JP3573724B2 - Transmission system, transmission device, reception device, and transmission method, transmission method, reception method - Google Patents

Description

[0001]
TECHNICAL 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]
[Prior 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 a video signal output device (transmission side) such as an STB (Set-top box), which 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 which 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. Reference numeral 1705 denotes a display device (reception side) such as a television monitor. A transmission line decoding circuit 1706 decodes a signal encoded by the transmission line encoding circuit 1704. Reference numeral 1707 denotes a signal conversion circuit which converts the RGB signals output from the transmission path decoding circuit 1706 into YP signals._BP_RConvert to a signal. 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 converts the Y color difference signal into an RGB signal. A display device 1711 receives an output of the signal conversion circuit 1710 and outputs it to an LCD or a CRT.
[0003]
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 data format of MPEG is a Y color difference signal, the output here is YP_BP_ROr YUV or YC_bC_rIt is. In addition, since this signal must be subjected to RGB conversion in order to perform transmission path coding, the Y color difference signal is converted into an RGB signal by the signal conversion circuit 1703. The converted RGB signal is encoded by a transmission path encoding circuit 1704 into a signal form suitable for the transmission path.
[0004]
On the other hand, on the television monitor 1705 side, the transmission line decoding circuit 1706 receives the encoded signal from the transmission line encoding circuit 1704 and generates the original RGB signal. The RGB signal is converted to YP of the Y color difference signal by the signal conversion circuit 1707._BP_RIs converted to Here, in order to perform unique processing on the side of the television monitor 1705, the Y signal is processed by the Y processing circuit 1708, and the color signal P_BP_RAre enhanced by the color processing circuit 1709 and output. The enhanced and output Y color difference signal is converted to an RGB signal by a signal conversion circuit 1710 for output to the last display device 1711. The display device 1711 can display by outputting the RGB signals output from the signal conversion circuit 1710.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional signal transmission system, since the transmission path encoding is performed using RGB signals, the output of the MPEG decoder is once converted into RGB signals, encoded and transmitted, and transmitted on the transmission path. In order to perform signal processing again, the RGB signal is converted to YP_BP_RIn order to output the RGB signals to the last display device as RGB signals, it is necessary to convert the Y color difference signals into RGB signals again, which has a disadvantage that much hardware is required. Was.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and has as its object to provide a signal transmission system capable of simplifying hardware configurations of a video signal transmitting side and a video signal receiving side.
[0007]
[Means for Solving the Problems]
In order to solve the above problems,A transmission system according to a first aspect of the present invention is a transmission system for digitally transmitting a video signal via a transmission path, wherein a compression-encoded signal is compressed and decoded, and a baseband luminance signal, a color difference signal, and the compression-encoded signal are transmitted. Compression decoding means for outputting a control signal used for controlling the image quality included in the image signal, the luminance signal and the chrominance signal are in a video period, the control signal is time-division multiplexed in a retrace period and transmitted to the transmission line. Channel coding means for coding into a suitable channel coded signal and I2C ( Inter IC control A) an I2C controller for outputting a signal; and a CPU for controlling the I2C controller and the compression / decoding means. The compression / decoding means is provided to the receiving device by the CPU based on the receiving device information received via the I2C controller. A transmission device controlled to perform output that can be displayed in, a transmission line decoding unit that decodes the transmission line encoded signal into the luminance signal, the color difference signal, and the control signal, and the reception device information. A ROM table to be stored, an I2C controller that outputs the receiving device information stored in the ROM table to the transmitting device according to the I2C signal output from the transmitting device, and the luminance signal and the luminance signal based on the control signal. And a picture quality control means for controlling the picture quality of the color difference signal.
This makes it possible to simplify the hardware configuration of the transmitting side and the receiving side of the video signal.transmissionThe system is feasible.
[0009]
Also,Since the transmitting device can know the performance of the signal receiving device in advance and transmit the signal based on the performance of the signal receiving device without transmitting a rate that cannot be scanned by the signal receiving device as in the related art, the signal receiving device side Can avoid problems such as no video or no sound.
[0017]
Also,Control information indicating whether or not the currently output video frame signal is generated by repeated output in the MPEG decoder.,Output multiplexed during vertical blanking interval of image signalByBased on the minimum required control informationReceiverCan be operated.
[0018]
In addition, transmissionsystemofControl informationButThat can classify I, P, and B pictures representing picture encoding schemes of the MPEG standardBeingWith this, parameters for removing noise can be set for each frame.transmissionThe system is feasible.
[0019]
Further transmissionsystemofControl informationBut, MPEG standard compression rate informationBeingWith this, parameters for removing noise can be set for each frame.transmissionThe system is feasible.
[0020]
In addition, transmissionsystemofControl informationBut, Information indicating whether the material before MPEG encoding was captured by progressive scan or interlaced scanByThe signal receiving device can select a conversion method from interlace to progressive.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment described here is merely an example, and the present invention is not necessarily limited to this embodiment.
[0022]
Embodiment 1 FIG.
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.
[0023]
In FIG. 1, reference numeral 101 denotes a video signal output device such as an STB, which outputs a video signal. An MPEG decoder 102 performs digital broadcast reception and the like, and outputs one luminance signal and two color difference signals. A transmission line encoding circuit 103 encodes the luminance signal and the chrominance signal output from the MPEG decoder 102 into a signal form suitable for the transmission line and transmits the signal. 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. A Y processing circuit 106 processes the decoded luminance signal output from the transmission path decoding circuit 105. A color processing circuit 107 processes a color signal among signals output from the transmission path decoding circuit 105. A signal conversion circuit 108 converts the Y color difference signals output from the Y processing circuit 106 and the color processing circuit 107 into RGB signals. A display device 109 receives an output from the signal conversion circuit 108 and performs display on a display or the like.
[0024]
The operation of the signal transmission system configured as described above will be described.
The MPEG decoder 102 receives the broadcast wave of the digital broadcast, and complies with the baseband YP according to the MPEG standard._BP_RThe signal of is output. Here, in the conventional signal transmission system, the RGB signal is encoded and transmitted instead of the Y color difference signal._BP_RIs converted to an RGB signal. However, in the signal transmission system according to the first embodiment, the YP_BP_RIs directly input to the transmission line encoding circuit 103 that performs encoding along the transmission line. The transmission path encoding circuit 103 receives the input YP_BP_RThe signal is encoded into a signal form along the transmission path, and the encoded signal is output to the transmission path.
[0025]
The transmission line decoding circuit 105 converts the encoded signal received via the transmission line into the original YP_BP_RThe signal is decoded and 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. Also, among the outputs of the transmission path decoding circuit 105, P_BAnd P_RThe color signals of are subjected to necessary processing by the color processing circuit 107. 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 the RGB signals to the display device 109. The display device 109 receives a RGB signal output from the signal conversion circuit 108 and displays a screen.
[0026]
In such a signal transmission system according to the first embodiment, since the Y color difference signal output from the MPEG decoder 102 is directly encoded and transmitted, the video signal output device 101 (transmitting side) converts the Y color difference signal to the Y signal. A circuit for converting an RGB signal into an RGB signal can be eliminated, and a circuit for converting an RGB signal into a Y color difference signal can be eliminated since the Y color difference signal is directly input to the display device 104 (reception side). Can be simplified.
[0027]
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.
[0028]
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. Numeral 203 denotes a time division multiplexing circuit, which outputs the P of the color difference signal output from the MPEG decoder 202._BAnd P_RAre time-division multiplexed and converted into one signal line. Reference numeral 204 denotes a transmission line encoding circuit, which is a Y signal output from the MPEG decoder 202 and a multiplexed P signal output from the time division multiplexing circuit 203._BP_RThe signal is encoded into a signal form suitable for the transmission path and transmitted. A display device 205 such as a television monitor displays a video signal. Reference numeral 206 denotes a transmission line decoding circuit which converts the transmission line encoded signal into the original Y signal and the multiplexed P signal._BP_RThe signal is decoded and output. Reference numeral 207 denotes a separation circuit, which is a multiplexed P_BP_RSignal to the original P_BSignal and P_RSeparate signals. A Y processing circuit 208 processes the Y signal output from the transmission path decoding circuit 206. Reference numeral 209 denotes a color processing circuit._BSignal and P_RPerform processing on the signal. Reference numeral 210 denotes a signal conversion circuit which receives the input YP_BP_RA display device 211 for converting a signal into an RGB signal displays the RGB output from the signal conversion circuit 210.
[0029]
The operation of the signal transmission system configured as described above will be described.
The MPEG decoder 202 receives and decodes the video signal, thereby obtaining the baseband Y and the YP of the color difference signal._BP_RAre output to the time-division multiplexing circuit 203. P_BSignal and P_RSince the signal has a horizontal sampling frequency half that of Y, the time division multiplexing circuit 203_BSignal and P_RTime-division multiplexing is performed on the signal, and P_BSignal and P_RThe signals are alternately arranged and output on one line. The transmission line encoding circuit 204 outputs the multiplexed signal P_BP_RAnd the Y signal output from the MPEG decoder 202 is encoded according to the transmission path and transmitted to the display device 205 side.
[0030]
The transmission path decoding circuit 206 converts the signal received via the transmission path into the original luminance signal Y and the multiplexed signal P._BP_RAnd outputs the result to the separation circuit 207. P_BP_RSince the signals are time-multiplexed, the separation circuit 207 outputs the original P_BSignal and P_RReturn to signal. Then, the Y processing circuit 208 performs predetermined processing on the luminance signal Y, and the color processing circuit 209 performs_BAnd P_RIs subjected to predetermined color processing. The YP thus obtained_BP_RThe signal is converted to an RGB signal by the signal conversion circuit 210, and the RGB signal is input to the display device 211 and displayed.
[0031]
The signal transmission system according to the second embodiment includes the time division multiplexing circuit 203 that multiplexes two color difference signals and outputs the multiplexed signal to one signal line. Therefore, the first embodiment requires three transmission paths. However, this embodiment has an advantage that only two transmission paths are required.
[0032]
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 Embodiment 3 of the present invention.
[0033]
In FIG. 3, reference numeral 301 denotes an STB that performs digital broadcast reception and the like, and outputs a video signal. Reference numeral 302 denotes a television monitor that displays a video signal received from the STB 301. In addition, between the STB 301 and the television monitor 302, I²It is assumed that bidirectional communication of C is enabled.
[0034]
FIG. 4 is a block diagram for describing the STB 301 and the TV monitor 302 in detail. In the figure, the same or corresponding components as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.
[0035]
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. A CPU 404 is operated by the program ROM 405 and controls the MPEG decoder 402 and its periphery. Also, the CPU 404²The C controller 406 can also be controlled. 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. 411 is I²C controller and I²It controls the C bus and has therein a ROM table 412 for storing information on the performance of the television monitor 302. Note that the ROM table 412 includes 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 the display device 410, and a signal conversion method for converting a luminance signal and a color difference signal into RGB signals. The information includes information relating to gamma correction of the video signal, information relating to whether or not the television monitor 302 has a mode in which video is not subjected to enhancement processing, and information relating to a maker code and a device code of the television monitor 302. Also, the television monitor 302 outputs to the STB 301 via the I2C controller 411 what kind of aspect conversion processing is currently being performed to output video.
[0036]
FIG. 5 illustrates the operation of the signal transmission system configured as described above. Here, I²The initial protocol by C will be described with reference to FIG.
First, the STB 301 asks the television monitor 302 for a maker code and a device code of the television monitor 302 (S1). The TV monitor 302 returns the maker code and the device code from the ROM table 412 to the STB side 301 (S2).
[0037]
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 TV monitor 302 corresponds to (S4). The television monitor 302 answers the scan rate at which the television monitor 302 can scan (S5).
[0038]
Next, the STB 301 asks what kind of sound the TV monitor 302 can reproduce (S6). The television monitor 302 returns the number of sound channels that can be output by itself (S7). Thus, the initial protocol between the STB 301 and the television monitor 302 ends.
[0039]
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 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 2, as a case 2, when the broadcast reception is a 5.1-channel broadcast of 1080i, the STB 301 sets an initial protocol negotiation that the connected TV monitor 302 cannot receive the image. Therefore, conversion from 1080i to 480p is performed on the STB 301 side. The conversion to 480p is performed because the TV monitor 302 knows that the display rate up to 480p is possible in the previous negotiation. Also, since it is known that 5.1-channel audio cannot be reproduced on the connected TV 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, the I in the TV monitor 302²The ROM table 412 inside the C controller 411 will be described with reference to FIG. For example, it is assumed that four bits representing a displayable rate are stored at address 01, and a value of 0000 is stored in a TV monitor capable of displaying a 480i 299.7 Hz signal, for example. . The number of channels that can output sound is stored at the address 02, and a value such as 0006 is stored if the number of channels that can be decoded is six. 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 video will not be displayed because the minimum protocol is fixed, Alternatively, it is possible to avoid a situation in which an image is projected in an abnormal aspect or 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 drawn on the PC monitor side or the television monitor side and cannot display an image as in the related art.
[0041]
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, conventionally, the STB may output a rate that cannot be scanned by the TV monitor. By performing such negotiation, it is possible to avoid problems such as no video or no sound on the television monitor.
[0042]
When the TV monitor transmits the maker code and the 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 image up-conversion is performed. Whether the STB should be performed or the TV monitor should be left can be automatically selected by comparing the up-conversion performance of each device.
[0043]
Also, as an example of the 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 a 4 TV monitor. If it is determined that the television is a normal television of No. 3, the correct aspect can be automatically obtained by automatically performing letter box 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 related art.
[0044]
In general, a television monitor does not output a received signal as it is, but outputs the signal with enhanced brightness and color among them. However, there is a case where it is not desirable for a user such as a personal computer to intentionally manipulate the luminance 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. By outputting the video signal in advance, it is possible to output a video signal which is not enhanced to the TV monitor side as a total.
[0045]
In addition, if a mode that does not enhance is provided on the television monitor side, the mode can be forcibly switched from the STB side to that mode, and reproduction without color enhancement can be ensured.
[0046]
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-to-9 monitor is connected, the reception mode is STB. If the material obtained is 16: 9, the STB is output without performing the aspect conversion as it is, but if the setting on the TV side is set to the normal display, as shown on the right side of FIG. It may happen that the image is displayed 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. FIG. 6 is a 16: 9 picture of the originally expected output on the left side, and the right side shows an incorrect aspect when the setting on the TV side is erroneously set to normal.
[0047]
Also, a Y color difference signal, that is, a YP_BP_RIn the case of transmission using such a signal, since the conversion formula for converting the original RGB signal on the television side may be different, the conversion formula itself can be transmitted. Since the conversion formula is described in the MPEG stream data, the conversion formula extracted on the STB side is expressed as I²By transmitting the data to the TV monitor via C, the TV monitor can convert the data into correct RGB.
[0048]
The data transmission in the signal transmission system according to the third embodiment may be multiplexed and transmitted using CTL0 or CTL1 of the video signal line as shown in FIG.
[0049]
Embodiment 4 FIG.
Hereinafter, a signal transmission system according to the fourth embodiment of the present invention will be described with reference to FIGS.
[0050]
FIG. 12 is a diagram illustrating a configuration of a selector included in a video output interface on a transmission side of a signal transmission system according to a fourth embodiment of the present invention. The difference from the third embodiment is that the video output interface 403 is provided with a selector.
[0051]
In FIG. 12, a selector (selector) 1201 temporally selects a red signal R and CTL0, which is another control signal, 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 distinguishing between an image scanning period and a blanking period.
[0052]
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 drawing, the DE signal is a HIGH period during a video period, and is a LOW signal during a retrace period.
[0053]
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, 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 state is a retrace period as shown on the left side of FIG. 8, and when the output video rate is progressive, the state is as shown on the right side of FIG.
[0054]
The operation of the signal transmission system configured as described above will be described with reference to FIG.
First, the STB inquires the TV side about the maker code and the device code (S12). If the TV monitor is a device that was shipped before the standardization, it is usually impossible to obtain an answer to the inquiry about the manufacturer code and device code. The process ends, and the STB understands that the connected monitor is I²C does not support TV monitor control function.²At C, it is determined that no control command is sent (S13).
[0055]
If there is a reply as a result of the inquiry about the maker code and the device 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). If it is detected in S14 that the type is unknown (UNKNOWN_TYPE), the rate at which the display can be displayed and the number of audio channels 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.
[0056]
FIG. 11 shows an example of the structure of control data. For example, 01 has a reserved pattern that continues for 2 bytes as a header, and then is it a write from the STB to the TV or a read to read the state of the TV? One piece of control data is composed of several bytes of R / W data for identifying the data, and then the address of what address to write on the television side, and the value of the data to be written or read. Constitute. With such a configuration of the control data, a desired command can be transmitted to the television.
[0057]
FIG. 13 is a block diagram showing a configuration of a receiving side, that is, a 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. Reference numeral 1304 denotes a temporary storage unit for temporarily storing control data. An image quality control unit 1305 performs image quality correction 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 processing. 1309 is I²C controller and I²Control the C bus. 1310 is I²It is a ROM table in the C controller 1309, and describes the performance of the television monitor 1301. Assuming that basic commands such as brightness, contrast, and volume are standardized in the industry, such control data is interpreted by the CPU 1308, and the CPU 1308 controls the image quality control unit 1305.
[0058]
Since it is desirable that data accompanying each frame be 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, and whether the material of each frame is progressive or interlaced. This is information indicating the distinction.
[0059]
By adopting such a configuration on the receiving side, it is possible to operate the television monitor side as control from the STB with the minimum necessary such as brightness, contrast, and volume, and to transmit a control signal for each frame, The STB can control image quality for each frame.
[0060]
FIG. 14 is a diagram illustrating an example of a control signal transmitted 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 by field repeat.Conventionally, the receiving side has a field memory, and by taking the difference between the two, it detects whether it is a field repeat and performs scan conversion. I was
[0061]
FIG. 15 is a block diagram showing a conversion circuit for converting a conventional 24p telecine material to, for example, 60p. In FIG. 15, reference numerals 1501, 1502, and 1503 denote field memories that output data with a delay of one field. Correlation calculation 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, judges that the current field has been subjected to field repeat. , And operates 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 a drawback that the calculation amount becomes extremely complicated and the hardware becomes heavy when trying to increase the detection accuracy. However, there is a problem that erroneous detection cannot be avoided.
[0062]
Therefore, in order to solve the above problem, in the present embodiment, as shown in FIG. 16, a method of transmitting a field repeat signal 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 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 according to the form of the control data described above during the flyback period. And the field repeat information. Reference numeral 1603 denotes a transmission line decoding circuit which decodes a signal received via the transmission line into original RGB, converts the RGB signal into a Y color difference signal, and outputs the result. Reference numerals 1604, 1605, and 1606 denote field memories that delay the video signal by one field. Reference numeral 1607 denotes a retrace 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 the output of the control period code analysis unit 1607 and selects which field memory to output the output from.
[0063]
With this configuration, the blanking period code analysis unit 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 the top / bottom information can be reproduced. Can be used to obtain a Y output signal.
[0064]
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. 14, A1 represents the first field of the 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 this case, as the output signal of the television monitor, first, one frame composed of A1 and A2 is output, and the next time, a frame made of A1 and A2 is also 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 there is an erroneous detection at this time, the picture is not correctly reproduced. In the configuration shown in FIG. 16 this time, whether or not a field is a repeat field is determined on the basis of the top and bottom information and field repeat information of the MPEG stream information superimposed on the broadcast station side. Will be reproduced correctly.
[0065]
In the fourth embodiment, the description has been given of the case where the field repeat and the 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, Can be similarly superimposed. 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 coded 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.
[0066]
Further, as another example, information on the MPEG compression ratio can be superimposed. In this case, the compression ratio of MPEG can be obtained from the megabit / second video stream from the header of the MPEG elementary stream. Further, since the horizontal and vertical sizes and the frame rate can also be obtained, by notifying the relationship between the horizontal and vertical sizes and the bit rate to the television side, it is possible to set noise removal parameters. With this configuration, unlike the related art, since the 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.
[0067]
Further, as another example, since it is also possible to know from the header of the MPEG stream information on whether the material is captured by a progressive camera or an interlaced camera, it is possible to transmit this information as similar control data. it can. Then, this data can be used for the selection of the method of IP conversion, that is, the method of conversion from interlace to progressive on the television monitor side. Therefore, in the past, a motion detection circuit was required to perform accurate IP conversion, and a still area was progressively interpolated using the motion detection circuit, and a moving image area was interpolated as an interlace. Then it becomes unnecessary. Even if the material is interlaced, if a graphics layer such as an OSD is placed on the majority 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.
[0068]
Further, in the data transmission of the signal transmission system according to the fourth embodiment, the data transmission with a slow transfer rate²Data may be sent using the C bus.
[0069]
In the second embodiment, since the color difference signals are multiplexed into one, three signal lines are required in the first embodiment, but all video signals are transmitted through two transmission paths. Therefore, it is possible to transmit a signal for distinguishing a natural image output from the MPEG decoder from an OSD area using the remaining one signal line. 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 characters and natural images can be separated for each pixel.
Further, in the second embodiment, since only two transmission paths are required, the remaining one can be defined as a user-defined signal line.
[0070]
Although FIG. 4 illustrates the case where the device that outputs the video signal is the STB, the same configuration can be applied to a digital camera or a notebook PC that 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 TV monitor side or a memory provided in, for example, the image quality control unit 1305 of the TV monitor main body. In such a case, the control side (portable terminal side) instructs the television monitor side to store the memory in the memory first by checking the presence or absence of the memory by 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 side can be continuously displayed on the TV 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 of the digital camera or the like on the video signal generating 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 second or resting, an image such as motion JPEG can be efficiently transmitted with low power consumption. Also becomes possible.
[0071]
【The invention's effect】
Transmission of the present inventionAccording to the system,It is possible to realize a signal transmission system that can simplify the hardware configuration of the image signal transmitting side and the image signal receiving side.
[0073]
Also,Since the transmitting device can know the performance of the signal receiving device in advance and transmit the signal based on the performance of the signal receiving device without transmitting a rate that cannot be scanned by the signal receiving device as in the related art, the signal receiving device side Can avoid problems such as no video or no sound.
[0081]
In addition,Video frame signal being outputIs MControl information indicating whether or not it is generated by repeated output in the PEG decoder,Output multiplexed during vertical blanking interval of image signalThan thatThe signal receiving device can be operated based on the minimum necessary control information.
[0082]
In addition, transmissionsystemofControl informationBut, P, and B pictures representing the picture encoding system of the MPEG standard can be classified, so that parameter setting for removing noise can be performed for each frame.transmissionThe system is feasible.
[0083]
In addition, transmissionsystemofControl informationBut, The compression ratio information of the MPEG standard allows the parameter setting for removing noise to be performed for each frame.transmissionThe system is feasible.
[0084]
In addition, transmissionsystemofControl informationButSince the information indicating whether the material before the MPEG encoding has been captured by the progressive scan or the interlace scan is information, the signal receiving apparatus can select a method of converting the interlace to the progressive. it can.
[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 the case where the output video rate is interlaced and the 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 illustrating 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 is a block diagram showing a conversion circuit for converting a conventional 24p telecine material into, for example, 60p.
16 is a diagram illustrating a method of transmitting a field repeat signal according to Embodiment 4. FIG.
FIG. 17 is a block diagram illustrating a configuration of a conventional signal transmission system.
[Explanation of symbols]
101,201 Video signal output device
102,202 MPEG decoder
103, 204 transmission line coding circuit
104, 205 display device
105,206 transmission line 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 I²C controller
408, 1302 Video input interface
409, 1306 Device interface
410, 1307 Display device
411,1309 I²C 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 (22)

In a transmission system for digitally transmitting a video signal via a transmission path,
Compression decoding means for compressing and decoding the compression coded signal and outputting a baseband luminance signal, a color difference signal, and a control signal used for controlling image quality included in the compression coded signal;
The luminance signal and the color difference signal are in a video period, the control signal is time-division multiplexed in a retrace period, and is a transmission line encoding unit that encodes the transmission signal into a transmission line encoded signal suitable for the transmission line,
I2C ( Inter IC control An I2C controller for outputting a signal;
A CPU for controlling the I2C controller and the compression / decoding means;
A transmitting device controlled by the CPU to perform an output that can be displayed on the receiving device based on the receiving device information received via the I2C controller;
Transmission path decoding means for decoding the luminance signal, the color difference signal, and the control signal from the transmission path encoded signal,
A ROM table for storing the receiving device information;
An I2C controller that outputs the receiving device information stored in the ROM table to the transmitting device according to the I2C signal output from the transmitting device;
A transmission system comprising: a reception device including: an image quality control unit configured to control image quality of the luminance signal and the color difference signal based on the control signal. In a transmission system for digitally transmitting a video signal and an audio signal via a transmission path,
Compression decoding means for compressing and decoding the compression coded signal and outputting a control signal used for controlling the image signal included in the audio signal, the baseband luminance signal, the color difference signal, and the compression coded signal,
The luminance signal and the color difference signal are in a video period, the control signal is time-division multiplexed in a retrace period, and is a transmission line encoding unit that encodes the transmission signal into a transmission line encoded signal suitable for the transmission line,
I2C ( Inter IC control An I2C controller for outputting a signal;
A CPU for controlling the I2C controller and the compression / decoding means;
A transmitting device controlled by the CPU to perform an output that can be displayed on the receiving device based on the receiving device information received via the I2C controller;
Transmission line decoding means for decoding the audio signal, the luminance signal, the color difference signal, and the control signal from the transmission line encoded signal,
A ROM table for storing the receiving device information;
An I2C controller that outputs the receiving device information stored in the ROM table to the transmitting device according to the I2C signal output from the transmitting device;
A transmission system comprising: a reception device including: an image quality control unit configured to control image quality of the luminance signal and the color difference signal based on the control signal. The transmission system according to claim 1, wherein the control signal is information indicating that an image of the compressed and decoded video signal is one of an I picture, a P picture, and a B picture. The transmission system according to claim 1, wherein the control signal is information indicating whether the image of the compressed and decoded video signal is captured progressively or interlaced. The transmission system according to claim 1, wherein the control signal is information indicating whether an image of the compressed and decoded video signal is a top field or a bottom field. The transmission system according to claim 1, wherein the control signal is field repeat information of an image of a video signal that has been compressed and decoded. The transmission system according to claim 1, wherein the control signal is information on an MPEG compression ratio. In a transmission device for digitally transmitting a video signal via a transmission path,
Compression decoding means for compressing and decoding the compression coded signal and outputting a baseband luminance signal, a color difference signal, and a control signal used for controlling image quality included in the compression coded signal;
The luminance signal and the color difference signal are in a video period, the control signal is time-division multiplexed in a retrace period, and is a transmission line encoding unit that encodes the transmission signal into a transmission line encoded signal suitable for the transmission line,
I2C ( Inter IC control An I2C controller for outputting a signal;
A CPU for controlling the I2C controller and the compression / decoding means;
A transmitting device, wherein the compression / decoding means is controlled by the CPU based on the receiving device information received via the I2C controller so as to perform an output which can be displayed on the receiving device. In a receiving device that receives a video signal digitally transmitted via a transmission path,
A control signal used for controlling image quality is time-division multiplexed during a retrace period and decoded together with the video signal from a transmission line coded signal suitable for the transmission line into a luminance signal, a color difference signal, and the control signal. Transmission path decoding means,
A ROM table for storing receiving device information, which is information indicating performance for enabling display, and an I2C ( Inter IC control An I2C controller that outputs the receiving device information stored in the ROM table to the transmitting device according to a signal;
A receiving unit comprising: an image quality control unit configured to control image quality of the luminance signal and the color difference signal based on the control signal. In a transmission device for digitally transmitting a video signal and an audio signal via a transmission path,
Compression decoding means for compressing and decoding the compression coded signal and outputting a control signal used for controlling the image signal included in the audio signal, the baseband luminance signal, the color difference signal, and the compression coded signal,
The luminance signal and the color difference signal are in a video period, the control signal is time-division multiplexed in a retrace period, and is a transmission line encoding unit that encodes the transmission signal into a transmission line encoded signal suitable for the transmission line,
I2C ( Inter IC control An I2C controller for outputting a signal;
A CPU for controlling the I2C controller and the compression / decoding means;
A transmitting device, wherein the compression / decoding means is controlled by the CPU based on the receiving device information received via the I2C controller so as to perform an output which can be displayed on the receiving device. In a receiving device that receives a video signal and an audio signal digitally transmitted through a transmission path,
The control signal used for controlling the image quality is time-division multiplexed during the retrace interval, and the audio signal and the luminance signal are obtained from a transmission path encoded signal that is encoded suitable for the transmission path together with the video signal and the audio signal. Transmission path decoding means for decoding into a color difference signal and the control signal,
A ROM table for storing receiving device information, which is information indicating performance for enabling display, and an I2C ( Inter IC control An I2C controller that outputs the receiving device information stored in the ROM table to the transmitting device according to a signal;
A receiving device comprising image quality control means for controlling the image quality of the luminance signal and the color difference signal based on the control signal. In a transmission method of digitally transmitting a video signal via a transmission path,
A compression decoding step of compressing and decoding the compression coded signal and outputting a baseband luminance signal, a color difference signal, and a control signal used for controlling image quality included in the compression coded signal;
The luminance signal and the chrominance signal are in a video period, the control signal is time-division multiplexed in a retrace period and is encoded in a transmission line encoding signal suitable for the transmission line,
I2C ( Inter IC control I) an I2C control step for outputting a signal;
Controlling the I2C control step and the compression / decoding step by a CPU;
The compression / decoding step is a transmission step in which the CPU controls the CPU to perform an output that can be displayed on the receiving device based on the receiving device information received through the I2C control step;
A transmission line decoding step of decoding the luminance signal, the color difference signal, and the control signal from the transmission line encoded signal,
Storing the receiving device information in a ROM table;
An I2C control step of outputting the receiving device information stored in the ROM table to the transmitting step according to the I2C signal output from the transmitting step;
An image quality control step of controlling the image quality of the luminance signal and the color difference signal based on the control signal. In a transmission method of digitally transmitting a video signal and an audio signal via a transmission path,
A compression decoding step of compressing and decoding the compression coded signal and outputting a control signal used for controlling an audio signal, a baseband luminance signal, a color difference signal, and image quality included in the compression coded signal,
The luminance signal and the chrominance signal are in a video period, the control signal is time-division multiplexed in a retrace period and is encoded in a transmission line encoding signal suitable for the transmission line,
I2C ( Inter IC control I) an I2C control step for outputting a signal;
Controlling the I2C control step and the compression / decoding step by a CPU;
A transmitting step in which the compression / decoding step is controlled by the CPU based on the receiving apparatus information received through the I2C control step so as to perform an output that can be displayed on the receiving apparatus;
A transmission line decoding step of decoding the audio signal, the luminance signal, the color difference signal, and the control signal from the transmission line encoded signal,
Storing the receiving device information in a ROM table;
An I2C control step of outputting the receiving device information stored in the ROM table to the transmitting device according to the I2C signal output from the transmitting step;
An image quality control step of controlling the image quality of the luminance signal and the color difference signal based on the control signal. 14. The transmission method according to claim 12, wherein the control signal is information indicating that an image of the compressed and decoded video signal is one of an I picture, a P picture, and a B picture. 14. The transmission method according to claim 12, wherein the control signal is information indicating whether the image of the compressed and decoded video signal has been captured progressively or interlaced. 14. The transmission method according to claim 12, wherein the control signal is information indicating whether an image of the compressed and decoded video signal is a top field or a bottom field. 14. The transmission method according to claim 12, wherein the control signal is field repeat information of an image of a video signal that has been compressed and decoded. 14. The transmission method according to claim 12, wherein the control signal is information on an MPEG compression ratio. In a transmission method of digitally transmitting a video signal via a transmission path,
A compression decoding step of compressing and decoding the compression coded signal and outputting a baseband luminance signal, a color difference signal, and a control signal used for controlling image quality included in the compression coded signal;
The luminance signal and the chrominance signal are in a video period, the control signal is time-division multiplexed in a retrace period and is encoded in a transmission line encoding signal suitable for the transmission line,
I2C ( Inter IC control I) an I2C control step for outputting a signal;
Controlling the I2C control step and the compression / decoding step by a CPU;
A transmitting method in which the compression / decoding step is controlled so as to perform an output which can be displayed on a receiving device by a CPU based on the receiving device information received via the I2C control step. In a receiving method for receiving a video signal digitally transmitted through a transmission path,
The control signal used for controlling the image quality is time-division multiplexed during the retrace period and transmitted together with the video signal A transmission line decoding step of decoding a transmission line encoded signal suitable for a channel into a luminance signal, a color difference signal, and the control signal,
A storage step of storing reception device information, which is information indicating performance for enabling display, in a ROM table;
I2C ( Inter IC control A) an I2C control step of outputting the receiving device information stored in a ROM table to the transmitting device according to a signal;
An image quality control step of controlling the image quality of the luminance signal and the color difference signal based on the control signal. In a transmission method of digitally transmitting a video signal and an audio signal via a transmission path,
A compression decoding step of compressing and decoding the compression coded signal and outputting a control signal used for controlling an audio signal, a baseband luminance signal, a color difference signal, and image quality included in the compression coded signal,
The luminance signal and the chrominance signal are in a video period, the control signal is time-division multiplexed in a blanking period and is a transmission line encoding step of encoding a transmission line encoded signal suitable for the transmission line,
I2C ( Inter IC control I) an I2C control step for outputting a signal;
Controlling the I2C control step and the compression / decoding step by a CPU;
A transmission method in which the compression / decoding step is controlled so that an output that can be displayed on a receiving device is performed by a CPU based on the receiving device information received through the I2C control step. In a receiving method for receiving a video signal and an audio signal digitally transmitted through a transmission path,
The control signal used for controlling the image quality is time-division multiplexed during the retrace interval, and the audio signal and the luminance signal are obtained from a transmission line encoded signal suitable for the transmission line together with the video signal and the audio signal. A transmission path decoding step of decoding into a color difference signal and the control signal,
A storage step of storing reception device information, which is information indicating performance for enabling display, in a ROM table;
I2C ( Inter IC control An I2C control step of outputting the receiving device information stored in the ROM table to the transmitting device according to a signal;
An image quality control step of controlling the image quality of the luminance signal and the color difference signal based on the control signal.

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