JPH08237610A - Video signal decoder - Google Patents

Abstract

PURPOSE: To switch one image to another instantaneously and to form one image by synthesizing output signals of the decoder. CONSTITUTION: A signal from an antenna terminal 1 is fed to demodulators 2, 3 and a demodulation signal of each channel to be demodulated is fed to a separator circuit 6 and the separated coding data are selected and fed to decoders 7-10. The decoded signal is fed respectively to picture element conversion circuits 11-14. Furthermore, a generating circuit 15 for a background signal is provided and the signals are fed to a synthesis circuit 16, in which the signals are synthesized in terms of an area. The digital signal synthesized in this way is fed to a D/A converter circuit 17, in which the signal is converted into an analog signal, and it is extracted at an output terminal 18. Furthermore, a selection signal or the like from a viewer is fed to a control circuit 5 through an input terminal 4 and the demodulators 2, 3, conversion circuits 11-14 and the synthesis circuit 16 or the like are controlled by a control signal to be generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal decoding apparatus suitable for use in receiving, demodulating and decoding digital television broadcasting, for example.

[0002]

2. Description of the Related Art For example, digital television broadcasting using broadcasting satellites has been carried out. In such digital television broadcasting, a transmission capacity of, for example, about 20 Mbps is provided for each channel, and it is designed so that so-called high definition television (HDTV) signals can be transmitted.

Therefore, for example, when transmitting a conventional standard definition television (SDTV) signal in such digital television broadcasting, one SDTV signal is compressed to about 5 Mbps by a technique such as image compression. It is possible to transmit four SDTV signals by the above-mentioned 1-channel broadcasting. Therefore, in the current digital television broadcasting, it is carried out to transmit four SDTV signals by one-channel broadcasting.

That is, in this case, on the transmitting side, for example, 4
Each of the SDTV signals has a vertical resolution (effective scanning line number) of 480 (pixels) and a horizontal resolution (effective horizontal pixel number) of 720 pixels. And these SDTV
Each signal is encoded by a motion compensation DCT encoding method or the like, and each is compressed to about 5 Mbps. Further, header information, synchronization information, etc. for identification are added to these compressed coded data, and four pieces of coded data added with these information and the like are multiplexed to obtain about 20 Mbps.
A bit string of is formed.

After this bit string is QPSK-modulated by a predetermined modulation carrier, for example, a modulated radio wave is transmitted toward a broadcasting satellite. When broadcasting is performed on a plurality of channels, for example, the above-mentioned multiplexed bit string of about 20 Mbps is formed for each channel, and after these bit strings are QPSK-modulated by different modulation carriers, respectively, For example, the modulated radio wave is transmitted toward the broadcasting satellite.

For such a digital television broadcast, the conventional video signal decoding device receives the signal as shown in FIG. 10, for example. That is, the electric wave retransmitted from the above-mentioned broadcasting satellite is received by a receiving antenna such as a parabolic antenna (not shown), and the antenna terminal 101
Is supplied to. Then, the signal from the antenna terminal 101 is supplied to the demodulator 102.

Further, an arbitrary selection signal or the like from the viewer is supplied to the control circuit 104 through the input terminal 103. Then, the control signal from the control circuit 104 is supplied to the demodulator 102, and the demodulator 1 is operated according to the input selection signal or the like.
The channel selected for demodulation at 02 and the SDTV signal to be decoded from that channel are selected.

Further, the demodulated signal of the selected SDTV signal is supplied to the decoder 105 and one of, for example, four SDTV signals transmitted in the selected one channel is decoded. Then, this decoded signal is supplied to the D / A conversion circuit 106 and converted into an analog signal, and the converted analog signal is taken out to the output terminal 107.

Thus, in the above-described conventional video signal decoding apparatus, the channel selected by the viewer is demodulated by the demodulator 102, and the SDTV signal selected from the demodulated one channel is decoded by the decoder 105. Then, it is taken out to the output terminal 107. This output terminal 10
A monitor receiver or the like (not shown) is connected to 7, and the video signal taken out to the output terminal 107 is displayed.

[0010]

However, in such a video signal decoding apparatus, for example, a compressed SDTV is used.
In order to decode a signal, a processing period of a fraction of a second to a few seconds is required from the supply of the demodulated signal to the start of normal decoding. For this reason, one SDT can be obtained with conventional equipment
If the user tries to switch from viewing the V signal to another SDTV signal, normal viewing cannot be performed during the above processing period, and meaningless images are displayed during this period. It was supposed to make viewers feel uncomfortable.

In addition, for example, in the above-mentioned digital television broadcasting, it is considered that the four SDTV signals broadcast on the above-mentioned one channel are integrated and used.
Thus, for example, in a relay of a baseball or the like, an SDTV signal of an image of a normal relay (main image), and an SD of an image of a pitcher, a batter, a runner, etc. individually taken
It is conceivable to perform various new forms of broadcasting such as transmitting TV signals respectively.

However, when watching such a broadcast, in the above-described conventional video signal decoding apparatus, when switching from the SDTV signal of one image to the SDTV signal of another image, there is a long waiting time as described above. Such a waiting time hinders good viewing. Also, when watching such a broadcast, there has been a demand for always watching what other images are like.

This application has been made in view of such a point, and a problem to be solved is that in the conventional video signal decoding apparatus, the SDTV signal of one image is changed to the SDTV signal of another image. A long waiting time occurs when switching to, and such waiting time hinders good viewing.

[0014]

Therefore, in the present invention, one or more independent demodulators, two or more independent decoders, and the output signals of these decoders are combined to form one screen. And an control circuit for switching the display method of the formed screen.

[0015]

According to this, by starting the decoding process of the signal of the other image in advance, it is possible to instantaneously switch from one image to another image. Also, by combining the output signals of the decoder to form one screen,
The state of other images can always be observed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described. The present invention is a video signal decoding apparatus for decoding a plurality of coded video signals, wherein M (M is an integer of 1 or more)
Independent demodulators, N (N is an integer of 2 or more) independent decoders, and an output conversion circuit that combines the output signals of the N decoders to form one screen. And a control circuit for switching a display method of a screen.

Therefore, FIG. 1 shows a video signal decoding apparatus according to the present invention, for example, a digital television broadcast (about 20M).
bps), multiple SDTV signals (480 vertical lines (pixels), horizontal 720 pixels, about 5 Mbp) per channel
It is a block diagram which shows the structure of an example of the apparatus applied when (s) is broadcasted through a broadcast satellite.

In FIG. 1, a signal from a receiving antenna (not shown) such as a parabolic antenna is the antenna terminal 1
The signal from the antenna terminal 1 is supplied to the first and second demodulators 2 and 3. Also, a selection signal or the like from a viewer's arbitrary remote control device (not shown) or the like is supplied to the control circuit 5 through the input terminal 4. Then, the control signal formed by the control circuit 5 is supplied to the demodulators 2 and 3, and the channel demodulated by the demodulators 2 and 3 is selected according to the input selection signal or the like.

As a result, in the demodulators 2 and 3, the above-mentioned approximately 20 Mb transmitted by one channel (one modulation carrier) selected according to the input selection signal or the like.
A first bit string of ps and a second bit string of the same about 20 Mbps transmitted on two channels (two modulation carriers) are demodulated. The demodulated signals of the respective channels demodulated by the demodulators 2 and 3 are supplied to the separation circuit 6,
The coded data (about 5 Mbps) of four SDTV signals in each channel are separated.

Further, the separation circuit 6 detects header information and the like in the separated encoded data, and according to the header information and the selection signal and the like inputted to the control circuit 5 described above, the code intended by the viewer is obtained. Data (SDTV signal)
Is selected. Then, these selected SDTV signals are supplied to the decoders 7, 8, 9, and 10, respectively. In this example, four SDTV signals are selected from a total of eight SDTV signals for two channels demodulated by the demodulators 2 and 3 and supplied to the decoders 7 to 10.

SD decoded by these decoders 7-10
The TV signals are supplied to the pixel conversion circuits 11, 12, 13, and 14 which respectively form part of the output conversion circuit. In each of the conversion circuits 11 to 14, filter processing, time axis conversion processing, and pixel conversion such as image enlargement and reduction including arbitrary vertical and horizontal scaling are performed as necessary. Further, for example, a circuit (15) for generating a background (BG) signal of a single color of blue is provided, and the background signal from the circuit 15 and the converted SDT from the conversion circuits 11 to 14 are provided.
The V signal is supplied to the combining circuit 16 which constitutes a part of the output conversion circuit.

Further, in the synthesizing circuit 16, the background signal from the generating circuit 15 and the converted SDTV signals from the converting circuits 11 to 14 are area-wise combined in accordance with the control signal from the control circuit 5. That is, each of the conversion circuits 11 to 14 described above is provided with an image memory, and the generation circuit 15 is provided with a register of data corresponding to a predetermined color signal. Therefore, these memories are read at a predetermined timing, and the read image data and the data from the register are combined at a predetermined timing by the synthesizing circuit 1.
By switching at 6, these images are combined in area.

The digital signal thus synthesized is D / A
It is supplied to the conversion circuit 17 and converted into an analog signal, and the converted analog signal is taken out to the output terminal 18.
Further, the sync signal separated by the separation circuit 6 is supplied to the sync generation circuit 19, and one or both of the channels demodulated by the demodulators 2 and 3 are taken into consideration to generate a sync signal or the like necessary for processing. The synchronization signal and the like are supplied to the control circuit 5, the decoders 7 to 10, the conversion circuits 11 to 14, and the generation circuit 15, and the respective circuits are synchronized to perform necessary processing and the like.

Therefore, in this device, an image of a normal relay (main image), for example, in the relay of the above-mentioned baseball, etc.
When the SDTV signal of the image obtained by individually photographing the pitcher, the batter, the runner, etc. is transmitted together with the SDTV signal of, the screen is divided into four as shown in A of FIG. (Main, pitcher, batter, runner) can be combined and displayed for each division.

In this case, when the connected monitor receiver has a high-definition screen having, for example, 1080 effective scanning lines (pixels) and 1440 effective horizontal pixels, for example, conversion is performed. The above-described SDTV signals having a resolution of 480 pixels in the vertical direction and 720 pixels in the horizontal direction are directly combined in the vertical and horizontal directions without converting the number of pixels in the circuits 11 to 14 to form a screen of 960 vertical pixels and 1440 horizontal pixels. , All the transmission images can be displayed by leaving 120 pixels (scan lines) in the vertical direction.

The above-mentioned remaining portion is divided into, for example, 60 pixels vertically and 1440 pixels horizontally to provide a background signal of, for example, a single blue color from the generating circuit 15 at the upper and lower ends of the screen. Alternatively, this background signal or the like is divided into three, for example, 40 pixels vertically and 1440 horizontally.
Pixels can also be provided between the top and bottom edges of the screen and the top and bottom images.

Further, for example, in the relay of the above-mentioned baseball, etc., when the viewer selects, for example, the image of the pitcher from the state in which four images of the main, pitcher, batter, and runner are simultaneously displayed, the image of the pitcher is displayed. Corresponding to the above, for example, the conversion circuit 11 performs an interpolation operation of a filtering process for doubling the image in the vertical and horizontal directions, and the interpolated image of, for example, 960 vertical pixels and 1440 horizontal pixels and the background from the generation circuit By synthesizing the signals and the like, for example, only the image of the pitcher can be enlarged and displayed as shown in B of FIG.

That is, according to a control signal from the control circuit 5, for example, an interpolation operation for doubling the vertical and horizontal images is performed in the conversion circuit 11 corresponding to the image of the pitcher, for example. Then, the interpolated image data, the background signal from the generation circuit 15 and the like are read at a predetermined timing according to the control signal from the control circuit 5,
The read image data and the data from the register are area-wise combined by being switched by the combining circuit 16 at a predetermined timing. This allows, for example, B in FIG.
As shown in, a screen in which only the pitcher image is enlarged is displayed.

Thus, in this apparatus, the viewer can view four images at the same time, select a desired image from the four images, and switch to the enlarged image of the image for viewing. be able to. In this case, this image switching is performed in a state where the decoding processing of each image has already been performed, so the switching can be performed instantaneously, and a meaningless image is displayed to the viewer. No discomfort.

That is, in the conventional video signal decoding device, a long waiting time occurs when switching from the SDTV signal of one image to the SDTV signal of another image, which has been a hindrance to good viewing. According to the invention, one or more independent demodulators, two or more independent decoders, an output conversion circuit that combines output signals of these decoders to form one screen, and a screen to be formed. By having a control circuit for switching the display method of 1) and starting the decoding process of the signal of another image in advance, the image can be switched instantaneously.

In the above description, the problem of the aspect ratio of the image is omitted, but the SDT being transmitted is transmitted.
When the aspect ratio of the V signal is 4: 3, for example, the vertical direction of the image is set to 2.25 by any of the conversion circuits 11 to 14.
2 times the horizontal direction by 1.5 times, for example, vertical 1080
By forming an image of pixels and horizontal 1080 pixels, for example, it is possible to perform display with an aspect ratio of 4: 3 as shown in C of FIG. In this case, a background signal and the like from the generation circuit 15 are provided on the left and right portions of the screen, for example, each of vertical 1080 pixels and horizontal 180 pixels.

That is, in this case, in accordance with a control signal from the control circuit 5, for example, in the conversion circuit 11 corresponding to the image of the pitcher, for example, the image is vertically 1080 pixels,
Interpolation calculation for horizontal 1080 pixels is performed. The interpolated image data, the background signal from the generation circuit 15, and the like are switched by the synthesis circuit 16 by designating the start points of a, b, and c in FIG. 2C according to the control signal from the control circuit 5. Area-wise synthesized by.

The combined digital signal is converted into an analog signal by the D / A conversion circuit 17 having an aspect ratio of 16: 9, an effective scanning line number of 1080 (pixels), and an effective horizontal pixel number of 1440 pixels. Figure 2
As shown in C of FIG. 5, for example, a screen having an aspect ratio of 4: 3 is magnified to 1080 effective scanning lines (pixels), and a video signal displayed on the screen of a high-definition monitor receiver is formed. . As a result, for example, a screen obtained by enlarging only the image of the pitcher at an aspect ratio of 4: 3 is displayed on a high-definition monitor receiver having an aspect ratio of 16: 9.

Further, in the above description, the split display of four screens is not limited to the above-mentioned relay example of baseball and the like, and may be similarly performed when four SDTV signals of different normal programs are transmitted. it can. Therefore, in this case, the viewer can view the images of the four programs as a list,
A desired program can be easily selected. And in this case as well, switching to the selected program is performed instantly,
The viewer does not feel uncomfortable, such as displaying a meaningless image.

Further, in the above example, two demodulators 2, 3 are provided.
Since two channels are simultaneously demodulated, it is possible to select and display any four of eight SDTV signals of two channels, for example. The four displayed SDTV signals can be instantaneously switched to each other for enlarged display. Again 8 S
By circulating and decoding and displaying the DTV signal at every predetermined time, it is possible to instantaneously switch and enlarge the desired signal by making a selection while the display is being performed.

In the above-mentioned embodiment, the four images can be displayed as shown in FIG. 3, for example. That is, FIG. 3 shows a screen displayed on a high-definition monitor receiver having, for example, an aspect ratio of 16: 9, effective scanning lines of 1080 lines (pixels), and effective horizontal pixels of 1440 pixels. In FIG. 3, images of vertical 480 pixels and horizontal 720 pixels are provided in regions A, B, C, and D, respectively. In this case, the conversion circuits 11 to 14 do not need to convert the number of pixels.

Then, the image data from these conversion circuits 11 to 14, the background signal from the generation circuit 15 and the like are read at a predetermined timing according to the control signal from the control circuit 5. Further, the read image data, the background signal, and the like are switched by the synthesizing circuit 16 at a predetermined timing, so that these images are area-wise synthesized. This allows, for example, FIG.
The screen as shown in is displayed.

That is, for example, a background (BG) signal of a single color of blue is provided in an area of 60 pixels vertically and 1440 pixels horizontally at the top of the screen. Further, in the rectangular areas overlapping each other, for example, the images A, B,
Areas C and D are combined. Further, for example, a background (BG) signal of a single color of blue is provided in an area of 60 pixels vertically and 1440 pixels horizontally at the bottom of the screen. In FIG. 3, for example, in the scanning lines indicated by the broken lines p, q, and r, the synthesizing circuit 16 switches as shown in the lower side of FIG.

For example, in the scanning line of p, the BG signal or the like is first selected, then the image A is selected, and finally the BG signal or the like is selected again. In the scanning line of q, the BG signal or the like is first selected, then the image A is selected, then the image C is selected, and finally the BG signal or the like is selected again. Further, in the scanning line of r, the BG signal or the like is first selected, then the image D is selected, then the image B is selected, then the image C is selected, and finally the BG signal or the like is selected again.

In this way, for example, the conversion circuits 11 to 1
4 and the background signal from the generation circuit 15 are combined to form a screen as shown in FIG. Therefore, on this screen, for example, the image desired by the viewer can be displayed by arranging it in the uppermost rectangular area, and in this case also, since the image decoding process has already been executed, it is not possible to switch images. Can be done instantly. In addition, switching and the like can be instantaneously performed even when enlarging an arbitrary image.

In the display of FIG. 3, the images A, B, C and D displayed in an overlapping manner can be amplitude-combined by using a circuit as shown in FIG. 4, for example. That is, in FIG. 4, the terminals X and Y are supplied with the signals of the upper two images displayed in an overlapping manner. Each of these signals is multiplied by a coefficient [k] by a multiplier [x].
And (1-k), and the multiplication results are added by the adder [+] and taken out to the terminal Z.

As a result, the two images supplied to the terminals X and Y are amplitude-wise combined and taken out to the terminal Z. Then, for example, according to the control signal from the control circuit 5 described above,
By controlling the value of k between 0 and 1, for example, it is possible to perform image switching such that the highest image is gradually changed to the second image. Further, by applying this, for example, an effect of pulling up a desired image from the lower side to the uppermost side can be added to switch the images.

Further, FIG. 5 shows another example of the displayed screen. This display is used, for example, when switching from the screen A in FIG. 2 to the screen B. Therefore, in FIG. 5, for example, when the viewer instructs, for example, to gradually enlarge the image of the pitcher on the screen of FIG. 2A described above, the image of the instructed pitcher is gradually enlarged. The screen is formed so that the images of other main, batter, and runners are reduced.

That is, in order to realize such a display, first, the conversion circuits 11 to 14 do not convert the number of pixels, and, for example, SDTV signals having a resolution of 480 vertical pixels and 720 horizontal pixels are combined vertically and horizontally. By vertical 96
A screen with 0 pixels and 1440 pixels in the horizontal direction is formed, and all the transmission images are displayed with 120 pixels left in the vertical direction. The remaining portion is, for example, vertical 60 pixels at the upper and lower edges of the screen,
A background signal or the like from the generation circuit 15 is provided by dividing each horizontal 1440 pixels.

Then, for example, when an image of the pitcher is designated, in the conversion circuit 11 to which the image of the pitcher is supplied, according to the control signal from the control circuit 5,
The interpolation calculation is performed such that the vertical is multiplied by v and the number of vertical pixels is, for example, m pixels, and the horizontal is multiplied by h, and the number of horizontal pixels is, for example, n pixels. Along with this, for example, in the conversion circuit 12 to which the main image is supplied, interpolation calculation is performed so that the number of vertical pixels is m pixels and the number of horizontal pixels is (1440-n) pixels.

Further, for example, in the conversion circuit 13 to which the runner image is supplied, interpolation calculation is performed so that the number of vertical pixels is (960-m) pixels and the number of horizontal pixels is n pixels. Further, for example, in the conversion circuit 14 to which the batter image is supplied, interpolation calculation is performed so that the number of vertical pixels is (960-m) pixels and the number of horizontal pixels is (1440-n) pixels. As a result, an image obtained by enlarging and reducing each image is formed by the interpolation calculation.

Further, the signals of these images are read out from the conversion circuits 11 to 14 at a predetermined timing, and these signals are switched and extracted by the synthesizing circuit 16, so that, for example, an image of a pitcher as shown in FIG. Is gradually expanded so that the composition is performed. The control circuit 5 specifies the x point on the screen to convert the conversion circuits 11 to 11.
Control of the number of converted pixels in 14 and control of switching in the synthesizing circuit 16 are performed.

FIG. 6 shows another example of the displayed screen. That is, A of FIG. 6 is applied, for example, when one image is vertically and horizontally divided into four, and each divided image is multiplexed and transmitted as the SDTV signal on the above-mentioned one channel. In this case, by performing the same display as in A of FIG. 2 above, for example, vertical 960 pixels,
It is possible to easily form a high-definition screen having 1440 horizontal pixels. In addition, for example, a background signal of a single color of blue is provided at the upper and lower ends of the screen by dividing the pixel into 60 pixels vertically and 1440 pixels horizontally.

That is, the divided images A, B, C and D respectively transmitted as SDTV signals are demodulated,
By decoding and performing the area synthesis of these decoded images seamlessly as shown in FIG. 6A, a high-definition screen of, for example, 960 vertical pixels and 1440 horizontal pixels can be formed. And in this case, since each image is transmitted digitally, the positions of the pixels of each image are accurately determined, and by synthesizing these images digitally, there is no disturbance in the seam and it is extremely good. A high-definition screen can be formed.

Further, FIG. 6B shows, for example, two SDTVs.
This is a case of using a signal to form an extremely horizontally long screen of, for example, 480 vertical pixels and 1440 horizontal pixels. In this case, for example, vertical 300 pixels and horizontal 1
A background signal of, for example, a single blue color is provided for each 440 pixels. Also in this case, for example, the images A and B transmitted as SDTV signals are respectively demodulated and decoded, and the decoded images are area-separated seamlessly as shown in B of FIG. It is possible to form a horizontally long screen having 1440 horizontal pixels.

FIG. 6C shows a case where a vertically long screen of, for example, 960 vertical pixels and 720 horizontal pixels is formed using, for example, two SDTV signals. In this case, for example, in addition to the vertical 60 pixels and the horizontal 1440 pixels at the upper and lower ends of the screen, for example, a background signal of one color of blue, such as vertical 960 pixels and horizontal 360 pixels, is provided on the left and right of the screen. Also in this case, for example, images A and B transmitted as SDTV signals are respectively demodulated and decoded, and these decoded images are subjected to area integration seamlessly as shown in FIG. 6C, for example, vertical 960 pixels, Horizontal 7
A vertically long screen of 20 pixels can be formed.

Further, D of FIG. 6 is a case of forming a screen of, for example, vertical 960 pixels and horizontal 810 pixels by using, for example, three SDTV signals. In this case, for example, a background signal of a single color of blue or the like is provided at vertical 60 pixels at the upper and lower ends of the screen, horizontal 1440 pixels, vertical 960 pixels on the left and right of the screen, and horizontal 315 pixels.

In this case, for example, the first and second
The SDTV signals are demodulated and decoded to obtain images A and B of 480 vertical pixels and 720 horizontal pixels, respectively, and the third SDTV signal is demodulated and decoded to obtain an image C of 960 vertical pixels and 90 horizontal pixels. . Then, the decoded images A, B, and C are area-combined seamlessly as shown in D of FIG. 6 to form a screen of vertical 960 pixels and horizontal 810 pixels, for example.

Therefore, for example, vertical 960 pixels, horizontal 8
A 10-pixel screen is displayed with the above-mentioned aspect ratio of 16:
9, a D / A conversion circuit 17 having 1,080 effective scanning lines (pixels) and 1,440 effective horizontal pixels converts the analog image into a square image as shown in D of FIG. : 9 can be displayed on a high-definition monitor receiver.

In this way, it is possible to arbitrarily form a screen according to the intention of the creator of the image to be transmitted, expand the degree of freedom in expressing the image, and create an image of more various expressions. You can Further, in this case, the conversion circuits 11 to 1
The conversion of the number of pixels in 4 is not performed, and the image data and the background signal from the generation circuit 15 are switched by the synthesizing circuit 16 in accordance with the control signal from the control circuit 5. Images can be obtained.

In the current digital television broadcasting, how to use about 20 Mbps to be transmitted is left to the discretion of the person who performs the broadcasting, and various screens as shown in FIG. 6 are formed. Can also be arbitrarily performed. In addition, the configuration of the screen formed in that case can be transmitted through header information in the encoded data, and this information or the like is discriminated by the control circuit 5 or the like, and the conversion circuits 11 to 14 and the synthesis circuit 16 or the like. Can be controlled.

Thus, according to the above-mentioned video signal decoding device, it is a video signal decoding device for decoding a plurality of encoded video signals, and M (M is an integer of 1 or more) independent demodulators. 2, 3 and N (N is an integer of 2 or more) independent decoders 7 to 10, and an output conversion circuit (conversion circuit) for forming one screen by combining output signals of at least N decoders. 11 to 14, a synthesizing circuit 16) and a control circuit 5 for switching a display method of a screen to be formed, so that a decoding process of a signal of another image is started in advance, so that one image From one image to another image can be instantaneously performed, and by combining the output signals of the decoder to form one screen, it is possible to always see the state of other images. .

Further, the above-mentioned output conversion circuit has a function (conversion circuits 11 to 14) of converting the number of pixels of each of the output signals of the N decoders 7 to 10,
A screen can be formed by enlarging or reducing an arbitrary image.

Further, the above-mentioned output conversion circuit has a means (combining circuit 16) for composing each image areawise with respect to the output signals of the N decoders 7 to 10, so that a plurality of decoded signals can be obtained. Images can be displayed in a list.

Further, the means for synthesizing the above-mentioned images in area (synthesis circuit 16) selectively and partially synthesizes the respective images with respect to the output signals of the N decoders 7 to 10 without interruption. By carrying out, it is possible to implement a wide variety of image representations (FIG. 6).

Further, the above-mentioned output conversion circuit has means (FIG. 4) for synthesizing the respective images in amplitude with respect to the output signals of the N decoders 7 to 10 to switch the overlapping images. It can be done well.

Further, FIG. 7 shows another embodiment of the video signal decoding apparatus according to the present invention. In this example, a still image generating means is provided, and the above-mentioned output conversion circuit has N number of output signals. It is a video signal decoding device characterized in that a signal of a still image is combined with an output signal of a decoder.

That is, in FIG. 7, for example, the separation circuit 6
The information of the still image is separated from the supplementary information such as the header information in the signal transmitted in step 1, and the still image information is supplied to the still image decoder 20. Then, the decoded still image data is stored in the memory 21, and the stored still image data is supplied to the synthesizing circuit 16. Other configurations are the same as those in FIG.

Therefore, in this apparatus, the still image stored in the memory 21 is combined with the images from the conversion circuits 11 to 14 and the background signal generating circuit 15 in the synthesizing circuit 16 in the above-mentioned versatile structure. It can be combined in terms of area or amplitude. It is also possible to enlarge or reduce the still image to an arbitrary size and synthesize the still image by providing a conversion unit having the same number of pixels as that of the conversion circuits 11 to 14 in the front or rear of the memory 21.

FIG. 8 shows another embodiment of the video signal decoding apparatus according to the present invention. In this example, a text data generating means is provided, and the output conversion circuit has N decoding units. The video signal decoding device is characterized in that the video signal decoding device is configured to perform synthesis on a signal obtained by converting text data into an image together with an output signal of the device.

That is, in FIG. 8, for example, the separation circuit 6
The information of the text data is separated from the supplementary information such as the header information in the signal transmitted by the above, and the text data information is supplied to the character generation circuit 22. Then, the image data of the character formed by the generating circuit 22 is supplied to the synthesizing circuit 16. Other configurations are the same as those in FIG.

Therefore, in this apparatus, the image of the character of the text data formed by the generating circuit 22 is combined with the images from the converting circuits 11 to 14 and the generating circuit 15 such as the background signal in the synthesizing circuit 16 as described above. It can be combined in terms of area or amplitude with various versatile configurations.

Further, FIG. 9 shows another embodiment of the video signal decoding apparatus according to the present invention. In this example, there is an external video signal input means and the output conversion circuit has N decoding units. The video signal decoding device is characterized in that the external video signal input from the input means together with the output signal of the video signal is combined.

That is, in FIG. 9, an external video signal from a video tape recorder or the like is input to the terminal 23.
The video signal from the input terminal 23 is transferred to the A / D conversion circuit 24.
Is converted into a digital signal of, for example, vertical 480 pixels and horizontal 720 pixels. Further, the synchronization detection circuit 25 extracts the synchronization information of the external video signal, and this synchronization information is supplied to the synchronization generation circuit 19. Further, the converted digital signal of the external video signal is stored in the memory 26, and the stored digital signal is supplied to the synthesis circuit 16. Other configurations are the same as those in FIG.

Therefore, in this apparatus, the digital signal of the external video signal stored in the memory 26 is converted into the conversion circuit 11
14 to 14 and the data from the generation circuit 15 such as the background signal, the combination circuit 16 can combine the data in terms of area or amplitude with the versatile configuration as described above.
It should be noted that the conversion circuit 1 described above may be provided at the front or rear of the memory 26.
It is also possible to enlarge or reduce the external video signal to an arbitrary size and synthesize the external video signal by providing a converting means for the number of pixels similar to 1 to 14.

Thus, according to the above-mentioned device, a still image, text data, or an external video signal can be combined with a plurality of transmitted images and displayed in a list.
Also, when an arbitrary image is selected from these images, it is possible to perform various displays such as enlarging and displaying the image, and at the same time, start the decoding processing of the image signal at that time. By doing so, the switching can be performed instantly.

Further, the video signal decoding apparatus of the present invention is not limited to the case of receiving and demodulating the digital television broadcasting using the broadcasting satellite described in the above-mentioned embodiment, but the transmission path is terrestrial or wired. Transmission or tape,
It can also be applied when using a storage medium such as a disk. The video signal encoding method is not limited to the above-described motion compensation DCT method, and other methods can be applied. Further, various methods such as JPEG method can be applied to the still image encoding method.

In the above embodiment, the case where two demodulators and four decoders are used has been described, but the numbers of these demodulators and decoders are not limited to those in the above embodiment. Further, the aspect ratios of video and image signals, the number of vertical and horizontal pixels, the enlargement and reduction ratios, and the like described in the embodiments are not limited to the numerical values of the above embodiments.

[0074]

According to the present invention, a plurality of images, still images, text images, and the like can be viewed at the same time, and a viewer can select a desired image, or When trying to switch from the currently displayed video to another non-displayed video, it is possible to immediately display the video on the display unit without interruption, and the size of each of the multiple screens. ,
It becomes possible to combine areas such as display positions and display multiple screens in an amplitude manner, and to provide a video signal decoding device that is convenient and comfortable for the viewer. .

[Brief description of drawings]

FIG. 1 is a configuration diagram of an example of a video signal decoding device to which the present invention is applied.

FIG. 2 is a diagram for explaining an example of the display.

FIG. 3 is a diagram for explaining another example of the display.

FIG. 4 is a configuration diagram of a main part of another example of a video signal decoding device to which the present invention is applied.

FIG. 5 is a diagram for explaining another example of the display.

FIG. 6 is a diagram for explaining still another example of the display.

FIG. 7 is a configuration diagram of another example of a video signal decoding device to which the present invention is applied.

FIG. 8 is a configuration diagram of another example of a video signal decoding device to which the present invention is applied.

FIG. 9 is a configuration diagram of another example of a video signal decoding device to which the present invention is applied.

FIG. 10 is a configuration diagram for explaining a conventional video signal decoding device.

[Explanation of symbols]

 2, 3 Demodulator 5 Control circuit 7-10 Decoder 11-14 Pixel conversion circuit 16 Compositing circuit

Claims (10)

[Claims] 1. A video signal decoding apparatus for decoding a plurality of encoded video signals, comprising M (M is an integer of 1 or more) independent demodulators, and N (N is 2 or more). Integer) independent decoders, an output conversion circuit that combines at least the output signals of the N decoders to form one screen, and a control circuit for switching the display method of the formed screen. A video signal decoding device having. 2. The video signal decoding device according to claim 1, wherein the output conversion circuit has a function of converting the number of pixels of each of the output signals of the N decoders. Video signal decoding device. 3. The video signal decoding device according to claim 1, wherein the output conversion circuit has means for synthesizing respective images areawise with respect to the output signals of the N decoders. Video signal decoding device. 4. The video signal decoding apparatus according to claim 3, wherein the means for area-wise combining the images selectively selectively outputs the respective images to the output signals of the N decoders. A video signal decoding device characterized by performing seamless area synthesis. 5. The video signal decoding device according to claim 1, wherein the output conversion circuit has means for synthesizing respective images amplitude-wise with respect to output signals of the N decoders. Video signal decoding device. 6. The video signal decoding device according to claim 1, further comprising: still image generating means, wherein the output conversion circuit outputs the still image signals together with the output signals of the N decoders. A video signal decoding device characterized by performing synthesis. 7. The video signal decoding apparatus according to claim 1, further comprising a text data generating means, wherein the output conversion circuit is a signal obtained by imaging the text data together with the output signals of the N decoders. A video signal decoding device, characterized in that the video signals are combined with respect to each other. 8. The video signal decoding device according to claim 1, further comprising an external video signal input means, wherein the output conversion circuit comprises:
A video signal decoding device, characterized in that the external video signals input from the input means are combined with the output signals of the N decoders. 9. The video signal decoding device according to claim 8, wherein the output conversion circuit performs area synthesis or amplitude synthesis of images in synchronization with a synchronization signal of the external video signal. Video signal decoding device. 10. The video signal decoding device according to claim 1, wherein the output signal of the decoder is a video signal for display at standard definition, and one screen synthesized by the output conversion circuit is high-quality. A video signal decoding device characterized in that the video signal is a video signal for display at a high definition.