EP1955554A1

EP1955554A1 - Method for providing 3d contents service based on digital broadcasting

Info

Publication number: EP1955554A1
Application number: EP06823836A
Authority: EP
Inventors: Kug-Jin Yun; Nam-Ho Hur; Soo-In Lee
Original assignee: Electronics and Telecommunications Research Institute ETRI
Current assignee: Electronics and Telecommunications Research Institute ETRI
Priority date: 2005-12-02
Filing date: 2006-11-30
Publication date: 2008-08-13
Also published as: EP1955554A4; WO2007064159A1; KR100818933B1; KR20070058302A

Abstract

Provided is a method for providing three-dimensional (3D) contents service based on digital broadcasting. The method includes the steps of: a) extracting Program Association Table (PAT) information on Packet Identification (PID); b) acquiring Program Map Table (PMT) PID from the extracted PAT; c) analyzing version_number and Contents_type_descriptor and dividing typical broadcasting contents and 3D broadcasting contents; d) extracting the PID for each media stream formed for a reference image and a 3D additional information broadcasting service; e) extracting a corresponding media stream in the Transport Stream and transmitting the media stream to a corresponding decoder; and f) recovering an image of the transmitted media stream in the decoder and displaying the media stream.

Description

METHOD FOR PROVIDING 3D CONTENTS SERVICE BASED

ON DIGITAL BROADCASTING

Technical Field

[1] The present invention relates to a method for providing three-dimensional (3D) contents service based on digital broadcasting; and, more particularly, a method for providing a 3D contents service based on digital broadcasting to provide realistic 3D contents by suggesting a formation and information of a Program Map Table (PMT) to provide a stereoscopic 3D moving picture service used for a 3D stereophonic broadcasting service.

[2]

Background Art

[3] A three-dimensional (3D) image and a stereophonic sound for providing a realistic service come into notice since the advent of high-definition digital broadcasting.

[4] As an information transmission speed is improved and the quantity of information increases, researchers have made a progress on establishment of an ultra-high speed communication network through an optic cable. Accordingly, a technology combining a 3D technology to provide a realistic service to a user gains ground.

[5] As a conventional technology, KR Patent Publication No. 1999-0060127 (reference

1) discloses a method and apparatus for transmitting/receiving a stereophonic image in a digital broadcasting. The reference 1 is a method including the steps of additionally transmitting Packet Identification (PID) for classifying left and right image signals with respect to a stereoscopic 3D moving picture as well as PID for classifying video/ audio information and additional information in MPEG-2 Transport Stream (TS), separating information on the left and right image added to the video information in a receiving part, recovering an image based on two decoders and displaying a 3D moving picture.

[6] Since the technology of the reference 1 can display only the 3D moving picture, it has a limitation in the method of recognizing the stereoscopic 3D moving picture in a 3D reception terminal in compatibility with an existing system.

[7] Also, KR Patent Publication No. 1989-0015620 (reference 2), discloses a stereophonic television broadcasting method and a stereophonic television receiver. KR Patent Publication No. 1995-0010662 (reference 3) discloses a method for processing a signal of a stereophonic image and transmitting/receiving stereophonic broadcasting. KR Patent No. 1993-0006188 (reference 4) discloses a circuit for processing a stereophonic video image signal for stereophonic television broadcasting. [8] The references 2, 3 and 4 relate to a method for transmitting left and right image signals through two channels to provide a stereophonic broadcasting service and additionally transmitting PID for separating the left and right image signals from program data showing a stereophonic image.

[9] Since the references 2, 3 and 4 require two channels to simultaneously transmit the left and right images and the receiving part requires two tuners to receive two channels, there is a problem that facilities and a circuit formation are complicated and become huge.

[10] KR Patent Publication No. 2000-0057398 (reference 5), discloses a digital broadcasting system. The reference 5 relates to a method for reorganizing the left and right images up and down or left and right to transmit the left and right images through one channel, and compressing and multiplexing the left and right images according to a conventional broadcasting method.

[11] There is a problem that the reference 5 does not maintain compatibility with the typical broadcasting.

[12] The stereoscopic 3D moving picture is used in diverse application fields due to development of a computer and a communication technology. Also, since the stereoscopic 3D moving picture is more realistic and stereophonic in comparison with a typical 2D moving picture, diverse services can be provided to the user. However, the stereoscopic 3D moving picture has a limit in a stereoscopic 3D moving picture process in digital broadcasting such as a quantity of 3D moving picture data, synchronization, and compatibility with the typical system.

[13]

Disclosure of Invention Technical Problem

[14] It is, therefore, an object of the present invention to provide a method for providing three-dimensional (3D) contents service based on digital broadcasting by using a Program Map Table (PMT) formation for recognizing two-dimensional (2D) or 3D contents and displaying a stereoscopic 3D moving picture with maintaining compatibility with a digital broadcasting system, a 2D/3D display mode and interaction of user-centered depth control.

[15] Other objects and advantages of the invention will be understood by the following description and become more apparent from the embodiments in accordance with the present invention, which are set forth hereinafter. It will be also apparent that objects and advantages of the invention can be embodied easily by the means defined in claims and combinations thereof.

[16] Technical Solution

[17] In accordance with one aspect of the present invention, there is provided a method for providing a three-dimensional (3D) contents service based on digital broadcasting, including the steps of: a) extracting Program Association Table (PAT) information on Packet Identification (PID) pre-set up for a stereophonic broadcasting service from a Transport Stream (TS); b) acquiring Program Map Table (PMT) PID from the extracted PAT; c) analyzing version_number and Contents_type_descriptor based on the acquired PMT information and dividing typical broadcasting contents and 3D broadcasting contents; d) extracting the PID for each media stream formed for a reference image and a 3D additional information broadcasting service based on the PMT information; e) extracting a corresponding media stream in the Transport Stream based on a PID value for the extracted media stream and transmitting the media stream to a corresponding decoder; and f) recovering an image of the transmitted media stream in the decoder and displaying the media stream.

[18]

Advantageous Effects

[19] The present invention can provide realistic three-dimensional (3D) broadcasting to a user by providing and using a Program Map Table (PMT) formation for a realistic 3D contents service while maintaining compatibility with digital broadcasting.

[20]

Brief Description of the Drawings

[21] The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:

[22] Fig. 1 shows a Program Map Table (PMT) for providing a three-dimensional (3D) contents service based on digital broadcasting in accordance with an embodiment of the present invention;

[23] Fig. 2 shows a Transport Stream (TS) packet in accordance with an embodiment of the present invention; and

[24] Fig. 3 is a flowchart describing a method for providing the 3D contents service based on the digital broadcasting in accordance with an embodiment of the present invention.

[25]

Best Mode for Carrying Out the Invention

[26] Other objects and advantages of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. Therefore, those skilled in the art of the present invention can embody the technological concept and scope of the invention easily. In addition, if it is considered that detailed description on a related art may obscure the points of the present invention, the detailed description will not be provided herein. The preferred embodiments of the present invention will be described in detail hereinafter with reference to the attached drawings.

[27] Program Specific Information (PSI) and a type of three-dimensional (3D) additional information will be described hereinafter before description of the present invention. [28] The PSI shows program information defined by a user such that a system decoder can decode programs in the inside of Transport Stream (TS). The PSI includes four tables, which are Program Association Table (PAT), Program Map Table (PMT), Network Information Table (NIT), and Conditional Access Table (CAT).

[29] The PAT and the PMT relate to program information included in the program and the NIT relates to a regulation value. The CAT relates to scrambling when conditional access is required. [30] The present invention suggests the PSI information through the PAT and the PMT for a stereophonic broadcasting service. That is, the NIT and the CAT are not mentioned in the present invention.

[31] The PAT and the PMT transmit information on which PID is included in a certain packet and the PID shows packet ID in a TS packet header. [32] The PID is used to divide the packet in the Transport Stream inputted in a receiving part. That is, the system decoder starts a service for the program from the PAT information.

[33] Table 1 is a type of 3D additional information. In Table 1, a reference image is allocated as left and right images and a type to be considered as the 3D additional information is shown.

[34] [35] Table 1

[36]

[37] A formation of the system for 3D broadcasting is changed according to the type of the 3D additional information as shown in Table 1.

[38] The present invention allocates and describes the 3D additional information as the additional video, i.e., the vertically half image as an embodiment. That is, the reference image and the allocated 3D additional information are decoded in the receiving part, synthesized and outputted according to characteristics of each monitor from a 3D scene creator. A function of the scene creator is changed according to the type of the 3D additional information. Also, the 3D additional information type is used as 3D_additional_information_type in the inside of 3D_information_descriptor to be described hereinafter.

[39] Fig. 1 shows the PMT for providing the 3D contents service based on digital broadcasting in accordance with an embodiment of the present invention.

[40] Fig. 1 uses the PAT without change in conformity to a MPEG-2 standard. The PMT includes a method for dividing typical broadcasting contents and 3D contents, and a method for describing 3D additional information.

[41] A user can recognize information on the typical broadcasting and the 3D broadcasting through a Program System Information Protocol (PSIP). However, a 3D reception terminal does not figure out the type of the actually transmitted contents. Accordingly, the present invention uses a version_number 101 and a Contents_type_descriptor 102 in the inside of the PMT to divide the typical broadcasting contents and the 3D contents in a channel. The Contents_type_descriptor 102 includes information below.

[42]

[43] Contents_type_descriptor

[44] {

[45] Descriptor_tag 8bits: tag ID

[46] Descriptor_length 8bits: future information length

[47] Contents_Format 8bits: contents format

[48] }

[49]

[50] That is, the Contents_type_descriptor 102 includes a Descriptor_tag for showing a contents type descriptor, a Descriptor_length for showing a length of future information and a Contents_Format for dividing contents.

[51] As an embodiment, the typical broadcasting is set up as version_number 101=0 and

Contents_Format=10 in the Contents_type_descriptor 102. When a predetermined time passes, the 3D broadcasting is changed into version_number 101=1 and Contents_Format=20 in the Contents_type_descriptor 102. Subsequently, the 3D reception terminal figures out whether the received contents are the typical broadcasting contents or the 3D contents.

[52] The Contents_Format can be extended with respect to the typical broadcasting contents and diverse 3D contents. Also, a Current_next_indicator 103 is used to previously notify start of the 3D broadcasting to the 3D reception terminal. That is, when the start of the 3D broadcasting is previously notified, it is set up as version_numberl01=l, Contents_Format=20 in Contents_Type_Descriptor 102 and Current_next_indicator=0. When the actual 3D broadcasting starts, it is changed as Current_next_indicator 103=1. The Contents_type_descriptor 102 maintains compatibility with a conventional digital broadcasting set-top by setting up a tag value as User Private and is located in a right after Program_info_length 104.

[53] In the present invention, an MPEG-2 stream type used to a digital broadcasting service is used without change in a reference image 130. 3D additional information 120 uses an Advanced Video Coding (AVC) stream type. The stream type of the 3D additional information 120 can be changed according to the type of the used CODEC. Accordingly, since the conventional digital broadcasting set-top does not recognize the stream of the 3D additional information 120, 3D contents are provided as 2D contents.

[54]

[55] A formation of a 3D_information_descriptor 121 in the 3D additional information

120 is as follows.

[56]

[57] 3D_information_descriptor

[58] {

[59] Descriptor_tag 8bits: tag ID

[60] Descriptor_length 8bits: future information length

[61] 3D_additional_information_type: 3D additional information type

[62] 3D_disparity_information

[63] {

[64] Min 4bits: minimum disparity size

[65] Max 4bits: maximum disparity size

[66] }

[67] Extended_descriptor[]: further extension

[68] }

[69]

[70] The 3D_information_descriptor 121 includes a kind of the type of the used 3D additional information 120 and the minimum-maximum value of the disparity value of the image acquired by taking a photograph by a stereophonic camera.

[71] Accordingly, the 3D reception terminal performs interaction such as 3D scene creation and depth control of the user.

[72] The 3D_additional_information_type describes a type defined in Table 1. [73] The 3D_disparity_information includes a maximum/minimum disparity value of the stereoscopic 3D moving picture and a value of the 3D_disparity_information is automatically changed according to movement of the future stereophonic camera.

[74] When information newly required for the 3D additional information is added, the Extended_descriptor is used. [75] Table 2 shows an embodiment of the PMT formation for servicing the 3D contents based on the above-mentioned contents.

[76] [77] Table 2

[78] [79] The 3D broadcasting reception terminal recognizes and services the typical broadcasting contents and the 3D contents while maintaining compatibility with the conventional digital broadcasting system. The 3D broadcasting reception terminal maintains typical channel setup and compatibility with the broadcasting by setting up a program based on the PMT.

[80] Fig. 2 shows a TS packet in accordance with an embodiment of the present invention. Fig. 2 shows a formation of a multiplexed TS packet of the reference image and the 3D additional information stream organized according to the PID of the PMT.

[81] In 210 of Fig. 2, when the reference image and the 3D additional information stream are continuously transmitted, multiplexing is performed by first transmitting the reference image and then the 3D additional information. In this case, the number of bits per a second of the consecutive stream increases in the 3D reception terminal and reception rate remarkably decreases. In the present invention, the reference image and the 3D additional information stream are combined as shown in 220 of Fig. 2 to multiplex 3D contents. Accordingly, the 3D contents are multiplexed and maximally scattered on the available bandwidth, and 3D additional information is synchronized based on a presentation time stamp (PTS) clock of the reference image.

[82] Fig. 3 is a flowchart describing a method for providing the 3D contents service based on the digital broadcasting in accordance with an embodiment of the present invention and it shows a procedure for processing a reception terminal for the 3D broadcasting service.

[83] The 3D contents service providing method based on the digital broadcasting of the present invention includes the procedures of extracting PAT information, which is PID=O, for a stereophonic broadcasting service at step S301, acquiring the PMT PID from the PAT at step S302, checking version_number and Contents_type_descriptor based on the acquired PMT information at step S303, extracting the PID for each media stream formed for the stereophonic broadcasting service from the PMT information at step S304, extracting a corresponding media stream in the Transport Stream based on a PID value for the media stream at step S305 and transmitting the extracted media stream to a corresponding decoder at step S306.

[84] Each decoder recovers an image and a 3D image creating unit creates a 3D moving picture based on the 3D monitor characteristics. The user can watch the created 3D moving picture as the 2D or 3D moving picture at step S307. One image of the left and right images is processed and displayed as the 2D image at step S309. The left and right images are simultaneously processed and displayed as a 3D moving picture based on the characteristics of the monitor at step S308. Also, since the 3D image creating unit controls depth as wanted in a regular range based on the 3D_disparity_information provided from the 3D_information_descriptor through the interface of the user, the user can watch the 3D moving picture in an optimal distance.

[85] As described above, the technology of the present invention can be realized as a program and stored in a computer-readable recording medium, such as CD-ROM, RAM, ROM, floppy disk, hard disk and magneto-optical disk. Since the process can be easily implemented by those skilled in the art, further description will not be provided herein.

[86] The present application contains subject matter related to Korean patent applications No. 2005-0116999 and No. 2006-0083138 filed in the Korean Intellectual Property Office on December 2, 2005, and August 30, 2006, respectively, the entire contents of which are incorporated herein by reference.

[87] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

Claims

[1] A method for providing a three-dimensional (3D) contents service based on digital broadcasting, comprising the steps of: a) extracting Program Association Table (PAT) information on Packet Identification (PID) pre-set up for a stereophonic broadcasting service from a Transport Stream (TS); b) acquiring a Program Map Table (PMT) PID from the extracted PAT; c) analyzing version_number and Contents_type_descriptor based on the acquired PMT information and separating typical broadcasting contents from 3D broadcasting contents; d) extracting the PID for each media stream formed for a reference image and a 3D additional information broadcasting service based on the PMT information; e) extracting a corresponding media stream from the Transport Stream based on a PID value for the extracted media stream and transmitting the media stream to a corresponding decoder; and f) recovering an image of the transmitted media stream in the decoder and displaying the media stream.

[2] The method as recited in claim 1, wherein a Contents_type_descriptor includes a

Descriptor_tag for showing a contents type descriptor, a Descriptor_length for showing a length of subsequent information, and a Contents_Format for dividing contents.

[3] The method as recited in claim 1, wherein the 3D additional information includes a 3D_information_descriptor of the 3D additional information and the 3D_information_descriptor includes a Descriptor_tag, a Descriptor_length, a 3D_additional_information_type, 3D_disparity_information, a type of the used 3D additional information, and the minimum and maximum values of the disparity value of the image photographed in a stereophonic camera, and the 3D reception terminal performs interaction based on 3D scene creation and depth control by the user.

[4] The method as recited in claim 1, wherein in the step c), a

Current_next_indicator of the PMT is used to previously notify start of the 3D broadcasting to the 3D reception terminal.

[5] The method as recited in claim 4, wherein in the step f), when one image of the left and right images is processed and displayed for a two-dimensional (2D) image, whereas the left and right images are simultaneously processed and displayed for a 3D moving picture based on the characteristics of the monitor, and the 3D image creating unit controls depth as wanted in a regular range based on the 3D_disparity_information provided from the 3D_information_descriptor through the interface of the user so that the user can watch the 3D moving picture in an optimal distance.

[6] The method as recited in claim 1, wherein the Transport Stream are multiplexed and maximally scattered on the available bandwidth by combining the reference image and the 3D additional information stream to multiplex 3D contents, , and 3D additional information synchronization is performed based on a Presentation Time Stamp (PTS) clock of the reference image.