JP7335764B2 - Transmitting device, receiving device and program - Google Patents

Description

The present invention relates to a transmitting device, a receiving device, and a program for dividing and encoding a predetermined video signal and multiplex-transmitting them in a TS (Transport Stream) packet format.

Conventionally, when encoding and transmitting a video signal with a certain resolution and frame rate, a video signal with a lower resolution and a lower frame rate is used for the purpose of reducing the scale of arithmetic circuits, speeding up processing, and utilizing existing equipment. There is known a transmission method in which the data is divided into two, encoded, and transmitted.

For example, when a so-called 8K signal for a 7680 x 4320 pixel video is divided into four 4K signals for a 3840 x 2160 pixel video and transmitted, a total of four pairs of encoding units and decoding units for 4K signals are transmitted. system (see, for example, Patent Document 1).

In recent years, 8K satellite broadcasting has started, and it has become possible to enjoy ultra-high-definition images full of presence at home. In order to further expand 8K programs, it is necessary to convert program production equipment to 8K, and wireless cameras are one of them.

A wireless camera configured as a video transmission device has a limited transmission band for wireless signals. An encoding unit on the transmitting device side generates a compressed signal by compressing the video and transmits it to the receiving device in a TS packet format. On the receiving device side, the compression signal can be decompressed and decoded by an encoding unit and a corresponding decoding unit on the transmitting device side to restore the original video.

By the way, a wireless camera is required to have a low delay of several milliseconds to several tens of milliseconds so that there is no sense of incongruity even when the image of a wired camera is switched. A dominant delay in a wireless camera is caused by a codec, and a codec that compresses and decompresses with low delay is required for transmission of a video signal (8K signal, for example) exceeding the image size of 4K.

However, most codecs that compress 8K signals have not been commercialized, and even if they have been commercialized, they are very large and expensive. On the other hand, a number of 4K signal codecs have been commercialized and are miniaturized with a low delay of several tens of milliseconds.

JP 2019-97076 A

As mentioned above, there is a demand for codecs that compress and decompress with low latency for the transmission of video signals that exceed the so-called 4K image size (e.g., 8K signals). It is possible to adopt a transmission system that uses a 4K signal codec that has been developed.

For example, FIG. 4 is a block diagram showing a schematic configuration of a transmission device 501 of a comparative example based on the prior art. Transmission device 501 includes first to fourth encoding units 511-1, 511-2, 511-3, and 511-4 (hereinafter collectively referred to as “encoding units 511”), TS signal multiplexing A unit 512 and a transmitting unit 513 are provided.

Each of the first to fourth encoding units 511 is configured to use a 4K signal codec, and divides an 8K signal into four 4K signals and outputs the four 4K signals from the 8K camera 10. Each 4K signal is input, compression encoding processing is performed using a 4K signal codec to generate a compressed signal, the compressed signal is stored in a TS packet, and a TS signal of a TS packet string is generated by a TS signal multiplexing unit. 512.

Here, the MPEG-2 TS format defines a program_number, and each of the first to fourth encoding units 511 has the same program_number for each 4K signal (all #1 in the example shown in FIG. 4). , and outputs the TS signals of the first to fourth TS packet sequences synchronized in TS packet units to the TS signal multiplexing unit 512 . In the conventional technology, program_number may be randomly assigned to each 4K signal in order to synchronize in units of TS packets, but in this example, program_number=1 for the convenience of explanation.

The TS signal multiplexing unit 512 receives the TS signals of the first to fourth TS packet sequences from the first to fourth encoding units 511 and sequentially time-division multiplexes them in units of TS packets. 4, the multiplexed TS signal of the first to fourth TS packet sequences with all program_number=1 is output to the transmission unit 513 . Incidentally, the TS signal multiplexing unit 512 is generally called a multiplexer.

Transmitting section 513 transmits the multiplexed TS signal obtained from TS signal multiplexing section 512 to receiving apparatus 502 wirelessly or by wire.

On the other hand, FIG. 5 is a block diagram showing a schematic configuration of a comparative receiver 502 based on the prior art. The receiving device 502 includes a receiving unit 521, a TS signal separating unit 522, and first to fourth decoding units 523-1, 523-2, 523-3, and 523-4 (hereinafter collectively referred to as “decoding unit 523 ).

Receiving section 521 receives the multiplexed TS signal transmitted from transmitting apparatus 501 and outputs it to TS signal separating section 522 .

The TS signal separation unit 522 receives the multiplexed TS signal from the reception unit 521, separates it into TS packets, and separates the synchronized TS signals of the first to fourth TS packet sequences into the first to fourth packets, respectively. Output to the decoding unit 523 . Here, the multiplexed TS signals of the first to fourth TS packet sequences are all assigned the same program_number (all #1 in the example shown in FIG. 5) on the transmitting device 501 side. is commonly called a demultiplexer.

Each of the first to fourth decoding units 523 is configured to use a 4K signal codec corresponding to each of the first to fourth encoding units 511 on the transmission device 501 side, and uses the 4K signal codec. Then, expansion decoding processing is performed to generate decoded signals of the first to fourth 4K signals, and the decoded signals are externally output toward the 8K display device 20 (display).

The 8K display 20 synthesizes the first to fourth 4K signals to restore and display the 8K signal.

In this way, on the transmitting device 501 side, the 4K signals obtained by dividing the 8K signal to be transmitted into four 4K signals are each compressed by the encoding unit 511 for 4K signals, and the compressed signals are used as the same program_number. (or random) TS packets are multiplexed and transmitted to the receiving device 502 . On the receiving device 502 side, the multiplexed TS packets are separated into four signals, decoded by the decoding unit 523 for 4K signals, and output to the 8K display device 20 . In this transmission method, since four 12G-SDIs that transmit 4K signals are often used as interfaces for the 8K camera 10 and the 8K display 20, there is an advantage that an existing interface can be used.

However, in the transmission system with a total of four pairs of encoding units 511 and decoding units 523 for 4K signals shown in FIGS. TS signals are multiplexed by the TS signal multiplexing unit 512 and transmitted as one multiplexed TS signal with the same (or random) program_number. It is necessary to separate the original four TS packet strings by the separating unit 522 .

However, in the case of a transmission method that requires a low delay of several milliseconds to several tens of milliseconds, such as when the transmitting device 501 is configured as a wireless camera, it is not sufficient to simply use a 4K signal codec to reduce the delay. In particular, the delay of the TS signal separating section 522 cannot be ignored, so a transmission method that reduces the transmission delay is desired.

Therefore, in view of the above problems, an object of the present invention is to provide a transmitting device, a receiving device, and a program that can further reduce the transmission delay, encode a signal obtained by dividing a predetermined video signal, and multiplex transmit in the TS packet format. to provide.

A transmitting apparatus according to the present invention is a transmitting apparatus that encodes signals obtained by dividing a predetermined video signal and multiplex-transmits them in TS packet format. and perform compression encoding processing, generate each compressed signal, store it in a TS packet, and program_number and packet identifier ( N encoding means for respectively outputting N TS signals assigned with different values of PID), and inputting the N TS signals, sequentially time-division multiplexing them in TS packet units to generate multiplexed TS signals. and transmission means for transmitting the multiplexed TS signal to a receiving device.

Further, in the transmission device of the present invention, the encoding means inputs a video signal exceeding an image size of 4K as the predetermined video signal, and divides the video signal into N signals having an image size of 4K or less. , compression encoding processing.

Further, the receiver of the present invention is a receiver that receives the multiplexed TS signal transmitted from the transmitter of the present invention and generates a signal for restoring the predetermined video signal, wherein the multiplexed receiving means for receiving a multiplexed TS signal; multiplexed TS signal distribution means for distributing the received multiplexed TS signal to N; and for each of the multiplexed TS signals distributed to the N, the program_number or A packet identifier (PID) is identified, a TS packet to be decoded is selected and extracted, and decompression decoding processing corresponding to the compression encoding processing in the N encoding means is performed to decode N 4K signals. and N decoding means for generating signals.

Moreover, the program of the present invention constitutes a program for causing a computer to function as the transmitting apparatus of the present invention.

Moreover, the program of the present invention constitutes a program for causing a computer to function as the receiving device of the present invention.

According to the present invention, in a transmission system in which a video signal exceeding a 4K image size (e.g., an 8K signal) is divided and encoded and multiplexed in the TS packet format, transmission delay can be further reduced, and a receiving apparatus is provided. You can configure the device.

1 is a block diagram showing a schematic configuration of a transmitter of one embodiment according to the present invention; FIG. 1 is a block diagram showing a schematic configuration of a receiving device of one embodiment according to the present invention; FIG. 3(a) and 3(b) are block diagrams showing schematic configurations of an n-th encoding unit and an n-th decoding unit in a transmitting device and a receiving device, respectively, according to an embodiment of the present invention; FIG. FIG. 3 is a block diagram showing a schematic configuration of a transmission device of a comparative example based on conventional technology; and FIG. 11 is a block diagram showing a schematic configuration of a receiving device of a comparative example based on conventional technology.

A transmitting device 1 and a receiving device 2 constituting a transmission system according to an embodiment of the present invention will be described below with reference to the drawings.

The transmission device 1 according to the present invention compresses and encodes signals obtained by dividing a video signal (for example, an 8K signal) exceeding an image size of 4K by N (an integer equal to or greater than 2) by N encoding units, and converts them into TS packets. It is configured to transmit one multiplexed TS signal multiplexed in the format toward the receiving device 2 . Further, the receiving device 2 according to the present invention distributes one multiplexed TS signal received from the transmitting device 1 to N, selects and decompresses and decodes TS packets to be processed by each of the N decoding units, It is configured to output N signals for restoring the original video signal. Therefore, in the following description, as an example, a transmitting apparatus 1 and a receiving apparatus 2 configured with N=4 assuming that a video signal to be transmitted is an 8K signal and a codec for a 4K signal is used will be described.

(Transmitter)
FIG. 1 is a block diagram showing a schematic configuration of a transmitter 1 of one embodiment according to the present invention. The transmitting device 1 includes first to fourth encoding units 11-1, 11-2, 11-3, and 11-4 (hereinafter collectively referred to as "encoding units 11"), TS signal multiplexing A unit 12 and a transmitting unit 13 are provided.

Each of the first to fourth encoding units 11 is configured to use a 4K signal codec, and divides an 8K signal into four 4K signals and outputs the four 4K signals from the 8K camera 10. 4K signals are input respectively. Then, each of the first to fourth encoding units 11 performs compression encoding processing using a 4K signal codec to generate a compressed signal, stores the compressed signal in a TS packet, and stores the TS packet string. TS signal to the TS signal multiplexing unit 12 . An existing 12G-SDI capable of transmitting 4K signals can be used for connection between the 8K camera 10 and the transmission device 1 .

Here, the MPEG-2 TS format defines a program_number, and each of the first to fourth encoding units 11 performs each Different program_numbers (#1, #2, #3, #4 in the example shown in FIG. 1) are assigned to the 4K signals, treated as if they were videos of different programs, and synchronized in units of TS packets. The first to fourth TS packet sequences are output to the TS signal multiplexer 12 as first to fourth TS signals, respectively. By assigning a different program_number (#1, #2, #3, #4 in the example shown in FIG. 1) to each 4K signal, the packet identifier (PID) included in the header information of each TS packet is also supported. assigned to different values as

The TS signal multiplexing unit 12 receives the first to fourth TS signals respectively from the first to fourth encoding units 11, sequentially time-division multiplexes them in units of TS packets, and converts them into program_number (shown in FIG. 1). For example, #1, #2, #3, #4) are sequentially repeated, and a multiplexed TS signal of the first to fourth TS signals is output to the transmitting section 13 .

The transmitting unit 13 transmits the multiplexed TS signal obtained from the TS signal multiplexing unit 12 to the receiving device 12 wirelessly or by wire.

(receiving device)
FIG. 2 is a block diagram showing a schematic configuration of the receiver 2 of one embodiment according to the present invention. The receiving device 2 includes a receiving unit 21, a multiplexed TS signal distribution unit 22, and first to fourth decoding units 23-1, 23-2, 23-3, and 23-4 (hereinafter collectively referred to as "decoding section 23”).

The receiving unit 21 receives the multiplexed TS signal of the first to fourth TS signals in which the program_number (#1, #2, #3, #4 in the example shown in FIG. 1) is repeated sequentially from the transmitting device 1. , to the multiplexed TS signal distribution unit 22 .

The multiplexed TS signal distribution unit 22 receives the multiplexed TS signal from the receiving unit 521, distributes the signals in the same signal format, and outputs the signals to the first to fourth decoding units 23, respectively. This multiplexed TS signal distribution unit 22 is generally called a distributor. In addition, as described above, the multiplexed TS signal according to the present invention has different program_numbers (example shown in FIG. , #1, #2, #3, and #4) are multiplexed from the first to fourth TS signals.

As described above, the receiver 2 of this embodiment is configured to use the multiplexed TS signal distribution section 22 instead of the conventional TS signal separation section 522 shown in FIG. Since the multiplexed TS signal distribution unit 22 simply distributes the same electrical signal, the delay is so small that it can be ignored.

Each of the first to fourth decoding units 23 is configured to use a 4K signal codec corresponding to each of the first to fourth encoding units 11 on the transmission device 1 side, and has a program_number or a packet identifier (PID ) is identified to select and extract only the TS packets to be decoded, decompression decoding processing is performed using a 4K signal codec to generate decoded signals of the first to fourth 4K signals, and the decoded signals is output to the 8K display device 20 (display).

The 8K display 20 synthesizes the first to fourth 4K signals to restore and display the 8K signal. Here, existing 12G-SDI capable of transmitting 4K signals can be used for connection between the receiving device 2 and the 8K display device 20 .

(encoder and decoder)
A configuration example of the n-th encoding unit 11-n and the n-th decoding unit 23-n in the N encoding units 11 and decoding units 23 will be described with reference to FIG.

3(a) and 3(b) respectively show schematic configurations of the n-th encoding unit 11-n and the n-th decoding unit 23-n in the transmitting device 1 and the receiving device 2 of one embodiment according to the present invention. It is a block diagram.

The n-th encoding unit 11-n shown in FIG. 3A includes an encoder 111, a TS packet transmission unit 112, an encoder control unit 113, and a TS management unit 114.

The encoder 111 receives the n-th 4K signal, and under the control of the encoder control unit 113, performs compression encoding processing using a predetermined encoding parameter for transmission based on the codec of the 4K signal to generate a compressed signal. and output to the TS packet transmission unit 112 . The encoder 111 in the n-th encoding unit 11-n may have encoding parameters different from those of the other encoding units, or may have the same encoding parameters.

The TS packet transmission unit 112 controls the synchronization of encoding and packet transmission under the control of the encoder control unit 113, sequentially stores the compressed signal input from the encoder 111 in the payload of the TS packet, and furthermore, the TS management unit 114 and the corresponding packet identifier (PID) are stored in the header of the TS packet sequence, and output to the TS signal multiplexing unit 12 as the TS signal of the TS packet sequence.

The encoder control unit 113 is a functional unit that controls encoding parameters for the encoder 111, and controls synchronization of encoding and packet transmission for the TS packet transmission unit 112. Its control information is sent to the TS management unit. 114 is notified.

The TS management unit 114 is a functional unit that assigns a unique program_number=n and a corresponding packet identifier (PID) based on the control information notified from the encoder control unit 113 and outputs it to the TS packet transmission unit 112 . Note that the TS management unit 114 in the n-th encoding unit 11-n assigns a unique program_number=n different from that of other encoding units and a corresponding packet identifier (PID).

On the other hand, the n-th decoding unit 23-n shown in FIG.

A TS packet receiving unit 231 receives a multiplexed TS signal, selects and extracts a TS packet having a unique program_number=n notified from the TS management unit 233 or a corresponding packet identifier (PID), and a decoder 232 output to As described above, the multiplexed TS signal has different program_numbers (#1, #2, #3, #4 in this example) according to the rules of the multiplexing order predetermined between the transmitter 1 and the receiver 2, and the corresponding It is obtained by multiplexing first to fourth TS signals to which packet identifiers (PIDs) are assigned. The TS packet receiving unit 231 in the n-th decoding unit 23-n receives and processes the same multiplexed TS signal as the other decoding units.

The decoder 232 extracts the compressed signal from the payload of the TS packet having program_number=n or a corresponding packet identifier (PID), and under the control of the decoder control unit 234, the n-th encoding unit 11-n and the corresponding 4K signal codec-based transmission, expansion decoding processing is performed with predetermined encoding parameters to generate a decoded signal of the n-th 4K signal, and the decoded signal is output to the 8K display 20 .

The TS management unit 233 is a functional unit that outputs a unique program_number=n and a corresponding packet identifier (PID) to the TS packet reception unit 231. The TS management unit 233 in the n-th decoding unit 23-n holds a unique program_number=n corresponding to the n-th encoding unit 11-n and a corresponding packet identifier (PID).

The decoder control unit 234 is a functional unit that controls predetermined encoding parameters corresponding to the n-th encoding unit 11-n for the decoder 232 .

In this way, the n-th encoding unit 11-n and the n-th decoding unit 23-n efficiently encode and TS packetize in relation to the reduction in delay by the multiplexed TS signal distribution unit 22, and efficiently It can extract and decode TS packets well.

As described above, in the transmission system of the present embodiment, four 4K signals obtained by dividing a video signal to be transmitted (8K signal in this example) are compressed and encoded by four encoding units. 4 TS signals assigned with different program_numbers and packet identifiers (PIDs) are multiplexed to transmit one multiplexed TS signal to the receiving device 2 . On the receiving device 2 side, one received multiplexed TS signal is divided into four, each of which selects a TS packet to be processed based on a program_number or a packet identifier (PID) and decompresses and decodes it, It is configured to output four 4K signals for restoring the original video signal.

Therefore, according to the transmitting device 1 and the receiving device 2 of the present embodiment, delay reduction by the multiplexed TS signal distribution unit 22 and low delay by the n-th encoding unit 11-n and the n-th decoding unit 23-n are achieved. Due to the delay, it can be suitably used as a transmission method requiring a low delay of several milliseconds to several tens of milliseconds, and the transmission delay can be reduced more than the conventional technology.

Further, according to the transmitting device 1 and the receiving device 2 of the present embodiment, unlike the comparative example based on the prior art as shown in FIG. 4 and FIG. Since each TS signal is identified by a packet train having a program_number and a packet identifier (PID), it is possible to easily absorb synchronization jitter that may occur in TS synchronization related to multiplexing or extraction of each TS signal. and the tolerance to synchronization jitter is increased.

Incidentally, the transmitting device 1 or the receiving device 2 of this embodiment can also be operated by a computer. A program for causing the computer to implement each component of the present invention is stored in a memory (not shown) provided inside or outside the computer. Under the control of a central processing unit (CPU) or the like provided in a computer, a program describing the processing details for realizing the function of each component is appropriately read from the memory, and the transmission device 1 or the reception device 2 is executed. The function of each component can be realized by a computer. Here, the function of each component may be realized by a part of hardware.

By the way, in the above-described embodiment, an example of using the 8K camera 10 as a device for outputting a video signal to be transmitted has been described, but it is also possible to input from a recording device, which is optional. Similarly, an example of using the 8K display 20 as a device for displaying video signals has been described, but an image processing device for processing video signals may also be used, and is optional.

Furthermore, in the above-described embodiment, the video signal to be transmitted is an 8K signal. Yes, and by transmitting signals divided into signals smaller than the image size of 4K, the existing 12G-SDI capable of transmitting 4K signals can be used as an interface. For this reason, the transmitting device 1 and the receiving device 2 according to the present invention, for example, divide the currently studied 6K signal, 16K signal, or 32K video signal into signals with an image size of 4K or less as transmission targets. can do.

Also, in the above-described embodiment, an example of multiplexing and dividing into 4 divided signals was described with N=4, but N can be any integer of 2 or more. However, in a preferred embodiment, any one of N=2, 3, 4, 6, 16, 64 can be set in advance assuming that 6K, 16K, or 32K video signals are handled. Furthermore, it is also possible to predetermine the maximum value of N to be 64, and to selectively operate even when video signals of various image sizes are input.

Accordingly, the present invention is not limited to the embodiments described above, but only by the scope of the appended claims.

INDUSTRIAL APPLICABILITY According to the present invention, since the transmission delay of video signals can be further reduced, it is useful for a transmitting device and a receiving device of a transmission system in which a video signal is divided, encoded, and multiplexed in TS packet format.

1 transmitter 2 receiver 10 8K camera 11, 11-1, 11-2, 11-3, 11-4, 11-n encoder 12 TS signal multiplexer 13 transmitter 20 8K display 21 receiver 22 Multiplexed TS signal distribution unit 23, 23-1, 23-2, 23-3, 23-4, 23-n decoding unit 111 encoder 112 TS packet transmission unit 113 encoder control unit 114 TS management unit 231 TS packet reception unit 232 Decoder 233 TS management section 234 Decoder control section 501 Transmitting apparatus of comparative example based on conventional technology 502 Receiving apparatus of comparative example based on conventional technology 511, 511-1, 511-2, 511-3, 511-4 Encoding section 512 TS signal multiplexer 513 transmitter 521 receiver 522 TS signal separator 523, 523-1, 523-2, 523-3, 523-4 decoder

Claims (5)

A transmission device that encodes a signal obtained by dividing a predetermined video signal and multiplex-transmits it in a TS packet format,
Signals obtained by dividing the video signal into N (N is an integer equal to or greater than 2) are inputted, each compression encoding process is performed, each compression signal is generated, stored in a TS packet, and predetermined multiplexing is performed between transmission and reception. N encoding means for respectively outputting as N TS signals assigned program_numbers and packet identifiers (PIDs) defined in MPEG-2 TS format with different values according to order rules;
TS signal multiplexing means for receiving the N TS signals and sequentially time division multiplexing them in TS packet units to generate multiplexed TS signals;
transmitting means for transmitting the multiplexed TS signal to a receiving device;
A transmitting device comprising: The encoding means uses a video signal exceeding an image size of 4K as the predetermined video signal, inputs signals of an image size of 4K or less obtained by dividing the video signal by N, and performs compression encoding processing. 2. A transmitting device according to claim 1, characterized in that it is configured as: A receiving device for receiving the multiplexed TS signal transmitted from the transmitting device according to claim 1 or 2 and generating a signal for restoring the predetermined video signal,
receiving means for receiving the multiplexed TS signal;
multiplexed TS signal distribution means for distributing the received multiplexed TS signal to N;
For each of the multiplexed TS signals distributed to the N pieces, identifying the program_number or packet identifier (PID) to select and extract the TS packet to be decoded, and compressing each by the N encoding means N decoding means for generating decoded signals of N 4K signals by performing decompression decoding processing corresponding to encoding processing;
A receiving device comprising: A program for causing a computer to function as the transmission device according to claim 1 or 2. A program for causing a computer to function as the receiving device according to claim 3.