JP4940537B2 - Transmitter - Google Patents

Description

  The present invention relates to a signal transmission system for transmitting an image signal, and relates to a signal transmission system capable of simplifying the hardware configuration of a video signal transmission side and a reception side.

A conventional example will be described with reference to FIG. FIG. 17 is a block diagram showing a configuration of a conventional signal transmission system.
In FIG. 17, reference numeral 1701 denotes a video signal output device (transmission side) such as an STB (Set-top box), which outputs a video signal. Reference numeral 1702 denotes an MPEG decoder which receives a digital broadcast and outputs a baseband Y color difference signal. A signal conversion circuit 1703 converts the Y color difference signal into an RGB signal. Reference numeral 1704 denotes a transmission path encoding circuit, which encodes the signal converted by the signal conversion circuit 1703 into a signal form suitable for the transmission path. Reference numeral 1705 denotes a display device (receiving side) such as a television monitor. Reference numeral 1706 denotes a transmission path decoding circuit, which decodes the signal encoded by the transmission path encoding circuit 1704. 1707 is a signal conversion circuit converts the RGB signals outputted from the transmission path decoding circuit 1706 in YP _B P _R signals. Reference numeral 1708 denotes a Y processing circuit which processes the luminance signal Y out of the output of the signal conversion circuit 1707. Reference numeral 1709 denotes a color processing circuit, which processes a color signal out of outputs from the signal conversion circuit 1707. A signal conversion circuit 1710 receives outputs from the Y processing circuit 1708 and the color processing circuit 1709 and converts the Y color difference signal into an RGB signal. Reference numeral 1711 denotes a display device which receives the output of the signal conversion circuit 1710 and outputs it to the LCD 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, the output here is YP _B P _R, or YUV, or YC _b C _r. In addition, since this signal must be RGB-converted in order to encode the transmission path, the signal conversion circuit 1703 converts the Y color difference signal into an RGB signal. The converted RGB signal is encoded by the transmission line encoding circuit 1704 into a signal form suitable for the transmission line.

On the other hand, on the television monitor 1705 side, the transmission path decoding circuit 1706 receives the encoded signal from the transmission path encoding circuit 1704 and generates the original RGB signal. RGB signals by the signal conversion circuit 1707 is converted into YP _B P _R of Y color difference signals. In order to perform its own processing where the TV monitor 1705 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 Y color difference signal is converted into an RGB signal by a signal conversion circuit 1710 for output to the final display device 1711. The display device 1711 can perform display by outputting the RGB signals output from the signal conversion circuit 1710.

However, in the above conventional signal transmission system, transmission path encoding is performed with RGB signals. Therefore, the output of the MPEG decoder is temporarily converted into RGB signals, encoded, transmitted, transmitted through the transmission path, and then on the monitor side. to perform again signal processing, it is necessary to convert the RGB signals into YP _B P _R, further, in order to output the RGB signals to the final display device, must be converted again from the Y color difference signals into RGB signals , Had the disadvantage of requiring a lot of hardware.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a signal transmission system capable of simplifying the hardware configuration of the video signal transmission side and reception side.

In order to solve the above problems, a transmitting apparatus according to the present invention includes a baseband luminance signal obtained by decoding a stream compressed in accordance with the MPEG standard in a transmitting apparatus that digitally transmits a video signal via a transmission path. A transmission line encoding unit that time-division-multiplexes the color difference signal in the video period and the control signal in the blanking period, and an interface that receives the receiving apparatus information via an I2C (Inter IC control) bus. The type includes information used when controlling the image quality and used when generating the baseband signal and describing the nature of the stream compressed in accordance with the MPEG standard. Outputs the audio signal and outputs the luminance signal and the color difference signal so as to perform output that can be displayed on the receiving device based on the receiving device information. It is characterized in that for outputting a serial audio signal.

According to the transmit device of the present invention, in a transmission apparatus for digital transmission over a transmission channel a video signal, a luminance signal and color difference signals of the baseband video period, time-division multiplexing control signal during a blanking period A transmission path encoding unit and an interface for receiving receiving device information via an I2C (Inter IC control) bus, and the type of the control signal includes a baseband signal used for image quality control. In addition, the transmission device outputs an audio signal, and the luminance signal, the color difference signal, and the audio signal are output so as to be output by the reception device based on the reception device information. since so as to output, performance of the transmission device signal receiving apparatus can know in advance without transmitting a conventional manner a rate that can not be scanned by the signal receiving apparatus, sexual signal receiving apparatus Because the signal is transmitted based on the performance of the receiver, the baseband video signal and the audio signal can be optimized and output in accordance with the capability of the receiver. In addition to avoiding problems, the control signal used to generate the baseband signal used to control the image quality is multiplexed and output during the vertical blanking period of the video signal, resulting in the minimum necessary control information. Based on this, the signal receiving apparatus can be operated .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, embodiment shown here is an example to the last, Comprising: It is not necessarily limited to this embodiment.

Embodiment 1 FIG.
A signal transmission system according to Embodiment 1 of the present invention will be described below 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. Reference numeral 102 denotes an MPEG decoder that performs digital broadcast reception and outputs one luminance signal and two color difference signals. Reference numeral 103 denotes a transmission path encoding circuit which encodes and transmits the luminance signal and color difference signal output from the MPEG decoder 102 into a signal form suitable for the transmission path. A display device 104 such as a television monitor displays a video signal. A transmission path decoding circuit 105 receives and decodes the luminance signal and the color difference signal encoded by the transmission path encoding circuit 103. A Y processing circuit 106 processes the decoded luminance signal output from the transmission path decoding circuit 105. Reference numeral 107 denotes a color processing circuit, which processes color signals among signals output from the transmission path decoding circuit 105. A signal conversion circuit 108 converts Y color difference signals output from the Y processing circuit 106 and the color processing circuit 107 into RGB signals. Reference numeral 109 denotes a display device, which receives the output of the signal conversion circuit 108 and displays it on a display or the like.

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.

Transmission path decoding circuit 105 decodes the encoded signal received over a transmission channel based on the YP _B P _R signal output. Among the outputs of the transmission path decoding circuit 105, the Y signal, which is a luminance signal, is input to the Y processing circuit 106, where luminance contrast adjustment and various signal processing are performed. Further, of the output of the transmission path decoding circuit 105, the color signal P _B and P _R are necessary processing respectively by the color processing circuit 107 is performed. The signal conversion circuit 108 converts the processed Y and color signals output from the Y processing circuit 106 and the color processing circuit 107 into RGB signals and outputs them to the display device 109. The display device 109 receives the RGB signal output from the signal conversion circuit 108 and performs screen display.

  In the signal transmission system according to the first embodiment, since the Y color difference signal output from the MPEG decoder 102 is encoded and transmitted as it is, the Y color difference signal is transmitted on the video signal output device 101 side (transmission side). A circuit for converting to an RGB signal can be eliminated, and a Y color difference signal is input as it is on the display device 104 side (reception side). Can be simple.

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

In FIG. 2, reference numeral 201 denotes a video signal output device such as an STB, which outputs a video signal. An MPEG decoder 202 receives a broadcast such as a digital broadcast and outputs one luminance signal and two color difference signals. 203 is a division multiplex circuit time, time-division multiplexes P _B and P _R of the output color difference signals from the MPEG decoder 202 is converted into a single signal line. 204 is a transmission path encoding circuit, transmitted coded P _B P _R signals multiplexed output from the Y signal and the time-division multiplexing circuit 203 which is output from the MPEG decoder 202 into a signal form to the transmission path To do. Reference numeral 205 denotes a display device such as a television monitor, which displays a video signal. 206 is a transmission path decoding circuit, and outputs the decoded to the original Y signal and multiplexed signals transmitted channel coding P _B P _R signals. A separation circuit 207 separates the multiplexed P _B P _R signal into the original P _B signal and P _R signal. A Y processing circuit 208 processes the Y signal output from the transmission path decoding circuit 206. 209 denotes a color processing circuit, the processing is performed on the separated P _B signal and P _R signals. 210 is a signal conversion circuit, converts the input YP _B P _R signals into RGB signals, 211 is a display device, and displays the RGB output of the signal conversion circuit 210.

The operation of the signal transmission system configured as described above will be described.
MPEG decoder 202 outputs the three signal lines of YP _B P _R Y and the color difference signal of a base band by receiving and decoding a video signal to the time division multiplexing circuit 203. 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.

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 the P _B P _R signal is time-multiplexed, the separation circuit 207 restores the original P _B signal and P _R signal. Then, Y processing circuit 208 performs predetermined processing on the luminance signal Y, the color processing circuit 209 performs 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.

Since the signal transmission system according to the second embodiment includes the time division multiplexing circuit 203 that multiplexes two color difference signals and outputs them to one signal line, the first embodiment requires three transmission lines. However, this embodiment has an advantage that only two transmission lines are required.
Embodiment 3 FIG.

The signal transmission system according to the third embodiment of the present invention will be described below with reference to FIGS.
FIG. 3 is a block diagram showing an outline of the configuration of the signal transmission system according to the third embodiment of the present invention.

In FIG. 3, reference numeral 301 denotes an STB that performs digital broadcast reception and outputs a video signal. Reference numeral 302 denotes a television monitor that displays a video signal received from the STB 301. Note that I ² C bidirectional communication is possible between the STB 301 and the television monitor 302.

  FIG. 4 is a block diagram for explaining the STB 301 and the television monitor 302 in detail. In the figure, the same or corresponding components as those in FIG.

In FIG. 4, reference numeral 402 denotes an MPEG decoder that receives digital broadcasts and outputs a video baseband signal. A video output interface 403 outputs the video signal output from the MPEG decoder 402. A CPU 404 is operated by the program ROM 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 which inputs 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 CRT. Reference numeral 411 denotes an I ² C controller that controls the I ² C bus, and has a ROM table 412 that stores therein information related to the performance of the television monitor 302. The ROM table 412 relates to information on the resolution of video that can be output from the display device 410, information on the number of audio channels that can be output from the display device 410, and a signal conversion method that converts luminance signals and color difference signals into RGB signals. Information, information relating to gamma correction of the video signal, information relating to whether or not the television monitor 302 has a mode in which the video is not enhanced, and information relating to the manufacturer code and device code of the television monitor 302. Also, the television monitor 302 outputs to the STB 301 what aspect conversion processing is currently being performed and video output via the I2C controller 411.

The operation of the signal transmission system configured as described above will be described with reference to FIG. 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 the manufacturer code and device code of the TV monitor 302 (S1). The TV monitor 302 returns the manufacturer code and the device code from the ROM table 412 to the STB side 301 (S2).

  If the received manufacturer code and device code are known, the STB 301 ends the protocol (S3). If the received manufacturer code and device code are not known, the STB 301 asks what scanning speed the television monitor 302 supports (S4). The television monitor 302 answers the scan rate that it can scan (S5).

  Next, the STB 301 side asks what kind of sound the television monitor 302 side can reproduce (S6). The TV monitor 302 returns the number of sound channels that it can output (S7). This completes the initial protocol between the STB 301 and the television monitor 302.

  Next, as a case 1, it is assumed that the STB 301 receives a broadcast having 480i LR2 channel audio. In this case, the STB 301 knows that the TV monitor 302 can output 480i and 2-channel LR by the initial access negotiation, so that the STB 301 outputs the data to the TV monitor 302 as it is without processing the display rate or sound. .

  In another case, as case 2, when the broadcast reception is a 1080i 5.1 channel broadcast, the initial protocol negotiation indicates that STB 301 cannot receive 1080i on the connected TV monitor 302. Therefore, conversion from 1080i to 480p is performed on the STB 301 side. The conversion to 480p is performed because it is known in the previous negotiation that the television monitor 302 can display a display rate up to 480p. Also, since it is known that 5.1-channel audio cannot be played back by a connected TV monitor, the STB 301 side performs a process of downmixing to 2-channel LR, resulting in video data. Outputs 480p, and audio data outputs LR downmix 2 channels.

Here, the ROM table 412 in the I ² C controller 411 in the television monitor 302 will be described with reference to FIG. For example, in the address 01, 4 bits representing a displayable rate are stored. For example, a TV monitor capable of displaying a 480i 299.7 Hz signal has a value of 0000. . Further, the address 02 stores the number of channels that can output sound, and if 6 channels can be decoded, a value such as 0006 is entered. Such codes are standard in address and numerical values in the industry, so even if the TV monitor is a manufacturer unknown to the STB, the minimum protocol is determined, so no video is displayed. Or, it is possible to avoid situations such as an image with an abnormal aspect or no sound. That is, it is possible to avoid the problem that the transmission side cannot transmit images by transmitting at a frame rate that cannot be withdrawn on the PC monitor side or the television monitor side as in the conventional case.

  As described above, in the signal transmission system according to the third embodiment, since the STB outputs after knowing the performance of the TV monitor, the STB may output a rate that cannot be scanned on the TV monitor side. By performing such negotiation, problems such as no video or no sound can be avoided on the television monitor side.

  Further, when the TV monitor transmits the manufacturer code and the device code to the STB, if the manufacturer and the device code are between manufacturers that disclose information between the STB and the TV monitor, for example, image up-conversion is performed. It is possible to automatically select the better one by comparing the performance of each up-conversion that the STB should do or leave it to the TV monitor side.

  In addition, as an example of initial access, an example in which only the 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 pairs. If the normal TV 3 is known, the correct aspect can be automatically obtained by automatically performing letterbox conversion or pan-scan conversion on the STB side and outputting. 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 prior art.

  In general, a television monitor does not output a received signal as it is, but particularly enhances and outputs luminance and color. However, in some cases, it is not desirable for a user such as a personal computer to intentionally manipulate the brightness and color. Therefore, the STB side is notified of the enhancement characteristics on the TV monitor side, and the enhancement is reversely corrected on the STB side. If a signal is output in advance, a video signal that is not enhanced can be output to the television monitor as a total.

  In addition, if a mode that does not enhance is provided on the television monitor side, it is possible to forcibly switch from the STB side to that mode, thereby ensuring reproduction without color enhancement.

  Next, when the connected monitor is a wide TV, it is common for the TV to have a display mode such as a wide mode or a normal mode. For example, when a 16-to-9 monitor is connected, it is received by the STB. If the material is 16: 9, the STB is output without aspect conversion as it is, but when the TV setting is set to normal display, as shown on the right side of FIG. It may happen that the image appears vertically long. In this case, a normal aspect image can be obtained by setting the TV side to the full display mode from the STB side. Note that FIG. 6 shows a 16: 9 picture with the output expected on the left side, and a picture of an incorrect aspect when the setting on the TV side becomes normal due to the right side.

Further, Y color difference signals rather than RGB signals between the STB and the TV monitor, that is, when transmitting a signal such as a YP _B P _R, when conversion formula for converting the TV side based on the RGB signals are different Since there is, it is also possible to transmit the conversion formula itself. Since the conversion formula is described in the MPEG stream data, the conversion formula extracted on the STB side is transmitted to the television monitor side via I ² C, so that it can be converted to the correct RGB on the television monitor side.

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

Embodiment 4 FIG.
The signal transmission system according to the fourth embodiment of the present invention will be described below with reference to FIGS.

  FIG. 12 is a diagram showing a configuration of a selector included in the video output interface on the transmission side of the signal transmission system according to the fourth embodiment of the present invention. Note that the difference from the third embodiment is that the video output interface 403 has a selector.

  In FIG. 12, a selector (selector) 1201 temporally selects a red color signal R and other control signals CTL0 by DE. The selector 1202 temporally selects the green signal G and the control signal CTL1. The selector 1203 temporally switches between the blue signal B and the HV sync signal. Here, DE is a signal for discriminating between the image scanning period and the blanking period.

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

  As the R signal and the CTL0 signal are input, the selector 1201 operates to pass the R signal when the DE signal is at the HIGH level and to pass the CTL0 signal when the DE signal is LOW. As a result, an R signal is input during the video period, and a CTL0 signal, that is, control data can be transmitted during the blanking period. In the blanking period, when the output video rate is interlaced, the blanking period is as shown on the left side of FIG. 8, and when progressive, the chart is 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, an inquiry about the manufacturer code and the device code is first made from the STB to the television side (S12). If the TV monitor is a device that was shipped before standardization, it is normal that an inquiry for the manufacturer code and device code cannot be answered, so in this case 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, it 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 manufacturer code and the device code, it is determined whether or not the STB is a known type (S14). In that case, if the type is a known type, the process ends, and the connected monitor knows all the performance on the STB side, so that the optimum video and audio output can be changed in combination with the STB itself. (S15). If it is detected in S14 that the type is not known (UNKNOWN_TYPE), the rate and the number of audio channels that can be displayed on the display are checked in order. STB determines that basic standards such as volume adjustment, mute, brightness, contrast adjustment, etc. can be created and used.

  FIG. 11 shows an example of the structure of the control data. For example, the header has a reservation pattern in which “01” is continued for 2 bytes, and then a read for reading the state on the TV side from the STB to the TV. One byte of R / W data for identifying the address, the address indicating what to write at the address on the TV side, and the value of the value to be written or read Configure control data. With the control data having such a configuration, a desired command can be sent to the television side.

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 the reception television monitor itself. Reference numeral 1302 denotes a video input interface which inputs a video signal received via a transmission path. A control data separator 1303 separates only control data from the video signal. Reference numeral 1304 denotes a temporary storage unit that temporarily stores control data. Reference numeral 1305 denotes an image quality control unit that corrects the image quality of the video signal. A device interface 1306 is an interface to the display device 1307. 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 characteristics. Reference numeral 1309 denotes an I ² C controller which controls the I ² C bus. A ROM table 1310 in the I ² C controller 1309 describes the performance of the television monitor 1301. Assuming that basic commands such as brightness, contrast, and volume are standardized in the industry, the control data is interpreted by the CPU 1308, and the CPU 1308 controls the image quality control unit 1305.

  Further, since the data accompanying each frame is preferably input to the image quality control unit 1305 without intervention of the CPU 1308, the control data separation unit 1303 also outputs a control signal directly to the image quality control unit 1305. . Examples of control signals include whether the decoded image is an I picture, a P picture, or a B picture, and whether the material for each frame is captured progressively or interlaced It is the information showing another.

  By having such a configuration on the receiving side, it is possible to operate the TV monitor side as a control from the STB with the minimum necessary items such as brightness, contrast, and volume, and to transmit a control signal for each frame, The STB can perform image quality control for each frame.

  FIG. 14 is a diagram illustrating an example of a control signal to be sent for each frame. Here, an example in which information of telecine is superimposed is described. In the case of a telecine image, there is a field that is output by repeating the field, and conventionally it has a field memory on the receiving side, and it performs scanning conversion by detecting whether it is a field repeat by taking the difference between them. It was.

  FIG. 15 is a block diagram showing a conversion circuit for converting from a conventional 24p telecine material to, for example, 60p. In FIG. 15, reference numerals 1501, 1502, and 1503 denote field memories that are delayed by one field and output. The correlation calculation means 1504 takes a correlation between the received signal delayed by the field memory and the current signal for each pixel, and if there is a correlation, determines that the current field is a field-repeat. , And operates to control the selection means 1505 for selecting which output of the field memory is output from each field memory. In such conventional field repeat detection means, the correlation calculation has the disadvantage that the calculation amount becomes very complicated and the hardware becomes heavy when trying to increase the detection accuracy, and the case of a very similar pattern There was a problem that false detection could not be avoided.

  Therefore, in order to solve the above problem, in this embodiment, as shown in FIG. 16, a field repeat signal transmission method is used.

  In FIG. 16, reference numeral 1601 denotes an MPEG decoder that decodes a broadcast wave and outputs a baseband video signal. At the same time, information on whether the frame included in the broadcast wave stream is a top field or a bottom field, and field repeat Outputs information on whether or not Reference numeral 1602 denotes a transmission line encoding circuit, which encodes and outputs the RGB signal output from the MPEG decoder 1601 during the scanning period, and outputs the top and bottom information according to the control data described above during the return period. And field repeat information is superimposed. Reference numeral 1603 denotes a transmission path decoding circuit, which decodes a signal received via the transmission path into original RGB, matrix-converts the RGB signal into a Y color difference signal, and outputs it. Reference numerals 1604, 1605, and 1606 denote field memories that respectively delay the video signal by one field. Reference numeral 1607 denotes a blanking period code analyzing means for extracting information superimposed on the control data from the output of the transmission path decoding circuit 1603. A selection unit 1608 receives an output from the control period code analysis unit 1607 and selects a field memory from which an output is to be output.

  By configuring in this way, the blanking period code analyzing means 1608 can reproduce the top / bottom information and field repeat information superimposed on the transmission side without error, so that the correct field repeat information and top / bottom information can be reproduced. Can be used to obtain a Y output signal.

  Next, an output image when 24p to 60p is converted on the television monitor side using such means and output will be described with reference to FIG. In FIG. 14, A1 represents the first field of frame A, and A2 represents the second field of the same frame A. The TV monitor input signal is assumed to be a case where A1, which is field-repeated once again with A1 and A2, for example, comes in time. In that case, as the output signal of the television monitor, first, one frame composed of A1 and A2 is outputted, and the frame made from A1 and A2 is outputted at the next time. Here, if 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 made from A1 and A2 if detected correctly. The correct picture is synthesized, but if there is a false detection at this time, there was a problem that it was not reproduced correctly. In the configuration as shown in FIG. 16, since it is determined whether or not the field is a repeat field based on the top / bottom information and field repeat information of the MPEG stream information superimposed on the broadcast station side, Will be reproduced correctly.

  In the fourth embodiment, the description has been given of the 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. This information can also be superimposed in the same manner. However, the I picture is an intra-coded image, the P picture is an image using a difference between frames, and the B picture is an image encoded using a bidirectional difference. This makes it possible to set noise removal parameters for each frame. Conventionally, since baseband video signals do not know whether each frame is an I picture, a B picture, or a P picture, noise removal cannot be performed adaptively.

  As another example, MPEG compression rate information can be superimposed. In this case, the MPEG compression rate can be obtained as many megabits / second video stream from the header of the MPEG elementary stream. Furthermore, since the horizontal, vertical size, and frame rate can be obtained, the parameters for noise removal can be set by notifying the television side of the relationship between the horizontal and vertical sizes and the frame rate. In this way, since the information regarding the MPEG compression rate is not known on the transmission side as in the prior art, the problem that appropriate processing cannot be performed can be avoided.

  Furthermore, as another example, since it is possible to know from the header of the MPEG stream whether the material is captured by a progressive camera or an interlaced camera, this information can be transmitted as similar control data. it can. This data can be used to select a method of IP conversion, that is, conversion from interlace to progressive, on the television monitor side. Therefore, conventionally, a motion detection circuit is necessary to perform accurate IP conversion. The motion detection circuit is used to perform progressive interpolation for a still area and interpolate a moving picture area as an interlace. Then it becomes unnecessary. In addition, even if the material is interlaced, even if a graphics layer such as OSD is placed on the majority of the screen, it is appropriate to insert it progressively. Since it is known internally, a correct interpolation can be performed by transmitting a control signal as a progressive signal at that time.

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

  In the second embodiment, since the color difference signals are multiplexed into one, the three signal lines are required in the first embodiment, but all the video signals are transmitted through the two transmission lines. Therefore, it is possible to transmit a signal for distinguishing the natural image output from the MPEG decoder and the OSD area using the remaining one signal line. By transmitting this signal, even if an IP conversion error occurs during broadcasting of 480p, it can be displayed with high image quality without affecting the data broadcasting of 480p. In addition, it has a feature that the processing of characters and natural images can be separated for each pixel.

  In the second embodiment, since only two transmission lines are required, the remaining one can be defined as a user-defined signal line.

  Although FIG. 4 describes the case where the device that outputs the video signal is the STB, the same configuration can be applied to a digital camera or notebook PC that requires power saving. In the case of a portable terminal such as a digital camera or a notebook PC, a still image is transmitted. Therefore, the video input interface 408 on the TV monitor side or, for example, the image control unit 1305 of the TV monitor main body has a memory. In this case, the control side (mobile terminal side) instructs the TV monitor side to first check the presence or capacity of the memory by 11C bus control or control using CTL0 or CTL1, and then store it in the memory. Next, the control side (portable terminal side) sends one sheet or the number of sheets in the memory capacity of the television monitor side to the television monitor side through the video output interface 403 in accordance with a user instruction. The TV monitor side 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 TV monitor does not have a memory in the first confirmation of the presence or absence of memory, a video signal is always output in the same way as a moving image. In addition, in the case of a PC or the like, the same control is performed every time the internal video is changed, and therefore, when the video of the PC is changed, still data is transmitted in the above sequence. By doing so, it is possible to continue displaying the still image held on the television monitor side 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 such as a digital camera on the video signal generation side needs to operate only when transmitting one still image, which has the effect of saving power. In addition, by repeating this still image transmission in time, for example, by repeatedly sending a still image every second or resting, it is possible to transmit an image such as motion JPEG with high efficiency and power saving. Is also possible.

  The signal transmission system according to the present invention can perform appropriate processing on the baseband video signal based on information about the new image signal before decoding the baseband video signal, and can transmit the video signal. This is useful for digital cameras, notebook PCs, and the like that require simpler hardware configurations on the reception side and on the reception side, and that require higher image quality and lower power consumption.

1 is a block diagram illustrating a configuration of a signal transmission system according to a first embodiment. 6 is a block diagram illustrating a configuration of a signal transmission system according to a second embodiment. FIG. FIG. 6 is a schematic configuration diagram of a signal transmission system according to a third embodiment. FIG. 10 is a block diagram showing a detailed configuration of a signal transmission system according to a third embodiment. FIG. 10 is a diagram for explaining an initial protocol in a signal transmission system according to a third embodiment. It is a figure which shows the mode of the screen display of the television which is a 16: 9 wide material. It is a figure which shows an example of a ROM table. It is a figure for demonstrating a blanking period in each of the case where an output video rate is an interlace, and a case where it is progressive. It is a flowchart figure for demonstrating operation | movement of the signal transmission system by Embodiment 4 of this invention. It is a figure for demonstrating operation | movement of a selector. It is a figure which shows the structural example of control data. FIG. 10 is a diagram illustrating a configuration of a selector in a signal transmission system according to a fourth embodiment. FIG. 10 is a block diagram illustrating a configuration of a reception side of a signal transmission system according to a fourth embodiment. FIG. 10 is a diagram illustrating an example of a control signal transmitted for each frame in the signal transmission system according to the fourth embodiment. It is a block diagram which shows the conversion circuit in the case of converting from the conventional 24p telecine material to 60p, for example. FIG. 10 is a diagram illustrating a field repeat signal transmission scheme in the fourth embodiment. It is a block diagram which shows the structure of the conventional signal transmission system.

Explanation of symbols

101, 201 Video signal output device 102, 202 MPEG decoder 103, 204 Transmission path coding circuit 104, 205 Display device 105, 206 Transmission path decoding circuit 106, 208 Y processing circuit 107, 209 Color processing circuit 108, 210 Signal conversion Circuits 109 and 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 Selector 1303 Control data separation unit 1304 Temporary storage unit 1305 Image quality Control unit 1308 CPU

Claims (1)

In a transmission device that digitally transmits a video signal via a transmission path,
A transmission path encoding unit for time-division multiplexing a baseband luminance signal and a color difference signal obtained by decoding a stream compressed in accordance with the MPEG standard in a video period and a control signal in a blanking period;
An interface for receiving receiving device information via an I2C (Inter IC control) bus,
The type of the control signal includes information used to control the image quality and information used when generating the baseband signal and describing the nature of the stream compressed in accordance with the MPEG standard .
Further, the transmission device outputs an audio signal,
A transmission apparatus that outputs the luminance signal, the color difference signal, and the audio signal so as to perform output that can be displayed on the reception apparatus based on the reception apparatus information.

Images