JP7065165B2 - Video transmitter - Google Patents

Description

The present invention is a method for transmitting a digital video signal and, for example, for receiving a digital broadcast signal.
Related to video processing devices such as STBs (Set top boxes) and television display devices.

With the spread of HD (High Definition) broadcasting by terrestrial digital broadcasting and the release of the Blu-ray (registered trademark) recorder that can record HD broadcasting, high-definition HD video can be recorded without deterioration.
There is an increasing need for a digital video interface that can transmit to V. As an interface for uncompressed video signal transmission, DVI (Digital Visual I) formulated by DDWG
HDMI (High Definition Multimedia) licensed by nterface), HDMI, and LLC
Interface (registered trademark). Further, as an interface for transmitting a video signal compressed by MPEG or the like, there are IEEE1394, LAN and the like. As a conventional technique for applying an interface for uncompressed video signal transmission to a television device, for example, Non-Patent Document 1 is described. This discloses that the format information of the video is packetized and multiplex transmitted to the uncompressed video signal which is not packetized. In HDMI, voice data is also transmitted in packets. As a conventional technique for applying a compressed video signal transmission interface to a television device, for example, Non-Patent Document 2 is described. As an example of the copyright protection technology used for these, HDCP (High-bandwidth Digital Conte) is used for uncompressed video.
nt Protection System), but for compressed video, DTCP (Digital Transmission Conte)
nt Protection).

Further, for example, Patent Document 1 describes an SDDI (Serial Digital Data Interface) method in which an uncompressed video signal and a compressed video signal are packetized and serially transmitted at the same time.

Japanese Unexamined Patent Publication No. 8-307455

Standard "CEA-861-B" US CEA 2002 Standard "CEA-775-B" US CEA 2004

It is expected that the types of signal sources will increase in the future, and TVs will increasingly be required to have input interfaces for uncompressed video signals and compressed video signals. However, when two types of interfaces with different connectors are provided in a television device (television receiver or the like), it is necessary to secure a connector space and prepare two types of cables. Patent Document 1
A method of simultaneously transmitting an uncompressed video signal and a compressed video signal is disclosed, which is a transmission method suitable for a broadcasting station. That is, in the transmission method described in Patent Document 1, since the uncompressed video signal is packetized, it is difficult to apply it to television equipment for general households.

Also, the types of copyright protection techniques used will increase depending on the type of interface handled. Even in such a case, it is necessary to appropriately deal with copyright protection technology.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique relating to an interface capable of transmitting both an uncompressed video signal and a compressed video signal. Another object of the present invention is to provide a technique capable of suitably protecting copyright.

In order to solve the above object, one aspect of the present invention is a video transmission device for transmitting a video signal to another device via a cable, and a first video transmission mode for transmitting an uncompressed video signal. It has a second video transmission mode of transmitting a multiplexed signal in which a compressed video signal and an uncompressed video signal are time-divided and multiplexed, and is connected to the cable. In the first video transmission mode, the uncompressed video signal Is transmitted to another device via the cable, and in the second video transmission mode, the transmission unit and the control unit for transmitting the multiplexed signal to the other device via the cable are provided. When information regarding the capability of the other device is transmitted from the device via the cable, and the control unit identifies that the other device can receive the multiplexed signal based on the information regarding the capability. Is transmitted in the second video transmission mode, and when it is identified that the other device cannot receive the multiplexed signal based on the information regarding the capability, is transmitted in the first video transmission mode. , Such as controlling the transmission unit .

Further, one aspect of the present invention is characterized in that the video transmission device includes a multiplexing processing unit that superimposes the compressed video signal on the return period of the uncompressed video signal and supplies it to the output unit .

According to the present invention, it is possible to provide an interface common to uncompressed video signals and compressed video signals. In addition, suitable copyright protection is possible.

The block diagram which shows the 1st Embodiment of the image processing apparatus which concerns on this invention. A block diagram showing a configuration example of a transmitting unit and a receiving unit of a video processing device. Diagram showing an example of the packet structure of compressed video A block diagram showing a second embodiment of the video processing apparatus according to the present invention. A block diagram showing a third embodiment of the video processing apparatus according to the present invention. Block diagram showing the flow of the video signal of the video processing device in the third embodiment The figure which shows one configuration example of an output circuit and an input circuit in 3rd Example A diagram showing a basic configuration example of an output circuit and an input circuit of a video processing device. The block diagram which shows the 4th Embodiment of the image processing apparatus which concerns on this invention. The figure which shows one configuration example of an output circuit and an input circuit in 4th Embodiment

Hereinafter, the best working liquid of the present invention will be described below with reference to the drawings. The present invention simultaneously transmits an uncompressed video signal and a compressed video signal through a common (same) interface. And such transmission is realized while maintaining interoperability with uncompressed digital interfaces such as DVI and HDMI which have begun to spread. In the embodiment described above, the video processing device includes, for example, an STB having a built-in digital tuner, a television display device, and the like (hereinafter referred to as “TV”). Of course, the following examples can be applied to devices other than these devices.

FIG. 1 is a block diagram of a first embodiment according to the present invention, and is an example of an image processing apparatus ST.
It includes a B (Set Top Box) 11, a TV 12 which is another example of a video processing device, and a mobile viewer 13 which allows video to be viewed on the go. An example of these operations will be described below.

The STB 11 receives an RF signal 101 supplied from a digital broadcast, a cable, or the like, and demodulates a compressed video transport stream (hereinafter abbreviated as TS) with a digital tuner 111. The demodulated TS is a program stream (hereinafter referred to as PS) by the TS / PS conversion unit 112.
(Abbreviated as) is extracted, and an uncompressed video signal is obtained by the decoding unit 113. This uncompressed video signal and OSD
The video composition unit 114 synthesizes the OSD screen generated by the unit 115. This uncompressed video signal is not packetized and is T from the transmission unit 117 via the video signal interface 103.
It is transmitted to the receiving unit 127 of V11. The uncompressed video signal received by the receiving unit 127 is sent to the display unit 129 via the video combining unit 124. The display unit 129 displays a real-time video screen based on this uncompressed video signal and provides it to the user. The control units 116 and 126 not only control the multiplexing and communication status of the transmission unit 117 and the reception unit 127, respectively, but also the TV.
The display capability (characteristics and specifications related to video display) of 12 is transmitted to STB11, and the video signal transmitted from STB11 is matched with the display characteristics of TV12. In addition, bidirectional communication control is also possible so that the STB11 and the TV12 can cooperate with each other by exchanging a remote control control code or the like.

On the other hand, the TS output of the digital tuner 111 and the OSD output of the OSD unit 115 are the transmission unit 11.
It is also sent to 7. The transmission unit 117 multiplexes the packet data of the TS and OSD into an uncompressed video signal to generate a multiplexed video signal, and transmits the multiplexed video signal to the reception unit 127 via the interface 103. The receiving unit 127 includes the uncompressed video signal, the TS, and the OS from the received multiplexed video signal.
Separate from D. The TS and OSD separated or extracted by the receiving unit 127 are stored in the storage unit 12.
Accumulate in 8. The storage unit 128 is composed of, for example, a hard disk. It may be configured by a semiconductor memory such as a flash memory. As a result, video recording based on TS is performed. The recorded TS is read out from the storage unit 128 according to the user's instruction, and is TS / PS.
The conversion unit 122 extracts PS, and the decoding unit 123 obtains an uncompressed video signal. At the same time, OSD data is also read from the storage unit 128 as needed, and the OSD unit 125 forms an uncompressed OSD video signal. This OSD video signal is video-composited with the uncompressed video signal output from the decoding unit 123 in the video compositing unit 124. The uncompressed video signal, which is a combination of the recorded video and the OSD, is displayed on the display unit 129 and is viewed in the time zone desired by the user (time-shifted viewing).
can do.

If the TV 12 is equipped with the digital tuner 121, the TS can be recorded by the storage unit 128 for time-shifted viewing by receiving a digital broadcast or the like as in the STB11. Further, the uncompressed video signal obtained through the TS / PS conversion unit 122 and the decoding unit 123, and ST.
It is also possible to combine the uncompressed video signal sent from B11 with the video synthesis unit 124 and display the two screens simultaneously on the display unit 129. The digital tuners 111 and 121 may receive different channels and synthesize two screens. Further, the video of the channel received by the terrestrial digital tuner and the video of the channel received by the cable TV tuner may be combined on two screens. S
If the TB 11 has a digital tuner 111 (that is, a digital tuner capable of receiving a channel that cannot be received by the digital tuner of the TV 12) different from the digital tuner built in the TV 12 with a digital tuner, real-time viewing of the channel that the TV 12 cannot receive is provided. There is also the effect of realizing time-shifted viewing. Further, even after the STB 11 is removed from the TV 12, there is an effect that the video received by the STB and remaining in the storage unit 128 can be viewed.

It is clear that the compressed video signal and the uncompressed video signal multiplexed by the transmission unit 117 may be different programs as long as the digital tuner 111 can simultaneously receive a plurality of channels. Further, the compressed video data multiplexed by the transmission unit 117 is not TS, but TS /
It may be PS after PS conversion. Compared to TS, PS has the advantage that the amount of data transmission is small.

The compressed video signal recorded in the storage unit 128 is further compressed by the code conversion unit 130 and code conversion such as a transmission format is performed, and then the interface unit 131 such as USB or IEEE 1394, the interface 104, and the interface unit 132. Through the storage unit 1
Can be transferred to 38. After transferring the video signal, the mobile viewer 14 is the interface 10.
It is separated from 4 and can be carried anywhere. Then, the mobile viewer 14 decodes the video stored in the storage unit 138 by the decoding unit 133 and displays it on the display unit 139 in response to the user's instruction. This allows the user to view the desired video at any location using the mobile viewer 14.

FIG. 2 is a block diagram showing a configuration example of the transmitting unit 117 and the receiving unit 127. An operation example thereof will be described below. Audio data 20 corresponding to the uncompressed video from the video compositing unit 114 (FIG. 1)
2. TS output 203 from digital tuner 111 (FIG. 1) and OSD unit 115 (FIG. 1).
) OSD data 204 is input to the packet generation units 211, 212 and 213 of the transmission unit 117, respectively. The packet generation units 211 to 213 form packets suitable for multiplexing with the uncompressed video signal based on the input signals, respectively. The buffer unit 214 receives the packets from the packet generation units 211 to 213, rearranges them according to the priority of packet transmission, and transmits them in order according to the return period of the uncompressed video signal. Buffer part 2
An error correction code is inserted in the ECC code unit 215 into the packets rearranged in 14. Then, the interleaving unit 216 is subjected to bit-wise interleaving processing to increase the resistance to burst errors, and is sent to the multiplex coding unit 217. The multiplexing unit 217 includes a multiplexing unit 401 for multiplexing the interleaved packet on the uncompressed video signal output 201 from the video compositing unit 114 (FIG. 1), and a copy control flag for the uncompressed video signal. It includes a copy flag adding unit 402 for imparting a signal, an encryption processing unit 403 for encrypting a video signal, and a transmission coding unit 404 for encoding for transmission. The output of the multiplexing code unit 217 is transmitted to the input circuit 228 of the receiving unit 127 as a multiplexed video signal 207 via the output circuit 218.

The multiplexed video signal received by the input circuit 228 is sent to the multiplex decoding unit 227. The multiplex decoding unit 227 includes a transmission decoding unit 411 that decodes the transmission coding, a decryption / decryption unit 412 that decrypts the video signal, a copy flag extraction unit 413 that extracts the copy flag, and an uncompressed video signal 291. And a separator 414 that separates other packet data. The packet data is interleaved by the deinterleaved circuit 226, restored to the original signal, error-corrected by the ECC decoding unit 225, and then transmitted to the buffer unit 224. Buffer part 2
24 temporarily holds the packet data and outputs the packet data to the packet decoding units 221 to 223, respectively. The packet decoding units 221 to 223 decode the packet data from the buffer unit 224 to obtain audio data 292, TS293, and OSD data 294 of the uncompressed video signal. These are the data sent from the receiving unit 127 to the accumulating unit 128 in FIG.

The capability transmission unit 229 transmits information regarding the display capability (display specification and / or display characteristic) of the TV to the capability identification unit 219 via the communication line 208. The ability identification unit 219 identifies the display ability of the TV 12 based on the information regarding the display ability and outputs the identification result 205. The identification result 205 is transmitted to the control unit 116 (FIG. 1). Then, the control unit 116 controls the elements related to the video processing or the video output in the STB 11 so as to send out the video format suitable for the connected TV 12, and after confirming the display capability on the TV 12 side, the control unit 116
The multiplexed video signal according to this embodiment is transmitted. With such a configuration, the multiplexed video signal is not transmitted to a configuration that does not have a configuration capable of inputting a multiplexed video signal (that is, a TV having a conventional interface), and only an uncompressed video signal is transmitted. Therefore, interoperability with a TV having a conventional interface is ensured. As a configuration for transmitting the capability on the TV12 side, for example, it is preferable to use the EDID system specified by VESA. In this embodiment, the information regarding the display capability of the TV includes, for example, the horizontal and vertical resolutions of the display unit 129, the color reproduction range, the gamma characteristics, and the like. Furthermore, in order to make effective use of this embodiment,
In addition to the above, as information on the display capability of the TV, for example, a video format indicating the display timing of the multiplexed video signal, a bit rate of the compressed video, a list of decodable coding methods, a storage capacity of the storage unit 128, and a free capacity. , It is good to add capabilities such as maximum recording speed and send.

In addition to the above, the capacity transmission unit 229 and the capacity identification unit 219 are also used for device authentication and capacity confirmation of encryption processing. For example, in DVI and HDMI, Digital Content Prot is used as this encryption process.
There is an HDCP licensed by ection, LLC. In the future, with the diversification of content, it may be necessary to manage multiple cryptographic processes by content or country. In such a case, in this embodiment, elements for device authentication and encryption processing are provided on the receiving side of the video signal, and which processing is appropriate by referring to the protocol for starting device authentication from the transmitting side. An automatic discrimination / selection circuit may be provided for discriminating and selecting. On the other hand, the sender determines the type of content, the country in which it is used, etc., and selects and switches the appropriate encryption process.
A selection circuit may be provided. For example, the region code recorded on the DVD disc may be read out, and the encryption process may be selected based on the region code. Further, in television broadcasting, the broadcasting station may be identified and encryption processing may be selected.

Cryptographic processing may need to be fixed due to national and business regulations. In such a case, if a dedicated video processing device is newly prepared, the development cost may increase. Therefore, the video processing device is provided with a plurality of encryption processing units capable of executing a plurality of types of encryption processing, and the type of encryption is determined.
A discrimination / selection circuit for selecting the encryption processing unit corresponding to the discrimination result may be provided. At this time, the discrimination / selection circuit may automatically discriminate the type of encryption and perform the selection operation. Further, a setting circuit may be provided so that the type of encryption processing can be set by the user. also,
By this setting circuit, one of a plurality of cryptographic processes may be set and fixed in advance at the time of shipment. In this case, the procedure for changing the setting of the encryption process (for example, STB11 or T) so that the user cannot change the setting of the encryption processing type by this setting circuit.
It is advisable to keep the command or password input for V12 secret from the user. When changing the encryption processing settings after shipping, make it possible to download the procedure related to the above setting changes from, for example, broadcasting and / or the Internet under specific conditions (for example, billing from the user). You may. In this way, the procedure for the concealed setting change is disclosed to the user under specific conditions, and the change of the encryption process by the user becomes effective. In implementing this example, such a service may be provided. Furthermore, the procedure related to the above setting change may be stored in a storage medium such as a DVD and distributed to the user as a setting change DVD.

Furthermore, when various types of encryption processing are used, the image quality can be changed by limiting the resolution, the bit rate of the compressed video signal, and the like depending on the grade of the encryption processing.

The communication circuits 220 and 230 perform bidirectional communication via the communication path 209, and the control unit 1 in FIG. 1
Control information is transmitted and received between 16 and 126. For example, as the bidirectional communication in this embodiment, a bidirectional communication configuration such as CEC specified by HDMI can be applied.
Further, when an error that cannot be corrected occurs in the ECC decoding unit 225, the TV 12 is set to the main communication path 2.
A retransmission request may be transmitted to the STB through 09, and the STB 11 may retransmit the compressed video signal that has caused an error in response to the retransmission request. This enables recording without errors. By assigning an identification number or symbol such as a time stamp to the compressed video signal packet included in the compressed / uncompressed video signal multiplexing signal 207, the TV 12 sends the error packet number or symbol to STB11 together with a retransmission request. You may send it. This will result in
When a retransmission request occurs, STB11 can retransmit only the error packet by referring to the error packet number or symbol. Therefore, the STB 11 does not need to retransmit the error-free packet, so that the transfer efficiency is improved.

The packet transmission process in the buffer unit 214 described above, that is, the packet rearrangement process according to the priority order will be described below. There is a limit to the transmission capacity of packets that are multiplexed and transmitted to uncompressed video signals. The packet that should be sent with the highest priority is the audio of an uncompressed video signal that needs to be reproduced in real time in synchronization with the video. Therefore, the priority of the audio packet of this uncompressed video signal is set to the highest priority, and the arrangement thereof is determined with the highest priority. Compressed video packets and OSD packets are placed in the remaining area. The priority of the compressed video packet and the OSD packet is arbitrarily determined, but if the OSD is related to (or highly related to) the uncompressed video signal, the priority of the OSD packet is set higher than that of the compressed video packet. You may. When there is a high need to use the compressed video in the TV 12, the priority of the compressed video packet may be higher than that of the OSD packet.

When sending the compressed video to the storage unit 128, it is necessary to arrange the packets so as not to exceed the maximum recording speed of the storage unit 128. Alternatively, the flow control may be performed by the communication path 209 to control the packet transmission amount. When the compressed video is reproduced on the TV 12 in almost real time, it is necessary to control the packet transmission amount according to the coding speed of the compressed video.

Depending on the format of the uncompressed video signal, the packet transmission capacity for multiplexing the compressed video signal may be insufficient. In this case, a format may be used in which the pixel clock of the uncompressed video signal is multiplied by n (n is 2 or more) or the return period of the uncompressed video signal is extended. By doing so, it is possible to improve the packet transmission capacity of the compressed video signal.

FIG. 3 is a diagram showing an example of the packet structure of the compressed video. TS as shown in FIG.
Packets have a 4-byte header and 184-byte adaptation (or payload).
It is composed of a total of 188 bytes. On the other hand, T in the gap of the uncompressed video signal (for example, the return period)
In order to multiplex S, it is better that the packet size is small. FIG. 3 shows a case where a packet is composed of a 3-byte header and a 28-byte payload. TS packet 188
It is preferable to divide the bytes into the payloads of seven compressed video packets and transmit them.

An example of the header configuration will be described below. The first byte represents a packet type such as compressed video or audio. A total of 16 bits of the second byte and the third byte may be allocated to the order of the TS packets divided into 7 (3 bits), the TS packet number (11 bits), and the copy control flag (2 bits). The TS itself also contains a time stamp, and by diverting this, the 11 bits of the above TS packet number in the header may be omitted, but it is easier to use if it is described in the header part. This TS packet number is used as an identification number for identifying the packet, and the retransmission request packet is specified when the transmission error occurs as described above.

For example, when transmitting HD video at 20 Mbps, 106,000 TS packets of 188 bytes are transmitted per second. When a reproduction request is made to the transmitting side when a transmission error occurs, if the speed of the communication path 209 is slow (that is, the transfer rate is low) and 100 mS is required for transmitting error information, a TS that discriminates at least 10,000 TS packets is discriminated. Packet number is required. That is, 14 bits are required for the TS packet number, and 11 bits in the header portion are not sufficient. On the other hand, as shown in the figure, the payload of the 7th compressed video packet has 8 bytes free. Therefore, one byte of this free area may be used to describe the missing TS packet number. Of course, 2 to 3 bytes may be used if necessary. Further, the copy flag may be described in this free area instead of the header. If there is room in the area, the number of copies, the storage time limit for permitting time-shifted viewing after transmission, and / or CGMS-D can also be described. If more information is required, eight compressed video packets instead of seven may be applied to one TS packet.

FIG. 4 is a block diagram showing another embodiment of the present invention. In this embodiment, in the system configuration shown in FIG. 1, the transmitting unit 117 and the receiving unit 127 are changed to the transmitting unit 230 and the receiving unit 250 of FIG. 4, respectively. In this embodiment, the transmitting unit 230 and the receiving unit 250 are connected to each other by an interface including three data lines 271, 272, 273 for transmitting a video signal and a clock line 274 for transmitting a clock signal. do. The three data lines are used, for example, for transmitting red, green, and blue uncompressed video signals. The clock line transmits a reference clock for receiving data. Further, the data line shall send 10 pieces of data during the clock period passing through the clock line. Multiple coding units 231 to 233 and 2
35, output circuits 241 to 244, input circuits 251 to 254, and multiple decoding units 261 to 264 are the multiple coding unit 217, output circuit 218, input circuit 228, and multiple decoding unit 2 of FIG. 2, respectively.
It corresponds to 27, and a detailed description thereof will be omitted. The explanation of the other blocks shown in FIG. 2 is omitted here.

The case where the switch 245 selects the clock supply unit 234 corresponds to the embodiment of FIG.
In this embodiment, when it is necessary to increase the speed of video data transmission, the switch 245 is set to the multiplex coding unit 2.
By switching to 35, the clock line is also used as the data line, and the video data transmission amount is multiplied by 4/3. In this case, the reference clock for reproducing the input data on the TV 12 side may be used by extracting the reference clock from the signal of each data line instead of the clock signal transmitted by the clock line. For this purpose, all or at least one of the received signals of each input circuit 251 to 254 may be guided to the PLL 256, and the clock component may be extracted from the input data. A bandpass filter or the like may be combined with a PLL or the like to extract the clock component. Of course, P
LL may be replaced with DLL.

By the way, there are various formats for video data, and there are many reference clocks. When the clock is extracted from the data line and used as the reference clock as described above, it is necessary to accurately detect the reference clock period, which requires a large amount of time. In this embodiment, the switch 245 selects the clock supply unit 235 in the initial state, and transmits the reference clock from the clock supply unit 235 to the reception unit 250 by the clock line 274. As a result, the reference clock cycle can be easily transmitted to the receiving unit 250. Therefore, according to this embodiment, there is an effect that the time for initial setting related to the cycle of the reference clock can be shortened.

Using the configuration for transmitting information regarding the display capability of the TV 12 to the STB 11 described in the form of FIG. 2, the transmission unit 230 determines whether or not the reception unit 250 has a mode in which the clock line is used as a data line. Can be told to. The time required for the default clock cycle extraction can be conveyed in the same manner. Further, by using the bidirectional communication path 209 shown in FIG. 2, it is possible to notify the transmitting unit 230 from the receiving unit 250 that the initial setting has been completed.

FIG. 5 is a block diagram showing another embodiment of the present invention. In this embodiment, in the system configuration shown in FIG. 1, the transmitting unit 117 and the receiving unit 127 are changed to the transmitting unit 240 and the receiving unit 260 of FIG. 4, respectively. The same components as those in the embodiment shown in FIG. 4 are numbered the same. In this embodiment, the PLL portion shown in FIG. 4 is also required as a component, but the description is omitted for the sake of simplification of the drawings. Then, in this embodiment, an input circuit 255, a multiple decoding unit 265, a multiplex coding unit 258, and an output circuit 257 are added to the embodiment shown in FIG.

In FIG. 5, when data is transmitted using the clock line, the STB 11 does not move to the TV 12 but the data is sent from the STB 11 to the TV 12.
On the contrary, it is characterized by having a function of transmitting data from the TV 12 to the STB 11. In the initial state, the output circuit 257 is in the OFF state, and data and a clock are transmitted from the transmitting unit 240 of the STB 11 to the receiving unit 260, as in the embodiment shown in FIG. After the clock extraction operation of each data is started, the data can be transmitted even on the clock line. At this timing, after turning off the output circuit 244, the operation of the output circuit 257 is started.
Data is sent back from the receiving unit 260 to the transmitting unit 240. At this time, if the clock period is set to the same clock period as the initial state, the clock extraction can be performed in the same way as other data lines even with this back-fed clock line. Of course, while the data is back-transmitted on the clock line, the video data is continuously transmitted from the transmitting unit 240 to the receiving unit 260 on the data line.

FIG. 6 shows an example of the flow of a video signal when the function of data transmission in the reverse direction is used in the system configuration shown in FIG. The TV 12 sends the compressed video signal recorded in the storage unit 128 to the STB 11 by data transmission in the reverse direction by this clock line, and ST.
The TS / PS conversion unit 112 and the decoding unit 113 of the B11 decode the uncompressed video signal. Then, it can be sent back to the TV 12 through the data line, and the video based on the decoded video signal can be displayed on the display unit 129. If it is necessary to display the OSD recorded in the storage unit, the OSD may be similarly sent to the OSD circuit of the STB 11 by a clock line, and the video synthesis unit 114 may synthesize the video with the uncompressed video signal and send it to the TV 12.

With this function, even a TV having no decoding unit can reproduce and display the video signal recorded in the storage unit for viewing. The same applies to a TV having a decoding unit when the decoding unit does not support the coding method used for the compressed video. Further, there is an advantage that the TV recording function and the time-shifted viewing function can be used even when high-compression broadcasting using a new coding method that did not exist at the time of TV release has started. In addition to coding, even when a compressed video that uses a copyright protection method that is not supported by the TV is recorded on the TV, the STB
However, if the method is compatible with the method, the recorded compressed video signal may be sent to the STB to perform copyright protection processing and decoding processing. Then, in the same manner as described above, by sending back the video signal to which the copyright protection processing and the decoding processing have been performed as an uncompressed video signal, it is possible to display the video based on the video signal.

Next, an example of the circuit configuration of the input circuits 254 and 255 and the output circuits 244 and 257 shown in FIG. 5 is shown in FIG. Prior to the description of FIG. 7, a basic configuration example of the input circuit and the output circuit is shown in FIG. 8, and the operation thereof will be described. The output circuit 31 includes an output control unit 311 and transistors 312, 31.
3. In the constant current source 314, the input circuit 32 includes a terminating resistor 336, 337, and a differential discriminator 338.

The output control unit 311 controls the ON / OFF operation of the transistors 312 and 313 (ON-OF).
It is switched so that it becomes a combination of F) or (OFF-ON). At (ON-OFF), the same current as the constant current source 314 flows through the signal line 321 and a voltage is generated across the terminating resistor 336.
Since no current flows through the signal line 322, the voltage across the terminating resistor 337 becomes 0. (OFF-
When (ON), no current flows through the signal line 321 so that the voltage across the terminating resistor 336 is 0 and the signal line 3
The same current as that of the constant current source 314 flows through 22, and a voltage is generated across the terminating resistor 337. This is so-called differential transmission. The potential difference of this terminating resistor is detected by the differential discrimination unit 338 to determine the logic level.

The configuration of FIG. 7 is a configuration in which the input circuit and the output circuit shown in FIG. 8 are connected in parallel using the configuration as it is. Since two output circuits connected in parallel cannot be operated at the same time,
The output control unit 331 (or 311) of the output circuit that is not in the operating state controls the transistors 312 and 313 (or the transistors 332 and 333) to be (OFF-OFF). Both input circuits may be in the operating state, or the terminating resistors 316 and 3 on the unused side.
17 (or 336, 337) may be separated. Further, the differential discrimination unit 318 (or 338)
) May be stopped to reduce power consumption.

FIG. 9 is a block diagram showing another embodiment of the present invention, in which two TVs 15 are used as video processing devices.
And 16 are used. That is, this embodiment is an example in which the STB 11 shown in FIG. 1 has a display unit and becomes a TV. Similar to the embodiment shown in FIG. 1, the video interface 10
A multiplexed video signal in which an uncompressed video signal and a compressed video signal are multiplexed is sent from the TV 15 to the TV 16 through 4, and the uncompressed video signal is displayed on the display unit 129 of the TV 16. On the other hand, the compressed video is recorded by the storage unit 128, reproduced at a time desired by the user, and displayed on the display unit 129.

FIG. 10 shows an example of the configuration of the transmission / reception units 157 and 167. In this example, both the data line 271 and the clock line 274 enable bidirectional transmission. The specific configuration of the input circuit and the output circuit may be the same as in FIG. 7. When transmitting data from the transmission / reception unit 157 to 167, the data is transmitted from the multiplex coding unit 231 through the output circuit 241 to the input circuit 251 and the multiplex decoding unit 26.
It is supplied to 1. On the other hand, the clock signal is supplied from the clock supply unit 235 to the input circuit 254 and the PLL 283 via the output circuit 244. On the contrary, when data is transmitted from the transmission / reception unit 167 to 157, the data is transmitted from the multiplex coding unit 282 to the input circuit 27 via the output circuit 281.
It is supplied to 1 and the multiple decoding unit 272. On the other hand, the clock signal is transmitted from the clock supply unit 284 to the input circuit 255 and the PLL 274 via the output circuit 257.

As described above, if the TV 15 or 16 has a function of transmitting a video signal in the reverse direction, the operation is as follows. That is, as shown by the broken line in FIG. 9, the compressed video recorded by the storage unit 128 of the TV 16 is sent to the TV 15, the TS / PS conversion unit 152 and the decoding unit 153 of the TV 15 form an uncompressed video signal, and the display unit 159. It can be displayed with. Of course, the TS of TV16
After the uncompressed video signal is formed by the / PS conversion unit 122 and the decoding unit 123, it is transmitted to the TV15.
It may be displayed on the display unit 159.

According to this embodiment, various resources such as a digital tuner, a storage unit, a decoding unit, and copyright protection can be exchanged between two TVs (video processing devices) connected to each other.

In the above examples, STB and TV are shown as video processing devices, but recorders and DVs have been shown.
Similar effects can be expected with a combination of a video signal source such as a D player or a monitor.

By utilizing the embodiment of the present invention described in detail above, it is possible to simultaneously transmit an unpacketized real-time uncompressed video signal and a packetized compressed video signal to one interface. That is, one interface can transmit a plurality of digital video signals according to different standards. In a video processing device such as a TV using this, the uncompressed video signal from a signal source such as STB is displayed in real time on the display unit of the TV, and the compressed video signal transmitted at the same time is a built-in HDD in the TV. It is possible to record in a storage device such as, etc. and watch it at another time. That is, it is possible to simultaneously display both the real-time video of a certain video content and the time-shifted video on one screen, and both real-time viewing and time-shifted viewing of the video content are possible.

Furthermore, by using the physical layer capable of high-speed transmission of the uncompressed video transmission interface for data transmission, when transmission of uncompressed video signals is unnecessary, transmission of a large number of compressed video signals and video transfer in a short time There is also an effect that makes it possible.

Further, according to the above embodiment, it is possible to appropriately cope with various copyright protection techniques, and there is also an effect that good viewing can be realized within fair use conditions.

The present invention is applied to a video signal transmission method for multiplexing and transmitting an uncompressed video signal and a compressed video signal with one interface. In particular, it is effective when transmitting and receiving video signals between video processing devices, for example, between a video signal source such as an STB and a video display device such as a TV.

11 ... STB, 12 ... TV, 14 ... Mobile viewer, 31 ... Output circuit, 32 ... Input circuit, 33-34 ... Input / output circuit, 101-102 ... RF signal, 103-104 ... Video signal interface, 111-121 ... Digital tuner, 112 to 122 ... TS / PS conversion unit, 113, 123, 133 ... Decoding unit, 114, 124 ... Video composition unit, 115, 125 ...
OSD unit, 116, 126 ... Control unit 117, 230, 240 ... Transmission unit 127, 250
260 ... Receiving unit, 128, 138 ... Storage unit, 129, 139 ... Display unit, 130 ... Code conversion unit, 131, 132 ... Interface unit, 211, 212, 213 ... Packet generation unit, 214, 224 ... Buffer, 215 ... ECC coding unit, 216 ... Interface unit, 21
7 ... Multiple coding unit, 218 ... Output circuit, 219 ... Capability identification unit, 220, 230 ... Communication circuit, 221 to 223 ... Packet decoding unit, 225 ... ECC decoding unit, 226 ... Deinterleaved unit, 227 ... Multiple decoding Unit, 228 ... Input circuit, 229 ... Capacity transmission unit, 231 to 234, 2
58, 282 ... Multiple coding section, 241 to 244, 257 ... Output circuit, 235, 284 ... Clock supply section, 251 to 255 ... Input circuit, 256, 274, 283 ... PLL section, 261
~ 265, 272 ... Multiple decoding unit, 311, 331 ... Output control unit, 312 to 313, 332
333 ... Transistor, 314, 334 ... Current source, 316 to 317, 337 to 336 ...
Termination resistor, 318, 338 ... Differential discrimination unit, 401 ... Multiplexing unit, 402 ... Copy flag addition unit, 403 ... Encryption processing unit, 404 ... Transmission coding unit 411 ... Transmission code decoding unit 412
... Cryptanalysis unit, 413 ... Copy flag extraction unit, 414 ... Separation unit

Claims (3)

A video transmission device that transmits video signals to other devices via a cable.
It has a first video transmission mode for transmitting an uncompressed video signal and a second video transmission mode for transmitting a time-division-multiplexed multiplexed signal of a compressed video signal and an uncompressed video signal.
It is connected to the cable, and in the first video transmission mode, the uncompressed video signal is transmitted to another device via the cable, and in the second video transmission mode, the multiplexed signal is transmitted via the cable. A transmitter that sends to other devices ,
With a control unit,
Information about the capabilities of the other device is transmitted from the other device via the cable.
The control unit
When the other device is identified as receivable based on the information regarding the capability, it is transmitted in the second video transmission mode.
If it is determined that the other device cannot receive the multiplexed signal based on the information regarding the capability, it is transmitted in the first video transmission mode.
To control the transmitter ,
A video transmission device characterized by this. In the video transmission device according to claim 1,
A multiplexing processing unit that superimposes the compressed video signal on the return period of the uncompressed video signal and supplies it to the output unit.
A video transmission device characterized by being provided with. In the video transmitting apparatus according to claim 2,
It also has an encryption processing unit.
The multiplexed video signal encrypted by the first encryption method in the encryption processing unit and the uncompressed video signal encrypted by the second encryption method in the encryption processing unit are multiplexed. Multiplexing in the encryption processing unit,
A video transmission device characterized by this.

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