[DESCRIPTION]

APPARATUS FOR REPRODUCING DATA, METHOD THEREOF, APPARATUS FOR

RECORDING THE SAME, METHOD THEREOF AND RECORDING MEDIUM

Technical Field

The present invention relates to a method and an apparatus

for reproducing data from and/or recording data in a

recording medium or storage and the recording medium.

Background Art

Recently, optical discs capable of recording large-scale data

as record media are widely used. To meet the rising demand

for video data of high image quality and audio data of high

sound quality, HDTV and MPEG2 have been provided. For

instance, if video data amounting to one HDTV movie is stored

in a disc with MPEG2 image quality, a high-density recording

medium having at least 20Gbyte data storage capacity is

demanded.

To meet this demand, Blu-ray disc, HD-DVD (high-definition

digital video versatile disc) and the like have been

developed as next generation recording media. And, many

efforts have been made to develop an optical record player

according to high definition recording medium specifications .

However, despite the increasing possibility in recording and

reproducing at least two kinds of video stream data

simultaneously due to the development of high definition

recording media, a suitable reproducing method has not been

proposed so far.

Disclosure of Invention

The present invention relates to a method of managing

reproduction of at least one picture-in-picture presentation

path.

In one embodiment, the method includes determining a

secondary video stream to reproduce with a primary video

stream based on management information stored in a memory. The secondary video stream represents the picture-in-picture

presentation path with respect to a primary presentation path

represented by a primary video stream. The management

information includes identifying information identifying the

secondary video stream to reproduce, and the management

information includes display information indicating whether

to display the secondary video stream. The determined

secondary video stream is selectively reproduced based on the

management information.

In one embodiment, a state of the display information is set

based on an instruction. For example, the instruction may be

received from a use, an application program interface, or etc,

One embodiment further includes decoding the secondary video

stream even if the display information indicates not to

display the secondary video stream.

Another embodiment further includes reading a management

table from navigation information recorded on a recording

medium. The navigation information includes secondary video

stream entries, and the identifying information for a

selected one of the secondary video stream entries is stored

in the memory.

In a further embodiment, the management table further

includes combination information. The combination information

indicates the secondary audio streams that are combinable

with the secondary video stream. A secondary audio stream number identifying a selected one of the secondary audio

streams indicated by the combination information is stored as

the identifying information.

Yet another embodiment further includes determining a

secondary audio stream to reproduce with the secondary video

stream based on the management information stored in the

memory. The determined secondary audio stream is reproduced

based on the management information.

The present invention also relates to a reproduction

apparatus .

In one embodiment, the reproduction apparatus includes a

memory unit and a controller. The memory unit is configured

to store management information. The management information

indicates a secondary video stream to reproduce and indicates

whether the secondary video stream is to be displayed. The

controller is configured to control reproduction of the

secondary video stream based on the management information.

The secondary video stream represents the picture-in-picture

presentation path with respect to a primary presentation path represented by a primary video stream.

In one embodiment, the memory unit includes at least one status register.

In one embodiment, the management information includes a flag

indicating whether to display the secondary video stream. In

this embodiment, the controller may set a state of the flag based on a received instruction. For example, the instruction

may be received from a user, an application program interface,

or etc. In one embodiment, the apparatus further includes a decoder

configured to decode the secondary video stream, and the

controller is configured to control the decoder to decode the

secondary video stream even if the management data indicates

not to display the secondary video stream.

Yet another embodiment includes a driver configured to drive

a reproducing device to reproduce data. The controller is

configured to control the driver to reproduce a management

table. The management table indicates a number of secondary

video stream entries, and the controller stores a secondary

video stream number identifying a selected one of the number

of secondary video stream entries in the memory unit as part

of the management information.

In one embodiment of the apparatus, the management

information indicates a secondary audio stream to reproduce

and indicates whether the secondary audio stream is to be played.

In a further embodiment of the apparatus, the management information includes size information indicating a size to

display the secondary video stream, and the controller is

configured to control reproduction such that the secondary

video stream is displayed at the size indicated by the size information .

For example, the size information stored in the memory may be received from a user, an application program interface, or

etc.

In one embodiment, the controller is configured to control a

driver to reproduce metadata from a playlist recorded in the

recording medium. The playlist indicates at least the primary

video stream to reproduce, and the metadata including the

size information. The controller is configured to store the

size information in the memory unit.

The present invention further relates to a recording medium

having a data structure for managing reproduction of at least

one picture-in-picture presentation path.

In one embodiment, the recording medium includes a secondary

video stream number area and a first flag area. The secondary

video stream number area stores a number identifying a

secondary video stream to reproduce from another recording

medium. The secondary video stream represents the picture-in-

picture presentation path with respect to a primary

presentation path represented by a primary video stream. The

first flag area stores a first flag indicating whether the

secondary video stream is to be played.

The present invention also relates to an apparatus and a

method for recording the data structure for managing

reproduction of at least one picture-in-picture presentation path.

Brief Description of Drawings

The accompanying drawings, which are included to provide a

further understanding of the invention and are incorporated

in and constitute a part of this application, illustrate

embodiment ( s ) of the invention and together with the

description serve to explain the principles of the invention.

In the drawings:

FIG. 1 is a diagram of one embodiment of reproducing data

within a recording medium and/or storage via an optical

record player;

FIG. 2 is a diagram of a file structure recorded in an

optical disc as a recording medium of the present invention;

FIG. 3 is a diagram of a recording structure of an optical

disc as a recording medium of the present invention;

FIG. 4 is a diagram for explaining a reproduction of a

secondary video according to an embodiment of the present

invention;

FIG. 5 is a schematic block diagram of an overall

configuration of an optical record player according to an

embodiment of the present invention;

FIG. 6 is a schematic block diagram of a playback system

according to one embodiment of the present invention;

FIG. 7 is a diagram of a data reproducing apparatus utilizing

a playback system according to an embodiment of the present

invention;

FIG. 8A is an exemplary diagram of a status memory unit

provided to a reproducing apparatus according to an

embodiment of the present invention;

FIG. 8B is an exemplary diagram of PSR14 as a part of the

status memory unit shown in FIG. 8A;

FIG. 9 is an exemplary diagram of syntax of a table including

information for a secondary video stream according to an

embodiment of the present invention; and

FIG. 10 is a flowchart of a method of reproducing data

according to an embodiment of the present invention.

Best Mode for Carrying Out the Invention

Reference will now be made in detail to example embodiments

of the present invention, which are illustrated in the

accompanying drawings. Wherever possible, the same reference

numbers will be used throughout the drawings to refer to the

same or like parts.

For the purposes of example only, an optical disc such as a

DVD, Blu-ray disc (BD) , HD-DVD, NFR (near field recording)

disc, etc., will be used as an example recording medium in describing the present invention, but it will be understood

that the present invention is not limited to optical discs as

the recording medium. For further convenience of explanation,

the present invention more particularly takes a "Blu-ray disc

(BD)" as an example of a record medium. Yet, it is apparent

that the technical idea of the present invention is

identically applicable to other record media including HD-DVD

and the like.

In the present invention, "Storage" may be a storage means provided within an optical record player such as shown in FIG.

1, and means an element which can randomly store information

and data. In particular, the storage currently used in

general, includes a "hard disc", "system memory", "flash

memory" or the like, which does not put limitation on the

scope of the present invention.

The "Storage" may be utilized as a means for storing data

associated with a recording medium. The data associated with

the recording medium to be stored within the storage may

include data externally downloadable such as from the

internet .

It will also be apparent that data directly read out of a

recording medium, in part, or a generated system data (e.g.,

metadata, etc.) associated with reproduction of data recorded

in the recording medium may be stored within the storage.

"Contents" in the following description may be data provided by a record medium author as contents configuring a title.

And, a party, who provides content, is generically named a

"content provider (CP)".

For convenience of explanation of the present invention, the

data recorded within the recording medium shall be called

"original data" and the data obtained outside the recording

medium and associated with the recording medium shall be

called "additional data". The original and additional data

are classified according to acquisition methods only. So,

data existing outside an optical disc and having any kind of

attribute associated with original data can be called

additional data.

"Title" as used in the following description may be a unit

of reproduction configuring an interface with a user. Each

title is linked to a specific object. And, a stream

associated with the corresponding title recorded within a

disc is reproduced according to a command or program within

the object. In particular, for explanation convenience of the

present invention, a title having a moving picture, movie and

interactive information according to MPEG2 compression among

titles recorded within a disc shall be named a "HDMV Title".

And, a title having moving picture, movie and interactive

information executed by a Java program among titles recorded

within a disc shall be named a "BD-J Title".

"PiP (Picture-in-Picture) " used in the following description

means a function of playing a secondary video on an image of

a primary video that is being reproduced.

"Reproduction management data" used in the following description means information used in managing a reproduction

of a video or audio stream. And, a stream number (STN) table

containing video stream entry information and audio stream

entry information and metadata managing a secondary video

playback are included in the "reproduction management data".

The above-explained terminologies are replaceable by any

terms indicating the same functions, respectively.

FIG. 1 shows one embodiment of reproducing data within a

recording medium and/or storage via an optical record player.

Referring to FIG. 1, "Optical record player" 10 according to

the present invention enables recording or playback of an

optical disc according to various specifications. And, the

optical record player 10 can be designed to record/play an

optical disc (e.g., BD) of a specific specification. Moreover,

the optical record player 10 can be made to play an optical

disc only. In the following description of the present

invention, by considering interactivity between a Blu-ray

disc (BD) and a peripheral device, a BD-player reproducing a

Blu-ray disc (BD) or a BD-recorder recording/playing a Blu-

ray disc (BD) will be taken as an example. And, it is

apparent that the "optical record player" 10 includes a "drive" loadable within a computer or the like.

The optical record player 10 according to the present invention is equipped with a function of recording/playing an

optical disc 30 and a function of receiving an external input

signal, performing signal-processing on the received signal,

and delivering a corresponding image to a user via another

external display 20. In this case, no limitation is put on

the external input signal. And, a DMB (digital multimedia

broadcast) signal, an Internet signal or the like can be a

representative one of the external input signals. In case of

the Internet, as an easily accessible medium, specific data

from the Internet can be downloaded via the optical record

player 10.

The original data and the additional data will be explained

in detail as follows. For instance, if a multiplexed AV

stream for a specific title is recorded as original data

within an optical disc and if an audio stream (e.g., English)

different from the audio stream (e.g., Korean) of the

original data is provided as an additional data from the

Internet, a request for downloading the audio stream (e.g.,

English) as the additional data from the Internet to

reproduce together with the AV stream of the original data,

or a request for downloading the audio stream (e.g., English)

as the additional data from the Internet to reproduce only,

may be made by a user. To enable the requests, association

between the original data and the additional data is

regulated and a systematic method of managing/reproducing the

data according to the user's request is provided.

To realize the user's requests, a file structure between the original data and the additional data is provided. File and

data structures usable for a Blu-ray disc (BD) are explained in detail with reference to FIG. 2 and FIG. 3 as follows.

FIG. 2 is a diagram of a file structure recorded within an optical disc as a recording medium according to an embodiment

of the present invention. In particular, FIG. 2 shows a file

structure for reproduction management of original data

recorded within a disc.

Referring to FIG. 2, at least one BDMV directory exists below

one root directory. An index file ("index") and an object

file ("MovieObject") as general file (higher file)

information to secure interactivity with a user exist within

the BDMV directory. And, the BDMV directory includes a

playlist directory ("PLAYLIST") , a clipinfo

directory ("CLIPINF") , a stream directory ("STREAM") , an

auxiliary directory ("AUXDATA") , a BD-J object

directory ("BDJO") , a metadata directory ("META") , a backup

directory ("BACKUP") and a JAR director. The BACKUP directory

has information of data actually recorded within a disc and

information about a method of reproducing the recorded data.

The other directories, and the files included in each of the

directories, are explained in detail as follows.

The JAR directory includes JAVA program files. The metadata directory ("META") includes a metadata file as

data about a data. Namely, in the metadata directory ("META") ,

a search file, a metadata file for Disc Library and the like

exist as the metadata files to use for efficient search or

management of data.

The BD-J object directory ("BDJO") includes a BD-J Object file

for reproducing a BD-J Title.

The auxiliary directory ("AUXDATA") includes auxiliary files

containing information for a disc playback. For instance, the

AUXDATA directory may include a sound file ("Sound. bdmv")

providing click sound in case of an execution of interactive

graphic and font files ("11111. otf" and "99999. otf")

providing font information in case of a disc playback.

In the stream directory ("STREAM") , AV stream files recorded

within a disc in a specific format exist. Each of the streams

is recorded as MPEG-2 transport packets in general, and

".m2ts" is used as an extension of a stream file (01000.m2ts,

02000.m2ts, etc.). In particular, a stream generated from

multiplexing video, audio and graphic information together is

named an AV stream and at least one or more AV stream files

construct a title.

The clipinfo directory ("CLIPINF") includes clip information

files (01000. clpi, 02000. clpi, etc.) one-to-one corresponding

to the stream files, respectively. In particular, a clip information file ("*.clpi") includes attribute information

and timing information of the corresponding stream file. In

particular, the stream file ("*.m2ts") and the clip

information file ("*.clpi") corresponding to the stream file

(*.m2ts) are called collectively a "clip". Namely, a "clip"

is the data containing both of the stream file ("*.m2ts") and

the clip information file ("*.clpi").

The playlist directory ("PLAYLIST") includes playlist files

("* .mpls") . A playlist is a group of playing intervals for

reproducing clips. And, a playing interval is called a

Playltem. Each of the playlist files ("*.mpls") includes at

least one Playltem and SubPlayltem (SPI) designating a

playing interval of reproducing a specific clip. The Playltem

and SubPlayltem (SPI) have information about a reproduction

start time (IN-Time) and reproduction end time (OUT-Time) of

a specific clip. So, the playlist can be called a set of

Playltems . And, metadata for managing a reproduction of a

secondary video is included within the playlist file.

Moreover, the metadata includes a reproduction time,

reproduction position and size of the secondary video in

association with the reproduction of the secondary video.

A reproduction process within PlayList file by at least one

Playltem is called "main path" and a reproduction process

within PlayList file by each SubPlayltem is called "sub path".

The main path provides a master presentation of a playlist

and the sub path provides auxiliary presentations associated with the master presentation. The main path should exist

within the PlayList file and at least one sub path may exist

according to a presence of SubPlayltem (SPI) .

In the present invention, video data reproduced by the main path is also called primary video, and video data reproduced

by the sub path is also called secondary video. A function of

reproducing both of the primary and secondary videos by an

optical record player may be "PiP (Picture in Picture).

The backup directory BACKUP stores a copy of the index file

("index") recording information associated with a disc

playback among data of the file structure, object files

(MovieObject, BD-J Object), unit key file, all playlist files

("*.mpls") within the playlist directory PLAYLIST, and all

clip information files ("*.clpi") within the clipinfo

directory CLIPINF. Since the loss of the files may be fatal

to the disc playback, the BACKUP directory stores these files

for backup .

It is apparent that the file structure of the present

invention is not limited to the above-explained names and

positions. Namely, the directories and files should be

understood not by their names and positions but by their

meanings .

FIG. 3 is a diagram of a data record structure written on an

optical disc as a recording medium according to an embodiment of the present invention, which shows how the aforesaid file

structure associated information is recorded within a

corresponding disc.

Referring to FIG. 3, in view from an inner circumference of a

disc, there exist a file system information area as system

information for managing an entire file, an area ("database

area") in which PlayList and clip information files are

written to reproduce a recorded AV stream (*.m2ts), and an AV

stream area in which a stream configured with

audio/video/graphic or a JAR file is recorded.

And, an area for recording file information for reproducing

contents within the stream area and the like is called a

"Reproduction management area" and corresponds to the file

system information area or the database area. In some cases,

reproduction information of a stream can be recorded in a

header of a stream within the stream area. In this case, the

header corresponds to the management area as well. So,

information associated with playback management can be

recorded in the "reproduction management area".

Yet, each area shown in FIG. 3 is exemplarily proposed. And,

it is apparent that the present invention is not limited to

the arrangement structure of the areas shown in FIG. 3.

FIG. 4 is a diagram of a reproduction mode of secondary video

according to embodiments of the present invention. One embodiment of playing a secondary video on an image of a

primary video that is being played is explained with

reference to FIG. 4 as follows.

Referring to FIG. 4, another video data associated with a primary video 410 can be requested to be output to a same

display unit 20 while the primary video is being played back.

For instance, in the course of playing a movie or documentary, in case that a director' s commentary for a shooting process

is to be provided to a user, a video showing the commentary

can be played back as a secondary video 420 together with the

primary video 410. In doing so, the secondary video 420 may

be played together with the playback of the primary video 410.

In some cases, a playback of the secondary video 420 may

start in the middle of reproducing the primary video 410. And,

it is also possible to display the secondary video 420 at a

different position or size on a screen according to a

playback process. Moreover, it is also possible to start or

end a corresponding playback separately from a playback of

the primary video 410. The primary video 410 can be played

together with an associated audio 410a and the secondary

video 420 can be played together with an associated audio

420a.

Information for a play timing point, play position, size of

the secondary video and a stream constructing the secondary

video is provided to play back the secondary video. And, information for defining an audio stream, presentation

graphic or text subtitle stream (e.g., PiP PG textST stream)

reproduced together with the secondary video and information

for defining a permitted reproduction combination of the

streams are provided as well. Moreover, an optical record

player is provided with a memory unit (e.g., PSRs) storing a

playback status of the secondary video and a playback

environment.

FIG. 5 is a block diagram of an overall configuration of an

optical record player according to an embodiment of the

present invention.

Referring to FIG. 5, an optical record player 10 according to

one embodiment of the present invention includes a pickup 11

for reproducing original data and reproduction management

information including playback management file information

recorded in an optical disc, a servo 14 for controlling an

action of the pickup 11, and a signal processor 13 for

restoring a reproduction signal received from the pickup 11

to a specific signal value. The signal processor 13 also

modulates a signal to be recorded into a signal recordable on

the optical disc. A microprocessor 16 controls the overall

operations of these elements.

The pickup 11, the servo 14, the signal processor 13, and the

microprocessor 16 are also collectively referred to as a

"recording/reproducing unit". In accordance with the present invention, the recording/reproducing unit reads data from an

optical disc 30 or storage 15 under the control of a

controller 12, and sends the read data to an AV decoder 17b.

The recording/reproducing unit also receives an encoded signal from an AV encoder 18, and records the received signal

in the optical disc 30. Thus, the recording/reproducing unit

can record video and audio data in the optical disc 30.

The controller 12 downloads additional data present outside

the optical disc 30 in accordance with a user command, and

stores the additional data in the storage 15. The controller

12 also reproduces the additional data stored in the storage

15 and/or the original data in the optical disc 30 at the

request of the user.

The optical recording/reproducing apparatus 10 further

includes a playback system 17 for finally decoding data, and

providing the decoded data to the user under the control of

the controller 12. The playback system 17 includes an AV

decoder 17b for decoding an AV signal. The AV decoder 17b

may include a plurality of decoders. The playback system 17

also includes a player model 17a for analyzing an object

command or application associated with playback of a

particular title, for analyzing a user command input via the

controller 12, and for determining a playback direction,

based on the results of the analysis. In an embodiment, the

player model 17a may be implemented as including the AV decoder 17a. In this case, the playback system 17 is the

player model itself. FIG. 6 is a schematic block diagram of a playback system

according to an embodiment of the present invention.

Referring to FIG. 6, a decoder 17b according to one

embodiment of the present invention includes a primary video

decoder 610a decoding a primary video and a secondary video

decoder 610b decoding a secondary video.

The decoded primary and secondary videos are output via

primary and secondary video planes 620a and 620b to be

provided to a user, respectively.

The controller 12 checks reproduction management data of the

secondary video and controls the secondary video decoder 610b

so that the secondary video can be decoded into a specific

position and size at a specific timing point according to the

metadata that manages a playback of the secondary video (this

is described in more detail below) . As stated, primary and/or

secondary video stream data may be recorded in a recording

medium 30 or may be downloaded to a storage 15 from an

outside of the recording medium.

And, the optical record player 10 according to the present

invention includes an AV encoder 18. To perform a function of

recording a signal on an optical disc, the AV encoder 18

converts an input signal to a signal of a specific format,

e.g., an MPEG2 transport stream according to a control of the

controller 12 and then provides the converted signal to the

signal processor 13. Like the AV decoder 17b, the AV encoder

18 can include a plurality of encoders. The controller 12 is

able to control the primary and secondary video streams,

primary and secondary audio streams, reproduction management

data and the like, which are converted by the corresponding

encoders to be provided to the signal processing unit 13,

respectively, to be recorded on the optical disc.

FIG. 7 shows a data reproducing apparatus utilizing a

playback system according to an embodiment of the present

invention, in which a secondary video is reproduced together

with a primary video by the data reproducing apparatus .

Referring to FIG. 7, a "playback system" includes collection

of reproduction processing means configured as programs

(software) and/or hardware provided within an optical record

player and/or stored on the recording medium and downloaded

on the optical record player. The playback system plays a

recording medium loaded in the optical record player, and

simultaneously reproduces and manages the data that is

associated with the recording medium such as that stored in a

storage (e.g., data downloaded from outside).

In particular, a playback system 17 includes "User Event

Manager (171)", "Module Manager (172) ", a "Metadata Manager

(173)", "HDMV Module (174) ", "BD-J Module (175) ", "Playback

control engine (176) ", "Presentation engine (177)" and "Virtual

File System(40)", which are explained in detail as follows. As separate reproduction processing management means for

reproducing HDMV Title and BD-J Title, respectively, the

"HDMV Module (174)" for HDMV Titles and the "BD-J Module

(175)" for BD-J Titles are independently configured. Each of

the "HDMV Module (174)" and the "BD-J Module (175)" has a

control function for receiving a command or program within

the aforesaid object (Movie Object or BD-J Object), and processing the command or program. The "Metadata Manager

(173)" is able to perform a title selection and to provide a

recording medium and title metadata to a user at any time

under a user's control. The "HDMV Module (174)" and "BD-J

Module (175)" enable a portability of a command or

application by separating the command or application from a

hardware configuration of the playback system. As a means for

receiving to process the command, application or the like, a

"Command processor (174a) is provided within the "HDMV Module

(174), and a "Java VM (175a)" and an "Application manager

(175b)" are provided within the "BD-J Module (175).

The "Java VM (175)" is "Virtual Machine" (VM) executing an

application. The "Application manager (175b)" includes an

application management function of managing a lifecycle of an

application.

Moreover, the "Module Manager (172)" is provided to deliver a

user command to the "HDMV Module (174)" or the "BD-J Module

(175)" and to control an operation of the "HDMV Module (174)"

or the "BD-J Module (175)". A "Playback control Engine (176)", which is also provided,

interprets PlayList file information recorded within a disc

according to a reproduction command of the "HDMV Module

(174)" or the "BD-J Module (175)" and performs a corresponding reproduction function. Moreover, a

"Presentation Engine (111)" for decoding a specific stream

reproduced and managed by the "Playback Control Engine (176)",

and for displaying the decoded stream on a screen is provided.

Specifically, the "Playback Control Engine (176)" includes

"Playback Control functions (176a)" actually managing

reproductions and "Player Registers (176b)" storing player

status registers (PSRs) and general purpose registers (GPRs) .

„ In some cases, "Playback Control functions (176a)" may mean

"Playback Control Engine (176)".

In an embodiment of the present invention, the "Player

registers (176b)" becomes a memory unit indicating a playback

status of the secondary video. The memory unit will be

explained in detail with reference to FIG. 8 later.

The HDMV title and BD-J title receive user commands in

separate types, respectively, and independently perform the

user commands. A means for receiving and delivering a user

command to either the "HDMV Module (174)" or "BD-J Module

(175)" is provided by the "User Event Manager (171)". So, if

a received command is a user command by "User Operation (UO) ", the "User Event Manager (171)" transfers it to the "Module

Manager (172)" or "UO controller (171a)" to perform the user

command. If a received command is a user command by "Key Event", the "User Event Manager (171)" transfers it to the

"Java VM (175a)" within the "BD-J Module (175)" to perform

the user command. And, the playback system 17 according to the present

invention may include the "Metadata Manager (173)" that

provides disc library and enhanced search metadata

applications to a user.

In the above-explained playback system of the present

invention, the "Module Manager (172)", the "HDMV Module

(174)", the "BD-J Module (175)" and the "Playback Control

Engine (176)" are enabled in software. Software processing

tends to be more advantageous than a hardware configuration

in design. Yet, the "Presentation Engine (177)", the decoders

and the planes are normally designed by hardware. In

particular, the elements (e.g., reference numbers 172, 174,

175, 176) performed by software can be configured with a

portion of the controller 12. Hence, the configuration of the

present invention should be understood by its meaning but is

not limited to a hardware configuration or a software

configuration .

FIG. 8A is an exemplary diagram of a status memory unit provided in a reproducing apparatus according to an

embodiment of the present invention and FIG. 8B is an

exemplary diagram of a player status register (PSR) 14 as a

part of the status memory unit shown in FIG. 8A.

The optical record player 10 includes "Player Registers

(176b)" as sort of memory units storing information for

record playback status and environment of the player. The

"Player Registers (176b)" can be divided into "General

purpose Registers (GPRs) " and "Player Status Registers

(PSRs) ".

The "Player Status Registers (PSRs)" can be divided into

"Playback Status Registers" storing playback status

parameters (e.g., interactive graphics stream number' and

^λ primary audio number' ) and "Player Setting Registers"

storing optical record player configuration parameters.

In the embodiment of the present invention, "Player Status

Registers (PSRs)" storing a playback status of a secondary

video is needed to play back the secondary video as well as a

primary video.

In particular, the present invention relates to PSR14 storing

status information of a secondary video (e.g., a number or

size of a currently reproduced video stream) or information

on enabling or disabling a playback possibility of the

secondary video.

In one embodiment, PSR14 810 as one of "Player Status

Registers (PSRs)" can store a secondary video stream number. And, the PSR (hereinafter named PSR14) can store a secondary

audio stream number associated with the secondary video.

As shown in FIG. 8B, the PSR 14 includes a "Secondary video

stream number" field, a "Secondary audio stream number" field,

a "Secondary Video Size" field, a "disp_v_flag" and a

"disp_a_flag".

A secondary video stream number is stored in the "Secondary

video stream number" field. In this case, the secondary video

stream number is used in specifying which secondary video

stream to present from secondary video stream entries within

an STN table of a current playitem.

The secondary video stream number is a value for a secondary

video stream entry and is obtained by adding ^λ l' to a

secondary video stream identifier defined in the STN table.

This is because the secondary video stream identifier is

initialized to ^λ 0' .

The secondary video stream number may be set in one

embodiment from 1 to 32. If a value stored in the "secondary

video stream number" field is ^λ OxFE', it means that a current

status is "Valid' , which means that a secondary video stream

is not selected although a secondary video can be played back.

If a value stored in the "secondary video stream number"

field is ^λ OxFF' , it means that a secondary video stream is

not selected or does not exist.

A secondary audio stream number is stored in the "Secondary audio stream number" field. In this case, the secondary audio

stream number is used in specifying the secondary audio

stream to be presented from secondary audio stream entries

within an STN table of a current playitem.

The secondary audio stream number is a value for a secondary

audio stream entry and is obtained by adding ^λ l' to a

secondary audio stream identifier defined in the STN table.

This is because the secondary audio stream identifier is

initialized to ^λ 0' .

The secondary audio stream number may be set, in one

embodiment, to 1 to 32. If a value stored in the "secondary

audio stream number" field is ^λ 0xFF' , it means that a

secondary audio stream is not selected or does not exist.

A secondary video size may be stored in the "Secondary Video

Size" field.

For instance, if a value stored in the "Secondary Video Size"

field is ^λ 0x0', a playback size of the secondary video is

adjusted according to secondary video size information

included in management data reproduced from the recording

medium. If a value stored in the "Secondary Video Size" field

is ^λ OxF', a size is adjusted into a full-screen size

regardless of secondary video size information included in

reproduced management data. In this case, the full-screen

size means that the playback size of the secondary video is

adjusted into the same size as that of the primary video.

The secondary video size information may be included in the

management data on the recording medium, and may be more particularly included in metadata for managing a playback of

a secondary video.

The "disp_v_flag" stored in the PSR14 810 is a flag indicating whether to 'enable' or 'disable' a screen display

of the secondary video.

For instance, if the flag "disp_v_flag" is set to ^disable'

(0 _b ), the secondary video is not played back although the

secondary video is being decoded by the decoder 610b. Hence,

a user is unable to view the secondary video. For example,

even if the secondary video stream presentation is disabled

by changing the disp_v_flag during presentation of the

secondary video stream, the secondary video decoder 610a may

continue to decode the secondary video stream, but the

secondary video is not displayed.

On the other hand, if the flag "disp_v_flag" is set to

^λ enable' (l _b ) , the secondary video is decoded by the decoder

610b and a user is able to view the secondary video via the

secondary video plane 620b.

A value of the flag "disp_v_flag" can be changed by a command

generated from a user operation (UO) , playback system or

application programming interface (hereinafter abbreviated

API) . Hence, a playback of the secondary video can be

controlled despite the execution of the PiP function.

The ^Nλ disp_a_flag" stored in the PSR14 810 is a flag

indicating whether to 'enable' or 'disable' a playback of the secondary audio.

For instance, if the flag "disp_a_flag" is set to Misable'

(Ob), the secondary audio is not played back although the secondary audio may continue to be decoded by the decoder

610b. Hence, a user is unable to listen to the secondary audio. On the other hand, if the flag "disp_a_flag" is set to

^λ enable' (l _b ) , the secondary audio is decoded by the decoder 610b, and a user is able to listen to the secondary audio.

A value of the flag "disp_a_flag" can be changed by a command

(specifically, navigation command in playback system)

generated from a user operation (UO) , playback system or

application programming interface (hereinafter abbreviated

API) . Hence, a playback of the secondary audio associated

with the secondary video can be controlled despite the

execution of the PiP function.

In the aforesaid PSR14, play status information associated

with a secondary video to be played according to reproduction

management data is stored. The controller 12 checks the

secondary video to be played according to the reproduction

management data and controls playback status information

associated with the checked secondary video stored in the

PSR14. And, the controller 12 may control the secondary video

to be played back by checking the playback status information

stored in the PSR14. It may happen that a secondary video is or is not displayed

regardless of metadata that manages a playback of the

secondary video included in the playback status management

data. For instance, if the playback status information

defines that the secondary video is not displayable, the

secondary video is not displayed regardless of other

information for the secondary video. If the playback status

information defines that a reproduction size of the secondary

video is equal to that of a primary video, the secondary

video is played back at the same size as the primary video

regardless of size information of the secondary video

included in the playback status information.

FIG. 9 is an exemplary diagram of the syntax of a table

including information for a secondary video stream according

to an embodiment of the present invention.

The table (hereinafter called the STN table) defines a list

of basic streams that can be selected by an optical record

player 10 during a playback of sub-paths associated with a

current playitem. And, the STN table is provided in each

playitem included in a playlist.

The optical record player 10 according to the present invention possesses a function of processing a secondary

video, a secondary audio and a text subtitle. So, the STN table according to the present invention stores entries

associated with a secondary video, a secondary audio, a

presentation graphic and a text subtitle.

Referring to FIG. 9, a

"number_of_secondary_audio_stream_entries" field 910, a

^λλ number_of_secondary_video_stream_entries" field 920 and

fields for defining entries of respective streams are

included in an STN table.

The ^vv number_of_secondary_audio_stream_entries" field 910

indicates a number of secondary audio stream entries recorded

on the recording medium.

The "number_of_secondary_video_stream_entries" field 920

indicates a number of recorded "secondary video stream

entries" recorded on the recording medium.

In association with the secondary audio streams, initially a

secondary audio stream identifier

( ' secondary_audio_stream_id' ) is initialized to '0' (930).

The secondary audio stream identifiers are generated by

adding 1 to the previous secondary audio stream identifier as

long as the ' number_of_secondary_audio_stream_entries ' has

not been reached (930).

Similarly in association with secondary video streams,

initially a secondary video stream identifier

( ' secondary_video_stream_id' ) is initialized to '0' (940).

The secondary video stream identifiers are generated by

adding 1 to the previous secondary video stream identifier as

long as the ' number_of_secondary_video_stream_entries ' has

not been reached (940) .

A "stream entry ()" field in the STN table indicates information for a stream entry. For instance, it indicates

information for length and type of a stream. And, depending on the indicated type, the stream entry identifies the

specific stream of a main clip or a sub clip, and may also identify a subpath for the stream.

In particular, a database for identifying an elementary

stream referred to by a stream number for a stream entry is

stored in a "type" field included in the "stream entry ()"

field.

And, the "stream entry ()" field includes a subclip entry id

defined by a subplayitem of a subpath referred to by an

identifier ("subpath entry id") identifying a subpath entry

associated with a playback of a secondary video.

A "stream attribute ()" field in the STN table indicates

information for a stream attribute. For instance, this field

indicates information for a frame rate of a video stream

associated with a video format.

An optical record player 10 according to an embodiment of the

present invention is able to reproduce a suitable video

stream according to information defined by the STN table

using information included in metadata for PiP playback

management . For instance, a stream entry field ("stream entry ()")

associated with a playback of a secondary video can be known

from "Playltem_id" and "secondary__video_stream_id" included

in metadata for PiP playback management. Since information

for identifying an associated subpath and subclip entry is

stored in the stream entry field ("stream entry ()"), streams

suitable for the secondary video playback can be reproduced.

Since the secondary video is played back according to the

subpath, once the "Playltem_id" and "secondary video_stream_id" are determined, a playback time

of the secondary video and a playback sequence of streams

configuring the secondary video are determined.

Furthermore, the STN table includes

"comb_info Secondary_video Secondary audio" field, as shown

in FIG. 9. This field includes combination information for

defining allowed combinations of secondary video and

secondary audio. In case that the secondary video is selected

in PSR14, the secondary audio is selected based on this

combination information.

FIG. 10 is a flowchart of a method of reproducing data

according to an embodiment of the present invention.

Referring to FIG. 10, an optical record player 10 according

to the present invention reads and checks information

associated with a secondary video stream included in data recorded in a recording medium (S1002) . Herein, the data

includes a primary video stream, a secondary video stream and

reproduction management data for managing reproductions of

theses streams.

For instance, in case of a recording medium input or power-on,

the optical record player 10 reads a STN-table within the recording medium and then checks information associated with

the secondary video stream. In this case, the information associated with the secondary video stream includes a number

of secondary video stream entries, a secondary video stream

entry id and the like.

Subsequently, the optical record player 10 stores the

playback status information associated with the secondary

video stream in a memory unit (S1004). The playback status

information includes a secondary video stream number,

information for a secondary video playback size, enablement

of a secondary video screen display and the like. The

secondary video stream number can indicate one of the

secondary video stream entries of the STN table included in a

playlist and corresponds to the secondary video stream entry

identifier. The memory unit may include one or more of the

player status registers (PSRs) included in the optical record

player 10.

For instance, the optical record player 10 selects a

secondary video stream having a lowest number from among secondary video stream numbers corresponding to the secondary

video stream entry identifiers read in the step S1002 and

then stores the corresponding secondary video stream number

in the PSR14.

Subsequently, (S1006) the optical record player 10 plays the

secondary video stream based on the playback status

information associated with the secondary video stream stored

in the memory unit (e.g., PSR 14).

Herein, the selected secondary video stream shall be a stream

reproducible in the player.

In case that there exists a secondary video stream previously

designated by a user operation (UO) , playback system or

application programming interface (hereinafter abbreviated

API) or the like, a number of the corresponding secondary

video stream shall be recorded in the memory unit (e.g., PSR

14). And, a priority of a playback sequence can be designated

according to a type of a secondary video stream as well.

Furthermore, where multiple secondary video streams are

available, it will be understood that selection may be made

by a user operation (UO) , playback system or application

programming interface (hereinafter abbreviated API) or the

like - including commands reproduced from the recording

medium.

Moreover, a secondary video stream is presented according to

information for a secondary video playback size included in

the playback status information. For instance, in reproducing the secondary video stream, if information for the secondary

video playback size included in the playback status

information defines that the secondary video shall be played

at a size defined by a playlist, it is able to play back the

secondary video at a secondary video size stored in the

playlist . Accordingly, the present invention provides the advantage such as a secondary video can be played together with a

primary video, a content provider may provide various

contents, and a user may simultaneously view the provided

various contents.

It will be apparent to those skilled in the art that various

modifications and variations can be made in the present

invention without departing from the spirit or scope of the

inventions. Thus, it is intended that the present invention

covers the modifications and variations of this invention.