FR2778300A1 - Reading of computer data to form images by synthesis for display on a television screen - Google Patents

Abstract

The data processing system has a microprocessor (11), a zone of permanent memory (12) containing a control program, a device (8) to restore the digital data from formatted digital video data, and an image synthesis device (10) allowing construction of images from program data and data delivered by the image restoration device.

Description

METHOD FOR READING COMPUTER DATA ALLOWING

  COMPOSING SYNTHESIS IMAGES AND DEVICE PROVIDING

IMPLEMENTING THE PROCESS

  The invention relates to a method for reading computer data making it possible to compose computer generated images as well

  than a device for implementing the method.

  The invention applies more particularly to the reading of computer data allowing the composition of synthetic images

  intended to be displayed on a television screen.

  The computer data which make it possible to compose synthetic images are made up of data corresponding to graphic objects and program data making it possible to construct the synthetic images from the corresponding data.

graphic objects.

  According to known art, the reading of computer data making it possible to constitute synthetic images is carried out using a computer. Once created, the synthetic images are displayed on the computer screen. The computer data read by the computer can be stored in a memory such as a hard disk, a floppy disk or a read-only compact disc commonly called

  CD-ROM (the abbreviation CD-ROM comes from the English "Compact Disc-

  Read Only Memory "). They can also come from a data stream carried according to the transport standard commonly known as the MPEG 2 System standard. In the latter case, the computer data are broadcast by a transmitting station. Generally, the data stream transported according to the transport standard MPEG 2 System contains, in addition to computer data, video and audio data corresponding to different television programs. In order to be transmitted to the computer intended to read and display them, computer data is extracted from the data stream. This extraction is commonly carried out by a demultiplexing circuit contained in a decoder working according to the MPEG 2 video standard. The video and audio data are routed, after decoding, to a television receiver and the computer data to a computer that stores them,

entirely, in a memory.

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  Thus, according to the prior art, a user who wishes to have access to all of the information contained in a data stream such as that mentioned above must be in possession of two different terminals - a television receiver and a computer- to view this information. This is a drawback. It is also necessary that the memory capacity of the computer can store all of the computer data that make up the computer graphics program. This represents a

additional disadvantage.

  The invention does not have these drawbacks.

  Indeed, the invention relates to a method of processing computer data stored in a memory and consisting of data corresponding to graphic objects and program data. The processing method comprises: _5 - a step of reading the memory so as to extract computer data therefrom; - a demultiplexing step of the computer data extracted so as to separate the data corresponding to graphic objects and the program data, and 2 o - a formatting step making it possible to transform the data corresponding to graphic objects into video data

digital formatted.

  The invention also relates to a device for processing computer data consisting of data corresponding to graphic objects and program data. The processing device comprises: - a memory where the computer data are stored; - a demultiplexer connected to the memory and making it possible to separate the data corresponding to graphic objects and the program data which are transmitted to it; - a formatting device making it possible to transform the data corresponding to graphic objects which come from the

  demultiplexer into formatted digital video data.

  The invention also relates to a data processing method intended to construct computer-generated images by

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  work of an application running on a microprocessor whose read only memory area contains an application control program. The data being made up of program data and formatted digital video data such as the data resulting from a processing method according to the invention mentioned above, the data processing method intended to construct synthetic images comprises: a step of loading, into a first RAM area, program data representing a main program of the application, said program data being kept in the first RAM area throughout the duration of the application; at least one step of loading program data representing at least one application subroutine into the first RAM memory area, said subroutine having the function of implementing at least one action among all of the actions that a user is likely to request using a command applied to the microprocessor; - at least one restitution step making it possible to restore computer data corresponding to graphic objects from formatted digital video data; - at least one step of loading data from the restitution step into a second RAM area; at least one step of constructing synthetic images from program data originating from the first RAM area and representing at least one subroutine of the application and from computer data originating from the second RAM area and

  corresponding to graphic objects.

  According to the preferred embodiment of the invention, the construction of synthetic images is carried out, interactively,

using a remote control.

  The invention also relates to a data processing device making it possible to construct computer generated images by implementing an application, said device containing a microprocessor for executing the application and a read-only memory area containing a program for controlling the application. The data being made up

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  program data and formatted digital video data such as data from a device according to the invention mentioned above, the data processing device for constructing synthetic images comprises: s - a device for restoring computer data made up of data corresponding to graphic objects from formatted digital video data and - an image synthesis device making it possible to construct synthesis images from program data and 0 computer data from the device to restore computer data . To read and visualize data intended to compose synthetic images, the invention advantageously makes it possible to avoid the use of a specific tool such as a computer having to have a

  memory capable of storing all of said data.

  Other characteristics and advantages of the invention will appear on reading a preferred embodiment made with reference to the appended figures among which: - Figure 1 represents, according to the invention, the block diagram of a device for reading of computer data intended to compose synthetic images, - Figure 2 represents, according to the invention, the block diagram of a system making it possible to create a flow of data intended to be conveyed according to the MPEG 2 System standard and comprising a device such as that shown in Figure 1, Figure 3 shows an application of the system shown in Figure 2, - Figure 4 shows, according to the invention, a device for reading data from a device such as that shown in Figure 1 , Figure 5 shows a particular embodiment of the

  Figure 4 reading device.

  In all the figures, the same references designate the same

elements.

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  FIG. 1 represents, according to the invention, the block diagram of a device for reading computer data intended for composing

synthesized images.

  The computer data intended to compose synthetic images are contained in a memory 1. The memory 1 can be, for example, a read-only memory of CD-ROM type. The computer data contained in memory 1 is composed of data

  corresponding to graphical and program data objects.

  The program data relates to a main program and to different subprograms. As will be specified later, each subroutine has the function, among other things, of implementing at least one action from among the set of actions that a user is likely to request using the remote control of the receiver on which it wishes to display the synthetic images and the main program is a program allowing to manage the call of

  different subroutines. By way of nonlimiting examples, a sub-

  program can execute an action to display and / or zoom an image.

  In the following description, all of the data

  relating to a main program and to the different sub-programs

  that are associated with this main program will be called an application.

  Each graphic object is associated with its own identifier. The same is true for each sub-program as well as for the main program. As is known to those skilled in the art, an identifier is a piece of data which, associated with another piece of data,

  identifies this other data.

  Under the action of a command C1 originating from a sequencer 4, the content of the memory 1 is read in a loop. The computer data I originating from memory 1 are transmitted to a demultiplexer 2 which separates them into two data streams: a first data stream Dl1 consisting of data relating to graphic objects and a second data stream D2 consisting of program data. The separation of data D1 and D2 is carried out under the action of a

  C2 command from sequencer 4 and applied to demultiplexer 2.

  Under the action of a command C3 originating from the sequencer 4, the data D1 is transmitted to a device 3 whose function is to transform

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  the computer data it receives in digital video data D3.

  According to the preferred embodiment of the invention, the data

  D3 digital videos are put in 4: 2: 2 format.

  As will appear later (see Figures 2, 3 and 5), the formatting of computer data D1 into digital video data D3 advantageously allows the use of processing circuits

  commonly used for processing digital video data.

  It is then possible, for example, to code according to the MPEG 2 video standard the data representing graphic objects (cf. FIGS. 2 and 3) or

  again to decode data thus coded (cf. FIG. 5).

  According to a modification of the device shown in dotted lines in FIG. 1, the data D2 and the digital video data D3 are transmitted to a multiplexer M1 which, under the action of a command CM1 coming from the sequencer 4, operates the multiplexing in order to constitute

a Fl data stream.

  FIG. 2 represents, according to the invention, the block diagram of a system making it possible to create a data stream intended to be conveyed according to the MPEG 2 System standard and comprising a device

  such as that shown in Figure 1.

  In addition to the elements 1, 2, 3, 4 represented in FIG. 1, the system described in FIG. 2 comprises an MPEG 2 coder referenced CD and a multiplexing circuit 5. The CD coder makes it possible to code the digital video data D3 according to the MPEG standard 2 video. Under the action of a command C5 coming from the sequencer 4, the multiplexer 5 allows the multiplexing of the data D2 and the data D4 coming from the encoder CD

  to create an F2 data stream according to the MPEG 2 System standard.

  Figure 3 shows an application of the system shown

in figure 2.

  In addition to elements 1, 2, 3, 4 and CD of figure 2, the system

  in Figure 3 includes m MPEG 2 coders referenced CD1, CD2 ......

  CDm, m being an integer greater than or equal to 1, a multiplexer 6 and a

multiplexer 7.

  Each CDi encoder (i = 1, 2 ....... m) receives on its input a signal Si which it transforms into a coded signal SCi. Each signal If

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  corresponds, for example, to a program which can be broadcast by a

TV channel.

  The multiplexer 6 operates the multiplexing of the data D2 and of the computer data TS which constitute a data stream commonly called "Transport Stream". As is known to a person skilled in the art, the TS data are the computer data which are associated with the data which make up the various Si signals. By way of nonlimiting example, the TS data can comprise -one among others- data which define the access rights of a user to 0 a program in the case of pay television. The data stream from the multiplexer 6 is denoted Dl. The multiplexer 7 operates the multiplexing of the data SC1, SC2 ....... SCm, D4 and Dl so as to

  generate an F3 data stream according to the MPEG 2 System standard.

  FIG. 4 represents, according to the invention, a device for reading data coming from a device such as that shown in

figure 1.

  The device of FIG. 4 comprises a circuit 8 making it possible to restore the computer data D1 from the data D3, a RAM area called "texture memory" 9 making it possible to store the data D1 coming from the circuit 8, a device 10 for image synthesis, a microprocessor 11, a read-only memory area 12 of ROM or FLASH ROM type and a random access memory area 13 of RAM type (the abbreviation RAM comes from the English "Random Access Memory"). The

  D2 data is transmitted to the microprocessor 1 1.

  The ROM memory area 12 contains an application control program, hereinafter called the master program, responsible for managing all the data D2 and D3 which are received by the reading device. The master program contains all the instructions allowing the main program and the subroutines to be executed. In particular, the master program allows the microprocessor 11 to recognize the main program in the data stream D2 which it receives. After it has been recognized, the program

  main memory is stored in RAM 13.

  During its execution, the main program calls all or

  part of the various subroutines associated with it. A coin-

  called program is stored in the RAM area 13. In order to store a called subroutine in the RAM area 13, the main program sends a request to the master program for loading the subroutine. The master program then takes control of the application. When the subroutine arrives in the data stream D2, the master program loads it into the RAM 13 and, once the subroutine is stored, signals to the main program that its request is served. The main program then temporarily regains control of the application. The subroutine called by the main program being loaded into the RAM 13, the

  main program then passes application control to that sub

program.

  As previously mentioned, a sub-

  program has the function of implementing at least one action among the set of actions that a user is likely to request using an input device such as, for example, the remote control of the television receiver on which he wishes to display the synthetic images or even the remote control of a device containing a device as described in FIG. 4. Thus, when a user uses a remote control to trigger a desired action, is a signal T representing this action applied to the microprocessor 11. If the computer and graphic data which allow the subroutine to execute are respectively loaded in the memory area

  vivid 13 and in texture memory area 9 then the sub

  program runs. If not, the subroutine sends

  a request to the master program to load them. The program-

  master then takes control of the application to load this data.

  Once the data has been loaded, the master program signals to the

  program that its request is served. The subroutine then resumes

  reading control to perform the action assigned to it.

  When a subroutine has the task of constituting a synthetic image from computer data and graphic data, the construction of this image is carried out, in a manner known per se, by the device 10. The signal V coming from the device 10 then constitutes a signal

  video that can be displayed, for example, on a television receiver.

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  In case, following a request to load sub-

  program in RAM 13, it appears that RAM 13 is completely filled, the master program selects one or more subroutines previously loaded and no longer useful for the action in progress so as to release the space. memory required and

ability to load.

  Similarly, in case o, following a request to load data representing a graphic object in texture memory 9, it

  appears that this memory is completely filled, the program-

  master selects the data representing one or more graphic objects previously loaded and no longer useful for the current action so as to free up the necessary memory space and be able to

proceed with loading.

  The data contained in memory 1 (cf. FIG. 1) is read in a loop. It follows that the data D2 and D3 which arrive at the reading device according to FIG. 4 arrive continuously on this device. According to the invention, it is therefore not necessary that all of the graphic data and of programs which allow the implementation of the application are stored in the memory areas 13 and 9. Advantageously, it follows that the capacity of the memory areas 13 and 9 may be much less than that which would be necessary to store all of the graphical and program data. By way of nonlimiting example, an application of 100 Megabytes of graphic data and programs can be executed using memory areas 13 and 9 having a capacity

of 3 Megabytes.

  According to a modification of the device shown in dotted lines in FIG. 4, the data D2 and D3 come from a demultiplexer M2 which receives on its input a data stream Fl1 such as that mentioned previously (cf. FIG. 1). The demultiplexing operation

  is then controlled by a command C4 from the microprocessor 11.

  According to the embodiment shown in FIG. 4, the graphic data are stored in a specific memory area: the texture memory area 9. According to another embodiment of the invention, the reading device does not include

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  specific memory area such as area 9. Graphic data

  are then stored in the RAM memory area 13.

  FIG. 5 represents a particular embodiment of the reading device of FIG. 4. The device of FIG. 5 is a device making it possible to read data contained in a flow such as the flow F2 or the flow F3 mentioned previously. It follows that the device of FIG. 5 can be, for example, a contained device

  in a decoder working according to the MPEG 2 video standard.

  In addition to the elements 8, 9, 10, 11, 12, 13 shown in FIG. 4, the device in FIG. 5 comprises a demultiplexer 14 and a decoding circuit 15 making it possible to decode video data coded according to the MPEG 2 video standard. The digital data stream (F2 or F3) is transmitted to the demultiplexer 14. Under the action of a command C6 originating from the microprocessor 11, the demultiplexer 14 distributes the data contained in the stream into data D2 transmitted to the microprocessor 11 and data D4 transmitted to the circuit 15. The decoding circuit 15 makes it possible to restore the data D3 from the coded data D4. D1 data from circuit 8 and D2 data from the multiplexer

  14 are treated according to the method described in FIG. 4.

  In the case where the digital data stream is a F3 type stream, the latter contains SCi data (i = 1, 2 ....... m) and TS data associated with the SCi data. When the user wishes to display the program corresponding to particular SCi and TS data on the screen of his television receiver, the command C6 makes it possible to select these data. The data SCi is transmitted to the circuit 8 and the data TS to the microprocessor 11. The circuit 15, the texture memory 9 and the device 10 are then transparent for the

  video data to be displayed on the screen.

  According to the embodiment represented in FIG. 5, the graphic data are stored in a specific memory zone: the texture memory zone 9. As for the device represented in FIG. 4, according to another embodiment of the Invention, the reading device does not include a specific memory area 9. The graphic data is then stored in the RAM area 13.

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Claims (15)

  1. Method for processing computer data stored in a memory (1) and consisting of data corresponding to graphic objects (D1l) and program data (D2), characterized in that it comprises: - a step of reading the memory (1) so as to extract computer data therefrom (I); - a step of demultiplexing the extracted computer data (I) so as to separate the data corresponding to graphic objects (D1) and the program data (D2), and - a formatting step comprising the transformation of the data corresponding to objects graphics (D1) in video data formatted numbers (D3).   2. Processing method according to claim 1, characterized in that the formatting step includes putting the data   corresponding to graphic objects (D1l) in 4: 2: 2 format.   3. Processing method according to claim 1 or 2, characterized in that it comprises a coding step according to the standard   MPEG 2 video data (D3) from the formatting step.   4. Processing method according to claim 3, characterized in that it comprises a step of multiplexing the data (D4) from the coding step and the program data (D2) so as to constitute a stream (F2) of data that can be conveyed according to the standard transport system MPEG 2 System.   5. Device for processing computer data consisting of data corresponding to graphic objects (D1) and program data (D2), characterized in that it comprises: - a memory (1) where the computer data are stored; - a demultiplexer (2) connected to the memory (1) and making it possible to separate the data corresponding to graphic objects (D1) and the program data (D2) which are transmitted to it; 12 2778300   - a formatting device (3) making it possible to transform the data corresponding to graphic objects (D1) which come from the   demultiplexer (2) into formatted digital video data (D3).   6. Processing device according to claim 5, characterized in that the formatting device is a device making it possible to put the data corresponding to graphic objects (D1l) in the format 4: 2: 2.   7. Processing device according to claim 5 or 6, characterized in that it comprises a device (CD) for coding according to the   MPEG 2 video standard data (D3) from the formatting device.   8. Processing device according to claim 7, characterized in that it comprises a multiplexer (5) making it possible to constitute a stream (F2) of data which can be conveyed according to the MPEG 2 System transport standard from the data (D4) from the coding device   (CD) and program data (D2).   9. Data processing method (D2, D3) intended for constructing synthetic images by the implementation of an application executing on a microprocessor (11) whose read-only memory area (12) contains a program for application control, characterized in that, said data consisting of program data (D2) and formatted digital video data (D3) originating from a processing method according to claim 1, it comprises: - a step of loading, into a first RAM area (13), of program data (D2) representing a main program of the application, said program data being kept in the first RAM area (13) throughout the duration of the application; - At least one step of loading in the first RAM area (13) program data (D2) representing at least one subroutine of the application, said subroutine having the function of implementing at least one action among the set 13 2778300   actions that a user is likely to request using a command (T) applied to the microprocessor (11); - at least one restitution step comprising the restitution of the computer data (D1) corresponding to graphic objects from the formatted digital video data (D3); - At least one step of loading in a second RAM area (9) data (D1l) from the restitution step; at least one step of constructing synthetic images from program data originating from the first RAM area (13) and representing at least one subroutine of the application and computer data (D1) originating from the second memory area   vivid (9) and corresponding to graphic objects.   10. Processing method according to claim 9, characterized in that the restitution step comprises the restitution of the data   computing (D1l) from data (D3) in 4: 2: 2 format.   11. Treatment method according to claim 9 or 1 0, characterized in that the restitution step is preceded by a step of   decoding of coded data (D4) according to the MPEG 2 video standard.   12. Data processing device (D2, D3) making it possible to construct computer generated images by implementing an application, said device containing a microprocessor (11) for executing the application and a read only memory area (12 ) containing an application control program, characterized in that, the data consisting of program data (D2) and formatted digital video data (D3) originating from a device according to claim 5, it comprises: - a device (8) for restoring computer data (Dl) made up of data corresponding to graphic objects from formatted digital video data (D3), and - a device (10) for synthesizing images for constructing the images of synthesis from program data (D2) and computer data (D1l) from the device (8) to restore computer data. 14 2778300   13. Processing device according to claim 12, characterized in that it comprises a texture memory area (9) making it possible to store the data (Dl) corresponding to graphic objects originating from the device (8) to restore computer data . 14. Device according to claim 12 or 13, characterized in that it comprises a decoding device (16) making it possible to decode video data coded according to the MPEG 2 video standard, the decoding device having its output connected to the input of the device (8) to restore computer data.   15. Decoder working according to the MPEG 2 video standard,   characterized in that it comprises a device according to claim 14.