JPH11168701A - Multi-screen display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the multi-screen display device which can attain practical multi-screen display, without increasing the number of descramblers with a simply configuration and economical advantage. SOLUTION: This multi-screen display device that receives a plurality of stream data each including a plurality of encrypted data, applies descramble processing and decode processing the each stream, composites the processed data and displays the data is provided with a plurality of descramblers 15-18 the number of which is less than the number of streams and with a setting means 22 that sets the priority of reproduction to the streams. The streams with higher priority set by the setting means 22 are assigned sequentially to the descramblers 15-18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a multi-screen display device for performing a descrambling process and a decoding process on a plurality of input stream data, each of which has been subjected to content encryption, to display a multi-screen.

[0002]

2. Description of the Related Art As is well known, in recent years, an image reproducing system for decoding a stream data using a DVD format to display an image has been developed, and has been widely used in various fields.

On the other hand, in the field of recent television image display systems, a so-called multi-screen, in which one screen is divided into two or more areas, and each area is independently displayed with an image. Techniques for displaying are advanced.

[0004] By the way, at present, the DVD image reproducing system basically presupposes that only one image is reproduced, and thus does not support a multi-screen display in which a plurality of images are displayed at a time. is there.

That is, in this DVD image reproducing system, in order to realize multi-screen display, all LSIs (Largs) for decoding input stream data are used.
It is necessary to take measures such as increasing the processing speed of the e Scale Integrated Circuit) according to the number of screens to be displayed, or paralleling data processing by arranging a plurality of LSIs in parallel.

In short, in order to display two images at the same time, it is necessary to decode the stream data for two images within the time required for decoding the stream data for one image in standard time. It is.

For example, when stream data for two images is input in parallel, two decoders are installed, each stream data is decoded in parallel, and each decoded output is combined to display two screens. Or a buffer for storing each stream data is provided in the preceding stage of one decoder, the transfer speed of each stream data is doubled, and the stream data is alternately input to the decoder to perform decoding processing. Means for displaying two screens by synthesizing the decoded output is used.

In the case where stream data for two images is alternately input by one input, a buffer for storing each stream data is provided in the preceding stage of one decoder, and the transfer speed of each stream data is doubled. Then, the image data is alternately input to the decoder for each image, decoded, and the decoded output of each image is combined to display two screens.

[0009]

Here, stream data in the DVD format is subjected to content encryption processing for copy protection. For this reason, DVD
The image reproduction system includes a copy protection module having a built-in descrambler for decrypting the content of stream data, and performs descramble processing on input stream data and then decode processing.

[0010] In this case, the stream data supplied to the copy protection module is transferred not serially in packet units but serially in byte units. However, the descrambler built in the copy protection module can perform the descrambling process on the next packet after the descrambling process on the last byte for one packet is completed.

For this reason, in the case where the DVD image reproducing system is configured to be capable of displaying a plurality of screens by inputting a plurality of stream data, the copy protection module includes descramblers corresponding to the number of input stream data. Need to be built in.

By the way, the stream data of the DVD format includes three types of a main image stream, an audio stream, and a sub-image stream, and each stream is subjected to content encryption processing for copy protection. . For this reason, at least three descramblers are installed in the copy protection module in order to decrypt the contents of the three types of streams.

Therefore, for example, in order to input two stream data and display it on a multi-screen, since each stream data includes three types of streams, it is necessary to incorporate six descramblers in the copy protection module. Will occur.

In short, in order to realize a multi-screen display in the DVD image reproducing system, it is necessary to incorporate three times as many descramblers as the input stream data in the copy protection module. As the number of images increases, the configuration becomes complicated and large, causing a problem of economic disadvantage.

Therefore, the present invention has been made in consideration of the above circumstances, and enables a practical multi-screen display without increasing the number of descramblers, and is economical with a simple configuration. It is an object of the present invention to provide a very good multi-screen display device which can also be advantageous.

[0016]

A multi-screen display device according to the present invention inputs a plurality of stream data each including a plurality of encrypted streams, and performs a descrambling process and a decoding process on each stream. It is intended to be composed and displayed on multiple screens. And, a plurality of descramblers prepared by the number smaller than the plurality of streams, and setting means for setting the priority of reproduction for the plurality of streams are provided, and a stream having a higher priority set by the setting means is provided. This is to sequentially assign to a plurality of descramblers.

According to the above configuration, descramblers of a number smaller than the number of input streams are prepared, and the streams are assigned to the descramblers in order from a stream having a high priority set in advance. Multi-screen display in a practical range can be performed without increasing the number of descramblers, and the configuration can be simplified, suitable for miniaturization, and economically advantageous.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 11 denotes a stream data output circuit. This stream data output circuit 11 outputs a main image stream,
A plurality of stream data including an audio stream and a sub-image stream are serially output on a line 12 in a time division manner in byte units, and an enable signal corresponding to each stream data is output on a line 13.
Output above.

The stream data output on these lines 12 and 13 and the enable signal thereof are transmitted to four descramblers 1 built in the copy protection module 14.
5, 16, 17, 18 and the register 19, respectively. This register 19 is connected via lines 20 and 21 to a control circuit 22 containing a microcomputer.

The register 19 stores the stream data output circuit 1 based on a command issued from the control circuit 22.
A setting signal for setting which stream of which stream data output from 1 is supplied to which descrambler 15, 16, 17, 18 is generated, and each descrambler 15, 16, 17, 18 via a line 23. Output to

The register 19 sends a request signal requesting that a stream not supplied to any of the descramblers 15, 16, 17, 18 be supplied to itself, via a line 24 to the stream data output circuit 11.
Output to Further, the register 19 is connected via lines 25 and 26 to an authentication circuit 27 for determining whether or not the copy protection module 14 has been selected.

Here, each of the descramblers 15, 1
The streams descrambled in 6, 17, and 18 are respectively supplied to the lines 28 and 28 together with the enable signal.
The data is output to the buffer 32 via 29, 30, and 31.
This buffer 32 accumulates each input stream and outputs it to a decoder (not shown) corresponding to each stream.

The buffer 32 outputs a request signal to the stream data output circuit 11 via a line 33. The control circuit 22 is connected to the line 3
4 and 35 are connected to the stream data output circuit 11.

The multi-screen display operation of the above configuration will be described below. In this operation description, an example is shown in which a child screen is displayed as a multi-screen display so as to overlap a part of the parent screen. In this case, the stream data output circuit 11 outputs the stream data (including the main image stream, the audio stream, and the sub-image stream) corresponding to the parent screen, and the stream data (the main image stream, the audio stream, and the sub-image stream) corresponding to the child screen. (Including an image stream).

The priority order of the stream to be reproduced is set in the control circuit 22 in advance. In this example: 1. Main screen main image stream 2. Main screen sub-image stream 3. Main screen audio stream 4. Small screen main image stream 5. Small screen sub-image stream It is assumed that the priorities are set in the following order. The priority may be set by a user's operation, or may be set in advance when the product is shipped from the factory.

The register 19 stores the number (4 in this case) of the descramblers 15, 16, 17, and 18 incorporated in the copy protection module 14 installed therein. Then, the control circuit 22 controls the line 20,
When connected to the register 19 via 21, the information is read.

Then, first, the control circuit 22 supplies the stream corresponding to the priority order 1 to the descrambler 15 and the stream corresponding to the priority order 2 to the descrambler 16 from the inputted six types of streams. , The stream corresponding to the priority 3 is supplied to the descrambler 17, the stream corresponding to the priority 4 is supplied to the descrambler 18, and the streams corresponding to the priority 5 and 6 are supplied to the register 19. Controls register 19.

In this case, the control circuit 22 reads a part called the stream ID (Identifier) or sub-stream ID from the input stream (this part is not scrambled),
Which stream it is.

Then, each of the descramblers 15, 16, 1
Each of the streams corresponding to the priorities 1, 2, 3, and 4 subjected to the descrambling process according to 7, 18 is stored in the buffer 3
2 and are decoded by a decoder (not shown) for each stream, then combined and provided for multi-screen display.

The respective streams corresponding to the priorities 5 and 6 supplied to the register 19 are not transferred to the buffer 32 but are transferred to the buffer 32, although the register 19 virtually substitutes for the descrambler interface. It will not be used for screen display.

FIG. 2 shows a display screen at this time. That is, the main screen main image 36 and the main screen sub image 37
(Subtitles in this case) and the main screen main image 38 are displayed, and the main screen audio is reproduced.

FIG. 3 shows a flowchart summarizing the above operation. First, when the process is started (step S1), the user sets the priority of the stream to be reproduced in the control circuit 22 in step S2, and the control circuit 22 in step S3 reads the desk stored in the register 19 in step S3. The number of ramblers 15, 16, 17, 18 is read.

Thereafter, the control circuit 22 proceeds to step S4
, A stream is selected from a plurality of input stream data in descending order of priority, and each descrambler 1
5, 16, 17, and 18. Control circuit 2
2 is the descrambler 15, 16, 1 in step S5.
The stream not allocated to 7, 18 is supplied to the register 19. In this case, the register 19 receives the enable signal and returns a request signal to the stream data output circuit 11.

Each of the descramblers 15, 16, 1
Each stream subjected to the descrambling process by 7 and 18 is stored in the buffer 32 in step S6, decoded by a decoder (not shown) for each stream, combined, provided for multi-screen display, and terminated. (Step S7).

According to the first embodiment, four descramblers 15, 16, 17, and 18, which are smaller than the number of input streams "6", are installed in the copy protection module 14 and set in advance. By assigning the four streams selected in the descending order of priority to the four descramblers 15, 16, 17, and 18, respectively, the descramblers 15, 16, 17, and 18 are assigned.
, Without increasing the number of screens. For this reason, it is possible to simplify the configuration, to be suitable for miniaturization, and to be economically advantageous.

FIG. 4 shows a modification of the first embodiment. That is, the same parts as those in FIG. 1 are denoted by the same reference numerals and described. A fifth descrambler 39 to which a stream output from the stream data output circuit 11 is supplied is installed in the copy protection module 14, and The stream descrambled by the rambler 39 is supplied to the buffer 32 via the line 40.

In this case, the control circuit 22 converts the streams corresponding to the priorities 1, 2, 3, and 4 from the input six types of streams into the descramblers 15, 1 respectively.
The register 19 is controlled so that the stream corresponding to the priority 5 is supplied to the descrambler 39 and the stream corresponding to the priority 6 is supplied to the register 19.

Then, each of the descramblers 15, 16, 1
The streams corresponding to the priorities 1, 2, 3, 4, and 5, which have been descrambled by 7, 18, and 39, are:
After being stored in the buffer 32 and decoded by a decoder (not shown) for each stream, the streams are combined and provided for multi-screen display.

FIG. 5 shows the display screen at this time. That is, the main screen main image 36, the main screen sub image 37, the sub screen main image 38, and the sub screen sub image 41 (subtitles in this case)
Is displayed, and the main screen audio is being reproduced.

Next, FIG. 6 shows a second embodiment of the present invention, and shows a flowchart in which other operations are added to the configuration shown in FIG. First, the process is started (step S8), and in step S9, the priority setting of the stream to be reproduced is set to the control circuit 22 and the control circuit 2
2 descrambler 15,1 from register 19
When the reading of the number “4” of 6, 17, 18 is completed,
The control circuit 22 determines in step S10 that the descrambler 1
It is determined whether or not the number “4” of 5, 16, 17, and 18 is sufficient for the number of input streams.

If it is determined that the stream is sufficient (YES), the control circuit 22 sequentially converts the input streams into descramblers 15, 16, 17, and at step S11.
Assign to 18. Then, each descrambler 15,1
The streams descrambled by 6, 17, and 18 are accumulated in the buffer 32 in step S14, decoded for each stream, combined, provided for multi-screen display, and terminated (step S15). ) Is done.

In step S10, the descrambler 1
If it is determined that the number “4” of 5, 16, 17, and 18 is not enough for the number of input streams (NO), the control circuit 22 determines in step S12 the priority order of the plurality of input streams. Are selected and assigned to the descramblers 15, 16, 17, and 18 in descending order of step S1.
In step 3, after the streams not allocated to the descramblers 15, 16, 17, 18 are supplied to the register 19, the process of step S14 is executed.

Next, FIG. 7 shows a third embodiment of the present invention. That is, the same parts as those in FIG.
The streams descrambled by 7 and 18 are supplied to the selector 42.

The selector 42 receives a select signal supplied from the register 19 via a line 43,
Among the streams output from the descramblers 15, 16, 17, and 18, the main image stream is output to the buffer 32 via the line 44, the audio stream is output to the buffer 32 via the line 45, and the sub-image stream is output. Is output to the buffer 32 via the line 46.

Therefore, in the buffer 32, the line 44
Can be determined as a main image stream, a stream input via line 45 is an audio stream, and a stream input via line 46 is a sub-image stream. .

Accordingly, the main image, audio, and sub-image streams can be arbitrarily read from the buffer 32, and each stream is led to the corresponding main image, audio, and sub-image decoder at the subsequent stage. Becomes possible.

FIG. 8 is a flowchart summarizing the operation of the third embodiment shown in FIG. That is, FIG.
The same steps as those described above are denoted by the same reference numerals. In step S14, the main image stream, the audio stream, and the sub-image stream output from the selector 42 are supplied to the corresponding decoders, and then combined to form a multi-screen. Display is performed. It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the scope of the present invention.

[0048]

As described in detail above, according to the present invention,
Practical multi-screen display can be performed without increasing the number of descramblers, and a very good multi-screen display device that can be economically advantageous with a simple configuration can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a multi-screen display device according to the present invention.

FIG. 2 is a diagram showing an example of a display screen according to the first embodiment.

FIG. 3 is a flowchart shown to explain an operation in the first embodiment.

FIG. 4 is a block diagram showing a modification of the first embodiment.

FIG. 5 is a view showing an example of a display screen in the modification.

FIG. 6 is a flowchart shown to explain a second embodiment of the present invention.

FIG. 7 is a block diagram showing a third embodiment of the present invention.

FIG. 8 is a flowchart for explaining the operation in the third embodiment.

[Explanation of symbols]

 11: stream data output circuit, 12, 13 ... line, 14: copy protection module, 15-18: descrambler, 19: register, 20, 21 ... line, 22: control circuit, 23-26 ... line, 27: authentication Circuit, 28-31 line, 32 buffer, 33-35 line, 36 main screen main image, 37 main screen sub image, 38 child screen main image, 39 descrambler, 40 line, 41 ... Sub-screen sub-images, 42 ... selectors, 43-46 ... lines.

Claims (6)

[Claims] 1. A multi-screen display device which receives a plurality of stream data each including a plurality of encrypted streams, performs descramble processing and decoding processing on each stream, synthesizes each stream, and displays a plurality of screens. A plurality of descramblers prepared by the number smaller than the number of streams, and setting means for setting a priority to reproduce the plurality of streams, and a stream having a higher priority set by the setting means A multi-screen display device, which is sequentially assigned to the plurality of descramblers. 2. The multi-screen display device according to claim 1, wherein each of the plurality of stream data includes a main image stream, an audio stream, and a sub-image stream. 3. The plurality of stream data comprises parent screen stream data constituting a parent screen and child screen stream data constituting a child screen displayed by being superimposed on a part of the parent screen. The multi-screen display device according to claim 2. 4. The priority order is, in descending order, a main image stream, a sub-image stream, an audio stream of the parent screen stream data, a main image stream, a sub-image stream, and an audio stream of the child screen stream data. 4. The multi-screen display device according to claim 3, wherein the multi-screen display device is set. 5. The multi-screen display according to claim 2, further comprising a selector for dividing each of the streams output from the plurality of descramblers into a main image stream, an audio stream, and a sub-image stream. apparatus. 6. A discriminating means for discriminating whether or not the number of the plurality of descramblers is sufficient for the number of the inputted plurality of streams, wherein when the discriminating means determines that the number is sufficient, A plurality of input streams are sequentially allocated to the plurality of descramblers, and when it is determined that the streams are not sufficient, the streams are sequentially allocated to the plurality of descramblers in descending order of priority set by the setting means. The multi-screen display device according to claim 1, wherein: