JP2002112285A - Signal transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal transmission system where the hardware configuration of a transmitter side and a receiver side of a video signal can be simplified. SOLUTION: The signal transmission system of this invention is provided with a signal transmitter 101 having an MPEG decoder 102 that receives a digital broadcast and outputs one luminance signal Y and two color difference signals PB/PR and a transmission line coding circuit 103 that codes signals YPRPB outputted from the MPEG decoder 102 into a signal form in matching with a transmission channel and transmits them, and with a signal receiver 104 having a transmission line decoding circuit 105 that receives the coded signals YPRPB and decodes them, a Y processing circuit 106 that processes the decoded luminance signal Y, a color processing circuit 107 that processes the decoded color difference signals PB/PR, a signal conversion circuit 108 that converts the signals YPRPB outputted from the Y processing circuit 106 and the color processing circuit 107 into RGB signals, and a display device 109 that displays the RGB signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission system for transmitting an image signal, and more particularly to a signal transmission system capable of simplifying a hardware configuration of a transmission side and a reception side of a video signal.

[0002]

2. Description of the Related Art A conventional example will be described with reference to FIG. FIG. 17 is a block diagram illustrating a configuration of a conventional signal transmission system. In FIG. 17, reference numeral 1701 denotes STB (Se
A video signal output device (transmission side) such as a t-top box, and outputs a video signal. An MPEG decoder 1702 receives a digital broadcast and outputs a baseband Y color difference signal. Reference numeral 1703 denotes a signal conversion circuit that converts a Y color difference signal into an RGB signal. Reference numeral 1704 denotes a transmission line encoding circuit, which encodes the signal converted by the signal conversion circuit 1703 into a signal form suitable for the transmission line. 17
Reference numeral 05 denotes a display device (reception side) such as a television monitor.
Reference numeral 1706 denotes a transmission line decoding circuit, which decodes a signal encoded by the transmission line encoding circuit 1704. 17
Reference numeral 07 denotes a signal conversion circuit, which is a transmission line decoding circuit 1706.
The RGB signal output from the converting into YP _B P _R signals.
Reference numeral 1708 denotes a Y processing circuit which processes the luminance signal Y from the output of the signal conversion circuit 1707. Reference numeral 1709 denotes a color processing circuit which processes a color signal out of the output of the signal conversion circuit 1707. Reference numeral 1710 denotes a signal conversion circuit which receives outputs from the Y processing circuit 1708 and the color processing circuit 1709, and
The color difference signals are converted into RGB signals. Reference numeral 1711 denotes a display device, which receives an output of the signal conversion circuit 1710 and
Output to CD or CRT.

The operation of the signal transmission system configured as described above will be described. The MPEG decoder 1702 receives a digital broadcast and outputs a baseband video signal. Since the MPEG data format has become Y color difference signals, wherein the output of the YP _B P _R, or YUV, or YC _b C _r
It is. Also, in order to perform transmission path coding on this signal, R
Since it is necessary to perform the GB conversion, the signal conversion circuit 170
3, the Y color difference signal is converted into an RGB signal. The converted RGB signal is encoded by the transmission path encoding circuit 1704 into a signal form suitable for the transmission path.

On the other hand, on the side of the television monitor 1705, a transmission path decoding circuit 1706 receives the encoded signal from the transmission path encoding circuit 1704 and generates an original RGB signal. RGB signals by the signal conversion circuit 1707 is converted into YP _B P _R of Y color difference signals. Here the TV monitor 17
In order to perform its own processing 05 side, Y signals are processed by the Y processing circuit 1708, the color signal P _B P _R is output is enhanced respectively by the color processing circuit 1709. The enhanced and output Y color difference signal is output to the last display device 1711 by the signal conversion circuit 1.
According to 710, it is converted into an RGB signal. The display device 1711 outputs the RG output from the signal conversion circuit 1710.
The display can be performed by outputting the B signal.

[0005]

However, in the above-mentioned conventional signal transmission system, since the transmission path encoding is performed using RGB signals, the output of the MPEG decoder is once converted to RGB signals.
Encoded into a signal and transmits, after along the transmission line, in order to carry out again the signal processing by the monitor side, it is necessary to convert the RGB signals into YP _B P _R, furthermore, the end of the display device In order to output an RGB signal, it is necessary to convert the Y color difference signal into an RGB signal again, which has a disadvantage that much hardware is required.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a signal transmission system capable of simplifying a hardware configuration of a transmitting side and a receiving side of a video signal. I do.

[0007]

According to a first aspect of the present invention, there is provided a signal transmission system for transmitting a video signal, receiving a digital broadcast and receiving one luminance signal. And a decoder that outputs two color difference signals, and a coding circuit that codes and transmits the luminance signal and each of the color difference signals into a signal form suitable for a transmission path. A decoding circuit that receives and decodes the luminance signal and each color difference signal, a luminance signal processing circuit that processes the decoded luminance signal, and a color difference signal processing circuit that processes the decoded color difference signals, The luminance signal output from the luminance signal processing circuit and each color difference signal output from the color difference signal processing circuit are
And a signal conversion circuit for converting the signal into a B signal. As a result, it is possible to realize a signal transmission system that can simplify the hardware configuration on the transmission side and the reception side of the video signal.

A signal transmission system according to a second aspect of the present invention is a signal transmission system for transmitting a video signal via a transmission line, wherein the decoder receives a digital broadcast and outputs one luminance signal and two color difference signals. A time-division multiplexing circuit for sub-sampling the two color difference signals to a half pixel rate, time-division multiplexing, and outputting a multiplexed signal; and converting the luminance signal and the multiplexed signal into a signal form suitable for a transmission path. An encoding circuit for encoding and transmitting the signal, a decoding circuit for receiving and decoding the encoded luminance signal and the multiplexed signal, and two A separation circuit that separates the color difference signals, a brightness signal processing circuit that processes the decoded brightness signal, and a color difference signal processing circuit that processes the separated color difference signals,
A signal conversion circuit that converts a luminance signal output from the luminance signal processing circuit and each color difference signal output from the color difference signal processing circuit into an RGB signal. It is assumed that. As a result, since two color difference signals are multiplexed and transmitted, only two transmission paths are required, and it is not necessary to prepare three transmission paths as in the related art, and hardware on the transmission side and reception side of the video signal is used. Can be realized.

According to a third aspect of the present invention, there is provided a signal transmission system for transmitting a video signal and an audio signal, wherein the MPEG decoder receives a digital broadcast and outputs the video and audio signals, and the MPEG decoder. An output interface for outputting a video / audio signal output from the I / C, an I2C controller for outputting an I2C (Inter IC control) signal, and a CPU for controlling the entire apparatus;
A program RO for storing the operation program of the CPU
M, a signal transmission device comprising: an input interface for receiving the video / audio signal from the signal transmission device; a device interface for converting the video / audio signal into video and audio; and a signal output from the device interface. A video and audio output device that outputs video and audio to the outside, and a ROM table that stores information related to the performance of the signal receiving device; an I2C signal is input from the signal transmitting device; and in accordance with a request from the signal transmitting device, A signal receiving device including: an I2C controller that outputs information stored in the ROM table to the signal transmitting device. Thereby, the signal transmitting device can know the performance of the signal receiving device in advance, and without transmitting a rate that cannot be scanned on the signal receiving device side as in the related art, transmits the signal based on the performance of the signal receiving device. Problems such as no video or no sound at the signal receiving device side can be avoided.

In the signal transmission system according to a fourth aspect of the present invention, in the signal transmission system according to the third aspect, the ROM table stores information relating to a resolution of a video that can be output from the video / audio output device. It is characterized by the following. This allows the signal transmitting device to know in advance the resolution of the video that can be output from the signal receiving device, and as a result, it is possible to realize a signal transmission system that can avoid problems such as no video being displayed.

According to a fifth aspect of the present invention, in the signal transmission system according to the third aspect, the ROM table stores information on the number of audio channels that can be output from the video / audio output device. It is characterized by doing. This allows the signal transmitting device to know in advance the number of audio channels that can be output by the signal receiving device, and as a result, it is possible to realize a signal transmission system that can avoid problems such as no sound.

According to a sixth aspect of the present invention, in the signal transmission system according to the third aspect, the ROM table stores the luminance signal and the color difference signal in RG format.
It stores information on a signal conversion method for converting into a B signal. As a result, the signal transmitting device can know in advance the signal conversion method on the signal receiving device side, and as a result, it is possible to realize a signal transmission system that can perform signal conversion correctly.

A signal transmission system according to a seventh aspect of the present invention is the signal transmission system according to the third aspect, wherein the ROM table stores information relating to gamma correction of a video signal. is there. This allows the signal transmitting device to know in advance information relating to gamma correction of the video signal on the signal receiving side, and can output a video signal that is not enhanced to the signal receiving device.

The signal transmission system according to an eighth aspect of the present invention is the signal transmission system according to the third aspect, wherein the ROM table has a mode in which the signal receiving device has a mode in which the video is not subjected to the enhancement processing. Characterized by storing information relating to This allows
If the signal receiving apparatus has a mode in which the signal receiving apparatus does not perform the enhancement processing, the signal transmitting apparatus can forcibly switch to the mode, and as a result, the signal receiving apparatus can display an image without color enhancement.

According to a ninth aspect of the present invention, in the signal transmission system according to the third aspect, the ROM table stores information on a maker code and a device code of the signal receiving device. It is a feature. Thereby, the signal transmitting device can know the maker code and the device code of the signal receiving device in advance, for example, when performing up-conversion of an image,
The performance of each of the signal transmitting device and the signal receiving device is compared, and a better device can be automatically selected.

According to a tenth aspect of the present invention, in the signal transmission system according to the third aspect,
The signal receiving apparatus outputs to the signal transmitting apparatus what kind of aspect conversion processing is currently performed and the image is output via the I2C controller. This allows the signal transmission device to transmit a video signal so that the signal reception device obtains a correct aspect.

The signal transmission system according to claim 11 of the present invention is the signal transmission system according to claim 3,
The signal transmission device transmits control information indicating whether or not a video frame signal that is currently output separately from the video and audio signals from the MPEG decoder is generated by repeated output in the MPEG decoder. A selector for multiplexing and outputting the signal in a vertical blanking period, the signal receiving device comprising: a control data separating unit for separating the control information from the video signal; And an image quality control unit that performs adaptive signal processing and outputs the result to the device interface. Thereby, the signal receiving device can be operated based on the minimum necessary control information such as brightness, contrast, and volume.

According to a twelfth aspect of the present invention, in the signal transmission system according to the eleventh aspect, the control information is capable of classifying I, P, and B pictures representing a picture encoding system of the MPEG standard. Information. As a result, it is possible to realize a signal transmission system that can set parameters for removing noise for each frame.

According to a thirteenth aspect of the present invention, in the signal transmission system according to the eleventh aspect, the control information is compression rate information based on the MPEG standard. As a result, it is possible to realize a signal transmission system that can set parameters for removing noise for each frame.

According to a fourteenth aspect of the present invention, there is provided the signal transmission system according to the eleventh aspect, wherein the control information indicates whether the material before the MPEG encoding is imaged by progressive scan or interlaced. The information is information indicating whether the image was captured by scanning. Thereby, the signal receiving apparatus can select a conversion method from interlace to progressive.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. The embodiment described here is merely an example, and the present invention is not necessarily limited to this embodiment.

Embodiment 1 Hereinafter, a signal transmission system according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a signal transmission system according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 101 denotes a video signal output device such as an STB, which outputs a video signal. 102 is M
The PEG decoder performs digital broadcast reception and outputs one luminance signal and two color difference signals. 10
Reference numeral 3 denotes a transmission line encoding circuit, which is an MPEG decoder 102
The luminance signal and the chrominance signal output from are encoded into a signal form suitable for the transmission path and transmitted. A display device 104 such as a television monitor displays a video signal. A transmission line decoding circuit 105 receives and decodes the luminance signal and the color difference signal encoded by the transmission line encoding circuit 103. 106 is a Y processing circuit, which is a transmission path decoding circuit 10
5 to process the decoded luminance signal. 1
A color processing circuit 07 processes a color signal among signals output from the transmission path decoding circuit 105. Reference numeral 108 denotes a signal conversion circuit, which is a Y processing circuit 106 and a color processing circuit 1
07 is converted to an RGB signal. A display device 109 is a signal conversion circuit 108.
And display on the display.

The operation of the signal transmission system configured as described above will be described. MPEG decoder 102 receives a broadcast wave of digital broadcasting, and outputs a signal YP _B P _R baseband along the MPEG standard. Here since the conventional signal transmission system has been so encoded and transmitted the RGB signals instead of the Y color difference signals, has been converted signals YP _B P _R of the MPEG decoder outputs the RGB signal, but the present embodiment the signal transmission system according to the first, signals YP _B P _R as it is, is inputted to the transmission path encoding circuit 103 for encoding along the transmission path. Transmission path encoding circuit 103 encodes the signal form along the transmission path with respect to the inputted YP _B P _R signals, and outputs the encoded signal to the transmission path.

The transmission path decoding circuit 105 outputs decodes the coded signal received via a transmission path based on the YP _B P _R signals. Among the outputs of the transmission path decoding circuit 105, the Y signal, which is a luminance signal, is input to a Y processing circuit 106, where luminance contrast adjustment and various signal processing are performed. Also, among the outputs of the transmission path decoding circuit 105, P _B and P _R
The color processing circuit 107 performs necessary processing on the color signals. The signal conversion circuit 108 is the Y processing circuit 1
06 and the processed Y and color signals output by the color processing circuit 107 are converted into RGB signals and output to the display device 109. The display device 109 receives a RGB signal output from the signal conversion circuit 108 and performs screen display.

In the signal transmission system according to the first embodiment, the Y color difference signal output from the MPEG decoder 102 is directly encoded and transmitted.
A circuit for converting the Y color difference signal into an RGB signal on the video signal output device 101 side (transmission side) can be unnecessary, and the Y color difference signal is directly input on the display device 104 side (reception side). A circuit for converting to a Y color difference signal is not required, and the hardware configuration can be simplified.

Embodiment 2 FIG. Hereinafter, a signal transmission system according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of a signal transmission system according to Embodiment 2 of the present invention.

In FIG. 2, reference numeral 201 denotes an image of an STB or the like.
The signal output device outputs a video signal. 202 is M
This is a PEG decoder that can receive broadcasts such as digital broadcasts.
Then, one luminance signal and two color difference signals are output. 2
03 is a time-division multiplexing circuit, which is an MPEG decoder 202
Of the color difference signal output from_BAnd P_RTime-division multiplexed,
Convert to one signal line. 204 is a transmission line encoding circuit
And the Y signal output from the MPEG decoder 202 and
The multiplexed P output from the time-division multiplexing circuit 203_B
P_REncode the signal into a signal format suitable for the transmission path and send it
You. Reference numeral 205 denotes a display device such as a television monitor,
Display the signal. Reference numeral 206 denotes a transmission line decoding circuit.
The channel coded signal is converted to the original Y signal and the multiplexed P signal.
_BP_RThe signal is decoded and output. 207 is a separation circuit
Multiplexed P_BP_RSignal to the original P _BSignal and P_Rsignal
Separation is performed. Reference numeral 208 denotes a Y processing circuit, which decodes the transmission path.
The Y signal output from the conversion circuit 206 is processed. 20
Reference numeral 9 denotes a color processing circuit,_BSignal and P_Rsignal
Perform processing for. 210 is a signal conversion circuit,
Forced YP_BP_RConvert the signal to an RGB signal, 211
Denotes a display device, and R represents an output of the signal conversion circuit 210.
Display GB.

The operation of the signal transmission system configured as described above will be described. The MPEG decoder 202
By receiving and decoding the video signal, the baseband Y
And outputs the time division multiplexing circuit 203 the three signal lines of YP _B P _R of the color-difference signals. Since P _B signal and P _R signals in the horizontal direction of the sampling frequency is a half that of Y, time division multiplexing circuit 203 performs time axis multiplexing against P _B signal and P _R signals, and P _B signal place the P _R signals alternately output to one line. Transmission path encoding circuit 204, a Y signal output from the multiplexing signal P _B P _R and MPEG decoder 202 performs a coding to the transmission line, and transmits to the display device 205 side.

The transmission path decoding circuit 206 decodes the original luminance signal received signals Y multiplexed signal P _B P _R through the transmission path, and outputs to the separation circuit 207. Since P _B P _R signals are time-division-multiplexed, the separation circuit 207 returns to the original P _B signal and P _R signals. Then, the Y processing circuit 208 performs predetermined processing on the luminance signal Y, and the color processing circuit 209
Performs a predetermined color processing on the P _B and P _R. YP _B P _R signals obtained in this way is converted into RGB signals by the signal conversion circuit 210, the RGB signal is input to the display device 211, it will be displayed.

In the signal transmission system according to the second embodiment, the time division multiplexing circuit 203 for multiplexing two color difference signals and outputting the multiplexed signal to one signal line is provided. Although three transmission lines are required, this embodiment has an advantage that only two transmission lines are required.

Embodiment 3 FIG. Hereinafter, a signal transmission system according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a block diagram schematically showing a configuration of a signal transmission system according to a third embodiment of the present invention.

In FIG. 3, reference numeral 301 denotes an STB for receiving a digital broadcast or the like, and outputs a video signal. 302
Is a television monitor for displaying a video signal received from the STB 301. The STB 301 and the TV monitor 30
It is assumed that I ² C bidirectional communication is enabled between the two.

FIG. 4 shows the STB 301 and the television monitor 30.
2 is a block diagram for explaining in detail 2, and in the figure, the same or corresponding components as those in FIG. 3 are denoted by the same reference numerals and description thereof is omitted.

In FIG. 4, reference numeral 402 denotes an MPEG decoder which receives a digital broadcast or the like and outputs a video baseband signal. Reference numeral 403 denotes a video output interface, which outputs a video signal output from the MPEG decoder 402. Reference numeral 404 denotes a CPU, and a program R
It is operated by the OM 405 and controls the MPEG decoder 402 and its periphery. The CPU 404 can also control the I ² C controller 406. Reference numeral 408 denotes a video input interface for inputting a video signal received via a transmission path. A device interface 409 converts the signal into a signal suitable for a display device for display. Reference numeral 410 denotes a display device itself such as an LCD or a CRT. Reference numeral 411 denotes an I ² C controller which controls the I ² C bus, and internally has a ROM table 412 for storing information relating to the performance of the television monitor 302. Note that the ROM table 412 stores information on the resolution of a video that can be output from the display device 410,
Information on the number of audio channels that can be output from 10,
Information on a signal conversion method for converting a luminance signal and a color difference signal into RGB signals, information on gamma correction of a video signal, information on whether or not the TV monitor 302 has a mode in which video is not subjected to enhancement processing, a maker code of the TV monitor 302 And information on the device code. The TV monitor 302 is an I2C
Through the controller 411, what kind of aspect conversion processing is currently performed to output video is output to the STB 301.

FIG. 5 illustrates the operation of the signal transmission system configured as described above. Here, an initial protocol based on I ² C will be described with reference to FIG. First, the STB 301 asks the TV monitor 302 for a maker code and a device code of the TV monitor 302 (S1). The TV monitor 302 converts the maker code and the device code from the ROM table 412 into STBs.
A reply is sent to the side 301 (S2).

If the received maker code and device code are known, the STB 301 ends the protocol (S3). If the received maker code and device code are not known, the STB 301 asks what scanning speed the television monitor 302 corresponds to (S4). The TV monitor 302 replies about the scan rate at which the TV monitor 302 can scan (S5).

Next, the TV monitor 3 is sent from the STB 301 side.
02 side asks what kind of sound can be reproduced (S
6). The television monitor 302 returns the number of sound channels that can be output by itself (S7). Thereby, STB3
01 and the television monitor 302, the initial protocol ends.

Next, as Case 1, STB 301
It is assumed that a broadcast having 80i LR2 channel audio is received. In this case, the STB 301 knows that the TV monitor 302 can output LR of 480i and 2 channels by the negotiation of the initial access described above, and thus outputs the TV monitor 302 as it is without processing the display rate or audio. . In another case, as case 2, the broadcast reception is 1080i.
In the case of 5.1 channel broadcasting, STB30
1, 1080i is the connected TV monitor 30
In No. 2, since it is known from the initial protocol negotiation that the image cannot be received, the STB 301 converts 1080i to 480p. The conversion to 480p is performed by the TV monitor 30 in the previous negotiation.
2 is known to be capable of display rates up to 480p. Also, since it is known that 5.1-channel audio cannot be reproduced on the connected television monitor, the STB 301 performs a process of downmixing to 2-channel LR, thereby resulting in video data. Outputs an output of 480p, and audio data outputs two channels of LR downmix.

[0040] Here, I
² ROM table 4 inside C controller 411
12 will be described with reference to FIG. For example, it is assumed that 4 bits indicating a displayable rate are stored at address 01, and a value of 0000 is stored in a TV monitor capable of displaying a 480i signal of 299.7 Hz, for example. . Also, the number of channels that can output sound is stored at address 02, and a value such as 0006 is stored if it can decode 6 channels. Such codes are standardized in the industry for addresses and numerical values, so even if the TV monitor side is a manufacturer that is not known to STB, the minimum protocol is decided,
It is possible to avoid a situation in which an image is not projected, an image is projected in an abnormal aspect, and no sound is produced. That is, it is possible to avoid the problem that the transmitting side transmits at a frame rate or the like that cannot be pulled in on the PC monitor side or the television monitor side and cannot display an image as in the related art.

As described above, in the signal transmission system according to the third embodiment, since the STB is output after knowing the performance of the TV monitor, there is a possibility that the STB conventionally outputs a rate that cannot be scanned by the TV monitor. However, by performing such negotiation, it is possible to avoid problems such as no video or no sound on the television monitor.

When the TV monitor transmits a maker code and a device code to the STB, if the maker and the device code are between manufacturers whose information is disclosed between the STB and the TV monitor, for example, the Whether the STB should perform the up-conversion or leave it up to the television monitor can automatically select the better one by comparing the up-conversion performances of the respective devices.

As an example of the initial access, an example in which only a scan type and how many channels of sound can be reproduced is negotiated earlier, but the other connected TV monitor is a 16: 9 wide TV. Or 4
STB automatically if you know whether it is a normal TV of 3
By performing letter box conversion or pan scan conversion on the side and outputting, the correct aspect can be obtained automatically. Therefore, it is not necessary to set whether the connected monitor is wide or normal in the initial menu on the STB side as in the related art.

In general, a television monitor does not output a received signal as it is, but outputs the signal with enhanced brightness and color. However, there is a case where it is not desirable for a user such as a personal computer to intentionally manipulate the brightness and the color. Therefore, the enhancement characteristics of the television monitor are notified to the STB side, and the enhancement is inversely corrected on the STB side. If you output things in advance,
As a whole, a video signal that is not enhanced can be output to the television monitor.

If a non-enhanced mode is provided on the television monitor side, the mode can be forcibly switched from the STB side to that mode to ensure color-enhanced reproduction.

Next, when the connected monitor is a wide-screen TV, the TV generally has a display mode such as a wide mode or a normal mode. For example, when a 16: 9 monitor is connected, If the material received by the STB is 16: 9, the STB is output without performing the aspect conversion as it is. However, if the setting of the TV is set to the normal display, as shown on the right side of FIG. May be reflected vertically. In this case, a normal aspect image can be obtained by setting the TV side to the full display mode from the STB side. In FIG. 6, the left picture is a 16: 9 picture of the originally expected output, and the right picture shows an erroneous aspect when the setting on the TV side is set to normal by mistake.

In addition, RGB between the STB and the television monitor
Y color difference signals rather than signal, that when transmitting a signal such as a YP _B P _R, because it may conversion formula for converting the TV side based on the RGB signals are different, transmits the conversion formula itself It is also possible. Since the conversion formula is described in the MPEG stream data, ST
By transmitting the conversion formula extracted on the B side to the TV monitor via I ² C, the correct RG
B can be converted.

The data transmission in the signal transmission system according to the third embodiment may be multiplexed and transmitted using the video signal line CTL0 or CTL1 as shown in FIG.

Embodiment 4 Hereinafter, a signal transmission system according to the fourth embodiment of the present invention will be described with reference to FIGS.

FIG. 12 is a diagram showing a configuration of a selector provided in the video output interface on the transmitting side of the signal transmission system according to the fourth embodiment of the present invention. The difference from the third embodiment is that the video output interface 403
Is a configuration provided with a selector.

In FIG. 12, a selector (selector) 12
01 is a red signal R and other control signals C
TL0 is temporally selected by DE. Selector 12
02 temporally selects the green signal G and the control signal CTL1. The selector 1203 selects the blue signal B
And the HV sync signal are temporally switched. Where DE
Is a signal for distinguishing the image scanning period from the blanking period.

FIG. 10 is a diagram for explaining the operation of the selector. Here, the selector 1201 will be described, but the other selectors 1202 and 1203 operate in the same manner, and a description thereof will be omitted. In the figure, the DE signal is HIGH during the video period,
The signal is LOW during the flyback period.

The selector 1201 receives the R signal and CTL0
As the signal is input, the R signal is passed when the DE signal is at the HIGH level, and the CTL0 signal is passed while the DE signal is LOW. As a result, the output signal can receive the R signal during the video period and transmit the CTL0 signal, that is, the control data during the flyback period. In the retrace period, when the output video rate is interlaced, the retrace period is as shown on the left side of FIG. 8, and when the output video rate is progressive, FIG.
Is as shown on the right side of FIG.

The operation of the signal transmission system configured as described above will be described with reference to FIG. First, S
The TB makes an inquiry about the maker code and the device code to the television side (S12). If the TV monitor is a device that was shipped before the standardization, it is normal for the manufacturer code and device code to be inquired, but no answer can be obtained. the process ends and the connected monitor as understanding of the STB does not support the function of TV monitor control to the I ² C, determined that that does not send the control command in I ² C future (S13).

If there is a reply as a result of the inquiry about the maker code and the equipment code, it is determined whether the reply is of a known type of the STB (S14). In this case, if the type is a known type, the process ends, and the connected monitor knows all its performance on the STB side, so that the optimal video and audio output can be changed in combination with the STB itself. (S15). In S14, unknown type (UNKNOWN_TYPE)
When it is detected that the number of audio channels is higher, the rate and the number of audio channels that can be displayed on the display are sequentially checked. The STB determines that basic adjustment functions such as volume adjustment, mute, brightness, and contrast adjustment have been prepared for industry standards and can be used.

FIG. 11 shows an example of the structure of the control data. For example, the STB has a reservation pattern in which 01 is continuous for two byte periods as a header, and then reads the state of the TV from the STB to the TV. One byte is composed of several bytes of R / W data for identifying a read, then an address of what address to write at what address on the TV side, and the value of the data to be written or read. Configure control data. With such a configuration of the control data, a desired command can be transmitted to the television.

FIG. 13 is a block diagram showing the configuration of the receiving side, that is, the television monitor. In FIG. 13, reference numeral 1301 denotes a receiving television monitor itself. Reference numeral 1302 denotes a video input interface, which inputs a video signal received via a transmission path. Reference numeral 1303 denotes a control data separation unit that separates only control data from a video signal. 13
Reference numeral 04 denotes a temporary storage unit that temporarily stores control data. An image quality control unit 1305 performs image quality correction of a video signal. 1306 is a device interface,
An interface to the display device 1307 is provided. Reference numeral 1308 denotes a CPU, which is used to control the image quality control unit 1305 for control signals from the control data separation unit 1303 that do not require real-time processing. An I ² C controller 1309 controls the I ² C bus. Reference numeral 1310 denotes a ROM table in the I ² C controller 1309.
301 is described. Assuming that basic commands such as luminance, contrast, and volume are standardized in the industry, such control data is interpreted by the CPU 1308, and the CPU 1308 executes the image quality control unit 1.
305 is to be controlled.

The data accompanying each frame is as follows:
Since it is desirable that the control signal is directly input to the image quality control unit 1305 without the intervention of the CPU 1308, the control data separation unit 1303 also outputs a control signal to the image quality control unit 1305 directly. Examples of the control signal include whether the decoded image is an I picture, a P picture, or a B picture, whether the material of each frame is progressive or interlaced, and the like. This is information indicating the distinction of.

By adopting such a configuration on the receiving side, it is possible to operate the television monitor side as control from the STB for the minimum necessary such as luminance, contrast, and volume, and to transmit a control signal for each frame. Transmit, ST
B can control image quality for each frame.

FIG. 14 is a diagram showing an example of a control signal sent for each frame. Here, an example in which telecine information is superimposed will be described. In the case of a telecine image, there is a field that has been output after field repeat.Conventionally, the receiving side has a field memory, and by taking the difference between the two, it detects whether or not it is a field repeat and performs scan conversion. I was

FIG. 15 is a block diagram showing a conversion circuit for converting a conventional 24p telecine material into, for example, 60p. In FIG. 15, 1501, 1502, 15
Reference numeral 03 denotes a field memory that outputs the data with a delay of one field. Correlation calculating means 1504 calculates a correlation between the signal received by the field memory delayed with the current signal and the current signal for each pixel, and when there is a correlation, determines that the current field has been subjected to field repeat. , And controls the selection means 1505 for selecting which output of the field memory is to be output from each field memory. In such conventional field repeat detection means, the correlation calculation has a drawback that the calculation amount becomes very complicated and the hardware becomes heavy when trying to increase the detection accuracy. However, there is a problem that erroneous detection cannot be avoided.

Therefore, in order to solve the above problem, in the present embodiment, a method of transmitting a field repeat signal is used as shown in FIG. In FIG. 16, reference numeral 1601 denotes an MPEG decoder which decodes a broadcast wave and outputs a baseband video signal. At the same time, information indicating whether the frame included in the broadcast wave stream is a top field or a bottom field, and a field repeater Outputs information as to whether or not it has been done. Reference numeral 1602 denotes a transmission line encoding circuit which performs transmission line encoding on the RGB signals output from the MPEG decoder 1601 during the scanning period, and outputs the top and bottom information in the flyback period according to the form of the control data described above. And field repeat information. A transmission line decoding circuit 1603 converts a signal received via the transmission line into the original RGB signal.
The RGB signals are matrix-converted into Y color difference signals and output. 1604, 1605, 1606 are
Each is a field memory for delaying a video signal by one field. 1607 is a transmission path decoding circuit 160
3 is a retrace period code analyzing means for extracting information superimposed on the control data from among the outputs of 3. A selection unit 1608 receives the output of the control period code analysis unit 1607 and selects which field memory to output.

With this configuration, the blanking period code analysis means 1608 can reproduce the top-bottom information and the field repeat information superimposed on the transmission side without error, so that the correct field repeat information and top, A Y output signal can be obtained using the bottom information.

Next, an output image in the case of converting from 24p to 60p on the television monitor side using such means and outputting the converted image will be described with reference to FIG. In FIG.
A1 represents the first field of frame A, and A2 represents the second field of the same frame A. It is assumed that the television monitor input signal is, for example, A1 which is temporally repeated once again at A1 and A2. In that case, the output signal of the TV monitor
One frame composed of A1 and A2 is output,
At the next time, a frame made of A1 and A2 is output. Here, if the third field of the input signal to the monitor is correctly detected such that the third field of the input signal to the monitor is the same A1 as the first field, the third frame of the output signal of the television monitor is also formed from A1 and A2. Although a correct picture is synthesized, there is a problem that if it is erroneously detected at this time, the picture is not correctly reproduced. In the configuration shown in FIG. 16 this time, the broadcast station determines whether or not a field is a repeat field based on top and bottom information and field repeat information of the superimposed MPEG stream information. Will be reproduced correctly.

In the fourth embodiment, a description has been given of a case where the field repeat and top / bottom information, which are telecine information, are superimposed. For example, whether the frame is an I picture, a P picture, or a B picture Information can also be superimposed in the same manner. However, an I picture is an image coded in a frame, a P picture is an image using a difference between frames, and a B picture is an image encoded using a bidirectional difference. This makes it possible to set noise removal parameters for each frame. Conventionally, it has not been possible to adaptively remove noise from a baseband video signal because it is not known whether each frame is an I picture, a B picture, or a P picture.

As another example, information on the compression ratio of MPEG can be superimposed. In this case, the compression rate of MPEG can be obtained from the megabit / second video stream from the header of the elementary stream of MPEG. Furthermore, since the horizontal and vertical sizes and the frame rate can also be obtained, the relationship between the horizontal and vertical sizes and the bit rate can be notified to the television side, so that noise removal parameters can be set. With this configuration, unlike the related art, since information on the MPEG compression ratio cannot be known on the transmission side, it is possible to avoid a problem that appropriate processing cannot be performed.

Further, as another example, since it is also possible to know from the header of the MPEG stream the information as to whether the material is captured by a progressive camera or an interlaced camera, this information is transmitted as similar control data. can do. Then, on the basis of this data, the TV monitor performs IP conversion, that is,
This can be used to select the method of conversion from interlace to progressive. Therefore, conventionally, accurate IP
A motion detection circuit was necessary to perform the conversion, and the still area was progressively interpolated using the motion detection circuit, and the moving image area was interpolated as an interlace,
Here it becomes unnecessary. Even if the material is interlaced, if a graphics layer such as an OSD is placed on a large part of the screen, it is appropriate to interpolate progressively. Since it is known internally, by transmitting the control signal as progressive at that time, correct interpolation can be performed.

In the data transmission of the signal transmission system according to the fourth embodiment, data having a low transfer rate may be transmitted using the I ² C bus shown in FIG.

In the second embodiment, the color difference signals are multiplexed into one signal.
Although two signal lines were required, it became possible to transmit all video signals over two transmission paths, so the natural image output from the MPEG decoder was output using the remaining one signal line. And a signal for distinguishing between the OSD region and the OSD region. By transmitting this signal, even if an IP conversion error occurs during the broadcast of 480p, it does not affect the data broadcast of 480p, and the image can be displayed with high image quality. In addition, there is a feature that the processing of the character and the natural image can be separated for each pixel. Further, in the second embodiment, since only two transmission paths are required, the remaining 1
The book can be defined as a user-defined signal line.

Although FIG. 4 shows the case where the device for outputting a video signal is an STB, the same configuration can be applied to a digital camera or a notebook PC which requires power saving. In the case of a portable terminal such as a digital camera or a notebook PC, since a still image is transmitted, the portable terminal has a video input interface 408 on the television monitor side or a memory provided in, for example, an image quality control unit 1305 of the television monitor main body. In this case, the control (mobile terminal side) instructs the television monitor to instruct the television monitor to store or not to store the memory by first using 11C bus control or control using CTL0 or CTL1. Then, the control side (portable terminal side) sends one or the number in the memory capacity of the television monitor to the television monitor through the video output interface 403 at the instruction of the user. The TV monitor stores the video set by the user in the video input interface 408 or, for example, the image quality control unit 1305 of the TV monitor main body. If the television monitor has no memory in the first confirmation of the presence or absence of the memory, the video signal is always output as in the case of the moving image. Further, in the case of a PC or the like, the same control is performed every time an internal image changes, so that when the image of the PC changes, still data is transmitted in the above sequence. By doing so, the still image held on the TV monitor can be continuously displayed on the TV monitor without continuously retransmitting the same still image from a portable terminal such as a digital camera or a notebook PC. As a result, the video output interface of the digital camera or the like on the video signal generation side only needs to operate when transmitting one still image, which has the effect of saving power. In addition, by repeating this still image transmission temporally, for example, by repeatedly sending a still image every one second or resting, an image such as motion JPEG can be transmitted with high efficiency and with low power consumption. Also becomes possible.

[0071]

According to the signal transmission system according to the first aspect of the present invention, in a signal transmission system for transmitting a video signal, a decoder for receiving a digital broadcast and outputting one luminance signal and two color difference signals is provided. An encoding circuit for encoding and transmitting the luminance signal and each of the color difference signals into a signal form suitable for a transmission path, and receiving and decoding the encoded luminance signal and each of the color difference signals Decoding circuit, a luminance signal processing circuit for processing the decoded luminance signal, a chrominance signal processing circuit for processing the decoded chrominance signals, and a luminance output from the luminance signal processing circuit. And a signal conversion circuit for converting the signal and each color difference signal output from the color difference signal processing circuit into an RGB signal. It is possible to realize a signal transmission system which can as simple a hardware configuration of the side.

According to the signal transmission system of the second aspect of the present invention, in a signal transmission system for transmitting a video signal via a transmission path, a digital broadcast is received and one luminance signal and two color difference signals are output. A time-division multiplexing circuit for sub-sampling the two color difference signals to a half pixel rate, time-division multiplexing, and outputting a multiplexed signal, and a signal for transmitting the luminance signal and the multiplexed signal on a transmission line. A signal transmission device comprising: an encoding circuit that encodes and transmits the encoded signal; a decoding circuit that receives and decodes the encoded luminance signal and the multiplexed signal; A separation circuit that separates the two color difference signals, a luminance signal processing circuit that processes the decoded luminance signal, a color difference signal processing circuit that processes each of the separated color difference signals, A signal conversion circuit that converts a luminance signal output from the processing circuit and each color difference signal output from the color difference signal processing circuit into an RGB signal. Since signals are multiplexed and transmitted, only two transmission paths are required, and it is not necessary to prepare three transmission paths as in the conventional case, and the hardware configuration of the transmission side and the reception side of the video signal is simple. It is possible to realize a signal transmission system that can be used.

According to a third aspect of the present invention, in the signal transmission system for transmitting a video signal and an audio signal, an MPEG decoder for receiving a digital broadcast and outputting the video and audio signals; An output interface for outputting a video / audio signal output from an MPEG decoder, an I2C controller for outputting an I2C (Inter IC control) signal, and a CP for controlling the entire apparatus
U, a program ROM for storing an operation program of the CPU, a signal transmission device, an input interface for receiving the video / audio signal from the signal transmission device, and converting the video / audio signal into video and audio. A device interface, a video / audio output device for outputting the video and audio output from the device interface to the outside, and a ROM table for storing information relating to the performance of the signal receiving device; and an I2C signal from the signal transmitting device. And an I2C controller that outputs the information stored in the ROM table to the signal transmitting device in accordance with a request from the signal transmitting device. The performance of the signal receiving device can be known in advance, and the signal receiving device In without transmitting a rate that can not be scanned, because the signal transmission based on the performance of the signal receiving apparatus can be avoided or not picture appears at the signal receiving apparatus, problems such as sound has not.

According to the signal transmission system of the fourth aspect of the present invention, in the signal transmission system of the third aspect, the ROM table stores information on a resolution of a video that can be output from the video / audio output device. Since the information is stored, the signal transmitting apparatus can know the resolution of the video that can be output from the signal receiving apparatus in advance, and as a result, it is possible to realize a signal transmission system that can avoid problems such as no video being displayed.

According to the signal transmission system of the fifth aspect of the present invention, in the signal transmission system of the third aspect, the ROM table stores information on the number of audio channels that can be output from the video / audio output device. Is stored, the signal transmitting device can know in advance the number of audio channels that can be output by the signal receiving device,
As a result, a signal transmission system that can avoid problems such as no sound can be realized.

According to the signal transmission system of claim 6 of the present invention, in the signal transmission system of claim 3, the ROM table converts the luminance signal and the color difference signal into RGB signals. Since the information about the signal transmission device is stored, the signal transmission device can know in advance the signal conversion method on the signal reception device side, and as a result, it is possible to realize a signal transmission system that can perform signal conversion correctly. .

According to the signal transmission system of claim 7 of the present invention, in the signal transmission system of claim 3, the ROM table stores information relating to gamma correction of a video signal. The signal transmitting device is
Information regarding gamma correction of a video signal on the signal receiving side can be known in advance, and a video signal that is not enhanced can be output to the signal receiving device.

According to the signal transmission system according to claim 8 of the present invention, in the signal transmission system according to claim 3, the ROM table has a mode in which the signal receiving device does not enhance the image. Since the information on whether or not the signal is received is stored, the signal transmitting apparatus can forcibly switch to the mode when the signal receiving apparatus has a mode in which the enhancement processing is not performed, and as a result, the signal receiving apparatus can use the color mode. Images without enhancement can be displayed.

According to the signal transmission system of the ninth aspect of the present invention, in the signal transmission system of the third aspect, the ROM table stores information on a maker code and a device code of the signal receiving device. As a result, the signal transmitting device can know the manufacturer code and the device code of the signal receiving device in advance, and for example, when performing up-conversion of an image, compare the performance of each of the signal transmitting device and the signal receiving device. , The better device can be automatically selected.

According to the signal transmission system according to the tenth aspect of the present invention, in the signal transmission system according to the third aspect, what kind of aspect conversion processing is currently performed by the signal receiving device via the I2C controller. Is output to the signal transmitting device as described above, so that the signal transmitting device can transmit a video signal so that the signal receiving device obtains a correct aspect.

According to a signal transmission system according to claim 11 of the present invention, in the signal transmission system according to claim 3, the signal transmission device is configured to output a signal currently output from the MPEG decoder separately from a video / audio signal. A selector for multiplexing and outputting control information indicating whether or not the video frame signal is generated by repeated output in the MPEG decoder during a vertical blanking period of the video signal; A control data separation unit that separates the control information from the video signal, and an image quality control unit that performs adaptive signal processing on the video signal according to the control information and outputs the processed signal to the device interface. Thus, the signal receiving device can be operated based on minimum necessary control information such as luminance, contrast, and volume.

According to a signal transmission system according to a twelfth aspect of the present invention, in the signal transmission system according to the eleventh aspect, the control information includes I, P, and B pictures representing a picture encoding system of the MPEG standard. Since the information is classifiable, it is possible to realize a signal transmission system capable of setting parameters for removing noise for each frame.

According to the signal transmission system of the thirteenth aspect of the present invention, in the signal transmission system of the eleventh aspect, since the control information is compression rate information of the MPEG standard, noise is removed. Transmission system that can set parameters for each frame.

According to the signal transmission system of the fourteenth aspect of the present invention, in the signal transmission system of the eleventh aspect, the control information indicates whether the material before the MPEG encoding is obtained by progressive scan. Since the information indicates whether the image is captured by the interlace scan, the signal receiving apparatus can select a conversion method from interlace to progressive. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a signal transmission system according to a first embodiment.

FIG. 2 is a block diagram showing a configuration of a signal transmission system according to a second embodiment.

FIG. 3 is a schematic configuration diagram of a signal transmission system according to a third embodiment.

FIG. 4 is a block diagram showing a detailed configuration of a signal transmission system according to a third embodiment.

FIG. 5 is a diagram for explaining an initial protocol in a signal transmission system according to a third embodiment.

FIG. 6 is a diagram showing a state of a screen display of a television which is a 16: 9 wide material.

FIG. 7 is a diagram showing an example of a ROM table.

FIG. 8 is a diagram for explaining a retrace period in each of a case where the output video rate is interlaced and a case where the output video rate is progressive.

FIG. 9 is a flowchart for explaining the operation of the signal transmission system according to the fourth embodiment of the present invention.

FIG. 10 is a diagram for explaining the operation of the selector.

FIG. 11 is a diagram illustrating a configuration example of control data.

FIG. 12 is a diagram showing a configuration of a selector in a signal transmission system according to a fourth embodiment.

FIG. 13 is a block diagram showing a configuration on a receiving side of a signal transmission system according to a fourth embodiment.

FIG. 14 is a diagram illustrating an example of a control signal transmitted for each frame in the signal transmission system according to the fourth embodiment.

FIG. 15 shows a conventional 24p telecine material, for example, 60
It is a block diagram which shows the conversion circuit in the case of converting into p.

FIG. 16 is a diagram illustrating a method of transmitting a field repeat signal according to the fourth embodiment.

FIG. 17 is a block diagram showing a configuration of a conventional signal transmission system.

[Explanation of symbols]

101, 201 Video signal output device 102, 202 MPEG decoder 103, 204 Channel coding circuit 104, 205 Display device 105, 206 Channel decoding circuit 106, 208 Y processing circuit 107, 209 Color processing circuit 108, 210 Signal conversion Circuit 109, 211 Display device 203 Time division multiplexing circuit 207 Separation circuit 301 STB 302, 1301 TV monitor 402 MPEG decoder 403 Video output interface 404 CPU 405 Program ROM 406 I ² C controller 408, 1302 Video input interface 409, 1306 Device interface 410 , 1307 display device 411,1309 I ² C controller 412,1309 ROM table 1201, 1202, 1203 Se Kuta 1303 control data separation unit 1304 temporary storage unit 1305 the image quality control section 1308 CPU

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 11/04 11/24 F term (Reference) 5C057 AA06 AA11 AA15 BA11 CA01 CE06 DA03 EA02 EJ02 EM04 EM09 EM16 5C059 LA04 LB05 PP01 PP05 PP06 PP07 PP15 PP16 RB01 RB09 UA04 5C063 AA20 AB03 AB07 AC01 AC10 CA11 DA13 5K028 AA06 CC02 CC05 EE05 EE08 KK01 KK03 KK12 MM05 MM12 SS05 SS15

Claims (14)

[Claims] 1. A signal transmission system for transmitting a video signal, comprising: a decoder for receiving a digital broadcast and outputting one luminance signal and two color difference signals; and a signal for transmitting the luminance signal and each color difference signal on a transmission line. A signal transmission device comprising: an encoding circuit that encodes and transmits the encoded luminance signal; a decoding circuit that receives and decodes the encoded luminance signal and each color difference signal; and processes the decoded luminance signal. A luminance signal processing circuit, a color difference signal processing circuit that processes the decoded color difference signals, a luminance signal output from the luminance signal processing circuit, and a color difference signal output from the color difference signal processing circuit. A signal transmission system, comprising: a signal conversion device that converts a signal into an RGB signal. 2. A signal transmission system for transmitting a video signal via a transmission line, comprising: a decoder for receiving a digital broadcast and outputting one luminance signal and two color difference signals; and a half pixel rate for said two color difference signals. A time-division multiplexing circuit that performs sub-sampling, time-division multiplexing, and outputs a multiplexed signal; and an encoding circuit that encodes and transmits the luminance signal and the multiplexed signal to a signal form suitable for a transmission path. A signal transmitting apparatus; a decoding circuit that receives and decodes the encoded luminance signal and the multiplexed signal;
A separation circuit that separates the two color difference signals, a luminance signal processing circuit that processes the decoded luminance signal, a color difference signal processing circuit that processes each of the separated color difference signals, and a signal output from the luminance signal processing circuit. And a signal conversion circuit that converts the luminance signal and each color difference signal output from the color difference signal processing circuit into an RGB signal. 3. A signal transmission system for transmitting a video signal and an audio signal, wherein the MPEG decoder receives a digital broadcast and outputs the video / audio signal.
An output interface for outputting a video / audio signal output from the decoder, an I2C controller for outputting an I2C (Inter IC control) signal, and a C for controlling the entire apparatus
A signal transmission device including a PU and a program ROM for storing an operation program of the CPU; an input interface for receiving the video / audio signal from the signal transmission device; and converting the video / audio signal into video and audio. A device interface, a video / audio output device for outputting the video and audio output from the device interface to the outside, and a ROM table for storing information relating to the performance of the signal receiving device; and an I2C signal from the signal transmitting device. A signal receiving device comprising: an input / output (I2C) controller for inputting and outputting information stored in the ROM table to the signal transmitting device in accordance with a request from the signal transmitting device; Transmission system. 4. The signal transmission system according to claim 3, wherein the ROM table stores information on resolution of a video that can be output from the video / audio output device. 5. The signal transmission system according to claim 3, wherein the ROM table stores information on the number of audio channels that can be output from the video / audio output device. 6. The signal transmission system according to claim 3, wherein the ROM table stores the luminance signal and the color-difference signal as R signals.
A signal transmission system for storing information relating to a signal conversion method for converting into a GB signal. 7. The signal transmission system according to claim 3, wherein said ROM table stores information relating to gamma correction of a video signal. 8. The signal transmission system according to claim 3, wherein the ROM table stores information on whether or not the signal receiving device has a mode in which video is not enhanced. Transmission system. 9. The signal transmission system according to claim 3, wherein the ROM table stores information on a maker code and a device code of the signal reception device. 10. The signal transmission system according to claim 3, wherein the signal receiving device informs the signal transmitting device of what aspect conversion process is currently being performed and the image is output via the I2C controller. Output, a signal transmission system. 11. The signal transmission system according to claim 3, wherein the signal transmission device generates a video frame signal currently output separately from the video / audio signal from the MPEG decoder by repeatedly outputting the video frame signal in the MPEG decoder. A selector for multiplexing and outputting control information indicating whether or not the video signal is a vertical flyback period of the video signal, wherein the signal receiving device is configured to separate the control information from the video signal. A signal transmission system, comprising: a separation unit; and an image quality control unit that performs adaptive signal processing on the video signal according to the control information and outputs the processed signal to the device interface. 12. The signal transmission system according to claim 11, wherein the control information is information capable of classifying I, P, and B pictures representing a picture encoding system of the MPEG standard. system. 13. The signal transmission system according to claim 11, wherein the control information is compression rate information based on the MPEG standard. 14. The signal transmission system according to claim 11, wherein the control information is information indicating whether the material before the MPEG encoding is captured by a progressive scan or an interlace scan. A signal transmission system characterized by the following.