Video transmission device, video reception device, video transmission system, video transmission method, and video reception method

Abstract

A video transmission device (10) can be connected to a stage before a preexisting transmission device (30) without a function for compressing inputted video, and comprises: a reception unit (11) that receives a video signal; a video signal compression unit (12) that, if the video signal received by the reception unit (11) is a video signal exceeding the bandwidth of a video transmission path used by the preexisting transmission device (30), compresses the video signal; a compressed video information generation unit (13) that generates first compressed video information including a parameter which was used in the compression of the video signal by the video signal compression unit (12); and a transmission unit (14) that transmits the video signal compressed by the video signal compression unit (12) and the first compressed video information to the preexisting transmission device (30).

Description

Video transmitting device, video receiving device, video transmission system, video transmitting method, and video receiving method

[0001] The present disclosure relates to a video transmission device and the like.

[0002] Patent Document 1 discloses a technique for transmitting video data that exceeds the bandwidth of a video transmission path.

[0003] JP 2009-213110 A

[0004] However, the technology disclosed in Patent Document 1 is based on the premise that the transmitting / receiving device has a compression function, and therefore, in order to apply the technology disclosed in Patent Document 1 to an existing transmitting / receiving device that does not have a compression function, it is necessary to change the configuration of the existing transmitting / receiving device.

[0005] Therefore, the present disclosure provides a video transmission device or the like that can transmit a video signal that exceeds the bandwidth of the video transmission path used by an existing transmission / reception device without changing the configuration of the existing transmission / reception device that does not have a compression function.

[0006] The video transmission device of the present disclosure can be connected in front of a transmission device that does not have a compression function for input video, and comprises a first receiving unit that receives a video signal, a first video signal compression unit that compresses the video signal if the video signal received by the first receiving unit is a video signal that exceeds the bandwidth of the video transmission path used by the transmission device, a compressed video information generation unit that generates first compressed video information including parameters used to compress the video signal by the first video signal compression unit, and a transmission unit that transmits the video signal compressed by the first video signal compression unit and the first compressed video information to the transmission device.

[0007] The video receiving device of the present disclosure is connectable downstream of a receiving device that does not have an expansion function for input compressed video, and comprises a second receiving unit that receives first compressed video information including a video signal compressed by a video transmitting device connected upstream of a transmitting device that does not have a compression function for input video and parameters used to compress the video signal, a compressed video information processing unit that processes the first compressed video information, and a second video signal expansion unit that uses the first compressed video information to expand the video signal compressed by the video transmitting device into a video signal that exceeds the bandwidth of the video transmission path used by the receiving device.

[0008] A video transmission system according to the present disclosure includes the above video transmitting device and the above video receiving device.

[0009] The video transmission method of the present disclosure is a video transmission method executed by a video transmission device, which is connectable to a preceding stage of a transmission device that does not have a compression function for input video, and which includes a first receiving step of receiving a video signal, a first video signal compression step of compressing the video signal if the video signal received in the first receiving step is a video signal that exceeds the bandwidth of the video transmission path used by the transmission device, a compressed video information generation step of generating first compressed video information indicating parameters used to compress the video signal in the first video signal compression step, and a transmission step of transmitting the video signal compressed in the first video signal compression step and the first compressed video information to the transmission device.

[0010] The video receiving method of the present disclosure is a video receiving method executed by a video receiving device, which is connectable downstream of a receiving device that does not have an expansion function for input compressed video, and which includes a second receiving step of receiving a video signal compressed by a video transmitting device connected upstream of the transmitting device that does not have a compression function for input video and first compressed video information indicating parameters used to compress the video signal, a compressed video information processing step of processing the first compressed video information, and a second video signal expansion step of using the first compressed video information to expand the video signal compressed by the video transmitting device into a video signal that exceeds the bandwidth of the video transmission path used by the receiving device.

[0011] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized as any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

[0012] According to a video transmission device according to one aspect of the present disclosure, it is possible to transmit a video signal that exceeds the bandwidth of the video transmission path used by an existing transmission / reception device without changing the configuration of the existing transmission / reception device that does not have a compression function.

[0013] FIG. 1 is a block diagram showing an example of a video transmission system according to a first embodiment. FIG. 2 is a flowchart showing an example of an operation of a video transmission device according to the first embodiment. FIG. 3 is a block diagram showing an example of a video transmission system according to a second embodiment. FIG. 4 is a diagram for explaining the operation of a compression control unit according to the second embodiment. FIG. 5 is a block diagram showing an example of a video transmission system according to a third embodiment. FIG. 6 is a flowchart showing an example of an operation of a video transmission device according to the third embodiment. FIG. 7 is a flowchart showing an example of an operation of a video reception device according to the third embodiment. FIG. 8 is a block diagram showing an example of a video transmission device according to a fourth embodiment.

[0014] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0015] The embodiments described below are all comprehensive or specific examples, and the numerical values, shapes, materials, components, arrangement and connection of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0016] (First Embodiment) Hereinafter, a video transmitting device, a video receiving device, and a video transmission system according to a first embodiment will be described.

[0017] Fig. 1 is a block diagram showing an example of a video transmission system 1 according to embodiment 1. In addition to the video transmission system 1, Fig. 1 also shows an existing transmitting device 30 and an existing receiving device 40.

[0018] The existing transmitting device 30 is an existing transmitting device (source-side device) that does not have a compression function for input video, and is, for example, an interface compatible with a communication standard such as HDMI (High Definition Multimedia Interface) (registered trademark). The existing receiving device 40 is an existing receiving device (sink-side device) that does not have a decompression function for input compressed video, and is, for example, an interface compatible with a communication standard such as HDMI. For example, the video transmission path used by the existing transmitting device 30 and the existing receiving device 40, specifically, the cable connecting the existing transmitting device 30 and the existing receiving device 40, is an HDMI cable. For example, the existing transmitting device 30, which is an HDMI interface provided in a PC (Personal Computer), etc., and the existing receiving device 40, which is an HDMI interface provided in a monitor, etc., are connected by an HDMI cable. Since the existing transmitting device 30 does not have a compression function and the existing receiving device 40 does not have a decompression function, the existing transmitting device 30 transmits the received video signal to the existing receiving device 40 as is without compressing it.

[0019] The video transmission system 1 includes a video transmitting device 10 and a video receiving device 20 .

[0020] The video transmitting device 10 can be connected in front of the existing transmitting device 30. The video transmitting device 10 receives a video signal, compresses the received video signal, and transmits it to the existing transmitting device 30. As described above, the existing transmitting device 30 does not have a compression function, and therefore transmits the compressed video signal received from the video transmitting device 10 directly to the existing receiving device 40. The video transmitting device 10 is a device that enables transmission of a video signal with a bandwidth for video with a resolution higher than 4K video (e.g., 8K video) without changing the configuration of the existing transmitting device 30, which, for example, only supports a maximum bandwidth of 4K video.

[0021] The video transmission device 10 includes a receiving unit 11, a video signal compression unit 12, a compressed video information generation unit 13, and a transmission unit 14. The video transmission device 10 is a computer including a processor (microprocessor), a memory, a communication interface, etc. The memory is a read-only memory (ROM) or a random access memory (RAM), etc., and can store programs executed by the processor. The video signal compression unit 12 and the compressed video information generation unit 13 are realized by a processor that executes programs stored in the memory, etc. The video transmission device 10 is, for example, an integrated circuit.

[0022] The receiving unit 11 is a communication interface that receives a video signal. The receiving unit 11 is an example of a first receiving unit. The receiving unit 11 receives, for example, an uncompressed video signal (uncompressed video).

[0023] The video signal compressor 12 compresses a video signal received by the receiver 11 if the video signal exceeds the bandwidth of the video transmission path used by the existing transmitter 30. The video signal compressor 12 is an example of a first video signal compressor. For example, the bandwidth of the video transmission path used by the existing transmitter 30 is the bandwidth of 4K video, and a video signal exceeding the bandwidth of the video transmission path used by the existing transmitter 30 is an 8K video signal or the like. The video signal compressor 12 performs, for example, DSC (Display Stream Compression) encoding. Details of the operation of the video signal compressor 12 will be described later with reference to FIG. 2.

[0024] The compressed video information generator 13 generates first compressed video information including parameters used in the compression of the video signal by the video signal compressor 12. Details of the operation of the compressed video information generator 13 will be described later with reference to FIG.

[0025] The transmitting unit 14 transmits the video signal compressed by the video signal compressing unit 12 and the first compressed video information to the existing transmitting device 30 .

[0026] The video receiving device 20 can be connected to the rear stage of the existing receiving device 40. The video receiving device 20 receives a video signal compressed by the video transmitting device 10 and expands the video signal to return it to the state before being compressed by the video transmitting device 10. The video receiving device 20 is a device that enables transmission of a video signal with a bandwidth of video with a resolution equal to or higher than 4K video (e.g., 8K video) without changing the configuration of the existing receiving device 40, which, for example, only supports a maximum bandwidth of 4K video.

[0027] The video receiving device 20 includes a receiving unit 21, a compressed video information processing unit 22, a video signal decompression unit 23, and a transmitting unit 24. The video receiving device 20 is a computer including a processor (microprocessor), a memory, a communication interface, etc. The memory is a ROM, a RAM, etc., and can store programs executed by the processor. The compressed video information processing unit 22 and the video signal decompression unit 23 are realized by a processor, etc., that executes programs stored in the memory. The video receiving device 20 is, for example, an integrated circuit.

[0028] The receiving unit 21 receives first compressed video information including a video signal compressed by the video transmitting device 10 (specifically, the video signal compressing unit 12) and parameters used to compress the video signal. The receiving unit 21 is an example of a second receiving unit. The receiving unit 21 receives the video signal compressed by the video transmitting device 10 via the existing transmitting device 30 and the existing receiving device 40.

[0029] The compressed video information processing section 22 processes the first compressed video information. Details of the operation of the compressed video information processing section 22 will be explained later with reference to FIG.

[0030] The video signal decompression unit 23 decompresses the video signal compressed by the video transmission device 10 (specifically, the video signal compression unit 12) into a video signal that exceeds the bandwidth of the video transmission path used by the existing receiving device 40 using the first compressed video information. The video signal decompression unit 23 is an example of a second video signal decompression unit. For example, the bandwidth of the video transmission path used by the existing receiving device 40 is the bandwidth of 4K video, and the video signal that exceeds the bandwidth of the video transmission path used by the existing receiving device 40 is a video signal such as 8K. The video signal decompression unit 23 performs, for example, DSC decoding. Details of the operation of the video signal decompression unit 23 will be described later with reference to FIG. 3.

[0031] The transmitting unit 24 transmits the decompressed video signal (uncompressed video) to, for example, a buffer.

[0032] Next, the operation of the video transmission device 10 will be described in detail with reference to FIG.

[0033] FIG. 2 is a flowchart showing an example of the operation of the video transmitting device 10 according to the first embodiment.

[0034] First, the receiving unit 11 receives a video signal, and the video signal compressing unit 12 determines whether the video signal received by the receiving unit 11 is equal to or smaller than the bandwidth of the video transmission path (also referred to as the existing transmission path) used by the existing transmitting device 30 and the existing receiving device 40 (step S11). If the video signal compressing unit 12 determines that the video signal received by the receiving unit 11 is equal to or smaller than the bandwidth of the existing transmission path (Yes in step S11), the video signal is not compressed, and the transmitting unit 14 transmits the video signal received by the receiving unit 11 (step S16). This is because if the received video signal is already equal to or smaller than the bandwidth of the existing transmission path, the video signal can be transmitted as is without compression.

[0035] If the video signal compressor 12 determines that the video signal received by the receiver 11 exceeds the bandwidth of the existing transmission path (No in step S11), it determines whether compressing the video signal will make the bandwidth of the video signal equal to or less than the bandwidth of the existing transmission path (step S12). If the video signal compressor 12 determines that the bandwidth of the video signal will not be equal to or less than the bandwidth of the existing transmission path (No in step S12), it does not compress the video signal, stops processing, and issues an error notification (step S17). In this way, if the video signal received by the receiver 11 does not become equal to or less than the bandwidth of the existing transmission path even after compression, it is possible to issue an error notification, for example, without compressing the video signal.

[0036] If the video signal compressor 12 determines that the bandwidth of the video signal received by the receiver 11 is equal to or less than the bandwidth of the existing transmission path (Yes in step S12), the compressed video information generator 13 determines a PPS (Picture Parameter Set) to be used for compressing the video signal (e.g., DSC encoding) and a format (size) after compression, thereby generating first compressed video information (step S13). The PPS is an example of a parameter used for compressing the video signal, and is included in the first compressed video information.

[0037] The compressed video information generator 13 sets a Vender Specific EM (Extended Metadata) Packet (step S14). Specifically, the compressed video information generator 13 generates a Vender Specific EM Packet that stores information about the video signal received by the receiver 11 and the first compressed video information. The information about the video signal received by the receiver 11 includes Hfront, Hsync, Hback, Hactive, etc.

[0038] Then, the video signal compression unit 12 starts DSC encoding by compressing the video signal received by the receiving unit 11 using the first compressed video information (step S15), and the transmitting unit 14 transmits the compressed video signal and the first compressed video information (specifically, a Vender Specific EM Packet including the PPS used for DSC encoding and information about the video signal before compression) to the existing transmitting device 30 (step S16).

[0039] Next, the operation of the video receiving device 20 will be described in detail with reference to FIG.

[0040] FIG. 3 is a flowchart showing an example of the operation of the video receiving device 20 according to the first embodiment.

[0041] First, the receiving unit 21 receives a video signal from the existing receiving device 40 (step S21). At this time, the compressed video information processing unit 22 determines whether a Vender Specific EM Packet has been received (step S22). If the compressed video information processing unit 22 determines that a Vender Specific EM Packet has not been received (No in step S22), the video signal received by the receiving unit 21 is a video signal that has not been compressed by the video transmitting device 10, and therefore the transmitting unit 24 transmits the video signal received by the receiving unit 21 as is without decompressing it (step S26).

[0042] If compressed video information processing unit 22 determines that a Vender Specific EM Packet is being received (Yes in step S22), it determines that the video signal received by receiving unit 21 is a video signal compressed by video transmission device 10 (specifically, video signal compression unit 12), and sets the format after decompression based on the original video information included in the Vender Specific EM Packet (i.e., information on the video signal received by receiving unit 11) (step S23). For example, compressed video information processing unit 22 sets the format after decompression based on information such as Hfront, Hsync, Hback, and Hactive.

[0043] Furthermore, the compressed video information processing unit 22 sets the PPS included in the Vender Specific EM Packet in the video signal decompression unit 23, which is a DSC decoder (step S24), and the video signal decompression unit 23 starts DSC decoding using the PPS (step S25).

[0044] Then, the transmitting unit 24 transmits the expanded video signal (step S26).

[0045] As described above, the video transmitting device 10 can compress a video signal that exceeds the bandwidth of the video transmission path used by the existing transmitting device 30 in a stage preceding the existing transmitting device 30 that does not have a compression function so that the video signal is equal to or smaller than the bandwidth. Furthermore, the compressed video signal can be expanded to the original video signal by using the first compressed video information on the receiving side. Therefore, by connecting the video transmitting device 10 in a stage preceding the existing transmitting device 30, a video signal that exceeds the bandwidth of the video transmission path used by the existing transmitting / receiving device can be transmitted without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0046] Furthermore, the video receiving device 20 can compress a video signal that exceeds the bandwidth of the video transmission path used by the existing receiving device 40 that does not have a compression function so that the compressed video signal is equal to or smaller than the bandwidth, and the compressed video signal can be decompressed at a stage subsequent to the existing receiving device 40. Furthermore, the compressed video signal can be decompressed to the original video signal by using the first compressed video information transmitted from the transmitting side. Therefore, by connecting the video receiving device 20 at a stage subsequent to the existing receiving device 40, a video signal that exceeds the bandwidth of the video transmission path used by the existing transmitting / receiving device can be transmitted without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0047] Second Embodiment Next, a video transmitting device, a video receiving device, and a video transmission system according to a second embodiment will be described.

[0048] Fig. 4 is a block diagram showing an example of a video transmission system 2 according to embodiment 2. In Fig. 4, an existing transmitting device 30 and an existing receiving device 40 are also shown in addition to the video transmission system 2.

[0049] Video transmission system 2 differs from video transmission system 1 according to embodiment 1 in that video transmission device 10a is provided instead of video transmission device 10. Video transmission device 10a also differs from video transmission device 10 according to embodiment 1 in that it further includes a compression control unit 15. Video reception device 20 is the same as that in embodiment 1, and other aspects are also basically the same as those in embodiment 1, so the following description will focus on the differences.

[0050] The compression control unit 15 controls the compression of the video signal by the video signal compression unit 12 so as to maintain the blanking period (e.g., horizontal blanking period) of the video signal before compression by the video signal compression unit 12. The operation of the compression control unit 15 will be described in detail with reference to FIG.

[0051] Fig. 5 is a diagram for explaining the operation of the compression control unit 15 according to embodiment 2. The left side of Fig. 5 shows frames of the video signal before compression, and the right side of Fig. 5 shows frames of the video signal after compression.

[0052] The horizontal blanking period of a video signal contains, for example, audio packets, and if the horizontal blanking period is also compressed, it becomes difficult to ensure the bandwidth for the audio packets. Therefore, as shown in Figure 5, the compression control unit 15 determines the format of the compressed video signal so that the blanking period of the video signal before compression is maintained. This makes it possible to ensure the bandwidth for packets other than video contained in the compressed video signal. For example, it is possible to ensure the bandwidth for audio packets contained in the horizontal blanking period.

[0053] Third Embodiment Next, a video transmitting device, a video receiving device, and a video transmission system according to a third embodiment will be described.

[0054] Fig. 6 is a block diagram showing an example of a video transmission system 3 according to embodiment 3. In Fig. 6, an existing transmitting device 30 and an existing receiving device 40 are also shown in addition to the video transmission system 3.

[0055] Video transmission system 3 differs from video transmission system 2 according to embodiment 2 in that video transmission device 10b is provided instead of video transmission device 10a, and video reception device 20b is provided instead of video reception device 20. Video transmission device 10b also differs from video transmission device 10a according to embodiment 2 in that it further includes a video signal decompression unit 16, and video reception device 20b also differs from video reception device 20 according to embodiment 2 in that it further includes a video signal compression unit 25. Since other points are basically the same as those in embodiment 2, the following description will mainly focus on the differences.

[0056] In the third embodiment, the receiving unit 11 receives a compressed video signal (compressed video 1) that is a video signal compressed by an external device, and second compressed video information that includes parameters used to compress the compressed video 1. That is, in the third embodiment, the receiving unit 11 receives compressed video 1 that has already been compressed. For example, the compressed video 1 is accompanied by a CVTEM (Compressed Video Transport Extended Metadata) packet as the second compressed video information. The CVTEM packet includes parameters (PPS) used to compress the compressed video 1 and video information (Hfront, Hsync, Hback, Hactive, etc.) of the video signal before compression of the compressed video 1.

[0057] The video signal decompression unit 16 decompresses the compressed video 1 received by the receiving unit 11 using the second compressed video information. The video signal decompression unit 16 is an example of a first video signal decompression unit. In the third embodiment, the compressed video 1 is once decompressed in the video transmitting device 10b. The video signal decompression unit 16 performs, for example, DSC decoding. Details of the operation of the video signal decompression unit 16 will be described later with reference to FIG. 7.

[0058] Although the video transmission device 10b includes the compression control unit 15, it does not necessarily have to include it.

[0059] In embodiment 3, the video signal compression unit 12 compresses the video signal expanded by the video signal expansion unit 16, and the transmission unit 14 transmits the video signal (compressed video 2), the first compressed video information, and the second compressed video information that have been re-compressed by the video signal compression unit 12 after expansion to the existing transmission device 30.

[0060] The video signal compressor 25 of the video receiving device 20b re-compresses the video signal decompressed by the video signal decompressor 23. The video signal compressor 25 is an example of a second video signal compressor. Details of the operation of the video signal compressor 25 will be described later with reference to FIG. 8.

[0061] Next, the operation of the video transmission device 10b will be described in detail with reference to FIG.

[0062] FIG. 7 is a flowchart showing an example of the operation of the video transmission device 10b according to the third embodiment.

[0063] First, the video signal compressor 12 determines whether the video signal (compressed video 1) received by the receiver 11 is equal to or smaller than the bandwidth of the existing transmission path (step S111), and if it is determined that the compressed video 1 is equal to or smaller than the bandwidth of the existing transmission path (Yes in step S111), the transmitter 14 transmits the compressed video 1 received by the receiver 11 (step S119). This is because if the compressed video 1 received by the receiver 11 is already equal to or smaller than the bandwidth of the existing transmission path, the compressed video 1 can be transmitted as is.

[0064] If the compressed video 1 received by the receiving unit 11 is a video signal that exceeds the bandwidth of the existing transmission path (No in step S111), the video signal compressing unit 12 determines whether the bandwidth of the video signal will be equal to or less than the bandwidth of the existing transmission path by further compressing the compressed video 1 (specifically, by expanding it once and then compressing it again) (step S112).If the video signal compressing unit 12 determines that the bandwidth of the compressed video 1 is not equal to or less than the bandwidth of the existing transmission path (No in step S112), it stops processing and issues an error notification (step S120).

[0065] If the video signal compressor 12 determines that the bandwidth of the compressed video 1 is equal to or less than the bandwidth of the existing transmission path (Yes in step S112), the video signal decompressor 16 determines the format after decompression based on the original information of the compressed video 1 contained in the CVTEM packet (information on the video signal before compression of the compressed video 1: Hfront, Hsync, Hback, Hactive, etc.) (step S113). The video signal decompressor 16, which is a DSC decoder, also sets the PPS used to compress the compressed video 1 contained in the CVTEM packet to the video signal decompressor 16 (step S114). The video signal decompressor 16 then uses the PPS and starts DSC decoding to obtain the determined format after decompression (step S115).

[0066] The compressed video information generation unit 13 generates the first compressed video information by determining the PPS to be used for compressing the expanded video signal (e.g., DSC encoding) and the format of the compressed video signal (compressed video 2) (step S116).

[0067] The compressed video information generator 13 sets a Vender Specific EM Packet (step S117). Specifically, the compressed video information generator 13 generates a Vender Specific EM Packet that stores information about the compressed video 1 received by the receiver 11 and the first compressed video information. The information about the compressed video 1 received by the receiver 11 includes Hfront, Hsync, Hback, Hactive, and the like of the compressed video 1.

[0068] Then, the video signal compression unit 12 compresses (DSC encodes) the video signal expanded by the video signal expansion unit 16 using the first compressed video information (step S118), and the transmission unit 14 transmits the compressed video signal (compressed video 2), the first compressed video information (specifically, a Vender Specific EM Packet including the PPS used for DSC encoding and information about compressed video 1), and the second compressed video information (specifically, a CVTEM Packet including the PPS used to compress compressed video 1 and information about the video signal of compressed video 1 before compression) to the existing transmission device 30 (step S119).

[0069] Next, the operation of the video receiving device 20b will be described in detail with reference to FIG.

[0070] FIG. 8 is a flowchart showing an example of the operation of the video receiving device 20b according to the third embodiment.

[0071] First, the receiving unit 21 receives a video signal from the existing receiving device 40 (step S211). At this time, the compressed video information processing unit 22 determines whether a Vender Specific EM Packet has been received (step S212). If the compressed video information processing unit 22 determines that a Vender Specific EM Packet has not been received (No in step S212), the video signal received by the receiving unit 21 is a video signal that has not been compressed by the video transmitting device 10b, and therefore the transmitting unit 24 transmits the video signal received by the receiving unit 21 as is without decompressing it (step S221).

[0072] If the compressed video information processing unit 22 determines that a Vender Specific EM packet has been received (Yes in step S212), it determines whether a CVTEM packet has been received (step S213).If the compressed video information processing unit 22 determines that a CVTEM packet has not been received (No in step S213), the same processes as in the first embodiment from step S23 to step S25 are performed, and the transmitting unit 24 transmits the decompressed video signal (step S221).

[0073] When it is determined that a CVTEM packet is being received (Yes in step S213), the compressed video information processing unit 22 sets the format after decompression from the original information of the compressed video 1 included in the CVTEM packet (i.e., information on the video signal before compression of the compressed video 1 received by the receiving unit 11) (step S214). For example, the compressed video information processing unit 22 sets the format after decompression from information such as Hfront, Hsync, Hback, and Hactive of the video signal before compression of the compressed video 1.

[0074] Furthermore, the compressed video information processing unit 22 sets the PPS used to compress the compressed video 2 contained in the Vender Specific EM Packet in the video signal decompression unit 23, which is a DSC decoder (step S215), and the video signal decompression unit 23 starts DSC decoding using the PPS (step S216).

[0075] The compressed video information processing unit 22 sets the format after compression from the information of the compressed video 1 included in the Vender Specific EM Packet (such as Hfront, Hsync, Hback, and Hactive of the compressed video 1) (step S217). The compressed video information processing unit 22 also sets the PPS used for compressing the compressed video 1 included in the CVTEM Packet to the video signal compression unit 25, which is a DSC encoder (step S218).

[0076] The video signal compressor 25 starts DSC encoding by compressing the video signal decompressed by the video signal decompressor 23 into the set format (i.e., the format of compressed video 1) using the set PPS (i.e., the PPS used to compress compressed video 1) (step S219). This restores the compressed video 1 received by the receiver 11 of the video transmitter 10b. Furthermore, since the CVTEM packet is information necessary for decompressing compressed video 1, the transmitter 24 sets up the transfer of the CVTEM packet (step S220).

[0077] Then, the transmitting unit 24 transmits the compressed video 1 and the CVTEM packet (step S221).

[0078] As described above, when a compressed video signal that exceeds the bandwidth of the video transmission path used by the existing transmitting device 30 is received, it can be decompressed once and then recompressed so that it is equal to or less than the bandwidth. Furthermore, the decompressed and recompressed video signal can be decompressed on the receiving side using the first compressed video information, and then further compressed to the original compressed video signal using the second compressed video information. Therefore, a compressed video signal that exceeds the bandwidth of the video transmission path used by the existing transmitting / receiving device can be transmitted without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0079] (Fourth embodiment) Next, a video transmitting device according to a fourth embodiment will be described.

[0080] FIG. 9 is a block diagram showing an example of a video transmission device 10c according to the fourth embodiment.

[0081] Video transmitting device 10c is an integrated circuit, and has both the functions of video transmitting device 10 and the functions of video receiving device 20. That is, video transmitting device 10c includes receiving unit 11, video signal compressing unit 12, compressed video information generating unit 13, and transmitting unit 14, as well as receiving unit 21, compressed video information processing unit 22, video signal expanding unit 23, and transmitting unit 24.

[0082] This allows the functions of a video transmitting device 10 connected in front of an existing transmitting device 30 that does not have a compression function and the functions of a video receiving device 20 connected in back of an existing receiving device 40 that does not have an expansion function to be combined into a single integrated circuit, which can be used as both a video transmitting device 10 and a video receiving device 20.

[0083] The video transmission device 10c may include a compression control unit 15. The video transmission device 10c may also include a video signal decompression unit 16 and a video signal compression unit 25.

[0084] (Other Embodiments) As described above, the embodiments have been described as examples of the technology according to the present disclosure. However, the technology according to the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. For example, the following modifications are also included in one embodiment of the present disclosure.

[0085] For example, the present disclosure can be realized not only as a video transmission device, but also as a video transmission method including steps (processing) performed by components that make up the video transmission device.

[0086] The video transmission method is a video transmission method executed by a video transmission device, which can be connected in front of a transmission device that does not have a compression function for input video, and as shown in Figure 2, the video transmission method includes a first receiving step (step S11) of receiving a video signal, a first video signal compression step (step S15) of compressing the video signal if the video signal received in the first receiving step is a video signal that exceeds the bandwidth of the video transmission path used by the transmission device, a compressed video information generation step (step S13) of generating first compressed video information indicating parameters used to compress the video signal in the first video signal compression step, and a transmission step (step S16) of transmitting the video signal compressed in the first video signal compression step and the first compressed video information to the transmission device.

[0087] For example, the present disclosure can be realized not only as a video receiving device, but also as a video receiving method including steps (processing) performed by components that make up the video receiving device.

[0088] The video receiving method is a video receiving method executed by a video receiving device, which is connectable to a downstream stage of a receiving device that does not have an expansion function for input compressed video, and the video receiving method includes, as shown in Figure 3, a second receiving step (step S21) of receiving a video signal compressed by a video transmitting device connected to a upstream stage of a transmitting device that does not have a compression function for input video and first compressed video information indicating parameters used to compress the video signal, a compressed video information processing step (step S24) of processing the first compressed video information, and a second video signal expansion step (step S25) of using the first compressed video information to expand the video signal compressed by the video transmitting device into a video signal that exceeds the bandwidth of the video transmission path used by the receiving device.

[0089] For example, the present disclosure can be realized as a program for causing a computer (processor) to execute steps included in the video transmission method and the video reception method. Furthermore, the present disclosure can be realized as a non-transitory computer-readable recording medium, such as a CD-ROM, on which the program is recorded.

[0090] For example, when the present disclosure is realized as a program (software), each step is performed by running the program using hardware resources such as a computer's CPU, memory, input / output circuits, etc. In other words, each step is performed by the CPU acquiring data from memory or input / output circuits, etc., performing calculations, and outputting the calculation results to memory or input / output circuits, etc.

[0091] In the above-described embodiments, each component included in the video transmitting device and the video receiving device may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0092] Some or all of the functions of the video transmitting device and video receiving device according to the above embodiments are typically realized as an LSI, which is an integrated circuit. These may be individually integrated into single chips, or may be integrated into a single chip that includes some or all of the functions. Furthermore, the integrated circuit is not limited to an LSI, and may be realized using a dedicated circuit or a general-purpose processor. It is also possible to use an FPGA (Field Programmable Gate Array), which can be programmed after LSI manufacturing, or a reconfigurable processor, which allows the connections and settings of circuit cells within the LSI to be reconfigured.

[0093] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, that technology may naturally be used to integrate the components included in the video transmitting device and video receiving device into integrated circuits.

[0094] In addition, this disclosure also includes forms obtained by making various modifications to the embodiments that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions in each embodiment within the scope that does not deviate from the intent of this disclosure.

[0095] (Additional Notes) The above description of the embodiments discloses the following techniques.

[0096] (Technology 1) A video transmission device that can be connected to a preceding stage of a transmission device that does not have a compression function for input video, and that includes: a first receiving unit that receives a video signal; a first video signal compression unit that compresses the video signal if the video signal received by the first receiving unit is a video signal that exceeds the bandwidth of a video transmission path used by the transmission device; a compressed video information generation unit that generates first compressed video information including parameters used to compress the video signal by the first video signal compression unit; and a transmission unit that transmits the video signal compressed by the first video signal compression unit and the first compressed video information to the transmission device.

[0097] According to this, in a stage preceding an existing transmitting device that does not have a compression function, a video signal that exceeds the bandwidth of the video transmission path used by the existing transmitting device can be compressed to be equal to or less than that bandwidth. Furthermore, the compressed video signal can be expanded to the original video signal by using the first compressed video information on the receiving side. Therefore, by connecting the video transmitting device of the present disclosure in a stage preceding an existing transmitting device, a video signal that exceeds the bandwidth of the video transmission path used by the existing transmitting / receiving device can be transmitted without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0098] (Technology 2) The video transmission device described in Technology 1, wherein the first video signal compression unit determines whether the video signal received by the first receiving unit is a video signal that is equal to or smaller than the bandwidth of the video transmission path, and if it determines that the video signal received by the first receiving unit is a video signal that is equal to or smaller than the bandwidth of the video transmission path, does not compress the video signal.

[0099] According to this, if the received video signal is already equal to or smaller than the bandwidth of the video transmission path used by the existing transmitting device, the video signal can be transmitted as is without being compressed.

[0100] (Technology 3) In the video transmission device described in Technology 2, when the first video signal compression unit determines that the video signal received by the first receiving unit is a video signal that exceeds the bandwidth of the video transmission path, it determines whether compressing the video signal will make the bandwidth of the video signal equal to or less than the bandwidth of the video transmission path, and when it determines that the bandwidth of the video signal will not be equal to or less than the bandwidth of the video transmission path, it does not compress the video signal.

[0101] According to this, if the received video signal is not compressed to a bandwidth equal to or less than the bandwidth of the video transmission path used by the existing transmitting device, it is possible to perform, for example, an error notification without compressing the signal.

[0102] (Technology 4) The video transmission device according to any one of Technologies 1 to 3, further comprising a compression control unit that controls the compression of the video signal by the first video signal compression unit so as to maintain a blanking period of the video signal before compression by the first video signal compression unit.

[0103] (Technology 5) A video transmission device described in Technology 4, wherein the compression control unit controls the compression of the video signal by the first video signal compression unit so as to maintain the horizontal blanking period of the video signal before compression by the first video signal compression unit.

[0104] This makes it possible to ensure a bandwidth for packets other than video packets included in the compressed video signal, for example, a bandwidth for audio packets included in the horizontal blanking interval.

[0105] (Technology 6) A video transmission device according to any one of Technologies 1 to 5, further comprising a first video signal decompression unit, wherein the first receiving unit receives a compressed video signal, which is a video signal compressed by an external device, and second compressed video information including parameters used to compress the compressed video signal, the first video signal decompression unit decompresses the compressed video signal received by the first receiving unit using the second compressed video information, the first video signal compression unit compresses the decompressed video signal, and the transmission unit transmits the video signal compressed by the first video signal compression unit, the first compressed video information, and the second compressed video information to the transmission device.

[0106] According to this, when a compressed video signal that exceeds the bandwidth of the video transmission path used by an existing transmitting device is received, it can be decompressed once and then recompressed so that it is equal to or less than the bandwidth. Furthermore, the decompressed and recompressed video signal can be decompressed on the receiving side using the first compressed video information, and then further compressed to the original compressed video signal using the second compressed video information. Therefore, a compressed video signal that exceeds the bandwidth of the video transmission path used by an existing transmitting / receiving device can be transmitted without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0107] (Technology 7) The video transmission device is an integrated circuit, and can be connected to a subsequent stage of a receiving device that does not have an expansion function. The video transmission device is equipped with: a second receiving unit that receives the video signal compressed by the first video signal compression unit and the first compressed video information from the receiving device; a compressed video information processing unit that processes the first compressed video information; and a second video signal expansion unit that expands the video signal compressed by the first video signal compression unit into a video signal that exceeds the bandwidth of the video transmission path using the first compressed video information.

[0108] This allows the functions of a video transmitting device that is connected in front of an existing transmitting device that does not have a compression function and the functions of a video receiving device that is connected in back of an existing receiving device that does not have an expansion function to be combined into a single integrated circuit, allowing it to be used as both a video transmitting device and a video receiving device.

[0109] (Technology 8) A video receiving device, which can be connected downstream of a receiving device that does not have a decompression function for input compressed video, and which comprises: a second receiving unit that receives first compressed video information including a video signal compressed by a video transmitting device connected upstream of a transmitting device that does not have a compression function for input video and parameters used to compress the video signal; a compressed video information processing unit that processes the first compressed video information; and a second video signal decompression unit that uses the first compressed video information to decompress the video signal compressed by the video transmitting device into a video signal that exceeds the bandwidth of the video transmission path used by the receiving device.

[0110] According to this, a video signal that exceeds the bandwidth of a video transmission path used by an existing receiving device that does not have a compression function can be compressed to be equal to or smaller than that bandwidth and then decompressed at a stage downstream of the existing receiving device. Furthermore, the compressed video signal can be decompressed to the original video signal by using the first compressed video information transmitted from the transmitting side. Therefore, by connecting the video receiving device of the present disclosure at a stage downstream of an existing receiving device, a video signal that exceeds the bandwidth of a video transmission path used by the existing transmitting / receiving device can be transmitted without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0111] (Technology 9) The video receiving device according to Technology 8, further comprising a second video signal compression unit that compresses the video signal expanded by the second video signal expansion unit.

[0112] This allows a video signal that has been expanded and then re-compressed so that it is equal to or smaller than the bandwidth of the video transmission path used by an existing receiving device to be expanded, and then re-compressed to the original compressed video signal. Therefore, a compressed video signal that exceeds the bandwidth of the video transmission path used by an existing transmitting / receiving device can be transmitted without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0113] (Technology 10) A video transmission system comprising a video transmitting device according to any one of technologies 1 to 7 and a video receiving device according to technology 8 or 9.

[0114] This makes it possible to provide a video transmission system that can transmit video signals that exceed the bandwidth of the video transmission path used by existing transmitting / receiving devices without changing the configuration of the existing transmitting / receiving devices that do not have a compression function.

[0115] (Technology 11) A video transmission method executed by a video transmission device, the video transmission device being connectable to a preceding stage of a transmission device that does not have a compression function for input video, the video transmission method including: a first receiving step of receiving a video signal; a first video signal compression step of compressing the video signal if the video signal received in the first receiving step is a video signal that exceeds the bandwidth of a video transmission path used by the transmission device; a compressed video information generating step of generating first compressed video information indicating parameters used to compress the video signal in the first video signal compression step; and a transmitting step of transmitting the video signal compressed in the first video signal compression step and the first compressed video information to the transmission device.

[0116] This makes it possible to provide a video transmission method that can transmit a video signal that exceeds the bandwidth of the video transmission path used by an existing transmitting / receiving device without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0117] (Technology 12) A video receiving method executed by a video receiving device, the video receiving device being connectable to a downstream stage of a receiving device that does not have a decompression function for input compressed video, the video receiving method including: a second receiving step of receiving a video signal compressed by a video transmitting device connected to a upstream stage of the transmitting device that does not have a compression function for input video, and first compressed video information indicating parameters used to compress the video signal; a compressed video information processing step of processing the first compressed video information; and a second video signal decompression step of using the first compressed video information to decompress the video signal compressed by the video transmitting device into a video signal that exceeds the bandwidth of a video transmission path used by the receiving device.

[0118] This makes it possible to provide a video receiving method that can transmit a video signal that exceeds the bandwidth of the video transmission path used by an existing transmitting / receiving device without changing the configuration of the existing transmitting / receiving device that does not have a compression function.

[0119] The present disclosure can be applied to existing transmitting / receiving devices that comply with communication standards such as HDMI.

[0120] 1, 2, 3 Video transmission system 10, 10a, 10b, 10c Video transmitting device 11, 21 Receiving unit 12, 25 Video signal compressing unit 13 Compressed video information generating unit 14, 24 Transmitting unit 15 Compression control unit 16, 23 Video signal expanding unit 20, 20b Video receiving device 22 Compressed video information processing unit 30 Existing transmitting device 40 Existing receiving device

Claims

1. A video transmission device that can be connected in front of a transmission device that does not have a compression function for input video, and that comprises: a first receiving unit that receives a video signal; a first video signal compression unit that compresses the video signal if the video signal received by the first receiving unit is a video signal that exceeds the bandwidth of the video transmission path used by the transmission device; a compressed video information generation unit that generates first compressed video information including parameters used to compress the video signal by the first video signal compression unit; and a transmission unit that transmits the video signal compressed by the first video signal compression unit and the first compressed video information to the transmission device.

2. The video transmission device according to claim 1, wherein the first video signal compression unit determines whether the video signal received by the first receiving unit is a video signal that is equal to or smaller than the bandwidth of the video transmission path, and if it determines that the video signal received by the first receiving unit is a video signal that is equal to or smaller than the bandwidth of the video transmission path, does not compress the video signal.

3. The video transmission device according to claim 2, wherein, when the first video signal compression unit determines that the video signal received by the first receiving unit is a video signal that exceeds the bandwidth of the video transmission path, it determines whether compressing the video signal will make the bandwidth of the video signal equal to or less than the bandwidth of the video transmission path, and when it determines that the bandwidth of the video signal will not be equal to or less than the bandwidth of the video transmission path, it does not compress the video signal.

4. A video transmission device according to any one of claims 1 to 3, further comprising a compression control unit that controls the compression of the video signal by the first video signal compression unit so as to maintain the blanking period of the video signal before compression by the first video signal compression unit.

5. The video transmission device according to claim 4, wherein the compression control section controls the compression of the video signal by the first video signal compression section so as to maintain the horizontal blanking period of the video signal before compression by the first video signal compression section.

6. A video transmission device according to any one of claims 1 to 5, further comprising a first video signal decompression unit, wherein the first receiving unit receives a compressed video signal that is a video signal compressed by an external device and second compressed video information including parameters used to compress the compressed video signal, the first video signal decompression unit decompresses the compressed video signal received by the first receiving unit using the second compressed video information, the first video signal compression unit compresses the decompressed video signal, and the transmission unit transmits the video signal compressed by the first video signal compression unit, the first compressed video information, and the second compressed video information to the transmission device.

7. The video transmission device according to any one of claims 1 to 6, wherein the video transmission device is an integrated circuit, connectable to a subsequent stage of a receiving device that does not have an expansion function, and comprises: a second receiving unit that receives the video signal compressed by the first video signal compression unit and the first compressed video information from the receiving device; a compressed video information processing unit that processes the first compressed video information; and a second video signal expansion unit that expands the video signal compressed by the first video signal compression unit into a video signal that exceeds the bandwidth of the video transmission path using the first compressed video information.

8. A video receiving device that can be connected downstream of a receiving device that does not have a decompression function for input compressed video, and that comprises: a second receiving unit that receives first compressed video information including a video signal compressed by a video transmitting device connected upstream of a transmitting device that does not have a compression function for input video and parameters used to compress the video signal; a compressed video information processing unit that processes the first compressed video information; and a second video signal decompression unit that uses the first compressed video information to decompress the video signal compressed by the video transmitting device into a video signal that exceeds the bandwidth of the video transmission path used by the receiving device.

9. The video receiving device according to claim 8, further comprising a second video signal compression section that compresses the video signal expanded by said second video signal expansion section.

10. A video transmission system comprising a video transmitting device according to any one of claims 1 to 7 and a video receiving device according to claim 8 or 9.

11. A video transmission method executed by a video transmission device, wherein the video transmission device is connectable to a preceding stage of a transmission device that does not have a compression function for input video, the video transmission method comprising: a first receiving step of receiving a video signal; a first video signal compression step of compressing the video signal if the video signal received in the first receiving step is a video signal that exceeds the bandwidth of the video transmission path used by the transmission device; a compressed video information generation step of generating first compressed video information indicating parameters used to compress the video signal in the first video signal compression step; and a transmission step of transmitting the video signal compressed in the first video signal compression step and the first compressed video information to the transmission device.

12. A video receiving method executed by a video receiving device, wherein the video receiving device is connectable to a downstream stage of a receiving device that does not have a decompression function for input compressed video, the video receiving method comprising: a second receiving step of receiving a video signal compressed by a video transmitting device connected to a upstream stage of the transmitting device that does not have a compression function for input video, and first compressed video information indicating parameters used to compress the video signal; a compressed video information processing step of processing the first compressed video information; and a second video signal decompression step of using the first compressed video information to decompress the video signal compressed by the video transmitting device into a video signal that exceeds the bandwidth of the video transmission path used by the receiving device.

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