WO2007013764A1 - Method and apparatus for reproducing data, recording medium, and method and apparatus for recording data - Google Patents

Abstract

In one embodiment, a primary video stream in data reproduced from the recording medium is decoded using a first decoder, and a secondary video stream in the reproduced data is decoded using a second decoder. The secondary video stream represents picture-in-picture video data with respect to the primary video stream.

Description

[DESCRIPTION]

METHOD AND APPARATUS FOR REPRODUCING DATA, RECORDING

MEDIUM, AND METHOD AND APPARATUS FOR RECORDING DATA

Technical Field

The present invention relates to recording and reproducing

methods and apparatuses, and a recording medium.

Background Art

Optical discs are widely used as a recording medium

capable of recording a large amount of data therein.

Particularly, high-density optical recording mediums such

as a Blu-ray Disc (BD) and a high definition digital versatile disc (HD-DVD) have recently been developed, and

are capable of recording and storing large amounts of

high-quality video data and high-quality audio data.

Such a high-density optical recording medium, which is

based on next-generation recording medium techniques, is

considered to be a next-generation optical recording

solution capable of storing much more data than

conventional DVDs. Development of high-density optical

recording mediums is being conducted, together with other

digital appliances. Also, an optical

recording/reproducing apparatus, to which the standard for

high density recording mediums is applied, is under development .

In accordance with the development of high-density

recording mediums and optical recording/reproducing

apparatuses, it is possible to simultaneously reproduce a

plurality of videos. However, there is known no method

capable of effectively simultaneously recording or

reproducing a plurality of videos. Furthermore, it is

difficult to develop a complete optical

recording/reproducing apparatus based on high-density recording mediums because there is no completely-

established standard for high-density recording mediums.

Disclosure of Invention

The present invention relates to method of decoding

picture-in-picture video data reproduced from a recording medium.

In one embodiment, a primary video stream in data

reproduced from the recording medium is decoded using a

first decoder, and a secondary video stream in the

reproduced data is decoded using a second decoder. The

secondary video stream represents picture-in-picture video

data with respect to the primary video stream.

In one embodiment, the method further includes reproducing

a main path data steam from a data file recorded on the

recording medium. The main data stream includes the primary and secondary video streams. This embodiment may

further include separating the primary video stream from

the main data stream, and separating the secondary video

stream from the main data stream.

In one embodiment, whether the secondary video stream is

recorded in a same data file as the primary video stream

based on type information recorded on the recording medium

is determined, and he main data stream is reproduced based

on the determining step. In another embodiment, a main path data stream is

reproduced from a first data file recorded on the recording medium. The main path data stream includes the

primary video stream. Also, a sub path data stream is

reproduced from a second data file recorded on the

recording medium. The second data file is separate from

the first data file, and the sub path data stream includes

the secondary video stream. This embodiment may include

separating the primary video stream from the main path

data stream, and separating the secondary video stream

from the sub path data stream.

In one embodiment, whether the secondary video stream is

recorded in a same data file as the primary video stream

or a data file separate from the primary video stream is

determined based on type information recorded on the

recording medium. Yet another embodiment further includes displaying the

secondary video stream synchronously with the primary

video stream based on type information recorded on the

recording medium.

A further embodiment includes displaying the secondary

video stream asynchronously with the primary video stream

based on type information recorded on the recording medium.

In one embodiment, a sum of bit rates of the primary and

secondary video streams is less than or equal to a set

value.

In another embodiment, the secondary video stream has a same scan type as the primary video stream.

Yet another embodiment of a method of decoding picture-in- picture video data includes decoding a primary video

stream in data reproduced from a recording medium using a

first decoder. The method further includes receiving the

sub path data stream from an external source other than

the recording medium, storing the sub path data stream

including at least a secondary video stream, and decoding

the secondary video stream using a second decoder. The

secondary video stream predetermined to serve as a

picture-in-picture data with respect to the primary video

stream.

The present invention also relates to a method of

processing picture-in-picture video data reproduced from a recording medium. One embodiment of this method includes

separating a primary video stream from a main path data

stream reproduced from the recording medium, and supplying

the primary video stream to a first decoder. The

embodiment further includes separating a secondary video

stream from one of the main path data stream and a sub

path data stream reproduced from the recording medium, and

supplying the secondary video stream to a second decoder.

The secondary video stream represents picture-in-picture video data with respect to the primary video stream.

The present invention further relates to methods and apparatuses for recording picture-in-picture video data on

a recording medium, an apparatus for decoding picture-in-

picture video data reproduced from a recording medium, and the recording medium.

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 schematic view illustrating an exemplary

embodiment of the combined use of an optical recording/reproducing apparatus according to an embodiment

of the present invention and a peripheral appliance;

FIG. 2 is a schematic diagram illustrating a structure of

files recorded in an optical disc as a recording medium

according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a data

recording structure of the optical disc as the recording

medium according to an embodiment of the present

invention;

FIG. 4 is a schematic diagram for understanding a concept

of a secondary video according to an embodiment of the

present invention;

FIG. 5 is a block diagram illustrating an overall configuration of an optical recording/reproducing

apparatus according to an embodiment of the present

invention;

FIG. 6 is a block diagram schematically illustrating an

exemplary embodiment of a playback system according to an

embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating an AV decoder

according to an embodiment of the present invention;

FIG. 8A is a schematic diagram illustrating a first

embodiment of the encoding type of the secondary video

according to the present invention;

FIG. 8B is a schematic diagram illustrating a second embodiment of the encoding type of the secondary video

according to the present invention;

FIGs. 9A to 9C are schematic diagrams illustrating various

presentation path types for the secondary video according

to an embodiment of the present invention, respectively;

and

FIG. 10 is a flow chart illustrating an exemplary

embodiment of a data reproducing method according to 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.

In the following description, example embodiments of the

present invention will be described in conjunction with an

optical disc as an example recording medium. In

particular, a Blu-ray disc (BD) is used as an example

recording medium, for the convenience of description.

However, it will be appreciated that the technical idea of

the present invention is applicable to other recording

mediums, for example, HD-DVD, equivalently to the BD.

"Storage" as generally used in the embodiments is a storage equipped in a optical recording/reproducing

apparatus (FIG. 1) . The storage is an element in which

the user freely stores required information and data, to

subsequently use the information and data. For storages,

which are generally used, there are a hard disk, a system

memory, a flash memory, and the like. However, the

present invention is not limited to such storages. In association with the present invention, the "storage"

is also usable as means for storing data associated with a

recording medium (for example, a BD) . Generally, the data

stored in the storage in association with the recording

medium is externally-downloaded data.

As for such data, it will be appreciated that partially- allowed data directly read out from the recording medium,

or system data produced in association with recording and

production of the recording medium (for example, metadata)

can be stored in the storage.

For the convenience of description, in the following

description, the data recorded in the recording medium

will be referred to as "original data", whereas the data

stored in the storage in association with the recording

medium will be referred to as "additional data".

Also, "title" defined in the present invention means a

reproduction unit interfaced with the user. Titles are

linked with particular objects, respectively. Accordingly, streams recorded in a disc in association with a title are

reproduced in accordance with a command or program in an

object linked with the title. In particular, for the

convenience of description, in the following description,

among the titles including video data according to an MPEG

compression scheme, titles supporting features such as

seamless multi-angle and multi story, language credits,

director's cuts, trilogy collections, etc. will be

referred to as "High Definition Movie (HDMV) titles". Also, among the titles including video data according to

an MPEG compression scheme, titles providing a fully programmable application environment with network

connectivity thereby enabling the content provider to

create high interactivity will be referred to as "BD-J

titles".

FIG. 1 illustrates an exemplary embodiment of the combined

use of an optical recording/reproducing apparatus

according to the present invention and a peripheral

appliance .

The optical recording/reproducing apparatus 10 according

to an embodiment of the present invention can record or

reproduce data in/from various optical discs having

different formats. If necessary, the optical

recording/reproducing apparatus 10 may be designed to have

recording and reproducing functions only for optical discs of a particular format (for example, BD) , or to have a

reproducing function alone, except for a recording

function. In the following description, however, the

optical recording/reproducing apparatus 10 will be

described in conjunction with, for example, a BD-player

for playback of a BD, or a BD-recorder for recording and

playback of a BD, taking into consideration the

compatibility of BDs with peripheral appliances, which

must be solved in the present invention. It will be appreciated that the optical recording/reproducing

apparatus 10 of the present invention may be a drive which

can be built in a computer or the like.

The optical recording/reproducing apparatus 10 of the

present invention not only has a function for recording

and playback of an optical disc 30, but also has a

function for receiving an external input signal,

processing the received signal, and sending the processed

signal to the user in the form of a visible image through

an external display 20. Although there is no particular

limitation on external input signals, representative

external input signals may be digital multimedia

broadcasting-based signals, Internet-based signals, etc.

Specifically, as to Internet-based signals, desired data

on the Internet can be used after being downloaded through

the optical recording/reproducing apparatus 10 because the Internet is a medium easily accessible by any person.

In the following description, persons who provide contents

as external sources will be collectively referred to as a

"content provider (CP)".

"Content" as used in the present invention may be the

content of a title, and in this case means data provided

by the author of the associated recording medium. Hereinafter, original data and additional data will be

described in detail. For example, a multiplexed AV stream

of a certain title may be recorded in an optical disc as

original data of the optical disc. In this case, an audio

stream (for example, Korean audio stream) different from

the audio stream of the original data (for example, English) may be provided as additional data via the

Internet. Some users may desire to download the audio stream (for example, Korean audio stream) corresponding to

the additional data from the Internet, to reproduce the

downloaded audio stream along with the AV stream

corresponding to the original data, or to reproduce the

additional data alone. To this end, it is desirable to

provide a systematic method capable of determining the

relation between the original data and the additional data,

and performing management/reproduction of the original

data and additional data, based on the results of the

determination, at the request of the user. As described above, for the convenience of description,

signals recorded in a disc have been referred to as

"original data", and signals present outside the disc have

been referred to as "additional data". However, the

definition of the original data and additional data is

only to classify data usable in the present invention in

accordance with data acquisition methods. Accordingly,

the original data and additional data should not be

limited to particular data. Data of any attribute may be

used as additional data as long as the data is present

outside an optical disc recorded with original data, and has a relation with the original data.

In order to accomplish the request of the user, the

original data and additional data must have file

structures having a relation therebetween, respectively.

Hereinafter, file structures and data recording structures

usable in a BD will be described with reference to FIGs. 2 and 3.

FIG. 2 illustrates a file structure for reproduction and

management of original data recorded in a BD in accordance

with an embodiment of the present invention.

The file structure of the present invention includes a

root directory, and at least one BDMV directory BDMV

present under the root directory. In the BDMV directory

BDMV, there are an index file "index. bdmv" and an object file "MovieObject .bdmv" as general files (upper files)

having information for securing an interactivity with the

user. The file structure of the present invention also

includes directories having information as to the data

actually recorded in the disc, and information as to a

method for reproducing the recorded data, namely, a

playlist directory PLAYLIST, a clip information directory CLIPINF, a stream directory STREAM, an auxiliary directory

AUXDATA, a BD-J directory BDJO, a metadata directory META, a backup directory BACKUP, and a JAR directory.

Hereinafter, the above-described directories and files

included in the directories will be described in detail. The JAR directory includes JAVA program files.

The metadata directory META includes a file of data about

data, namely, a metadata file. Such a metadata file may

include a search file and a metadata file for a disc

library. Such metadata files are used for efficient

search and management of data during the recording and

reproduction of data.

The BD-J directory BDJO includes a BD-J object file for

reproduction of a BD-J title.

The auxiliary directory AUXDATA includes an additional

data file for playback of the disc. For example, the

auxiliary directory AUXDATA may include a "Sound. bdmv"

file for providing sound data when an interactive graphics function is executed, and "11111. otf" and "99999. otf"

files for providing font information during the playback

of the disc.

The stream directory STREAM includes a plurality of files

of AV streams recorded in the disc according to a particular format. Most generally, such streams are

recorded in the form of MPEG-2-based transport packets.

The stream directory STREAM uses "*.m2ts" as an extension

name of stream files (for example, 01000.m2ts, 02000.m2ts,

...) . Particularly, a multiplexed stream of

video/audio/graphic information is referred to as an "AV stream". A title is composed of at least one AV stream

file. The clip information (clip-info) directory CLIPINF

includes clip-info files 01000. clpi, 02000. clpi,

respectively corresponding to the stream files "*.πι2ts"

included in the stream directory STREAM. Particularly,

the clip-info files "*.clpi" are recorded with attribute

information and timing information of the stream files

"*.m2ts". Each clip-info file "*.clpi" and the stream

file "*.m2ts" corresponding to the clip-info file "*.clpi"

are collectively referred to as a "clip". That is, a clip

is indicative of data including both one stream file

"*.m2ts" and one clip-info file "*.clpi" corresponding to

the stream file "*.m2ts". The playlist directory PLAYLIST includes a plurality of

playlist files "*.mpls". "Playlist" means a combination

of playing intervals of clips. Each playing interval is

referred to as a "playitem". Each playlist file "*.mpls"

includes at least one playitem, and may include at least

one subplayitem. Each of the playitems and subplayitems

includes information as to the reproduction start time IN-

Time and reproduction end time OUT-Time of a particular

clip to be reproduced. Accordingly, a playlist may be a

combination of playitems.

As to the playlist files, a process for reproducing data using at least one playitem in a playlist file is defined

as a "main path", and a process for reproducing data using

one subplayitem is defined as a "sub path". The main path

provides master presentation of the associated playlist,

and the sub path provides auxiliary presentation

associated with the master presentation. Each playlist

file should include one main path. Each playlist file

also includes at least one sub path, the number of which

is determined depending on the presence or absence of

subplayitems. Thus, each playlist file is a basic

reproduction/management file unit in the overall

reproduction/management file structure for reproduction of

a desired clip or clips based on a combination of one or

more playitems. In association with the present invention, video data,

which is reproduced through a main path, is referred to as

a primary video, whereas video data, which is reproduced

through a sub path, is referred to as a secondary video.

The function of the optical recording/reproducing

apparatus for simultaneously reproducing primary and

secondary videos is also referred to as a "picture-in- picture (PiP)". In association with the present invention,

the sub paths, which are used in a data reproduction

operation, along with the main path, are mainly classified

into three types. This will be described in detail below with reference to FIGs. 9A to 9C.

The backup directory BACKUP stores a copy of the files in the above-described file structure, in particular, copies

of files recorded with information associated with

playback of the disc, for example, a copy of the index

file "index. bdmv", object files "MovieObject .bdmv" and

^λλBD-JObject .bdmv", unit key files, all playlist files

"*.mpls" in the playlist directory PLAYLIST, and all clip-

info files "*.clpi" in the clip-info directory CLIPINF.

The backup directory BACKUP is adapted to separately store

a copy of files for backup purposes, taking into

consideration the fact that, when any of the above-

described files is damaged or lost, fatal errors may be

generated in association with playback of the disc. Meanwhile, it will be appreciated that the file structure

of the present invention is not limited to the above-

described names and locations. That is, the above-

described directories and files should not be understood

through the names and locations thereof, but should be

understood through the meaning thereof.

FIG. 3 illustrates a data recording structure of the

optical disc according to an embodiment of the present invention. In FIG. 3, recorded structures of information

associated with the file structures in the disc are

illustrated. Referring to FIG. 3, it can be seen that the

disc includes a file system information area recorded with

system information for managing the overall file, an area

recorded with the index file, object file, playlist files, clip-info files, and meta files (which are required for

reproduction of recorded streams ^λλ*.m2ts"), a stream area

recorded with streams each composed of audio/video/graphic

data or STREAM files, and a JAR area recorded with JAVA

program files. The areas are arranged in the above-

descried order when viewing from the inner periphery of

the disc.

In the disc, there is an area for recording file

information for reproduction of contents in the stream

area. This area is referred to as a "management area".

The file system information area and database area are included in the management area.

The areas of FIG. 3 are shown and described only for

illustrative purposes. It will be appreciated that the

present invention is not limited to the area arrangement

of FIG. 3.

In accordance with the present invention, stream data of a

primary video and/or a secondary video is stored in the

stream area. In the present invention, the secondary

video may be encoded in the same stream as the primary

video (referred to as in-mux) , or may be encoded in a

stream different from that of the primary video (referred to as out-mux of out-of-mux) . The management area may be

recorded with information indicating the kind of the stream in which the secondary video is encoded, namely,

the encoding type information (out-mux and in-mux) of the

secondary video.

FIG. 4 is a schematic diagram for understanding of the

concept of the secondary video according to embodiments of

the present invention.

The present invention provides a method for reproducing

secondary video data, simultaneously with primary video

data. For example, the present invention provides an

optical recording/reproducing apparatus that enables a PiP

application, and, in particular, effectively performs the

PiP application. During reproduction of a primary video 410 as shown in FIG.

4, it may be necessary to output other video data

associated with the primary video 410 through the same

display 20 as that of the primary video 410. In

accordance with the present invention, such a PiP

application can be achieved. For example, during playback

of a movie or documentary, it is possible to provide, to

the user, the comments of the director or episode

associated with the shooting procedure. In this case, the

video of the comments or episode is a secondary video 420.

The secondary video 420 can be reproduced simultaneously with the primary video 410, from the beginning of the

reproduction of the primary video 410. The reproduction of the secondary video 420 may be begun

at an intermediate time of the reproduction of the primary

video 410. It is also possible to display the secondary

video 420 while varying the position or size of the

secondary video 420 on the screen, depending on the

reproduction procedure. A plurality of secondary videos

420 may also be implemented. In this case, the secondary

videos 420 may be reproduced, separately from one another,

during the reproduction of the primary video 410. The

primary video 410 can be reproduced along with an audio

410a associated with the primary video 410. Similarly,

the secondary video 420 can be reproduced along with an audio 420a associated with the secondary video 420.

For reproduction of the secondary video, the AV stream, in

which the secondary video is multiplexed, is identified

and the secondary video is separated from the AV stream,

for decoding of the secondary video. Accordingly,

information is provided as to the encoding method applied

to the secondary video and the kind of the stream in which

the secondary video is encoded. Also, information as to

whether or not the primary and secondary videos should be synchronous with each other is provided. This

presentation path type information (synchronous or asynchronous) may be provided as part of the encoding type

information. In addition, a new decoder model should be

defined for simultaneous reproduction of the primary and

secondary videos. The present invention provides a method capable of satisfying the above-described requirements,

and efficiently reproducing the secondary video along with

the primary video. Hereinafter, the present invention

will be described in detail with reference to FIG. 5 and

the remaining drawings.

FIG. 5 illustrates an exemplary embodiment of the overall

configuration of the optical recording/reproducing

apparatus 10 according to the present invention.

As shown in FIG. 5, the optical recording/reproducing

apparatus 10 mainly includes a pickup 11, a servo 14, a signal processor 13, and a microprocessor 16. The pickup

11 reproduces original data and management data recorded

in an optical disc. The management data includes

reproduction management file information. The servo 14

controls operation of the pickup 11. The signal processor

13 receives a reproduced signal from the pickup 11, and

restores the received reproduced signal to a desired

signal value. The signal processor 13 also modulates

signals to be recorded, for example, primary and secondary

videos, to signals recordable in the optical disc,

respectively. The microprocessor 16 controls the

operations of the pickup 11, the servo 14, and the signal

processor 13. 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. In accordance

with the present invention, the controller 12 produces

encoding type information in accordance with the kind of

the stream, in which the secondary video is encoded, and

controls the recording/reproducing unit to record the encoding type information in the optical disc 30, along

with video data. The encoding type of the secondary video

will be described with reference to FIGs. 8A to 8C. 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

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.

The AV encoder 18, which is also included in the optical recording/reproducing apparatus 10 of the present

invention, converts an input signal to a signal of a

particular format, for example, an MPEG2 transport stream,

and sends the converted signal to the signal processor 13,

to enable recording of the input signal in the optical

disc 30.

FIG. 6 is a schematic diagram explaining the playback

system according to an embodiment of the present invention.

In accordance with the present invention, the playback system can simultaneously reproduce the primary and

secondary videos.

"Playback system" means a collective reproduction

processing means which is configured by programs

(software) and/or hardware provided in the optical

recording/reproducing apparatus. That is, the playback system is a system which can not only play back a

recording medium loaded in the optical

recording/reproducing apparatus, but also can reproduce

and manage data stored in the storage of the apparatus in

association with the recording medium (for example, after

being downloaded from the outside of the recording medium) .

In particular, as shown in Fig. 6, the playback system 17

may include a user event manager 171, a module manager 172,

a metadata manager 173, an HDMV module 174, a BD-J module

175, a playback control engine 176, a presentation engine 177, and a virtual file system 40. This configuration

will be described in detail, hereinafter.

As a separate reproduction processing/managing means for

reproduction of HDMV titles and BD-J titles, the HDMV

module 174 for HDMV titles and the BD-J module 175 for BD-

J titles are constructed independently of each other.

Each of the HDMV module 174 and BD-J module 175 has a

control function for receiving a command or program contained in the associated object "Movie Object" or "BD-J

Object", and processing the received command or program.

Each of the HDMV module 174 and BD-J module 175 can

separate an associated command or application from the

hardware configuration of the playback system, to enable portability of the command or application. For reception

and processing of the command, the HDMV module 174 includes a command processor 174a. For reception and

processing of the application, the BD-J module 175 includes a Java Virtual Machine (VM) 175a, and an

application manager 175b.

The Java VM 175a is a virtual machine in which an

application is executed. The application manager 175b

includes an application management function for managing

the life cycle of an application processed in the BD-J

module 175.

The module manager 172 functions not only to send user commands to the HDMV module 174 and BD-J module 175,

respectively, but also to control operations of the HDMV

module 174 and BD-J module 175. A playback control engine

176 analyzes the playlist file actually recorded in the

disc in accordance with a playback command from the HDMV

module 174 or BD-J module 175, and performs a playback

function based on the results of the analysis. The

presentation engine 177 decodes a particular stream

managed in association with reproduction thereof by the

playback control engine 176, and displays the decoded

stream in a displayed picture. In particular, the

playback control engine 176 includes playback control

functions 176a for managing all playback operations, and player registers 176b for storing information as to the

playback status and playback environment of the player

(information of player status registers (PSRs) and general

purpose registers (GPRs)). In some cases, the playback

control functions 176a mean the playback control engine

176 itself.

The HDMV module 174 and BD-J module 175 receive user

commands in independent manners, respectively. The user

command processing methods of HDMV module 174 and BD-J

module 175 are also independent of each other. In order

to transfer a user command to an associated one of the

HDMV module 174 and BD-J module 175, a separate transfer means should be used. In accordance with the present

invention, this function is carried out by the user event

manager 171. Accordingly, when the user event manager 171

receives a user command generated through a user operation

(UO) controller 171a, the user event manager sends the

received user command to the module manager 172 or UO

controller 171a. On the other hand, when the user event manager 171 receives a user command generated through a

key event, the user event manager sends the received user

command to the Java VM 175a in the BD-J module 175.

The playback system 17 of the present invention may also

include a metadata manager 173. The metadata manager 173

provides, to the user, a disc library and an enhanced search metadata application. The metadata manager 173 can

perform selection of a title under the control of the user.

The metadata manager 173 can also provide, to the user,

recording medium and title metadata.

The module manager 172, HDMV module 174, BD-J module 175,

and playback control engine 176 of the playback system

according to the present invention can perform desired

processing in a software manner. Practically, the

processing using software is advantageous in terms of

design, as compared to processing using a hardware

configuration. Of course, it is general that the

presentation engine 177, decoder 19, and planes are designed using hardware. In particular, the constituent

elements (for example, constituent elements designated by

reference numerals 172, 174, 175, and 176), each of which

performs desired processing using software, may constitute

a part of the controller 12. Therefore, it should be

noted that the above-described constituents and

configuration of the present invention be understood on

the basis of their meanings, and are not limited to their

implementation methods such as hardware or software

implementation. Here, "plane" means a conceptual model

for explaining overlaying procedures of the primary video,

secondary video, PG (presentation graphics) , IG

(interactive graphics), text sub titles. In accordance with the present invention, the secondary video plane is

arranged in front of the primary video plane. Accordingly,

the secondary video output after being decoded is

presented on the secondary video plane.

FIG. 7 schematically illustrates the AV decoder 17b

according to an embodiment of the present invention.

In accordance with the present invention, the AV decoder

17b includes a secondary video decoder 730b for

simultaneous reproduction of the primary and secondary

videos, namely, implementation of a PiP application. The

secondary video decoder 730b decodes the secondary video.

The secondary video may be recorded in the recording medium 30 in a state of being contained in an AV stream,

to be supplied to the user. The secondary video may also

be supplied to the user after being downloaded from the

outside of the recording medium 30. The AV stream is

supplied to the AV decoder 17b in the form of a transport stream (TS) .

In the present invention, the AV stream, which is

reproduced through a main path, is referred to as a main

transport stream or main TS (hereinafter, also referred to

as a "main stream") , and an AV stream other than the main

stream is referred to as a sub transport stream or sub TS

(hereinafter, also referred to as a "sub stream") .

In the AV decoder 17b, a main stream from the optical disc 30 passes through a switching element to a buffer RBl, and

the buffered main stream is depacketized by a source

depacketizer 710a. Data contained in the depacketized AV

stream is supplied to an associated one of decoders 730a

to 73Og after being separated from the depacketized AV

stream in a PID (packet identifier) filter-1 720a in

accordance with the kind of the data packet. That is, in

case that a secondary video is contained in the main

stream, the secondary video is separated from other data

packets in the main stream by the PID filter-1 720a, and

is then supplied to the secondary video decoder 730b. As

shown, the packets from the PID filter-1 720a may pass through another switching element before receipt by the

decoders 730b-730g.

FIG. 8A illustrates a first embodiment of a method for

encoding a secondary video. In this embodiment, the

secondary video is encoded together with the primary video.

The case in which the secondary video is encoded in the

same stream as the primary video, namely, the main stream.

This encoding type can be called ^λλin-mux". In the

embodiment of FIG. 8A, the playlist includes one main path

and three sub paths. The main path is a presentation path

of a main video/audio, and each sub path is a presentation

path of video/audio additional to the main video/audio.

Playitems ^ΛPlayItem-l' and ^ΛPlayItem-2' configuring the main path refer to associated clips to be reproduced, and

to playing intervals of the clips, respectively. In an

STN table of each playitem, elementary streams are defined

which are selectable by the optical recording/reproducing apparatus of the present invention during the presentation

of the playitem. The playitems ^ΛPlayItem-l' and

^ΛPlayItem-2' refer to a clip ^λClip-0' . Accordingly, the

clip ^λClip-0' is reproduced for the playing intervals of

the playitems ^ΛPlayItem-l' and ^ΛPlayItem-2' . Since the

clip ^ΛClip-0' is reproduced through the main path, the

clip ^λClip-0' is supplied to the AV decoder 17b as a main stream. Each of the sub paths ^ΛSubPath-l' , ^ΛSubPath-2' , and

^ΛSubPath-3' associated with the main path is configured by

a single associated subplayitem. The subplayitem of each

sub path refers to a clip to be reproduced. In the

illustrated case, the sub path ^λSubPath-l' refers to the

clip ^ΛClip-0' , the sub path ^ΛSubPath-2' refers to a clip

^λClip-l' , and the sub path ^λSubPath-3' refers to a clip

^ΛClip-2' . That is, the sub path ^λSubPath-l' uses

secondary video and audio streams included in the clip

^ΛClip-0' . On the other hand, each of the sub paths

^ΛSubPath-2' and ^λSubPath-3' uses audio, PG, and IG streams included in the clip referred to by the associated

subplayitem. In the embodiment of FIG. 8A, the secondary video is

encoded in the clip ^ΛClip-0' to be reproduced through the

main path. Accordingly, the secondary video is supplied

to the AV decoder 17b, along with the primary video, as a

main stream. In the AV decoder 17b, the secondary video

is supplied to the secondary video decoder 730b via the

PID filter-1, and is then decoded by the secondary video

decoder 730b. In addition, the primary video of the clip

^λClip-0' is decoded in a primary video decoder 730a, and

the primary audio is decoded in a primary audio decoder

73Oe. Also, the PG (presentation graphics), IG

(interactive graphics) , and secondary audio are decoded in a PG decoder 730c, an IG decoder 73Od, and a secondary-

audio decoder 73Of, respectively.

FIG. 8B illustrates a second embodiment of the method for

encoding the secondary video. In this embodiment, the

secondary video is encoded in a stream different from that

of the primary video.

In the embodiment of FIG. 8B, the playlist includes one main path and two sub paths ^ΛSubPath-l' and ^λSubPath-2' .

Playitems ^ΛPlayItem-l' and ^λPlayItem-2' are used to

reproduce elementary streams included in a clip ^λClip-0' .

Each of the sub paths ^λSubPath-l' and ^ΛSubPath-2' is

configured by a single associated subplayitem. The

subplayitems of the sub paths ^λSubPath-l' and ^λSubPath-2' refer to clips ^λClip-l' and ^ΛClip-2' , respectively. In

case that the ^ΛSubPath-l' is presented along with the main

path, the secondary video referred to by the sub path

^ubPath-1' is reproduced along with the primary video

referred to by the main path. On the other hand, when the

^λSubPath-2' is presented along with the main path, the

secondary video referred to by the sub path ^λSubPath-2' is

reproduced along with the primary video.

In the embodiment of FIG. 8B, the secondary video is

contained in a stream other than the stream which is

reproduced through the main path. Accordingly, streams of

the encoded secondary video, namely, the clips ^λClip-l' and ^ΛClip-2' , are supplied to the AV decoder 17b as sub

streams. The case in which the secondary video is encoded

in a stream different from that of the primary video, as

described above, is referred to as an ^Λout-of-mux' .

In the AV decoder 17b, each sub stream from the optical

disc 30 or local storage 15 passes through a switching

element to a buffer RB2, the buffered sub stream is

depacketized by a source depacketizer 710b. Data contained in the depacketized AV stream is supplied to an

associated one of the decoders 730a to 73Og after being

separated from the depacketized AV stream in a PID filter-

2 720b in accordance with the kind of the data packet. As

shown, the packets from the PID filter-2 720b may pass

through another switching element before receipt by the

decoders 730b-730f. For example, when the ^λSubPath-l' is presented along with the main path, the secondary video

included in the clip ^ΛClip-l' is supplied to the secondary

video decoder 730b after being separated from secondary

audio packets, and is then decoded by the secondary video

decoder 730b. In this case, the secondary audio is

supplied to the secondary audio decoder 73Of, and is then

decoded by the secondary audio decoder 73Of. The decoded

secondary video is displayed on the primary video, which

is displayed after being decoded by the primary video

decoder 730a. Accordingly, the user can view both the primary and secondary videos through the display 20.

Referring to the description given with reference to FIGs.

7 to 8B, it can be seen that the presentation path of the

secondary video is varied depending on the encoding method

for the secondary video. In this regard, the presentation

paths for the secondary video according to the present

invention may be mainly classified into three types.

Hereinafter, the presentation path types for the secondary

video according to the present invention will be described

with reference to FIGs. 9A to 9C.

FIG. 9A illustrates the case in which the encoding type of the secondary video is the ^Λout-of-mux' type, and the

secondary video is synchronous with the primary video. Referring to FIG. 9A, the playlist for managing the

primary and secondary videos includes one main path and

one sub path. The main path is configured by four

playitems ( ^λPlayItem_id' = 0, 1, 2, 3), whereas the sub path is configured by a plurality of subplayitems . The

secondary video, which is reproduced through the sub paths,

is synchronous with the main path. In detail, the

secondary video is synchronized with the main path, using

an information field ^Λsync-Playltem_id' , which identifies

a playitem associated with each subplayitem, and a

presentation time stamp information

^λsync_start_PTS_of_PlayItem' , which indicates a presentation time of the subplayitem in the playitem.

That is, when the presentation point of the playitem

reaches a value referred to by the presentation time stamp

information, the presentation of the associated

subplayitem is begun. Thus, reproduction of the secondary

video through one sub path is begun at a time during the

presentation of the primary video through the main path.

In this case, the playitem and subplayitem refer to different clips, respectively. The clip referred to by

the playitem is supplied to the AV decoder 17b as a main

stream, whereas the clip referred to by the subplayitem is

supplied to the AV decoder 17b as a sub stream. The

primary video contained in the main stream is decoded by the primary video decoder 730a after passing through the

depacketizer 710a and PID filter-1 720a. On the other hand, the secondary video contained in the sub stream is

decoded by the secondary video decoder 730b after passing

through the depacketizer 710b and PID filter-2 720b.

FIG. 9B illustrates the case in which the encoding ^' type of

the secondary video is the ^Λout-of-mux' type, and the

secondary video is asynchronous with the primary video.

Similar to the presentation path type of FIG. 9A,

secondary video streams, which will be reproduced through

sub paths, are multiplexed in a state separate from a clip

to be reproduced based on the associated playitem. However, the presentation path type of FIG. 9B is

different from the presentation path type of FIG. 9A in

that the presentation of the sub path can be begun at any

time on the time line of the main path.

Referring to FIG. 9B, the playlist for managing the

primary and secondary videos includes one main path and

one sub path. The main path is configured by three

playitems ( ^ΛPlayItem_id' = 0, 1, 2), whereas the sub path

is configured by one subplayitem. The secondary video,

which is reproduced through the sub path, is asynchronous

with the main path. That is, even when the subplayitem includes information for identifying a playitem associated

with the subplayitem and presentation time stamp

information indicating a presentation time of the

subplayitem in the playitem, these informations are not

valid in the presentation path type of FIG. 9B. Thus,

reproduction of the secondary video through one sub path is begun at any time during the reproduction of the

primary video. Accordingly, the user can view the

secondary video at any time during the reproduction of the

primary video.

In this case, since the encoding type of the secondary

video is the ^λout-of-mux' type, the primary video is

supplied to the AV decoder 17b as a main stream, and the

secondary video is supplied to the AV decoder 17b as a sub stream, as described above with reference to FIG. 9A.

FIG. 9C illustrates the case in which the encoding type of

the secondary video is the ^λin-mux' type, and the

secondary video is synchronous with the primary video.

The presentation path type of FIG. 9C is different from

those of FIGs. 9A and 9B in that the secondary video is

multiplexed in the same AV stream as the primary video.

Referring to FIG. 9C, the playlist for managing the

primary and secondary videos includes one main path and

one sub path. The main path is configured by four

playitems ( ^ΛPlayItem_id' = 0, 1, 2, 3), whereas the sub

path is configured by a plurality of subplayitems . Each

of the subplayitems configuring the sub path includes information for identifying a playitem associated with the

subplayitem, and presentation time stamp information

indicating a presentation time of the subplayitem in the

playitem. As described above with reference to FIG. 9A,

each subplayitem is synchronized with the associated

playitem, using the above-described information. Thus,

the secondary video is synchronized with the primary video.

In the presentation path type of FIG. 9C, each of the

playitems configuring the main path and an associated one

or ones of the subplayitems configuring the sub path refer

to the same clip. That is, the sub path is presented

using a stream included in the clip managed by the main path. Since the clip is managed by the main path, the

clip is supplied to the AV decoder 17b as a main stream.

The main stream, which is packetized data including

primary and secondary videos, is sent to the depacketizer

710a which, in turn, depacketizes the packetized data. The depacketized primary and secondary videos are supplied

to the primary and secondary video decoders 730a and 730b

in accordance with associated packet identifying

information, and are then decoded by the primary and secondary video decoders 730a and 730b, respectively.

The main stream and sub stream may be supplied from the

recording medium 30 or storage 15 to the AV decoder 17b.

Where the primary and secondary videos are stored in

different clips, respectively, the primary video may be

recorded in the recording medium 30, to be supplied to the

user, and the secondary video may be downloaded from the

outside of the recording medium 30 to the storage 15. Of

course, the case opposite to the above-described case may

be possible. However, where both the primary and

secondary videos are stored in the recording medium 30,

one of the primary and secondary videos may be copied to

the storage 15, prior to the reproduction thereof, in

order to better enable the primary and secondary videos to

be simultaneously reproduced. Where both the primary and

secondary videos are stored in the same clip, they are supplied after being recorded in the recording medium 30.

In this case, however, it is possible that both the

primary and secondary videos are downloaded from outside

of the recording medium 30.

Meanwhile, the optical recording/reproducing apparatus 10 has a maximum transport stream bit rate set to a specific

value (for example, 48 Mbps) or set to a predetermined

value. Accordingly, the bit rate of a transport stream,

which is decoded, cannot exceed the set value. In case

that the secondary video is reproduced with the primary

video asynchronously after being supplied from the storage 15, the set value is applied to both the stream containing

the primary video and the stream containing the secondary

video. For example, where the set value is 48 Mbps, the

primary video is a stream having a bit rate of 40 Mbps,

and the secondary video is downloaded from a network and

has a bit rate of 30 Mbps, the total bit rate in this case

may exceed the set value of, for example, 48 Mbps, because

the total bit rate is 70 Mbps. In this case, it is not

possible to reproduce the secondary video harmoniously

with the primary video, due to a restriction caused by the

set bit rate. To this end, in accordance with an

embodiment of the present invention, the total bit rate of

the transport streams, which are simultaneously decoded,

are prevented from exceeding the set bit rate. Where the secondary video is synchronous with the primary video, the

content provider should provide content, taking into

consideration the combination of the bit rates of the

primary and secondary videos. Even in the case in which

the presentation path of the secondary video is

asynchronous with the primary video, the set bit rate

should be taken into consideration.

Meanwhile, the primary and secondary videos can be encoded to a high definition (HD) grade or to a standard

definition (SD) grade. In this regard, a restricted bit

rate can be set with respect to the set bit rate in accordance with a combination of HD and SD videos. For

example, for a primary video of an HD grade and a

secondary video of an HD grade, the maximum bit rates

thereof may be set to 20 Mbps or less, respectively. On

the other hand, for a primary video of an HD grade and a

secondary video of an SD grade, the maximum bit rates

thereof may be set to 30 Mbps or less and 15 Mbps or less,

respectively. A similar restriction of bit rates may be

applied to a combination of a primary video of an SD grade

and a secondary video of an HD grade, and a combination of

a primary video of an SD grade and a secondary video of an

SD grade.

Furthermore, the secondary video should have a same scan

type (e.g., progressive or interlaced) as the primary video .

FIG. 10 illustrates an exemplary embodiment of a data

reproducing method according to the present invention.

In accordance with the data reproducing method, when a

playlist is executed, presentation of the main and sub

paths included in the playlist is begun. In order to

display a secondary video on a primary video in accordance

with the present invention, the sub path used to reproduce

the secondary video should be presented along with the main path used to reproduce the primary video.

Accordingly, the controller 12 checks whether the

secondary video is encoded in a main stream, based on the

encoding type information of the secondary video (SlO) .

For example, as discussed above, encoding type information

may be provided indicating the type of subpath (e.g., out-

of-mux or in-mux) . Alternatively, the type of subpath may

be determined based on whether the subplayitem associated

with a subpath identifies the same clip as a playitem in

the main path. In case that the secondary video is

encoded in the main stream, namely, where the encoding

type of the secondary video is an ^Λin-mux' type, the

secondary video is separated from the main stream, and is

then sent to the secondary video decoder 730b (S20) . On

the other hand, in case that the secondary video is

encoded in a sub stream, namely, where the encoding type of the secondary video is an ^λout-of-mux' type, the

secondary video is separated from the sub stream, and is

then sent to the secondary video decoder 730b (S30) .

After being decoded by the secondary video decoder 730b

(S40), the secondary video is displayed on the primary

video, which is being displayed on the display 20 (S50) .

Meanwhile, in case that the presentation path type of the

secondary video corresponds to the presentation path type of FIG. 9A, the controller 12 controls the AV decoder 17b

to decode the secondary video synchronously with the

primary video. On the other hand, in case that the presentation path type of the secondary video corresponds

to the presentation path type of FIG. 9B, the controller

12 controls the AV decoder 17b to decode the secondary

video at any time during the reproduction of the primary

video, for example, in response to user input.

In case that the primary video is displayed on the display

20, it can be scanned in an interlaced type or in a

progressive type. In accordance with the present

invention, the secondary video uses the same scan type

(scanning scheme) as the primary video. That is, when the

primary video is scanned in a progressive type, the

secondary video is also scanned in a progressive manner on

the display 20. On the other hand, in case that the

primary video is scanned in an interlaced type, the secondary video is also scanned in an interlaced type on

the display 20.

As apparent from the above description, in accordance with

the recording medium, data reproducing method and

apparatus, and data recording method and apparatus of the

present invention, it is possible to reproduce the

secondary video simultaneously with the primary video. In

addition, the reproduction can be efficiently carried out.

Accordingly, there are advantages in that the content

provider can compose more diverse contents, to enable the

user to experience more diverse contents.

Industrial Applicability

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.

Claims

[CLAIMS]

1. A method of decoding picture-in-picture video data

reproduced from a recording medium, comprising:

decoding a primary video stream in data reproduced

from the recording medium using a first decoder; and

decoding a secondary video stream in the reproduced

data using a second decoder, the secondary video stream

representing picture-in-picture video data with respect to

the primary video stream.

2. The method of claim 1, further comprising:

reproducing a main path data steam from a data file

recorded on the recording medium, the main path data steam

including the primary and secondary video streams.

3. The method of claim 2, further comprising:

separating the primary video stream from the main

path data steam based on packet identifiers in data

packets of the main path data stream; and

separating the secondary video stream from the main

path data steam based on the packet identifiers in the

data packets of the main path data stream; and wherein

the decoding a primary video stream step decodes the

separated primary video stream; and the decoding a secondary video stream step decodes

the separated secondary video stream.

4. The method of claim 2, further comprising:

determining whether the secondary video stream is

recorded in a same data file as the primary video stream

based on type information recorded on the recording

medium; and wherein

the reproducing step reproduces the main path data

steam based on the determining step.

5. The method of claim 2, further comprising:

displaying the secondary video stream synchronously with the primary video stream based on type information

recorded on the recording medium.

6. The method of claim 5, further comprising:

determining a playitem of the primary video stream

with which to reproduce the secondary video stream based

on an identifier recorded on the recording medium if the

type information indicates to present the secondary video

stream synchronously with the primary video stream; and

wherein

the displaying step displays the secondary video

stream synchronously with the primary video stream based on the type information and the identifier.

7. The method of claim 1, further comprising:

reproducing a main path data stream from a first data

file recorded on the recording medium, the main path data

stream including the primary video stream; and

reproducing a sub path data stream from a second data

file recorded on the recording medium, the second data

file being separate from the first data file, and the sub

path data stream including the secondary video stream.

8. The method of claim 7, further comprising:

separating the primary video stream from the main

path data stream based on packet identifiers in data

packets of the main path data stream; and separating the secondary video stream from the sub

path data stream based on packet identifiers in data

packets of the sub path data stream; and wherein

the decoding a primary video stream step decodes the

separated primary video stream; and

the decoding a secondary video stream step decodes

the separated secondary video stream.

9. The method of claim 7, further comprising:

determining whether the secondary video stream is recorded in a same data file as the primary video stream

based on type information recorded on the recording

medium; and wherein the reproducing a main path data stream step

reproduces the main path data stream based on the

determining step; and

the reproducing a sub path data stream step

reproduces the sub path data stream based on the

determining step.

10. The method of claim 7, further comprising:

displaying the secondary video stream synchronously

with the primary video stream based on type information

recorded on the recording medium.

11. The method of claim 10, further comprising:

determining a playitem of the primary video stream

with which to reproduce the secondary video stream based

on an identifier recorded on the recording medium if the

type information indicates to present the secondary video

stream synchronously with the primary video stream; and

wherein

the displaying step displays the secondary video

stream synchronously with the primary video stream based

on the type information and the identifier.

12. The method of claim 11, further comprising:

determining a presentation timing of the secondary

video stream based on presentation timing information

recorded on the recording medium if the type information

indicates to present the secondary video stream

synchronously with the primary video stream; and wherein

the displaying step displays the secondary video

stream synchronously with the primary video stream based

on the type information, the identifier and the

presentation timing information.

13. The method of claim 10, further comprising:

determining a presentation timing of the secondary

video stream based on presentation timing information

recorded on the recording medium if the type information

indicates to present the secondary video stream

synchronously with the primary video stream; and wherein

the displaying step displays the secondary video

stream synchronously with the primary video stream based

on the type information and the presentation timing

information.

14. The method of claim 7, further comprising:

displaying the secondary video stream asynchronously with the primary video stream based on type information

recorded on the recording medium.

15. The method of claim 1, wherein a sum of bit rates of

the primary and secondary video streams is less than or

equal to a set value.

16. The method of claim 1, wherein the secondary video

stream has a same scan type as the primary video stream.

17. A method of decoding picture-in-picture video data, comprising:

decoding a primary video stream in data reproduced

from a recording medium using a first decoder;

receiving the sub path data stream from an external source

other than the recording medium;

storing the sub path data stream including at least a secondary video stream, the secondary video stream

predetermined to serve as a picture-in-picture data with

respect to the primary video stream; and

decoding the secondary video stream using a second

decoder.

18. A method of processing picture-in-picture video data

reproduced from a recording medium, comprising: separating a primary video stream from a main path

data stream reproduced from the recording medium;

supplying the primary video stream to a first decoder;

separating a secondary video stream from one of the

main path data stream and a sub path data stream

reproduced from the recording medium, the secondary video

stream representing picture-in-picture video data with

respect to the primary video stream; and

supplying the secondary video stream to a second

decoder.

19. A recording medium having a data structure for

managing decoding of picture-in-picture video data stored

on the recording medium, comprising:

a data area storing a primary video stream and a secondary video stream, the secondary video stream

representing picture-in-picture video data with respect to

the primary video stream; and

a management area storing management information for

managing reproduction of the primary and secondary video

streams such that the secondary video stream is decoded

using a different decoder than a decoder used to decode

the primary video stream.

20. The recording medium of claim 19, wherein the managing information includes type information indicating whether

the primary and secondary video streams are stored in a

same data file.

21. The recording medium of claim 20, wherein the type

information indicates whether to display the secondary

video stream synchronously with the primary video stream.

22. The recording medium of claim 19, wherein the managing information includes type information indicating whether

to display the secondary video stream one of synchronously

and asynchronously with the primary video stream.

23. An apparatus for decoding picture-in-picture video

data reproduced from a recording medium, comprising:

a first decoder configured to decode a primary video

stream in data reproduced from the recording medium; and

a second decoder configured to decode a secondary

video stream in the reproduced data, the secondary video

stream representing picture-in-picture video data with

respect to the primary video stream.

24. The apparatus of claim 23, further comprising:

a filter separating the primary video stream from the

main path data steam, and separating the secondary video stream from the main path data steam; and wherein

the first decoder decodes the separated primary video

stream; and

the second decoder decodes the separated secondary

video stream.

25. The apparatus of claim 24, wherein the filter separates the primary and secondary video

streams based on packet identifiers in data packets of the

main path data steam.

26. The apparatus of claim 24, further comprising:

a controller determining whether the secondary video stream is recorded in a same data file as the primary

video stream based on type information recorded on the

recording medium, and controlling reproduction of the main

path data steam based on the determination.

27. The apparatus of claim 24, wherein the second decoder

decodes the secondary video stream such that the secondary

video stream is displayed synchronously with the primary

video stream based on the type information recorded on the

recording medium.

28. The apparatus of claim 23, further comprising: a first filter separating the primary video stream

from the main path data stream; and

a second filter separating the secondary video stream

from the sub path data stream; and wherein

the first decoder decodes the separated primary video

stream; and

the second decoder decodes the separated secondary

video stream.

29. The apparatus of claim 28, wherein

the first filter separates the primary video stream based on packet identifiers in data packets of the main path

data stream; and the second filter separates the secondary video stream

based on the packet identifiers in the data packets of the

sub path data stream.

30. The apparatus of claim 28, further comprising:

a controller determining whether the secondary video

stream is recorded in a separate data file as the primary

video stream based on type information recorded on the

recording medium, and controlling reproduction of the main

and sub path data stream based on the determination.

31. The apparatus of claim 28, wherein the second decoder decodes the secondary video stream such that the secondary

video stream is displayed synchronously with the primary

video stream based on the type information recorded on the

recording medium.

32. An apparatus for decoding picture-in-picture video

data, comprising:

a first decoder decoding a primary video stream in data reproduced from a recording medium;

a local storage receiving the sub path data stream from an

external source other than the recording medium, and storing the sub path data stream including at least a

secondary video stream, the secondary video stream predetermined to serve as a picture-in-picture data with

respect to the primary video stream; and

a second decoder decoding the secondary video stream

33. The apparatus of claim 32, further comprising:

a first filter separating the primary video stream

from the main path data stream; and

a second filter separating the secondary video stream

from the stored sub path data stream; and wherein

the first decoder decodes the separated primary video

stream; and

the second decoder decodes the separated secondary video stream.

34. The apparatus of claim 33, wherein

the first filter separates the primary video stream based

on packet identifiers in data packets of the main path

data stream; and

the second filter separates the secondary video stream

based on the packet identifiers in the data packets of the

sub path data stream.

35. A method of recording picture-in-picture video data on a recording medium, comprising:

recording a primary video stream and a secondary

video stream on the recording medium, the secondary video

stream representing picture-in-picture video data with

respect to the primary video stream; and

recording management information on the recording

medium, the management information for managing

reproduction of the primary and secondary video streams

such that the secondary video stream is decoded using a

different decoder than a decoder used to decode the

primary video stream.

36. The method of claim 35, wherein the managing

information includes type information indicating whether the primary and secondary video streams are stored in a

same data file.

37. The method of claim 35, wherein the management

information includes type information indicating whether

to display the secondary video stream synchronously with

the primary video stream.

38. An apparatus for recording picture-in-picture video

data on a recording medium, comprising:

a driver configured to drive a recording device to record

data on the recording medium;

a controller configured to control the driver to record a primary video stream and a secondary video stream on the

recording medium, the secondary video stream representing

picture-in-picture video data with respect to the primary

video stream; and

the controller configured to record management

information on the recording medium, the management

information for managing reproduction of the primary and

secondary video streams such that the secondary video

stream is decoded using a different decoder than a decoder

used to decode the primary video stream.

39. The apparatus of claim 38, wherein the management information includes type information indicating whether

to display the secondary video stream synchronously with

the primary video stream.

40. The apparatus of claim 38, wherein the managing

information includes type information indicating whether

the primary and secondary video streams are stored as

separate data files.

41. The apparatus of claim 40, wherein the type

information indicates whether to display the secondary

video stream one of synchronously and asynchronously with

the primary video stream.