there is data in each of BG1 to BG8 of“ Binary Group Data ”. In this “Binary Group Data”, for example, the Gregorian calendar (GregorianCalender) and the Julian calendar (Julian calendar)
Calender) can be displayed in two digits.

FIG. 6 shows the structure of "Metadata Set", in which one word "Metadata Co."
"metadata Bl" in the set
The number of “ocks” is indicated. In addition, "Metadata
When the value of “Set” is 00h, “Metadata
Since there is no "Block", "Me
“tadata Set” is one word.

Here, "Metadata Bloc
“k” indicates “Package Metadata Set” indicating content package information such as a program title.
In the case of, the one-word "Metadata Type
"e", a two-word "Word Count", and an information area "Metadata" is provided.
If the number of words of this “Metadata” is “Word C
"out" is indicated by bits b15 to b0.

[0061] "Picture Metadata Set", "A" indicating information on packaged items such as video, audio or AUX data.
audio Metadata Set "and" Auxili
The “ary MetadataSet” further includes “Element Type” and “Element” of one word.
“Element Number” is provided, and “Element Data” of items such as video and audio described below is provided.
"Element Type" and "E"
element Number ", and is linked to" Element Data Block ".
Metadata can be set for each time. After these “Metadata Set”, “Cont.
A "rollElement" region can be provided.

Next, a block of each item such as video and audio will be described with reference to FIG. Block of each item such as video and audio "Item Type
e "(corresponding to the SDTI format data type)
Indicates the type of item as described above, and is "05h" for a picture item, "06h" for an audio item, and "07h" for an AUX data item. “Item Word Count” indicates the number of words up to the end of this block (corresponding to “Word Count” in SDTI format). "I
"Item HedCount" followed by "Item He
ader "," Element Data Blo
ck "is indicated. Here, "Item Head
Since “er” is 8 bits, “Element D”
The number of “ata block” ranges from 1 to 255 (0 is invalid). The “Element Data Block” following the “Item Header” is the data area of the item.

"Element Data Bloc"
k "means" Element Type "and" Element
t Word Count "," Element Num "
ber "and" Element Data ", and" Element Type "and" Element ".
Word Count "by" Element
The type and amount of data of “Data” are shown.
The “Element Number” indicates the number of the “Element Data Block”.

Next, the structure of “Element Data” will be described. MPEG, one of the elements
The -2 picture element is an MPEG-2 video elementary stream (V-ES) of any profile or level. Profiles and levels are defined in the decoder template document. FIG. 8 is an example of the format of MPEG-2 V-ES in the SDTI-CP element frame. This example is a V-ES bitstream that specifies a key, ie, an MPEG-2 start code (according to SMPTE recommended practices). MPEG
The -2 V-ES bitstream is simply formatted into data blocks as shown in FIG.

Next, metadata for a picture item, for example, MPEG-2 picture image editing metadata will be described. This metadata is a combination of edit and error metadata, compression encoded metadata, and source encoded metadata. These metadata can be inserted mainly in the system items described above, as well as in auxiliary data items.

FIG. 9 shows “Picture Editing Bitma” provided in the MPEG-2 picture editing metadata inserted in the “Picture MetadataSet” area of the system item shown in FIG.
A “p” area, a “Picture Coding” area, and an “MPEG User Bitmap” area are shown. Further, the MPEG-2 picture editing metadata includes a “Profile / Level” area indicating the profile and level of MPEG-2, and an SMPTE1
It is also conceivable to provide video index information defined in 86-1995.

One word "Picture Edit"
ng Bitmap ”bits b7 and b6 are“ Ed
It flag ", which is a flag indicating editing point information. The following four types of states are indicated by the 2-bit flag.

00: No editing 01: The editing point is before the picture unit with this flag (Pre-picture edit) 10: The editing point is after the picture unit with this flag (Post-picture edit) -picture edit) 11: Only one picture unit is inserted, and the edit point is before and after the picture unit with this flag (single
le frame picture)

That is, whether the video data (picture unit) inserted in the picture item is before the edit point,
A flag indicating whether it is after the edit point or is sandwiched between two additional edit points is set to “Picture Metadata”.
a Set ”(see FIG. 4)“ Picture Edi ”
Insert into the “Ting Bitmap” region.

Bits b5 and b4 are set to "Error"
flag ". This "Error flag"
Whether the picture contains an uncorrectable error, the picture contains a concealment error, the picture contains no errors,
Furthermore, it indicates whether it is in an unknown state. Bit b3 is "P
Picture Coding ”is the“ Picture
This is a flag indicating whether or not it is in the “MetadataSet” area. Here, when “1” is set, “P”
icture coding ”is included.

Bit b2 is “Profile / Lev”
"el". here,
When it is set to “1”, the “Metadata
The “Block” includes “Profile / Level”. This “Profile / Level” is M
MP @ ML or HP indicating PEG profile or level
＠ Indicates HL or the like.

Bit b1 is a flag indicating whether or not "HV Size" exists. Here, when “1” is set, “HV Size” is included in the “Metadata Block”. Bit b0 is
This flag indicates whether or not “MPEG User Bitmap” is present. Here, when “1” is set, “MPE” is added to the “Metadata Block”.
G User Bitmap "is included.

One word "Picture Coden"
“Closed GOP” is provided in bit b7 of “g”. This “Closed GOP” indicates that the GOP (Group Of Picture) when MPEG-compressed is Closed.
d Indicates whether this is a GOP.

The bit b6 contains “Broken Lin”.
k ”is provided. This "Broken Link"
Is a flag used for reproduction control on the decoder side.
That is, each picture of MPEG is arranged like a B picture, a B picture, an I picture, etc., but when there is an editing point and a completely different stream is connected, for example, the B picture of the stream after switching is There is a possibility that decoding is performed with reference to the P picture of the stream before switching. By setting this flag, it is possible to prevent the decoding as described above on the decoder side.

Bits b5 to b3 contain "Picture"
“Coding Type” is provided. This "Pi
"cure Coding Type" is a flag indicating whether the picture is an I picture, a B picture, or a P picture. Bits b2 to b0 are undefined areas (Reserved).

One word "MPEG User Bit"
"History dat" is set in bit b7 of "map".
a "is provided. This "History dat"
“a” indicates that the encoded data such as the quantization step, the macro type, and the motion vector, which are necessary for the encoding of the previous generation, are stored in the user data area existing in “Metadata” of “Metadata Block”, for example. , History data, or not. Bit b6 contains “Anc
data ”is provided. This "Anc dat
"a" is the data inserted in the ancillary area (for example,
This is a flag indicating whether or not data necessary for MPEG compression is inserted as Anc data in the user data area.

In the bit b5, “Video inde
x "is provided. This "Video inde
“x” is a video index in the video index area.
This is a flag indicating whether index information is inserted. The video index information is inserted into a 15-byte video index area. In this case, the insertion position is determined for each of the five classes (1.1, 1.2, 1.3, 1.4, and 1.5). For example, the video index information of the 1.1 class is inserted into the first three bytes.

Bit b4 contains “Picture or
der "is provided. This "Picture o
“rder” is a flag indicating whether or not the order of each picture of the MPEG stream has been changed. In addition, MPE
Changing the order of the pictures in the G stream is required for multiplexing.

Bits b3 and b2 contain "Timecode
e2 "and" Timecode1 ". This "Timecode2", "Timecode1"
Is in the area of Timecode2, 1
ical Interval Time Code), LTC (Longitudinal Ti)
me Code) is inserted. Bits b1 and b0 include “H-Phase” and “V
-Phase "is provided. This "H-Phas
"e" and "V-Phase" are flags indicating which horizontal pixel and vertical line are being encoded at the time of encoding, that is, whether or not the information of the frame actually used is in the user data area.

Next, the audio item will be described. The audio item "Element Dat
“a” is “Element Dat” as shown in FIG.
"a" is "Element Header", "Audio"
“Sample Count”, “Stream Val”
id Flags "and" Data Area ".

The one-word “Element Head”
The bit b7 of “r” is “FVUCPVValid Fla.
g), and FVUCP defined in the AES-3 format standardized by the AES (Audio Engineering Society) is the AES of “Data Area”.
-3 format audio data (audio data)
Indicates whether or not it has been set. Bits b6 to b3
Is an undefined area (Reserved), and bits b2 to b0
Sequence number of 5-frame sequence (5-sequ
ence counter) is indicated.

Here, the five-frame sequence will be described. One frame is composed of 525 scanning lines (30/1.
001) synchronized with the video signal of frame / second,
When an audio signal having a sampling frequency of 48 kHz is divided into blocks of each frame of a video signal,
The number of samples per video frame is 1601.6 samples / frame, which is not an integer value. For this reason,
A sequence in which two frames of 1601 samples are provided and three frames of 1602 samples are provided so that five frames have 8008 samples is called a five-frame sequence.

The 5-frame sequence is synchronized with the reference frame signal shown in FIG. 11A. For example, as shown in FIG. 11B, the frames of sequence numbers 1, 3, and 5 are 1602 samples, and the frames of sequence numbers 2 and 4 are 1601 samples. The sequence number is represented by bit b2
Ｂb0.

A two-word "Audio Sample"
"Count" includes bits c15 to c15 as shown in FIG.
This is a 16-bit counter in the range of 0 to 65535 using 0, and indicates the number of samples of each channel. Note that all channels have the same value in the element.

One-word “Stream Valid”
"Flags" indicates whether or not each stream of eight channels is valid. Here, when significant audio data is included in the channel, the bit corresponding to this channel is set to “1”, and otherwise, the bit is set to “0” and the bit is set to “1”. Only the audio data of the channel set to "" is transmitted.

"S2-s0" of "Data Area"
Is a data area for identifying each stream of eight channels. “F” indicates the start of a subframe.
“A23 to a0” are audio data, and “P,
"C, U, V" are channel status, user bit, V
The parity bits include parity bits, parity bits, and the like.

Next, metadata for an audio item will be described. Audio editing metadata (Aud
io Editing Metadata) is a combination of editing metadata, error metadata, and source coding metadata. As shown in FIG. 12, the audio editing metadata includes one word “Field / Frame fl”.
ags ", 1-word" Audio Editing "
Bitmap ", 1-word" CS Valid Bi
tmap "and" Channel Status "
Data ”.

The number of valid audio channels is determined by the “Stream Val” shown in FIG.
id Flags ". If the flag of “Stream Valid Flags” is set to “1”, “Audio E
"Diting Bitmap" becomes effective.

"Audio Editing Bitm"
“first editing flag” of “ap” is the first field, “Second editing flag”.
“lag” indicates information on the editing status in the second field, and indicates whether the editing point is before or after the field with this flag. "Error
“lag” indicates whether or not an error that cannot be corrected has occurred.

“CS Valid Bitmap” is
"Ch" of n (n = 6, 14, 18, or 22) bytes
"annule Status Data" header, which indicates which of the 24 channel status words is present in the data block. Here, "CS
Valid1 ”is“ Channel Status ”
This is a flag indicating whether or not there is data in 0 to 5 bytes of “Data”. "CS Valid2"-"CS
Valid4 ”is“ Channel Status ”
This is a flag indicating whether or not there is data in 6 to 13 bytes, 14 to 17 bytes, and 18 to 21 bytes of “Data”. In addition, "ChannelStatus
Data ”is set to 24 bytes, and 2
Depending on the data of the 22nd byte, whether or not there is data from 0 to 21 bytes is indicated.
The 3-byte data is used as a CRC from 0 to 22 bytes. In addition, "Fielded / Frame flag
The flag "s" indicates whether the audio data of eight channels is packed in frame units or field units.

A general data format (General Data
Format) is used to carry all freeform data types. However, this free form data type does not include special auxiliary element types such as IT nature (word processing, hypertext, etc.).

The SDTI-CP format is composed of the data streams as described above.

In the present invention, a data transfer mode and a data timing mode are defined in order to realize real-time transmission within a fixed time. FIG. 13 shows the relationship between the transfer mode and the timing mode. The transfer mode includes a synchronous transfer mode (Synchronous Mode) in which information is periodically and regularly transferred to a transmission side, and an asynchronous transfer mode (Asochronous Mode) in which information is transferred randomly instead of periodically.
Mode) and an isochronous transfer mode (Isochronous Mo Mode) in which data is continuously transferred in real time within a certain period of time.
de) there.

In the timing mode, a normal timing mode (Normal Timin) in which a transmission packet is transmitted at the timing of transmitting the first field of the video frame.
g Mode), an advanced timing mode for transmitting a transmission packet at the timing of transmitting the second field of the video frame, and a transmission packet for transmitting the first field and the second field of the video frame. There is a dual timing mode (Dual Timing Mode).

FIG. 13 shows the relationship between the transfer mode and the timing mode, and FIGS. 14A to 14D and FIGS.
F indicates the arrangement of transmission packets in units of one picture in each mode.

As shown in FIG. 14A, when the transfer mode is the synchronous mode and the timing mode is the normal timing mode, the transmission packet including the content package (CP) at the reference 1 × speed is transmitted in the first field of each frame. Place and transfer from. In FIG. 14A, the bars illustrated in the content package indicate the arrangement positions of the system items. The same applies to the following.

When the transfer mode is the synchronous mode and the timing mode is the advanced timing mode, the transmission packet including the content package is arranged and transferred from the second field of each frame as shown in FIG. 14B.

When the transfer mode is the synchronous mode and the timing mode is the dual timing mode, FIG.
As shown in (1), the transmission packet including the content package is arranged and transferred in the first field and the second field of each frame. In this dual timing mode, compressed video data of 525 lines / 60 frames and compressed video data obtained by performing MPEG compression by field coding are transferred.

In the normal timing mode, a transmission packet is inserted from a predetermined line in the first field. 5
In the 25 line / 60 field, a system item is inserted in the 13th line. By the way, 625 lines / 50
In the field, a system item is inserted at the ninth line.

In the advanced timing mode, a transmission packet is inserted from the second field. In the 525 line / 60 field, a system item is inserted at the 276th line.
A system item is inserted in two lines.

In this dual timing mode, 52
13th line and 2nd line in 5 lines / 60 frames
The system item is inserted in each of the 76 lines.
In the 25 line / 50 frame, the system item is inserted into the ninth line and the 322nd line.

When the transfer mode is the asynchronous mode,
As shown in FIG. 14D, a transmission packet including a content package is arranged and transferred in an arbitrary area.

FIGS. 15A to 15C illustrate the transfer mode in the isochronous transfer mode. FIG. 15A shows an example of the arrangement of transmission packets when the transfer mode is the isochronous mode and the timing mode is the normal timing mode. In this example, the transmission packet including the content package (CP) is transmitted at the double speed at the double speed from the first field of each frame.

When the transfer mode is the isochronous transfer mode and the timing mode is the advanced timing mode, the transmission packet including the content package is arranged and transferred from the area of the second field of each frame as shown in FIG. 15B. I do.

When the transfer mode is the isochronous transfer mode and the timing mode is the dual timing mode, as shown in FIG. 15C, the transmission packet including the content package is arranged in the area of the first field and the second field of each frame. And transfer.

In the case of 1/2 speed, FIGS.
An example of such an arrangement as shown in FIG. A transmission packet including a content package whose transfer mode is the isochronous mode and whose timing mode is the normal timing mode is arranged and transferred from the first field of each frame as shown in FIG. 15D.

When the transfer mode is the isochronous transfer mode and the timing mode is the advanced timing mode, the transmission packet including the content package is arranged and transferred from the second field of each frame as shown in FIG. 15E.

When the transfer mode is the isochronous transfer mode and the timing mode is the dual timing mode, as shown in FIG. 15F, the transmission packet including the content package is arranged in the area of the first field and the second field of each frame. And transfer.

The line into which the system item is inserted is the same line as the corresponding timing mode in FIGS. 14A to 14C.

Here, the amount of data that can be transmitted in one frame is up to 6.048 Mbits (= 1440 bytes × 8
On the other hand, when the average compression rate is 50 Mbps when MPEG data is compressed under the condition that each picture rate is the same, a data amount of 1.66 M bits per frame is obtained. Therefore, 6.048 Mbits / 1.66 Mbits =
Up to 3.6 times data can be sent. Therefore, in this isochronous transfer mode, the above 50 Mbp
With data of s, high-speed transfer up to triple speed can be realized.

In order to identify the three transfer modes and the three timing modes, respectively, of the payload portion included in the transmission packet defined by the SDTI format, as shown in FIG. Type area indicating data type (item type area)
The data representing the transfer mode described above is inserted and transmitted in the content / package type area in the vicinity of using the 2-bit data (b2, b3).

Further, according to the present invention, of the payload portion included in the transmission packet defined in the SDTI format, the content package near the type area indicating the data type of the data block area as shown in FIG. In the type area, 2-bit data (b0, b
Using 1), the data representing the timing mode described above is inserted and transmitted.

Next, the transmission system for transmitting the above-mentioned transmission packet will be described in detail.

The description starts with data transmission in the asynchronous transfer mode. FIG. 16 shows an outline of a data transmission system in the asynchronous transfer mode.

This data transmission system comprises a transmission system 10 and a reception system 20.

The transmission system 10 includes a storage unit (data storage unit) 12 for storing data to be transmitted, an interface (I / Ft) 14 for issuing a data transfer request, and a transmission unit (Tx) for transmitting read data. 16 and a control unit (CPU) 18 for sending a transfer result to the interface 14.

The storage means 12 includes a hard disk device (HDD device) which is a non-linearly accessible recording medium, a semiconductor memory such as a D-RAM and a flash memory, and a video tape recorder (a tape tape) for recording data in a tape-like field. VTR) can be used.

The interface 14 issues an instruction to read the data Sb stored in the storage unit 12 to the storage unit 12 based on the control instruction indicating the transmission instruction received from the control unit 18. The transmission unit 16 converts the data Sb read from the storage unit 12 into a transmission packet in the above-described SDTI-CP format, and further converts the data into a serial and outputs the packet. The specific configuration of the transmission unit 16 will be described later.

The control unit 18 receives the transfer request transmitted from the receiving system 20, and transmits a control command indicating a transfer instruction to the interface 14.

The receiving system 20 includes a data receiving unit (Rx) 2
2, a storage unit 24 for storing received data, and a control unit (CPUr) for monitoring received data and sending a data transmission instruction for receiving the next data. As the storage means 24, a hard disk drive or a VTR used in the transmission system 10 can be used.

The operation of the data transmission system shown in FIG. 16 will now be described. The receiving unit 22 converts the received data into parallel data, and converts the parallel data into original data and other data (ancillary data). Data and system item data) are separated, original data such as video data is stored in a data storage unit (data storage unit) 24, and information on the presence or absence of the received data is sent to a control unit 26. Control unit 26
Then, based on the presence or absence of this data, the control unit 1
8, a control command indicating a data transmission instruction is issued.

FIGS. 17A to 17F are timing charts when transmitting and receiving transmission packets in the asynchronous mode in the data transmission system configured as shown in FIG.

In the control unit 26 provided in the receiving system 20,
After confirming that no data has been input to the receiving unit 22 and that the transfer (storage) of all the received data has been completed, a data transfer enable command is sent to the transmission control unit 18. The fact that the transferable command has been transmitted at the same time is stored.

Control unit 18 that has received the transfer enable command
Issues a data transfer command to the interface 14. Upon receiving this command, the interface 14 instructs the storage means 12 to output a data valid pulse Sa corresponding to 5 words (FIG. 17A)
Is sent. In response to this, the storage unit 12 outputs the data Sb (FIG. 17B) for five words with a delay of one word, for example, in consideration of the data delay to the transmission unit 16. In the interface 14, the data valid pulse Sc delayed by one word
(FIG. 17C) is output to the transmission unit 16.

The transmitting section 16 inserts the above-mentioned data into the area of the system item and the picture item of the SDTI-CP format into the transmission data read from the storage means 12, and further includes a separator defined by the SDTI format, Insert an end code, etc.
An EAV, SAV, or the like defined in the DI format is inserted to generate a transmission packet in the SDTI-CP format. FIG. 17D shows transmission data inserted into the payload area for convenience in the transmission packet.

The receiving section 22 generates a data valid pulse Se (FIG. 17F) from the received transmission packet, sends the valid data Sb (FIG. 17E) to the storage section 24 and stores it, and also outputs the data valid pulse Se to the control section 26. To monitor the end of data accumulation. When the data storage is completed, a data transfer enable command is sent from the control unit 26 again. As described above, in the asynchronous transfer mode, transmission / reception of a transmission packet is performed using the idle time of the receiving system 20.

FIG. 18 shows a data transmission system in which the transfer mode is the synchronous transfer mode (reference 1 × speed) and the timing mode is the normal timing mode.

The reception system 10 of this data transmission system
A video camera 42, an encoder 40 to which a video signal from the video camera 42 is supplied to generate compression-encoded video data, and an SDTI
And an encoder 50 for generating a CP format transmission packet.

In the encoder 40, MPEG (Moving Pic)
Experts Group) encoder is used, MPEG
Compressed video data is generated. In the next encoder 50, a system item in the SDTI-CP format,
The above-described compressed video data is inserted into an area such as a picture item, and a separator, an end code, etc. defined in the SDTI format are inserted, and the SDI is further inserted.
A transmission packet in the SDTI-CP format is generated by inserting EAV, SAV, etc. defined in the format.

The receiving system 20 includes a decoder 60 for receiving a transmission packet in the SDTI-CP format, and an M to which the compressed video data separated by the decoder 60 is supplied.
It is composed of a PEG decoder 70, a monitor 80 for supplying decoded video data and monitoring the video, and a storage 82 for storing the decoded video data. As the data storage unit 82, a hard disk device, a semiconductor memory, a video tape recorder, or the like can be used as in the storage units 12, 24 shown in FIG.

The video signal output from the video camera 42 is converted into MPEG compressed video data by the MPEG encoder 40. An enable pulse indicating an output section of the compressed video data is also generated. The compressed video data and the enable pulse are supplied to the encoder 50, and the above-described SD
It is converted into a transmission packet in the TI-CP format.
This transmission packet is transferred after serial conversion.

The compressed video data and the enable pulse are separated from the received transmission packet. The compressed video data is restored by the MPEG encoder 70 using an enable pulse.

In such a data transmission / reception mode, it is necessary to complete the transmission of one frame of video data within a certain period (in this example, one video frame period). Then, data processing needs to be performed in synchronization with the video frame. Therefore, the following processing is performed in the transmission / reception system.

In the transmission system 10, for example, a process synchronized with a video frame signal (pulse) (FIG. 19A), which is a reference signal in the station, is performed. The video frame signal is a signal obtained in synchronization with the fourth line of the video frame. The video signal of the first field and the second field is obtained from the video camera 42 in synchronization with the video frame signal (FIG. 19B).

In the MPEG encoder 40, in order to perform data compression processing in units of frames, the video signal having this field cycle is delayed by one field (FIG. 19C). The timing of the conversion process is performed in synchronization with the second field. The converted frame video signals are simultaneously compression-encoded (FIG. 19D). In this compression encoding, since the code amount differs depending on the block to be compressed as shown in FIG. 20A, an enable pulse (FIG. 19E and FIG.
B) are generated simultaneously. Since the compression encoding by MPEG is completed within one frame, the data compression processing for one frame is completed at least by the third video frame period (the period during which the pulse F3 is obtained).

The MPEG compressed data and the enable pulse are supplied to the next SDTI-CP encoder 50. SDTI- inserted into the payload portion by this encoder 50
Each item of the CP is generated, and a header of the SDTI format is added to each item, and EAV, ANC, SAV, etc. are further added thereto.
A transmission packet in the CP format is generated. This transmission packet is sent to a transmission system (such as a communication cable) 45 at a transmission speed such as 270 Mbps.

FIG. 19F shows transmission data inserted into the payload area for convenience. The same applies to the following. The transmission of the transmission packet to the transmission system 45 is performed in synchronization with the third video frame pulse F3 (FIG. 19).
F).

The receiving section 60 extracts vertical blanking data F (see FIG. 2) inserted into the EAV area into which the end synchronization code is inserted in this example from the received transmission packets, and generates a video frame pulse. , The MPEG decoder 70, the monitor 80,
The storage means 82 is controlled to operate.

The receiving unit 60 is configured as an SDTI-CP decoder, in which the payload is separated from the transmission packet in the SDTI-CP format, and is separated for each item using the data of the system item from the separated payload. And decoded (FIG. 19G).
At the same time, the enable pulse is also decoded (FIG. 19)
H). This decoding process is also performed in synchronization with the video frame pulse.

Thereafter, the MPEG decoder 70 decodes the frame video signal and the enable pulse, respectively, and converts the decoded frame video signal into a field-based video signal in synchronization with the next video frame pulse F5 (FIG. 19I). 19J, 19K). The restored video signal in units of fields is supplied to the monitor 80, and the video captured by the video camera 42 is displayed in real time, and is stored in the storage unit 82.

FIGS. 21A to 21K show timing charts in data transmission and reception when the transfer mode is the synchronous transfer mode and the timing mode is the advanced timing mode.

In this case, FIGS. 21A to 21E correspond to FIGS.
19E is the same as FIG. Therefore, the frame pulse F
The encoding process in the SDTI-CP encoder 50 is completed by the second field of the second half of the second video frame period in which the second No. 2 is obtained, and the processed transmission packet can be sent to the transmission system 45 from the second field. (Figure 2
1F). In this advanced timing mode, the transmission system 10 can reduce the time for at least one field.

On the other hand, the received transmission packet is SDTI-
The decoding process is performed by the CP decoder 60, and this process can also be started from the second field of the third video frame period in which the frame pulse F3 is obtained (FIG. 21G,
(FIG. 21H). That is, the third pulse in which the frame pulse F3 is obtained
SDTI-C from the second field of the video frame period
P decoding and MPEG decoding can be started (FIGS. 21I and 21J).

Since the original video signal in the field unit to be finally output is synchronized with the frame pulse, it can be output in synchronization with the frame pulse F4 as shown in FIG. 21K. As a result, the reception system 20 can also reduce the time for at least one field, and when this advanced timing mode is used, the transmission and reception time for one frame is reduced as a whole transmission system, and the system delay is minimized. Can be.

FIG. 22 shows a data transmission system for transmitting and receiving a transmission packet of the SDTI-CP format in the synchronous transfer mode and the dual timing mode in the transfer mode. In particular, 525 lines / 60
1 shows a configuration of a data transmission system when transmitting and receiving a progressive video signal of a frame as the above-described transmission packet.

The receiving system 10 of this data transmission system
A video camera 48, an encoder 46 to which a progressive video signal from the video camera 48 is supplied to generate compression-encoded video data, and an additional data to the compressed video data to generate a transmission packet in the SDTI-CP format And an encoder 50 that performs the operation.

The encoder 50 uses an MPEG encoder to generate MPEG compressed video data. In the next encoder 50, the above-mentioned compressed video data is inserted into an area such as a system item and a picture item of the SDTI-CP format, and a separator, an end code and the like defined in the SDTI format are inserted, and further, the SDI format is inserted. EAV defined in
A transmission packet in the SDTI-CP format is generated by inserting a SAV or the like.

The receiving system 20 includes a decoder 60 for receiving a transmission packet in the SDTI-CP format, and an M to which the compressed video data separated by the decoder 60 is supplied.
It is composed of a PEG decoder 72, a monitor means 84 for supplying decoded video data and monitoring the video, and a storage means 82 for storing the decoded video data. As the data storage unit 82, a hard disk device, a semiconductor memory, a video tape recorder, or the like can be used as in the storage unit 82 shown in FIG.

The progressive video signal output from the video camera 48 is converted into MPEG compressed video data by the MPEG encoder 46. An enable pulse indicating an output section of the compressed video data is also generated. Since the MPEG encoder 46 handles progressive video signals, it does not include processing means for performing field / frame conversion. The compressed video data and the enable pulse are supplied to the encoder 50, and the SDTI-C
It is converted into a transmission packet of the P format. This transmission packet is transferred after serial conversion.

The compressed video data and the enable pulse are separated from the received transmission packet. The compressed video data is subjected to a progressive video signal restoration process by the MPEG encoder 72 using an enable pulse. MP
Since the EG decoder 72 handles progressive video signals, it does not include processing means for performing frame / field conversion.

FIGS. 23A to 23H are timing charts for data transmission / reception in this data transmission system.
Shown in

In the transmission system 10, for example, a process synchronized with a video frame signal (pulse) (FIG. 23A) as a reference signal in the station is performed. The video frame signal is a signal obtained in synchronization with the fourth line of the video frame. A progressive video signal is obtained from the video camera 48 in synchronization with the frame pulse (FIG. 23B).

In the case of a progressive video signal, FIG.
As shown in FIGS. 3A to 23C, a video signal corresponding to two frames is output within one video frame period. Since it is a progressive video signal, data compression and encoding can be performed simultaneously with the input of the progressive video signal to the MPEG encoder 46. The obtained compressed data and enable pulse are shown in FIGS. 23C and 23D.

The compressed data of the progressive video signal (frame 1) corresponding to the first field in the video frame period of the frame pulse F1 is supplied to the SDTI-CP encoder 50, and the SDTI is used by using the second field period. -CP format transmission packet, and the compressed data of the progressive video signal (frame 2) obtained from the second field is SDTI-CP
S is supplied to the encoder 50 using the first field in the video frame period of the frame pulse F2.
The transmission packet is in the DTI-CP format (FIG. 23E).

The transmission packets corresponding to the progressive video signals (frame 1 and frame 2) are the first and second packets in the video frame period of the same frame pulse F2.
Transmitted in synchronization with the field (pulse), SDTI-
The decoding process is performed by the CP decoder 60. FIGS. 23F and 23G show the progressive video signal resulting from the processing and the enable pulse at that time. Then MPEG decoder 7
23, the original progressive video signal is restored (see FIG. 23).
H).

As described above, in the dual timing mode, the video can be monitored during the video frame period of the frame pulse F2, and the system delay in the entire data transmission system is minimized in the above-described timing mode.

FIGS. 24A to 24C show specific examples of the transmission packet in the dual timing mode. FIG. 24B shows the structure of each picture item, which is synchronized with the first field and the second field. Therefore, the first half of the compressed video data (picture) is arranged and transmitted in synchronization with the first field, and the second half of the compressed video data (picture) is arranged and transmitted in synchronization with the second field.

Next, the isochronous transfer mode (isochronous transfer mode) will be described. FIG. 25 shows an embodiment of a data transmission system in which video signals of two video cameras 42 and 43 are multiplexed and can be transmitted within one video frame period which is a fixed period.

In this data transmission system, transmission system 1
0 indicates two video cameras 42 and 43, MPEG encoders 40 and 41 to which the video signals are supplied, and a transmission packet in the SDTI-CP format to which the compressed video data from the MPEG encoders 40 and 41 is supplied. And an encoder 50 for conversion into The MPEG encoders 40 and 41 have the same configuration. In the encoder 50, the MPEG encoders 40 and 41
Multiplexes the two systems of compressed video data output from
It is converted into a transmission packet in the DTI-CP format.

Therefore, in this encoder 50, S
Each item in the DTI-CP format is generated, each item is inserted into the payload area, the above-described header data and the like are inserted into the ancillary area, and EAV, SAV and the like defined in the SDI format are inserted. -Create a transmission packet in CP format.

FIGS. 26A to 26C show specific examples of transmission packets obtained by multiplexing two systems of compressed video data. FIG.
B indicates the configuration of the multiplexed picture item,
After the compressed video data (picture) of the video camera 42, the compressed video data (picture) of the video camera 43
Are multiplexed with a separator, an end code, and the like added thereto. Then, as shown in FIG. 26C, the compressed video data (picture) of the video camera 42 is arranged in the first half of the video frame, and the compressed video data (picture) of the video camera 43 is arranged and transmitted in the second half. .

The reception system 20 of the data transmission system is an SD
A decoder 60 that receives a transmission packet in the TI-CP format, and two MPEG decoders 70 and 7 to which compressed video data output from the decoder 60 is supplied.
1 and two monitor means 80, 8 to which the video data output from the MPEG decoders 70, 71 are supplied.
1 and storage means 82 for storing video data. The MPEG decoders 70 and 71 have the same configuration. The decoder 60 separates the transmission packet of the SDTI-CP format into two systems of compressed video data.

FIGS. 27A to 27 are timing charts of data transmission and reception in the data transmission system thus configured.
27A to FIG. 27T are shown in FIGS.
27F to 27I are the same as FIGS.
Same as 9E.

Normal video signals (interlaced signals) are output from the video cameras 42 and 43 in synchronization with the intra-station video frame signals (FIGS. 27A, 27B and 27F).

The MPEG encoders 40 and 41 convert the data into compressed video data of two systems after the field / frame conversion (FIGS. 27C, 27D, 27G and 27).
H). At the same time, an enable pulse is also output (see FIG. 27).
E, FIG. 27I).

The SDTI-CP encoder 50 multiplexes two systems of compressed video data, converts the multiplexed video data into a transmission packet in the SDTI-CP format, and serially converts and transmits the packet (FIG. 27J). SDTI-CP decoder 6
At 0, the received transmission packet is returned to compressed video data of two systems and an enable pulse (FIGS. 27K, 27L, 27P, and 27Q). Each of the compressed video data is supplied to the corresponding MPEG decoders 70 and 71 and decoded into uncompressed video data and an enable pulse (FIGS. 27M, 27N, 27R, and 27).
S). Thereafter, field conversion is performed to obtain two video signals.

FIGS. 28A to 28T are timing charts in the advanced timing mode in the isochronous transfer mode when the data transmission system of FIG. 25 is used.

In the advanced timing mode, the transmission packet is transmitted in synchronization with the second field of the video frame period. Therefore, the processing timing of the SDTI-CP encoder 50 is smaller than that of FIG. Shifting forward, frame conversion processing of video signals from two systems from the second field, MPEG
The encoding process is performed simultaneously, and two compressed video data obtained at that time are used to perform 2
A transmission packet in the SDTI-CP format in which the compressed video data of the system is multiplexed is generated.
This transmission packet is transmitted in synchronization with the field (FIGS. 28A to 28J).

Since the processing in the receiving system 20 is also all faster by one video field, the processing from the second field in the video frame period of the frame pulse F3 starts from the second field from the transmission packet.
Separation processing of compressed video data of the system, MPEG decoding processing, and the like are performed, and field conversion processing can be performed from the first field of the video frame period of the frame pulse F4. Can be obtained (FIGS. 28K to 28K).
(FIG. 28T).

As described above, in the advanced timing mode, the delay time of the data transmission system can be reduced, so that the advanced timing mode is suitable for application to data transmission during live broadcasting between studios in a station.

In such an isochronous transfer mode, in the advanced timing mode, 2
FIGS. 29A and 29B show specific examples of transmission packets obtained by multiplexing the compressed video data of the systems. FIG. 29A shows the structure of a multiplexed picture item.
After the second compressed video data (picture), the compressed video data (picture) of the video camera 43 is multiplexed with a separator, an end code, etc. added thereto. Then, as shown in FIG. 29B, the second
From the field, the compressed video data (picture) of the video camera 42 and the compressed video data (picture) of the video camera 43 are arranged and transmitted.

The S provided in the transmission system 10 described above
FIG. 30 shows a specific configuration of the DTI-CP encoder 50.

The encoder 50 receives the MPEG compressed video data supplied to the terminal 52, and
A first formatter (SDTI-CP formatter) 51 that inserts the compressed video data into an area such as a picture item inserted into the payload part of the DTI-CP format, an item header inserted into each item, and a system item. A CPU 53 for outputting, a timing signal generator 54 for generating a timing signal for inserting an item header or a system item, and an SDTI for each of the items to be inserted in the payload portion.
A second formatter (SDTI formatter) 55 for inserting additional data (separator, end code, word count, etc.) defined in the format, and EAV, AN defined in these in the SDI format;
C, a third formatter (S) that inserts SAV and finally generates a transmission packet in the SDTI-CP format
A DI formatter) 56 and a P / S converter 57 for converting parallel data of a transmission packet into serial data.

Information indicating the data length of the system item from the CPU 53 and the length information of the header of the content package are supplied to the timing generator 54. The timing generator 54 generates a timing pulse for packing a system item, a picture item, or the like from the length information.

FIGS. 31A to 31E are timing charts showing a processing example of the SDTI-CP encoder 50.

In the SDTI-CP formatter 51, the MPEG compressed data supplied from the terminal 52 (FIG. 31A)
Into the picture item area. Further, the items shown in FIGS. 4 and 7 are configured using the header information of each item. Therefore, the CPU 53 sends the SDTI-C
First additional data required to format the content package CP in the P format, that is, a system item and a content package item header (CP header) are supplied.

Data indicating the length of the system item and data indicating the length of the CP header are further supplied from the CPU 53 to the timing generator 54 for inserting data synchronized with the field pulse V and the horizontal pulse H. An enable pulse and a timing pulse (FIG. 31C shows only the enable pulse) are generated.

The SDTI-CP formatter 51 generates a system item as shown in FIG. 31B and MPEG compressed video data to which a CP header is added, based on the enable pulse and the timing pulse.

The system item and the compressed video data are added by the SDTI formatter 55 to the SDTI format as shown in FIG. 31D by adding second additional data defined in the SDTI format such as a separator, word count, and end code. Generated data is generated. The SDTI format data further includes S
The end synchronization code EAV, auxiliary data ANC, start synchronization code SA defined in the SDI format which is supplied to the DI formatter 56 and used as the third additional data
A transmission packet in the SDTI-CP format is generated by adding V or the like. The transmission packet in the SDTI-CP format is converted from parallel to serial by the P / S converter 57 and sent out to the transmission line 45. FIG. 31E is an example of data arrangement when the SDTI-CP format is expanded into a frame.

FIG. 32 shows an embodiment of the SDTI-CP decoder 60.

This decoder 60 receives the SDTI-
An S / P converter 67 for converting the data of the transmission packet in the CP format into parallel data, an SDI receiving unit 61 for separating the third additional data defined in the SDI format from the transmission packet subjected to the parallel conversion, and an output thereof. To separate the second additional data defined in the SDTI format and the first additional data defined in the SDTI-CP format from the compressed video data
An I receiving unit 64, a data extracting unit 100 to which the output is supplied to extract compressed video data, and a transfer mode and a timing mode of a transmission packet based on the separated first to third additional data Mode detector 65, a controller 66 that outputs mode information based on the mode detection output, and a timing signal for extracting data based on the first to third additional data and the mode detection output. And a timing signal generator 62.

As shown in FIG. 32, the data extraction circuit 100 includes two bank memories 101 and 102, a pair of changeover switches 103 and 104 provided on the input and output sides thereof and which can be switched in opposite directions. And a memory control circuit 105 for control.

In the decoder 60 thus configured, the SDI receiver 61 detects EAV, which is one of the third additional data, from the received transmission packet in the SDTI-CP format, and stores the F data (bit data) in the EAV. b7)
Is supplied to the timing signal generator 62 to generate a frame pulse.

The output of the SDI receiving section 61 is SDTI
The SDTI format is supplied to the receiving unit 64 and decoded. The SDTI receiving unit 64 extracts data indicating the line number inserted into the ancillary data area ANC, as well as the separator, word count, end code, etc. inserted at the beginning of the payload. The separator, word count, and end code data are all supplied to the timing generator 62.

The write and read enable pulses required for data extraction are generated based on data indicating a transmission mode (transfer mode and timing mode) extracted from the payload area in addition to these data.

The mode detection section 65 is supplied with the transmission packet subjected to the parallel conversion, and is supplied with data such as the above-described frame pulse, separator pulse, line number, and the like.

The mode detector 65 detects the transfer mode inserted in the transfer mode area provided near the type area (Item Type area) in which type data indicating the type of data in the data block area of the payload area is inserted. The extracted data (b2, b3) and the data (b0, b1) indicating the timing mode inserted in the timing area provided near the type area are also extracted.

The data indicating the transfer mode and the timing mode can be extracted by referring to the line numbers. Incidentally, in the 525 line / 60 field, data indicating the transfer mode and the timing mode is inserted in the thirteenth line or the 276th line.

Data indicating the extracted transfer mode and timing mode is supplied to the controller 66, which determines which type of the transfer mode and timing mode of the transmission packet corresponds to FIG. 13, and transmits the determination result. The mode information is sent to the timing generator 62 described above. The timing generator 62 generates a frame pulse or a field pulse according to the transmission mode.

That is, a video frame pulse F is generated in the normal timing mode, a video field pulse V is generated in the dual timing mode, and a frame pulse F for the advanced timing mode is generated in the advanced timing mode.

Based on these pulses, write and read enable pulses for data extraction and a switching signal (bank select signal) for the bank memories 101 and 102 are generated.

The memory control circuit 105 is supplied with the above-described write enable pulse, read enable pulse, and bank switching signal, thereby generating alternate bank switching pulses SW1 and SW2, and transmitting original video data. In synchronization with the timing, the write and read addresses (W1, R
1) and (W2, R2) are generated. On the other hand, for example, the bank memories 101 and 102
Is in the write state, the other bank memory 10
2 is controlled to be in the read state.

The read enable pulse supplied to the memory control circuit 105 is also used as a write enable pulse for the storage means 82.

Next, an example of data reception processing (decoding processing) in the data transmission system configured as described above will be described below.

FIGS. 33A to 33K show the synchronous transfer mode.
4 shows a timing chart of a decoding process in a normal timing mode.

In this mode, the speed is 1 × the reference speed.
In the first field (F = 0), each item is inserted into the payload area (FIG. 33A). Since the frame pulse in each video frame period starts from the fourth line, the generated frame pulse F is synchronized with the fourth line (FIG. 33B). Based on the frame pulse F, data indicating a separator inserted in the separator area of the payload portion is detected, and a separator pulse (FIG.
3C) is generated. Also, data indicating the end code inserted into the end code area is detected, and an end pulse (FIG. 33D) is generated at the timing when the data indicating the end code is detected.

Since the picture item is inserted in an area five words away from the separator, in this example, a write enable pulse which is enabled from the sixth word is generated in consideration of data delay (FIG. 33E). The width of the enable pulse is determined using the word count data. The bank memory 10 is synchronized with the enable pulse.
Data writing is performed on the memory cells 1 and 102 (FIG. 33E,
FIG. 33F).

Since a read enable pulse is generated in synchronization with the frame pulse F of the next cycle (FIG. 33G), data is read from the bank memories 101 and 102 only during the period of the enable pulse (FIG. 33K). ). Therefore, the switching pulses SW1 and SW2 for the switches 103 and 104 in frame units are shown in FIG.
3H and FIG. 33I.

The width of the read enable pulse shown in FIG. 33G is the same as the width of the write enable pulse, and is generated from the above-described word count data similarly to the write enable pulse.

FIGS. 34A to 34K are timing charts of the decoding process in the synchronous transfer mode and in the advanced timing mode.

In this case, the second frame of each video frame period
Based on the advanced frame pulse F (FIGS. 34A and 34B) obtained in synchronization with the fourth line in the field (F = 1), data indicating the separator inserted in the separator area of the payload portion is detected. A separator pulse (FIG. 34C) is generated at the timing when the data indicating the separator is detected. In addition, it detects data indicating the end code inserted in the end code area,
An end pulse (FIG. 34D) is generated at the timing when the data indicating the end code is detected.

Since the picture item is inserted in an area five words away from the separator, a write enable pulse which is enabled from the sixth word is generated in consideration of data delay (FIG. 34E). The width of the enable pulse is determined using the word count data. The bank memories 101 and 102 are synchronized with the enable pulse.
34E and FIG. 34E.
F).

Since a read enable pulse is generated in synchronization with the frame pulse F of the next cycle (FIG. 34G), data is read from the bank memories 101 and 102 only during the period of the enable pulse (FIG. 34K). ). Therefore, the switching pulses SW1 and SW2 for the switches 103 and 104 in frame units are shown in FIG.
4H, I. The width of the read enable pulse shown in FIG. 34G is the same as the width of the write enable pulse, and is generated from the above-described word count data similarly to the write enable pulse.

As described above, in the advanced timing mode, an advanced frame pulse is generated at a position corresponding to the second field, and decoding is performed with reference to the second field.

FIGS. 35A to 35K are timing charts of the decoding process in the dual timing mode in the synchronous transfer mode.

In this case, since the decoding process is performed using both the first field and the second field, field pulses (FIGS. 35A and 35B) are generated in the first field and the second field, respectively. The decoding process is executed based on this field pulse.
Therefore, the data indicating the separator included in the separator area of the payload portion inserted into the first field and the second field, respectively, is detected based on the field pulse, and the data indicating the separator is detected at the timing when the data indicating the separator is detected. A pulse (FIG. 35C) is generated. Further, data indicating the end code inserted into the end code area of the payload portion inserted into the first field and the second field is detected, and an end pulse (FIG. 35D) is generated.

Since the picture item is inserted in an area five words away from the separator, a write enable pulse that is enabled from the sixth word is generated in this example in consideration of data delay (FIG. 35E). The width of the enable pulse is determined using the word count data. The bank memory 10 is synchronized with the enable pulse.
Data writing is performed on the memory cells 1, 102 (FIG. 35E,
(FIG. 35F).

Then, since a read enable pulse is generated in synchronization with the second field (FIG. 35G),
Only during the period of this enable pulse, the bank memories 101,
Data is read from 102 (FIG. 35K).
Therefore, the switching pulses SW1 and SW2 for the switches 103 and 104 in units of fields are shown in FIGS.
Becomes

FIG. 36 shows an example of processing for generating transmission mode information indicating a transfer mode and a timing mode in the controller 66 shown in FIG. 32 among the above processing.

First, the line number inserted into the header data area of the ancillary data area ANC is detected (step 111). When the line number matches the 13th line (step 112), the system item information is added to this line. "Item" next to "separator" inserted in the payload part assuming that
"Type" is detected (step 113). When the item type is data indicating a system item (step 114), data indicating a transfer mode or a timing mode inserted in the content / package type area is extracted, and detection mode information is sent to the timing generator 62. (Step 115), First Step 11
Return to 1.

On the other hand, if it is determined in step 114 that the information is not system item information, for example, 1 /
In a data transmission in which system item information is inserted in a line other than the thirteenth line, such as in an isochronous transfer mode, an advanced timing mode, or an asynchronous transfer mode in which a transmission packet is transmitted per frame at a double speed. It is possible that there is.

In consideration of such a case, step 11
If the “Item Type” is not a system item in step 4, the next line number in the header area is detected (steps 116 and 117), and the start line code is inserted based on the start synchronization code SAV inserted immediately before the payload section. The next word of the synchronization code SAV is detected (step 11).
7).

Then, the word is "separato"
r ”is determined (step 11).
8) If the word indicates "separator", the next word area is searched (step 119). If the word is an item type indicating a system item (step 120), the content / package type area is searched as described above. The data indicating the transfer mode and the timing mode inserted into the timing generator 62 are extracted, and the detection mode information is sent to the timing generator 62 (step 12).
1) Return to the first step 111.

If the separator cannot be detected in step 118, the separator detection processing is continued until the line number becomes 12 (step 122). It is determined that no system item is included in the video frame that has been set (step 12).
3) In this case, the detected frame information in the previous frame is sent to the timing generator 62, and the state transitions to the initial state (step 111).

FIG. 37 shows an embodiment of a mode detecting method for detecting the transfer mode and the timing mode more easily than in FIG.

In this case, the next word of the start synchronization code SAV is detected (step 131). If the word is a separator word (step 132), the next word is detected and the next word is detected. It is determined whether the information is information representing an item (step 13).
3,134). If it is a system item, the data of bits b0 to b3 in which the data of the transfer mode and the timing mode are inserted are stored in a mode register (not shown).
(Step 135).

Then, the data of the bit b7 for generating the frame pulse in the end synchronization code EAV is detected (step 136), and when this data is present, the value of the mode register is transferred as it is in the next video frame for the first time. It is adopted as data indicating the mode and the timing mode (step 137).

As described above, there is no particular problem if the transfer mode and the timing mode one video frame before are used as the data of the transfer mode and the timing mode in the next video frame. During transmission packet data,
This is because it is unlikely that the transfer mode is frequently changed.

[0219]

As described above, in the present invention, the SD
The transfer mode and the timing mode inserted in the payload portion of the TI format can be automatically detected, and the timing generator for data extraction can be controlled.

According to this, since the transfer mode and the timing mode of the transmission packet can be accurately grasped, regardless of the transmission mode of the transmission packet, the data such as the video signal contained in the transmission mode can be reliably extracted. Features that can be.

Therefore, the present invention is suitably applied to a case where a transmission packet of the SDTI-CP format in which a transfer mode area and a timing mode area are prepared is transmitted, such as a data transmission system in a station.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a mapping example of an SDTI-CP format to which the present invention can be applied.

FIG. 2 is a configuration diagram showing a format of an EAV and header data.

FIG. 3 is a configuration diagram showing a format of a variable-length block.

FIG. 4 is a configuration diagram of a system item.

FIG. 5 is a configuration diagram of a time code.

FIG. 6 is a configuration diagram of a metadata set.

FIG. 7 is a configuration diagram of items excluding system items.

FIG. 8 is a configuration diagram of an SDTI-CP element frame.

FIG. 9 is a configuration diagram of MPEG-2 picture editing metadata.

FIG. 10 is a configuration diagram of an element data block of an audio item.

FIG. 11 is a timing chart showing a 5-frame sequence.

FIG. 12 is a configuration diagram of audio editing metadata.

FIG. 13 is a diagram illustrating a relationship between a transfer mode and a timing mode.

FIG. 14 is a diagram illustrating a positional relationship of inserting a content package in a synchronous transfer mode, an asynchronous transfer mode, and a timing mode.

FIG. 15 is a diagram illustrating the insertion positional relationship of a content package in an isochronous transfer mode and a timing mode.

FIG. 16 is a system diagram showing an outline of a data transmission device for explaining an asynchronous transfer mode.

FIG. 17 is a timing chart illustrating the data transfer.

FIG. 18 is a system diagram showing an outline of a data transmission device for explaining a synchronous transfer mode.

FIG. 19 is a timing chart illustrating data transfer in a normal timing mode in a synchronous transfer mode.

FIG. 20 is a timing chart showing a relationship between compressed data and an enable pulse.

FIG. 21 is a timing chart illustrating data transfer in the advanced mode in the synchronous transfer mode.

FIG. 22 is a system diagram showing an outline of a data transmission device when a dual timing mode in a synchronous transfer mode is adopted.

FIG. 23 is a timing chart illustrating data transfer in a dual timing mode in a synchronous transfer mode.

FIG. 24 is a diagram showing an example of data mapping in an isochronous mode.

FIG. 25 is a system diagram showing an outline of a data transmission device when a normal timing mode in an isochronous mode is adopted.

FIG. 26 is a diagram illustrating an example of data mapping of multiplexed data.

FIG. 27 is a timing chart illustrating data transfer in a normal timing mode in the isochronous mode.

FIG. 28 is a timing chart illustrating data transfer in an advanced timing mode.

FIG. 29 is a diagram illustrating an example of data mapping in the advanced timing mode.

FIG. 30 is a system diagram of a main part showing an embodiment of an SDTI-CP encoder.

FIG. 31 is a diagram showing an example of data mapping for explaining the operation.

FIG. 32 is a system diagram of a main part showing an embodiment of an SDTI-CP decoder.

FIG. 33 is a timing chart showing an example of data transmission in a normal timing mode in a synchronous transfer mode.

FIG. 34 is a timing chart showing an example of data transmission in the advanced timing mode in the synchronous transfer mode.

FIG. 35 is a timing chart showing an example of data transmission in a dual timing mode in a synchronous transfer mode.

FIG. 36 is a flowchart illustrating an embodiment for detecting a transfer mode and a timing mode.

FIG. 37 is a flowchart showing another embodiment for detecting a transfer mode and a timing mode.

[Explanation of symbols]

60... Decoder, 61... SDI receiver, 62.
..Timing generator, 64... SDTI receiving unit, 6
5 ... mode detection unit, 100 ... data extraction unit, 1
01, 102: Bank memory, 105: Memory control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/081 F term (Reference) 5C063 AA20 AB03 AB07 AC01 AC05 CA23 CA34 CA36 DA01 DA05 DA07 DA13 5K028 AA15 EE03 KK32 MM12 MM16 SS05 SS15 5K030 GA11 HA08 HB01 HB02 HB11 HB12 HB15 HB21 JA01 JA05 LA15 5K034 AA06 CC03 CC05 CC06 EE11 HH12 HH16 HH17 HH46 MM25 MM32 MM36 5K047 AA12 CC01 DD01 DD02 HH01 LL08 MM12

Claims (6)

[Claims] 1. A section of one line of a video frame includes an end synchronization code area in which an end synchronization code is inserted, an auxiliary data area in which auxiliary data is inserted, a start synchronization code area in which a start synchronization code is inserted, A data receiving apparatus for receiving a transmission packet of a serial digital transfer interface constituted by a payload area into which data including a video signal is inserted, the data receiving apparatus comprising: An extraction unit, mode detection means for determining data indicating a transfer mode of the transmission packet inserted into the payload area and / or data of a timing mode indicating a transmission timing of the transmission packet, and supplied to the data extraction unit. A timing generator for generating a timing signal; Output means, data receiving apparatus, characterized in that the transfer mode and or timing signal corresponding to the timing mode is adapted to be generated by the timing generator. 2. The data indicating the transfer mode includes:
In addition to the asynchronous transfer mode in which the transmission packet subjected to serial conversion is transferred asynchronously between the transmission side and the reception side, a synchronous transfer mode in which the transmission packet is transmitted in a state where the transmission side and the reception side are synchronized. And data indicating one of the isochronous transfer modes in which high-speed transmission or multiplex transmission is performed while synchronizing between the transmitting side and the receiving side.
The data receiving device according to the above. 3. The data indicating the timing mode is a normal timing mode in which the transmission packet is transmitted at a timing of transmitting the first field of the video frame, or the transmission packet is transmitted in a second field of the video frame. Data indicating an advanced timing mode in which the transmission packet is transmitted at a timing of transmitting the data, or a dual timing mode in which the transmission packet is transmitted at a timing of transmitting the first and second fields of the video frame. The data receiving device according to claim 1, wherein 4. The data receiving apparatus according to claim 1, wherein said video signal is data compressed according to the MPEG standard. 5. The mode extracting section includes a pair of memories in which data writing and reading are alternately performed, and a control section for the memory. The memory control section includes a pair of memories based on the timing signal. 2. The data receiving apparatus according to claim 1, wherein a switching pulse of said memory and write and read addresses for these memories are generated. 6. The data receiving apparatus according to claim 1, wherein the timing signal includes at least a write enable pulse for the memory and a read enable pulse.