Video and audio processing method and apparatus

This Application is a Continuation of Ser. No. 08/977,984, Nov. 25, 1997, now U.S. Pat. No. 6,049,568.

This invention relates to a video and audio data processing method and apparatus by which digital data representative of a video signal and digital data representative of an audio signal are processed so as to have a format for transmission thereof through a data transmission line such as a coaxial cable.

In order to allow transmission of digital video data (DV data) and digital audio data (DA data) obtained by digitizing a video signal and an audio signal which make signal elements which form a television broadcasting signal and representative of the video signal and the audio signal, respectively, through a data transmission line formed from, for example, a coaxial cable, the DV data and the DA data are normally processed so that they may have a format set in advance. Various formats are available for the format, and a format called serial data interface (SDI) format has been proposed as one of such formats.

In order to transmit DV data and DA data using the SDI format, the DV data and the DA data to be transmitted are divided into and placed as a series of successive data segments DP each of which corresponds to a one line period (1 H) beginning with a horizontal synchronizing signal SSH of a video signal SV. Each data segment DP includes an EAV part of a 4 word-structure, an ancillary area part of a 268 word-structure, an SAV part of a 4 word-structure and a payload area part of a 1,440 word-structure and is totally composed of 1,716 words.

In each data segment DP, DV data are placed for 1,440 words in the maximum in the payload area part, and DA data are placed for 268 words in the maximum in the ancillary area part. Where the DV data and the DA data to be transmitted are a video signal and an audio signal which form a television signal conforming to the NTSC system, DV data for a one frame period of the video signal (for the first and second field periods) and corresponding DA data are placed in 525 successive data segments DP.

FIG. 2 illustrates an example of a condition wherein DV data for a one frame period of a video signal and corresponding DA data are placed in 525 successive data segments DP. It is to be noted that reference symbol NL in FIG. 2 represents the number of each data segment DP. In the example illustrated in FIG. 2, DV data for a 240 line period which is a first field period for the video signal are placed in the payload area parts of 244 data segments DP beginning with the 20th one and ending with the 263rd one of the 525 successive data segments DP, and DA data corresponding to the DV data are placed in the ancillary area parts of the 244 data segments DP beginning with the 20th data segment DP and ending with the 263rd data segment DP. Further, DV data for another 240 line period which is a second field period for the video signal are placed in the payload area parts of 243 data segments DP beginning with the 283rd one and ending with the 525th one of the 525 successive data segments DP, and DA data corresponding to the DV data are placed in the ancillary area parts of the 243 data segments beginning with the 283rd data segment DP and ending with the 525th data segment DP.

When transmission of DV data and DA data is performed using the SDI format in such a manner as described above, data segments DP in the payload area parts of which the divided DV data are placed and in the ancillary area parts of which the divided DA data are placed are successively transmitted through data transmission lines. In this instance, one set of DV data and DA data is transmitted for each one data transmission line. Accordingly, in order to transmit a plurality of sets of DV data and DA data which are different from each other substantially simultaneously or in a common transmission period, a plural number of data transmission lines equal to the number of sets of DV data and DA data are required even if the data are to be transmitted to a common transmission destination.

For example, in order to transmit 10 sets of DV data and DA data substantially simultaneously or in a common transmission period to a common transmission destination, 10 data transmission lines are required, and if it is assumed that each of the data transmission lines is formed by a coaxial cable, then it is required to lay 10 coaxial cables. To provide a plurality of data transmission lines each formed from, for example, a coaxial cable in this manner gives rise to complication and increase in scale of an apparatus or equipment for data transmission and further to an increase in cost for data transmission.

It is an object of the present invention to provide a video and audio data processing method and apparatus by which, when a plurality of sets of DV data and DA data are to be processed so as to have a data format such as the SDI format which allows them to be transmitted substantially simultaneously or in a common transmission period to a common transmission destination, the necessity for provision of a number of data transmission lines equal to the number of sets of DV data and DA data in order to allow transmission of the plurality of sets of DV data and DA data can be eliminated to eliminate complication and increase in scale of an apparatus or equipment for data transmission and decrease the cost for data transmission.

In order to attain the object described above, according to an aspect of the present invention, there is provided a video data processing method, comprising the steps of performing compressed video data selective extraction wherein data compression is performed for a plurality of digital video data individually representative of a plurality of video signals to obtain a plurality of compressed video data and a predetermined number of words are successively and repetitively extracted from each of the plurality of compressed video data and audio data selective extraction wherein a predetermined number of words are successively and repetitively extracted from a plurality of digital audio data individually representative of a plurality of audio signals, successively forming data segments each having a first data area in which the predetermined number of words of each of the plurality of digital audio data extracted by the audio data selective extraction are placed and a second data area in which the predetermined number of words of each of the plurality of compressed video data extracted by the video data selective extraction are placed such that the plurality of compressed video data individually representative of the plurality of video signals for a predetermined period are placed divisionally with the predetermined numbers of words in the second data areas of a predetermined number of the successive data segments, and successively sending out the predetermined numbers of data segments.

Preferably, each of the data segments corresponds to a one line period of a video signal, and the plurality of compressed video data representative of the plurality of video signals for the one frame period are placed divisionally with the predetermined number of words in the second data areas of a number of the successive data segments equal to the number of line periods which form the one frame period of the video signal.

According to another aspect of the present invention, there is provided a video data processing apparatus, comprising a plurality of data compression sections for performing data compression individually for a plurality of digital video data individually representative of a plurality of video signals to obtain a plurality of compressed video data, a plurality of first memory sections for storing the plurality of compressed video data obtained by the plurality of data compression sections and successively and repetitively reading out the plurality of compressed video data for each predetermined number of words, a plurality of second memory sections for storing a plurality of digital audio data individually representative of a plurality of audio signals and successively and repetitively reading out the plurality of digital audio data for each predetermined number of words, and an encoder section for successively forming data segments each having a first data area in which the predetermined number of words of each of the plurality of digital audio data read out from the plurality of second memory sections are placed and a second data area in which the predetermined number of words of each of the plurality of compressed video data read out from the plurality of first memory sections are placed such that the plurality of compressed video data individually representative of the plurality of video signals for a predetermined period are placed divisionally with the predetermined numbers of words in the second data areas of a predetermined number of the successive data segments and successively sending out the predetermined numbers of data segments.

Preferably, the encoder section forms data segments such that each of the data segments corresponds to a one line period of a video signal, and divisionally places the plurality of compressed video data representative of the plurality of video signals for the one frame period with the predetermined number of words into the second data areas of a number of the successive data segments equal to the number of line periods which form the one frame period of the video signal.

In the video and audio data processing method and the video and audio data processing apparatus according to the present invention described above, data segments formed for transmission of video data and audio data are placed, for each predetermined number of words of each of a plurality of audio data, into a first data area and placed, for each predetermined number of words of each of a plurality of compressed video data based on a plurality of video data, into a second area. Then, a group unit of data segments is formed from a predetermined number of successive data segments wherein the predetermined numbers of words of the audio data are placed in the first data areas and the predetermined numbers of words of the compressed video data are placed in the second data areas such that the plurality of compressed video data individually representative of the plurality of video signals for a predetermined period are placed divisionally with the predetermined numbers of words in the second data areas of a predetermined number of the successive data segments included in each of the group units. In this instance, in the first data areas of the predetermined number of data segments included in each of the group units, the plurality of audio data corresponding to the plurality of compressed video data of the plurality of video signals for the predetermined period are divisionally placed with the predetermined numbers of words.

Where each of the data segments corresponds to a one line period of a video signal, the number of data segments included in each of the group units corresponds to the number of line periods which form a one frame period of the video signal, and in the predetermined number of data segments, the plurality of compressed video data corresponding to the one frame periods of the plurality of video signals are divisionally placed with the predetermined numbers of words in the second data areas while the plurality of audio data corresponding to the one frame periods of the video signals are divisionally placed with the predetermined numbers of words in the first data areas.

Consequently, a plurality of sets of compressed video data and audio data are successively placed, for each data amount corresponding to a one frame period of a video signal, into group units each of which is formed from a predetermined number of successive data segments. Then, the group units of the data segments formed successively in this manner can be successively transmitted through a single transmission line formed from a coaxial cable. Accordingly, a condition wherein a plurality of sets of compressed video data and audio data can be transmitted substantially simultaneously or in a common transmission period to a common transmission destination.

Therefore, where the video and audio data processing method or the video and audio data processing apparatus according to the present invention is applied to perform processing for formation of a large number of successive data segments so that a plurality of sets of video data and audio data may have a data format such as the SDI format with which they can be transmitted substantially simultaneously or in a common transmission period to a common transmission destination, in order to transmit a plurality of sets of video data and audio data, there is no need of providing a plural number of data transmission lines equal to the number of sets of video data and audio data. Therefore, such a situation that complication and increase in scale of an apparatus or equipment for data transmission are invited can be eliminated, and further, reduction in cost for data transmission can be achieved.

The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference characters.

FIG. 1 is a diagrammatic view illustrating a concept of data segments according to the SDI format;

FIG. 2 is a diagrammatic view illustrating a concept of a data segment group according to the SDI format;

FIG. 3 is a block diagram of a video and audio data processing apparatus to which the present invention is applied;

FIG. 4 is a diagrammatic view illustrating a concept of a data segment group formed by the video and audio data processing apparatus of FIG. 3;

FIG. 5 is a block diagram of another video and audio data processing apparatus to which the present invention is applied; and

FIG. 6 is a diagrammatic view illustrating a concept of formatting of data performed for the data segment group illustrated in FIG. 4 .

Referring first to FIG. 3, there is shown a video and audio data processing apparatus to which the present invention is applied and on which a video and audio data processing method according to the present invention is performed.

The video and audio data processing apparatus receives 10 different DV data DV 1 , DV 2 , DV 3 , . . . , DV 10 representative of 10 different video signals through data input terminals data input terminals 11 A to 11 J thereof and receives 10 different DA data DA 1 , DA 2 , DA 3 , . . . , DA 10 representative of 10 different audio signals through data input terminals 12 A to 12 J.

Of the 10 different DV data DV 1 to DV 10 and the 10 different DA data DA 1 to DA 10 , the set of the DV data DV 1 and the DA data DA 1 , the set of the DV data DV 2 and the DA data DA 2 , the set of the DV data DV 3 and the DA data DA 3 , . . . , and the set of the DV data DV 10 and the DA data DA 10 represent video signals and audio signals which form a television broadcasting signal conforming to the NTSC system. Thus, the video and audio data processing apparatus of FIG. 3 performs processing of forming, based on 10 sets of DV data and DA data representative of video signals and audio signals which form a television signal conforming to the NTSC system, data with which the video data and the audio data can be transmitted via a transmission line formed by, for example, a coaxial cable.

Each of the DV data DV 1 to DV 10 represents, for example, a corresponding video signal for a one line period (for a video signal 1 line period) with 1,440 words=1,440×8=11,520 bits. Accordingly, where the effective image line period number in a one frame period of the video signal is 480, each of the DV data DV 1 to DV 10 represents a corresponding video signal for a one frame period (for a video signal 1 line period) with 1,440×480=691,200 words=691,200×8≈5.53 megabits (Mb).

Meanwhile, each of the DA data DA 1 to DA 10 represents a stereo audio signal for a 5 frame period of the video signal with 32,032×2=64,064 words. Accordingly, the audio signal corresponding to a one frame period of the video signal is represented with 64,064/5=12,812.8 words=64,064×8/5≈102.5 kilobits (Kb). In other words, each of the DA data DA 1 to DA 10 represents the audio signal corresponding to the video signal for a one frame period with 64,064/5=12,812.8 words.

The DV data DV 1 to DV 10 received at the data input terminals 11 A to 11 J are supplied to data compression sections 13 A, 13 B, 13 C, . . . , and 13 J, respectively. The data compression section 13 A performs data compression processing for the DV data DV 1 . The data compression processing performed for the DV data DV 1 , for example, compresses the DV data DV 1 for 1,440×480=691,200 words=691,200×8≈5.53 megabits for a video signal one frame period to data of 1/10, that is, to data of 1,440×480/10=1,440×48=69,120 words=69,120×8≈553 kilobits. Consequently, since one period corresponds to a 30 frame period, compressed video data DX 1 having a bit rate of 69,120×8×30≈16.6 megabits/second (Mb/s) are formed based on the DV data DV 1 by the data compression section 13 A.

Similarly, the data compression section 13 B forms compressed video data DX 2 having a bit rate lower than 16.6 megabits/second based on the DV data DV 2 , and the data compression sections 13 C to 13 J form compressed video data DX 3 to DX 10 having bit rates lower than 16.6 megabits/second based on the DV data DV 3 to DV 10 , respectively.

The compressed video data DX 1 to DX 10 obtained from the data compression sections 13 A to 13 J are supplied to memory sections 14 A, 14 B, 14 C, . . . , and 14 J, respectively. Meanwhile, the DA data DA 1 to DA 10 received at the data input terminals 12 A to 12 J are supplied directly to memory sections 15 A, 15 B, 15 C, . . . , and 15 J, respectively.

A write control signal QW from a memory control signal formation section 20 is supplied to the memory sections 14 A to 14 J and the memory sections 15 A to 15 J. In response to the write control signal QW, the compressed video data DX 1 to DX 10 arriving from the data compression sections 13 A to 13 J are successively written into the memory sections 14 A to 14 J, respectively. Meanwhile, in response to the write control signal QW, the DA data DA 1 to DA 10 arriving from the data input terminals 12 A to 12 J are successively written into the memory sections 15 A to 15 J, respectively.

Read control signals QX 1 to QX 10 from the memory control signal formation section 20 are supplied to the memory sections 14 A to 14 J, respectively. The read control signals QX 1 to QX 10 are used to control the memory sections 14 A to 14 J to successively assume a reading out condition for a predetermined period of time. In particular, the read control signal QX 1 first controls the memory section 14 A to assume a reading out condition for a predetermined time, and after the reading out condition of the memory section 14 A comes to an end, the read control signal QX 2 controls the memory section 14 B to assume a reading out condition for a next predetermined time. Then, after the reading out condition of the memory section 14 B comes to an end, the read control signal QX 3 controls the memory section 14 C to assume a reading out condition for a further predetermined time. Such a sequence of operations is successively performed until after the read control signal QX 10 controls the memory section 14 J to assume a reading out condition for a predetermined period. Then, after the reading out condition of the memory section 14 J comes to an end, the read control signal QX 1 controls the memory section 14 A to assume a reading out condition for a predetermined period again, and thereafter, the sequence of operations described above is repeated.

Here, the predetermined period in which a reading out condition is assumed by each of the memory sections 14 A to 14 J is selected, for example, to a period corresponding to the period required for reading out of compressed video data for 1,440 words written in each of the memory sections 14 A to 14 J. Accordingly, a condition wherein 1,440-words-data DXD 1 of the compressed video data DX 1 written in the memory section 14 A are read out from the memory section 14 A in response to the read control signal QX 1 , another condition wherein 1,440-words-data DXD 2 of the compressed video data DX 2 written in the memory section 14 B are read out from the memory section 14 B in response to the read control signal QX 2 , a further condition wherein 1,440-words-data DXD 3 of the compressed video data DX 3 written in the memory section 14 C are read out from the memory section 14 C in response to the read control signal QX 3 , . . . , and a yet further condition wherein 1,440-words-data DXD 10 of the compressed video data DX 10 written in the memory section 14 J are read out from the memory section 14 J in response to the read control signal QX 10 are successively assumed. Further, this sequence is repeated.

The 1,440-words-data DXD 1 of the compressed video data DX 1 to the 1,440-words-data DXD 10 of the compressed video data DX 10 successively y read out from the memory sections 14 A to 14 J in this manner are supplied to an encoder section 21 .

Each of the compressed video data DD 1 to DX 10 written in the memory sections 14 A to 14 J, respectively, includes 1,440×48=69,120 words for a video signal 1 frame period. Accordingly, the 1,440-words-data DXD 1 of the compressed video data DD 1 to the 1,440-words-data DXD 10 of the compressed video data DX 10 are read out from the memory sections 14 A to 14 J by 1,440×48/1,440=48 reading out operations for each of the video signal 1 frame periods of the compressed video data DX 1 to the video signal 1 frame periods of the compressed video data DX 10 .

Meanwhile, read control signals QA 1 , QA 2 , QA 3 , . . . , and QA 10 from the memory control signal formation section 20 are supplied to the memory sections 15 A to 15 J, respectively. The read control signals QA 1 to QA 10 are used to control the memory sections 15 A to 15 J to successively assume a reading out condition for a predetermined period. In particular, the read control signal QA 1 first controls the memory section 15 A to assume a reading out condition for a predetermined time, and then after the reading out condition of the memory section 15 A comes to an end, the read control signal QA 2 controls the memory section 15 B to assume a reading out condition for another predetermined time. Then, after the reading out condition of the memory section 15 B comes to an end, the read control signal QA 3 controls the memory section 15 C to assume a reading out condition for a further period, and such a sequence of operations is successively performed until the read control signal QA 10 controls the memory section 15 J to assume a reading out condition for a yet further predetermined time. Then, after the reading out condition of the memory section 15 J comes to an end, the read control signal QA 1 controls the memory section 15 A to assume a reading out condition for a predetermined period again, and thereafter, such a sequence of operations as described above is repeated.

Here, the predetermined period in which a reading out condition is assumed by each of the memory sections 15 A to 15 J is selected, for example, to a period corresponding to the period required for reading out of 268 words of each of the DA data DA 1 to DA 10 written in the memory sections 15 A to 15 J, respectively. Accordingly, a condition wherein 268-words-data DAD 1 of the DA data DA 1 written in the memory section 15 A are read out from the memory section 15 A in response to the read control signal QA 1 , another condition wherein 268-words-data DAD 2 of the DA data DA 2 written in the memory section 15 B are read out from the memory section 15 B in response to the read control signal QA 2 , a further condition wherein 268-words-data DAD 3 of the DA data DA 3 written in the memory section 15 C are read out from the memory section 15 C in response to the read control signal QA 3 , . . . , and a yet further condition wherein 268-words-data DAD 10 of the DA data DA 10 written in the memory section 15 J are read out from the memory section 15 J in response to the read control signal QA 10 are successively assumed. Further, this sequence is repeated.

The 268-words-data DAD 1 of the DA data DA 1 to the 268-words-data DAD 10 of the DA data DA 10 successively read out from the memory sections 15 A to 15 J in this manner are supplied to the encoder section 21 .

Each of the DA data DA 1 to DA 10 written in the memory sections 15 A to 15 J, respectively, includes 64,064/5=12,812.8 words for a video signal 1 frame period. Accordingly, the 268-words-data DAD 1 of the DA data DA 1 to the 268-words-data DAD 10 of the DA data DA 10 are read out from the memory sections 15 A to 153 by 64,064/(5×268)≈47.8 reading out operations, that is, 48 reading out operations, for each of the video signal 1 frame periods of the DA data DA 1 to the video signal 1 frame periods of the DA data DA 10 .

The encoder section 21 performs formatting of successively placing the 1,440-words-data DXD 1 of the compressed video data DX 1 to the 1,440-words-data DXD 10 of the compressed video data DX 10 successively read out from the memory sections 14 A to 14 J and the 268-words-data DAD 1 of the DA data DA 1 to the 268-words-data DAD 10 of the DA data DA 10 successively read out from the memory sections 15 A to 15 J into the payload area parts and the ancillary area parts, respectively, of data segments DP conforming to such an SDI format as illustrated in FIG. 1 . Consequently, data segments DP wherein the 1,440-words-data DXD 1 of the compressed video data DX 1 to the 1,440-words-data DXD 10 of the compressed video data DX 10 are successively placed in the payload area parts and the 268-words-data DAD 1 of the DA data DA 1 to the 268-words-data DAD 10 of the DA data DA 10 are successively placed in the ancillary area parts are formed.

For such formatting of the encoder section 21 , a data segment group including 525 successive data segments DP is prepared for placement of 48×1,440-words-data DXD 1 which form video signal 1 frame periods of the compressed video data DX 1 to 48×1,440-words-data DXD 10 which form video signal 1 frame periods of the compressed video data DX 10 and 48×268-words-data DAD 1 which form video signal 1 frame periods of the DA data DA 1 to 48×268-words-data DAD 10 which form video signal 1 frame periods of the DA data DA 10 . Further, data segment groups each including 525 data segments DP in which the compressed video data DX 1 to DX 10 for video signal 1 frame periods and the DA data DA 1 to DA 10 for video signal 1 frame periods are placed are successively produced.

In a data segment group formed from 525 successive data segments DP, as seen in FIG. 4 in which NL represents the number of each data segment DP, 1,440-words-data DXD 1 to 1,440-words-data DXD 10 which form video signal 1 frame periods of the compressed video data DX 1 to DX 10 and the 268-words-data DAD 1 to 268-words-data DAD 10 which form video signal 1 frame periods of the DA data DA 1 to DA 10 are not placed in the 19 data segments DP beginning with the first data segment DP and ending with the 19th data segment DP.

Then, in the 240 data segments DP beginning with the 20th data segment DP and ending with the 259th data segment DP, a condition wherein the 268-words-data DAD 1 which form a video signal 1 frame period of the DA data DA 1 to the 268-words-data DAD 10 which form a video signal 1 frame period of the DA data DA 10 are successively placed in the ancillary area parts of a 268 word-structure repetitively appears. Consequently, 24×268-words-data DAD 1 to 24×268-words-data DAD 10 each of which forms ½ of the DA data DA 1 for a video signal 1 frame period to ½ of the DA data DA 10 for a video signal 1 frame period are placed.

Further, in the 240 data segments DP beginning with the 20th data segment DP and ending with the 259th data segment DP, a condition wherein the 1,440-words-data DXD 1 which form a video signal 1 frame period of the compressed video data DD 1 to the 1,440-words-data DXD 10 which form a video signal 1 frame period of the compressed video data DX 10 are successively placed in the payload area parts of a 1,440 word-structure repetitively appears. Consequently, 24×1,440-words-data DXD 1 to 24×1,440-words-data DXD 10 each of which forms ½ of the compressed video data DX 1 for a video signal 1 frame period to ½ of the compressed video data DX 10 for a video signal 1 frame period are placed.

Then, in the 23 data segments DP beginning with the 260th data segment DP and ending with the 282nd data segment DP, the 1,440-words-data DXD 1 to 1,440-words-data DXD 10 which form the compressed video data DD 1 to DX 10 for a video signal 1 frame period, respectively, and the 268-words-data DAD 1 to 268-words-data DAD 10 which form the DA data DA 1 to DA 10 for a video signal 1 frame period, respectively, are not placed.

Further, in the succeeding 240 data segments DP beginning with the 283rd data segment DP to the 522nd data segment DP, a condition wherein the 268-words-data DAD 1 which form a video signal 1 frame period of the DA data DA 1 to the 268-words-data DAD 10 which form a video signal 1 frame period of the DA data DA 10 are successively placed in the ancillary area parts of a 268 word-structure repetitively appears. Consequently, 24×268-words-data DAD 1 to 24×268-words-data DAD 10 each of which forms ½ of the DA data DA 1 for a video signal 1 frame period to ½ of the DA data DA 10 for a video signal 1 frame period are placed.

Further, in the succeeding 240 data segments DP beginning with the 283rd data segment DP to the 522nd data segment DP, a condition wherein the 1,440-words-data DXD 1 which form a video signal 1 frame period of the compressed video data DX 1 to the 1,440-words-data DXD 10 which form a video signal 1 frame period of the compressed video data DX 10 are successively placed in the payload area parts of a 1,440 word-structure repetitively appears. Consequently, 24×1,440-words-data DXD 1 to 24×1,440-words-data DXD 10 each of which forms ½ of the compressed video data DX 1 for a video signal 1 frame period to ½ of the compressed video data DX 10 for a video signal 1 frame period are placed.

Then, in the 3 data segments DP beginning with the 523rd data segment DP and ending with the 525th data segment DP, the 1,440-words-data DXD 1 to 1,440-words-data DXD 10 which form video signal 1 frame periods of the compressed video data DX 1 to DX 10 and the 268-words-data DAD 1 to 268-words-data DAD 10 which form video signal 1 frame periods of the DA data DA 1 to DA 10 , respectively, are not placed.

In this manner, in the data segment group which includes 525 successive data segments DP, 48×268-words-data DAD 1 to 48×268-words-data DAD 10 which form video signal 1 frame periods of the DA data DA 1 to video signal 1 frame periods of the DA data DA 10 are placed in the ancillary area parts of a 268 word-structure of totalling 480 data segments DP including the 240 data segments DP beginning with the 20th data segment DP and ending with the 259th data segment DP and the 240 data segments DP beginning with the 283rd data segment DP and ending with the 522nd data segment DP, and 48×1,440-words-data DXD 1 to 48×1,440-words-data DXD 10 which form video signal 1 frame periods of the DV data DV 1 to video signal 1 frame periods of the DV data DV 10 are placed in the payload area parts of a 1,440 word-structure of totalling 480 data segments DP including the 240 data segments DP beginning with the 20th data segment DP and ending with the 259th data segment DP and the 240 data segments DP beginning with the 283rd data segment DP and ending with the 522nd data segment DP. Then, data groups each formed from such 525 data segments DP are successively obtained from the encoder section 21 and form multiplexed video and audio data DSD.

The multiplexed video and audio data DSD sent out from the encoder section 21 include the set of the DV data DV 1 and the DA data DA 1 to the set of the DV data DV 10 and the DA data DA 10 which represent video signals and audio signals, respectively, which form 10 different television broadcasting signals conforming to the NTSC system while the DV data DV 1 to DV 10 are formed as the compressed video data DX 1 to DX 10 . The multiplexed video and audio data DSD are transmitted via one transmission line connected to the output terminal of the encoder section 21 and formed from, for example, a coaxial cable.

Referring now to FIG. 5, there is shown another video and audio data processing apparatus to which the present invention is applied and on which the video and audio data processing method according to the present invention is performed. The video and audio data processing apparatus is a modification to and is different from the video and audio data processing apparatus described above with reference to FIG. 3 in that it additionally includes a set of an encoder section 22 A, a data transmission line 23 A and a decoder section 24 A, another set of an encoder section 22 B, a data transmission line 23 B and a decoder section 24 B, a further set of an encoder section 22 C, a data transmission line 23 C and a decoder section 24 C, . . . , and a yet further set of an encoder section 22 J, a data transmission line 23 J and a decoder section 24 J are interposed between the data compression section 13 A and data input terminal 12 A and the memory section 14 A and memory section 15 A, between the data compression section 13 B and data input terminal 12 B and the memory section 14 B and memory section 15 B, between the data compression section 13 C and data input terminal 12 C and the memory section 14 C and memory section 15 C, . . . , and between the data compression section 13 J and data input terminal 12 J and the memory section 14 J and memory section 15 J, respectively.

Compressed video data DX 1 from the data compression section 13 A and DA data DA 1 from the data input terminal 12 A are supplied to the encoder section 22 A. The encoder section 22 A places, as seen in FIG. 6, the DA data DA 1 for video signal 1 frame periods into the ancillary area parts of 243 data segments DP beginning with the 20th data segment DP and ending with the 262nd data segment DP of a data segment group formed from 525 successive data segments DP and the ancillary area parts of the 243 data segments DP beginning with the 283rd data segment DP and ending with the 525th data segment DP and places compressed video data DX 1 for video signal 1 frame periods into the payload area parts of 48 data segments DP beginning with the 20th data segment DP of the data segment group formed from the 525 successive data segments DP to effect formatting of the compressed video data DX 1 and the DA data DA 1 in accordance with the SDI format. Consequently, composite data DZ 1 conforming to the SDI format are sent out from the encoder section 22 A.

Similarly, compressed video data DX 2 from the data compression section 13 B and DA data DA 2 from the data input terminal 12 B, compressed video data DX 3 from the data compression section 13 C and DA data DA 3 from the data input terminal 12 C, . . . , and compressed video data DX 10 from the data compression section 13 J and DA data DA 10 from the data input terminal 12 J are supplied to the encoder sections 22 B, 22 C, . . . , and 22 J, respectively. Then, the encoder sections 22 B, 22 C, . . . , and 22 J perform formatting of the compressed video data DX 2 and the DA data DA 2 , the compressed video data DX 3 and the DA data DA 3 , . . . , and the compressed video data DX 10 and the DA data DA 10 in accordance with the SDI format and send out resulting composite data DZ 2 , DZ 3 , . . . , and DZ 10 conforming to the SDI format, respectively.

The composite data DZ 1 to DZ 10 sent out from the encoder sections 22 A to 22 J are transmitted via the data transmission lines 23 A, 23 B, 23 C, . . . , and 23 J and supplied to the decoder sections 24 A, 24 B, 24 C, . . . , and 24 J, respectively. The decoder section 24 A performs format releasing processing of the composite data DZ 1 received via the data transmission line 23 A to obtain the compressed video data DD 1 and the DA data DA 1 in a demultiplexed condition from each other.

Similarly, the decoder sections 24 B to 24 J perform format releasing processing of the composite data DZ 2 transmitted via the data transmission line 23 B to the composite data DZ 10 transmitted via the decoder section 24 J to obtain the compressed video data DX 2 and the DA data DA 2 to the compressed video data DX 10 and the DA data DA 10 in a demultiplexed condition from each other, respectively. Then, the compressed video data DX 1 to DX 10 obtained from the decoder sections 24 A to 24 J are supplied to the memory sections 14 A to 14 J, respectively. Meanwhile, the DA data DA 1 to DA 10 obtained from the decoder sections 24 A to 24 J are supplied to the memory sections 15 A to 15 J, respectively.

Writing and reading out of the compressed video data DX 1 to DX 10 into and from the memory sections 14 A to 14 J are performed in a similar manner as in the case illustrated in FIG. 3 . Thus, 1,440-words-data DXD 1 of the compressed video data DX 1 to 1,440-words-data DXD 10 of the compressed video data DX 10 are read out from the memory sections 14 A to 14 J, respectively, and supplied to the encoder section 21 . Meanwhile, writing and reading out of the DA data DA 1 to DA 10 into and from the memory sections 15 A to 15 J are performed in a similar manner as in that of the case illustrated in FIG. 3 . Thus, 268-words-data DAD 1 of the DA data DA 1 to 268-words-data DAD 10 of the DA data DA 10 are read out from the memory sections 15 A to 15 J, respectively, and supplied to the encoder section 21 .

The encoder section 21 performs formatting wherein it places the 1,440-words-data DXD 1 of the compressed video data DX 1 to the 1,440-words-data DXD 10 of the compressed video data DX 10 successively read out from the memory sections 14 A to 14 J and the 268-words-data DAD 1 of the DA data DA 1 to the 268-words-data DAD 10 of the DA data DA 10 successively read out from the memory sections 15 A to 15 J into the payload area parts and the ancillary area parts of data segments DP, respectively, in accordance with such an SDI format as illustrated in FIG. 1, in a similar manner as in the case illustrated in FIG. 3 . consequently, from the encoder section 21 , data segment groups each of which includes 525 data segments DP including those data segments DP wherein the 1,440-words-data DXD 1 of the compressed video data DX 1 to the 1,440-words-data DXD 10 of the compressed video data DX 10 are successively placed in the payload area parts and the 268-words-data DAD 1 of the DA data DA 1 to the 268-words-data DAD 10 of the DA data DA 10 are successively placed in the ancillary area parts are successively obtained to form multiplexed video and audio data DSD.

Also the multiplexed video and audio data DSD sent out from the encoder section 21 in this manner include the set of the DV data DV 1 and the DA data DA 1 to the set of the DV data DV 10 and the DA data DA 10 which represent video signals and audio signals, respectively, which form different television broadcasting signals conforming to the NTSC system while the DV data DV 1 to DV 10 are formed as the compressed video data DX 1 to DX 10 . The multiplexed video and audio data DSD are transmitted via one transmission line connected to the output terminal of the encoder section 21 and formed from, for example, a coaxial cable.

It is to be noted that, while the video and audio data processing apparatus of the embodiments described above are constructed so as to perform processing, based on 10 sets of DV data and DA data representative of video signals and audio signals of television broadcasting signals conforming to the NTSC system, for forming data with which the DV data and the DA data can be transmitted via a single transmission line formed from, for example, a coaxial cable, in the video and audio data processing method or the video and audio data processing apparatus according to the present invention, the number of sets of DV data and DA data is not limited at all, but may be set suitably taking the data compression processing of DV data into consideration.

In the video and audio data processing method and the video and audio data processing apparatus described above, data segments formed for transmission of DV data and DA data are placed, for each predetermined number of words of each of a plurality of DA data, into a first data area and placed, for each predetermined number of words of each of a plurality of compressed video data based on a plurality of DV data, into a second area. Then, a group unit of data segments is formed from a predetermined number of successive data segments wherein the predetermined numbers of words of the DA data are placed in the first data areas and the predetermined numbers of words of the compressed video data are placed in the second data areas such that the plurality of compressed video data individually representative of the plurality of video signals for a predetermined period which is, for example, a one frame period are placed divisionally with the predetermined numbers of words in the second data areas of a predetermined number of the successive data segments included in each of the group units. In this instance, in the first data areas of the predetermined number of data segments included in each of the group units, the plurality of DA data corresponding to the plurality of compressed video data of the plurality of video signals for the predetermined period are divisionally placed with the predetermined numbers of words.

Consequently, a plurality of sets of compressed video data and DA data are successively placed, for each data amount corresponding to a one frame period of a video signal, into group units each of which is formed from a predetermined number of successive data segments. Then, the group units of the data segments formed successively in this manner can be successively transmitted through a single transmission line formed from a coaxial cable. Accordingly, a condition wherein a plurality of sets of compressed video data and DA data can be transmitted substantially simultaneously or in a common transmission period to a common transmission destination.

Therefore, where the video and audio data processing method or the video and audio data processing apparatus described above is applied to perform processing for formation of a large number of successive data segments so that a plurality of sets of DV data and DA data may have a data format such as the SDI format with which they can be transmitted substantially simultaneously or in a common transmission period to a common transmission destination, in order to transmit a plurality of sets of DV data and DA data, there is no need of providing a plural number of data transmission lines equal to the number of sets of DV data and DA data. Therefore, such a situation that complication and increase in scale of an apparatus or equipment for data transmission are invited can be eliminated, and further, reduction in cost for data transmission can be achieved.

Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein.