[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 a method of managing

reproduction of audio for at least one picture-in-picture

presentation path.

In one embodiment, the method includes reproducing management

information for managing reproduction of at least one

secondary video stream and at least one secondary audio

stream. 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 first combination information,

and the first combination information indicates the secondary

audio streams that are combinable with the secondary video

stream. At least one of the secondary audio streams may be

reproduced based on the first combination information.

In one embodiment, the first combination information

includes an information field indicating a number of

secondary audio stream entries associated with the secondary

video stream, and the combination information provides a

secondary audio stream identifier for each of the number of

the secondary audio stream entries.

In another embodiment, the management information indicates a

number of secondary video stream entries, and for each of the

number of secondary video stream entries, the management

information provides a secondary video stream identifier and

the first combination information.

In a further embodiment, the management information includes

second combination information, and the second combination

information indicates the primary audio streams that are

combinable with the secondary audio stream.

In one embodiment, the second combination information

includes an information field indicating a number of primary

audio stream entries associated with the secondary audio

stream, and the second combination information provides a

primary audio stream identifier for each of the number of the

primary audio stream entries.

The present invention further relates to an apparatus for

managing reproduction of audio for at least one picture-in-

picture presentation path.

In one embodiment, the apparatus includes a driver configured

to drive a reproducing device to reproduce data from the

recording medium. A controller is configured to control the

driver to reproduce management information for managing

reproduction of at least one secondary video stream and at

least one secondary audio stream. 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

first combination information, and the first combination

information indicates the secondary audio streams that are

combinable with the secondary video stream. The controller is also configured to reproduce at least one of the secondary

audio streams based on the first combination information.

One embodiment further includes a secondary audio decoder

configured to decode one of the secondary audio streams

indicated as combinable with the secondary video stream.

Another embodiment further includes a secondary audio decoder

and a primary audio decoder. The secondary audio decoder is

configured to decode one of the secondary audio streams

indicated as combinable with the secondary video stream. The

primary audio decoder is configured to decode at least one of

the primary audio streams indicated as combinable with the

decoded secondary audio stream.

The present invention further relates to a recording medium

having a data structure for managing reproduction of audio

for at least one picture-in-picture presentation path.

In one embodiment, the recording medium includes a data area

storing a primary video stream, a secondary video stream, at

least one primary audio stream, and at least one secondary

audio stream. The primary video stream represents a primary

presentation path, and the secondary video stream represents

a picture-in-picture presentation path with respect to the

primary presentation path. The primary audio stream is

associated with the primary video stream, and the secondary

audio stream is associated with the secondary video stream.

The recording medium also includes a management area storing

management information for managing reproduction of the

secondary video stream and at least one of the secondary

audio streams. The management information includes first

combination information, and the first combination

information indicates the secondary audio streams that are

combinable with the secondary video stream.

The present invention still further relates to a method and

an apparatus for recording a data structure for managing

reproduction of audio for 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 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 schematic diagram illustrating an exemplary

embodiment of a table including stream entries of the

secondary video;

FIG. 6 is a schematic diagram illustrating an exemplary

embodiment of the secondary video metadata according to the

present invention;

FIG. 7 is a block diagram illustrating the overall

configuration of an optical recording/reproducing apparatus

according to an embodiment of the present invention;

FIG. 8 is a block diagram illustrating an AV decoder model

according to an embodiment of the present invention;

FIG. 9 is a block diagram illustrating the overall

configuration of an audio mixing model according to an

embodiment of the present invention;

FIGs. 1OA and 1OB are schematic diagrams illustrating

embodiments of a data encoding method according to the present invention, respectively;

FIG. 11 is a schematic diagram explaining a playback system

according to an embodiment of the present invention;

FIG. 12 is a schematic diagram illustrating an exemplary

embodiment of status memory units equipped in the optical

recording/reproducing apparatus according to the present

invention;

FIGs. 13A to 13C are schematic diagrams illustrating sub path

types according to embodiments of the present invention,

respectively; and

FIG. 14 is a flow diagram illustrating a method for

reproducing data in accordance with 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.

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 "*.m2ts" included in the

stream directory STREAM. Particularly, the clip-info files

"*.clpi" are recorded with attribute information and timing

information of the stream files "*.πι2ts". 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-T±me 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)". The sub

path can reproduce audio data associated with the primary

video or secondary video. The sub path associated with

embodiments of the present invention will be described in

detail with reference to FIGs. 13A to 13C.

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 "BD-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 (database area) recorded

with the index file, object file, playlist files, clip-info

files, and meta files (which are required for reproduction of

recorded streams "*.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 accordance with the present invention, stream data of a

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

stream area. The secondary video may be multiplexed in the

same stream as the primary video, or may be multiplexed in a

stream different from that of the primary video. In

accordance with the present invention, a secondary audio

associated with the secondary video is multiplexed in the

same stream as the primary video, or in a stream different

from that of the primary video.

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 sub path used to reproduce the

secondary video may have a sub path type selected from three sub path types based on the kind of the stream in which the

secondary video is multiplexed, and whether or not the sub

path is synchronous with the main path. The sub path types

will be described with reference to FIGs. 13A to 13C. Since

the method for reproducing the secondary video and secondary

audio is varied depending on the sub path type, the

management area includes information as to the sub path type.

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.

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 secondary video may be reproduced along with an audio

420a associated with the secondary video. The audio 420a may

be output in a state of being mixed with an audio 410a

associated with the primary video. Embodiments of the

present invention provide methods for reproducing the

secondary video along with an audio associated with the

secondary video (hereinafter, referred to as a "secondary

audio") . Embodiments of the present invention also provide

methods for reproducing the secondary audio along with an

audio associated with the primary video (hereinafter,

referred to as a "primary audio") .

In this regard, in accordance with the present invention,

information as to a combination of the secondary video and

secondary audio allowed to be simultaneously reproduced

(hereinafter, referred to as "secondary video/secondary audio

combination information) is included in the management data

for the secondary video. Also, embodiments of the present

invention provide information defining the primary audio

allowed to be mixed with the secondary audio, and provide for

reproducing the secondary audio along with the primary audio

using the information. The management data may include

metadata as to the secondary video, a table (hereinafter,

referred to as an "STN table") defining at least one stream

entry of the secondary video, and a clip information file as

to the stream in which the secondary video is multiplexed.

Hereinafter, the case in which the combination information is

included in the STN table will be described with reference to

FIG. 5.

FIG. 5 illustrates an exemplary embodiment of a table

including stream entries of the secondary video.

The table (hereinafter, referred to as an "STN table")

defines a list of elementary streams selectable by the

optical recording/reproducing apparatus during the

presentation of the current playitem and sub paths associated

with the current playitem. The elementary streams of the

main clip and the sub paths that have an entry in the STN

table may be at the content provider's discretion.

The optical recording/reproducing apparatus of the present

invention has functions for processing the primary video,

primary audio, secondary video, and secondary audio.

Accordingly, the STN table of the present invention stores

the entries associated with the primary video, primary audio,

secondary video, and secondary audio.

Referring to FIG. 5, the STN table includes a value

indicating the secondary video stream number corresponding to

the video stream entry associated with the value of

^λ secondary_video_stream_id' . The value of

^λ secondary_video_stream_id' is initially set to ^λ 0' , and is

incremented by ^λ l' unless the value of ^λ secondary_video_stream_id' is equal to the number of

secondary video streams, namely, the value of

^λ number__of_secondary_video_stream_entries' . Accordingly, the

secondary video stream number is equal to a value obtained by

adding ^λ l' to the value of ^λ secondary_video_stream_id' .

A stream entry block is defined in the STN table in

accordance with the above-described

^λ secondary_video_stream_id' . The stream entry block includes

the type of database for identifying an elementary stream

referred to by the stream number for the stream entry. In

accordance with an embodiment of the present invention, the

stream entry block may include information for identifying

the sub path associated with the reproduction of the

secondary video, and information for identifying the sub clip

entry defined in the subplayitem of the sub path referred to

by the sub path identifying information. Thus, the stream

entry block functions to indicate a source of the secondary

audio stream to be reproduced.

In accordance with the present invention, the STN table also

includes secondary video/secondary audio combination

information 520 corresponding to ^λ secondary_video_stream__id' .

The secondary video/secondary audio combination information

520 defines secondary audio allowed to be reproduced with the

secondary video. Referring to FIG. 5, the secondary

video/secondary audio combination information 520 includes

the number of secondary audio streams 520a allowed to be

reproduced along with the secondary video and information

520b identifying the secondary audio streams. In accordance

with an embodiment of the present invention, one of the

secondary audio streams defined by the secondary

video/secondary audio combination information 520 is

reproduced along with the secondary video, so as to be

provided to the user.

In accordance with the present invention, the STN table also

includes primary audio information 510 defining primary audio

allowed to be mixed with the secondary audio. Referring to

FIG. 5, the primary audio information 510 includes the number

of primary audio streams 510a allowed to be mixed with the

secondary audio, and information 510b identifying the primary

audio streams. In accordance with the present invention, one

of the primary audio streams defined by the primary audio

information 510 is reproduced in state of being mixed with

the secondary audio, so as to be provided to the user.

FIG. 6 illustrates an exemplary embodiment of the secondary

video metadata according to the present invention. The

playitem including the above-described STN table, and streams

associated with reproduction of the secondary video can be

identified using the secondary video metadata.

In accordance with an embodiment of the present invention,

reproduction of the secondary video is managed using metadata.

The metadata includes information about the reproduction time,

reproduction size, and reproduction position of the secondary

video. Hereinafter, the management data will be described in

conjunction with an example in which the management data is

PiP metadata.

The PiP metadata may be included in a playlist which is a

kind of a reproduction management file. FIG. 6 illustrates

PiP metadata blocks included in an ^λ ExtensionData' block of a

playlist managing reproduction of the primary video. Of course, the information may be included in headers of

secondary video streams implementing PiP.

The PiP metadata may include at least one block header

^λ block_header[k] ' 910 and block data ^λ block_data [k] ' 920. The

number of the block header and block data is determined

depending on the number of metadata block entries included in

PiP metadata blocks. The block header 910 includes header

information of the associated metadata block. The block data

920 includes information of the associated metadata block.

The block header 910 may include a field indicating playitem

identifying information (hereinafter, referred to as

^λ PlayItem_id[k] ' ) , and a field indicating secondary video

stream identifying information (hereinafter, referred to as

^λ secondary_video_stream_id[k] ' ) • The information ^λ PlayItem_id[k] ' has a value for a playitem of which the STN

table contains ^λ secondary_video_stream__id' entry that is

referred to by ^v secondary_video_stream_id [k] ' . The value of

^λ PlayItem_id[k] ' is given in the playlist block of the

playlist file. In one embodiment, in the PiP metadata, the

entries of the ^λ PlayItem_id' value in the PiP metadata are

sorted in an ascending order of the ^λ PlayItem_id' value. The

information ^λ secondary_video_stream_id [k] ' is used to

identify a sub path, and a secondary video stream to which

the associated block data 920 is applied. As the stream

corresponding to ^λ secondary_video_stream_id [k] ' included in

the STN table of the playitem ^λ PlayItem' corresponding to

^λ PlayItem_id [k] is reproduced, the secondary video is

provided to the user.

In accordance with an embodiment of the present invention,

the secondary audio defined by the secondary video/secondary

audio combination information corresponding to

^λ secondary_video_stream_id [k] ' is reproduced along with the

secondary video. Also, the primary audio defined by the

secondary audio/primary audio combination information

associated with the secondary audio is output mixed with the

secondary audio.

In addition, the block header 910 may include information

indicating a timeline referred to by associated PiP metadata

(hereinafter, referred to as a "PiP timeline type

^λ pip_timeline_type' ") . The type of the secondary video

provided to the user is varied depending on the PiP timeline

type. Information ^λ pip_composition_metadata' is applied to

the secondary video along the timeline determined in

accordance with the PiP timeline type. The information

^λ pip_composition_metadata' is information indicating the

reproduction position and size of the secondary video. The

information ^λ pip_composition_metadata' may include position

information of the secondary video, and size information of

the secondary video (hereinafter, referred to as

^λ pip_scale [i] ' ) . The position information of the secondary

video includes horizontal position information of the

secondary video (hereinafter, referred to as

^λ pip_horizontal_position [i] ' ) , and vertical position information of the secondary video (hereinafter, referred to

as ^λ pip_vertical_position [i] ' ) . The information

^λ pip_horizontal_position [i] ' indicates a horizontal position

of the secondary video displayed on a screen when viewing

from an origin of the screen, and the information

^λ pip_vertical_position [i] ' indicates a vertical position of

the secondary video displayed on the screen when viewing from

the origin of the screen. The display size and position of

the secondary video on the screen are determined by the size

information and position information.

FIG. 7 illustrates an exemplary embodiment of the overall

configuration of the optical recording/reproducing apparatus

10 according to the present invention. Hereinafter,

reproduction and recording of data according to the present

invention will be described with reference to FIG. 7.

As shown in FIG. 7, 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 corresponding

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 a storage 15 under the control of a

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

That is, from a viewpoint of reproduction, the

recording/reproducing unit functions as a reader unit for

reading data. 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 may download additional data present

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

and store 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

performs a control operation for selecting a secondary audio

to be reproduced along with a secondary video, based on

secondary video/secondary audio combination information

associated with the secondary video. The controller 12

performs a control operation for selecting a primary audio to

be mixed with the secondary audio, based on primary audio

information indicating primary audios allowed to be mixed

with the secondary audio. Also, the optical

recording/reproducing apparatus 10 of the present invention

operates to record data in the recording medium, namely, the

optical disc 30. Here, the controller 12 produces management

data including the above-described combination information,

and performs a control operation for recording the management

data on the optical disc 30.

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, analyzing a user command input via the

controller 12, and 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 17b.

In this case, the playback system 17 is the player model

itself. The AV decoder 17b may include a plurality of

decoders respectively associated with different kinds of

signals .

FIG. 8 schematically illustrates the AV decoder model

according to 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 an AV stream, to be provided to the

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

after being downloaded from outside of the recording medium

30. The AV stream is provided 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 (hereinafter, referred to as a "main stream" or main

TS) , and an AV stream other than the main stream is referred

to as a sub transport stream (hereinafter, referred to as a

"sub stream" or sub TS) . In accordance with the present

invention, the secondary video may be multiplexed in the same

video as the primary video. In this case, the secondary

video is provided to the AV decoder 17b as a main stream. In

the AV decoder 17b, the main stream passes through a

switching element to a buffer RBl, and the buffered main

stream is depacketized by a source depacketizer 710a. Data

included in the depacketized AV stream is provided to an

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

from the depacketized AV stream in a packet identifier (PID)

filter-1 720a in accordance with the kind of the data packet.

That is, where a secondary video is included 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 provided to the secondary video decoder 730b. As shown,

packets from the PID filter-1 720a may pass through another

switching element before receipt by the decoders 730b-730g.

In accordance with the present invention, the secondary video

may also be multiplexed in a stream different from that of

the primary video. For example, the secondary video may be

stored as a separate file on the recording medium 30 or

stored in the local storage 15 (e.g., after being downloaded

from the internet) . In this case, the secondary video is

provided to the AV decoder 17b as a sub stream. In the AV

decoder 17b, the sub stream passes through a switching

element to a buffer RB2, and the buffered sub stream is

depacketized by a source depacketizer 710b. Data included in

the depacketized AV stream is provided to an associated one

of 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. That is, where a secondary-

video is included in the sub stream, the secondary video is

separated from other data packets in the sub stream by the

PID filter-2 720b, and is then provided to the secondary

video decoder 730b. As shown, packets from the PID filter-2

720b may pass through another switching element before

receipt by the decoders 730b-730f.

In accordance with the present invention, the secondary audio

may be multiplexed in the same stream as the secondary video.

Accordingly, similar to the secondary video, the secondary

audio is provided to the AV decoder 17b as a main stream, or

as sub stream. In the AV decoder 17b, the secondary audio is

separated from the main stream or sub stream in the PID

filter-1 720a or PID filter-2 720b after passing through the

source depacketizer 710a or 710b, and is then provided to the

secondary audio decoder 73Of. The secondary audio decoded in

the secondary audio decoder 73Of is provided to an audio

mixer (described below) , and is then output from the audio

mixer after being mixed with a primary audio decoded in the

primary audio decoder 73Oe.

FIG. 9 illustrates the overall configuration of an audio

mixing model according to the present invention.

In the present invention, "audio mixing" means that the

secondary audio is mixed with the primary audio and/or an

interactive audio. In order to perform the decoding and mixing operation, the audio mixing model according to an

embodiment of the present invention includes two audio

decoders 73Oe and 73Of, and two audio mixers 750a and 750b.

The content provider controls an audio mixing process carried

out by the audio mixing model, using audio mixing control

parameters Pl, P2, P3, and P4.

Generally, the primary audio is associated with the primary

video, and may be, for example, a movie sound track included

in the recording medium. However, the primary audio may

instead be stored in the storage 15 after being downloaded

from a network. In accordance with one embodiment of the

present invention, the primary audio is multiplexed with the

primary video, and is provided to the AV decoder 17b as part

of a main stream. The primary audio transport stream (TS) is

separated from the main stream by the PID filter-1 720a,

based on a PID, and is then provided to the primary audio

decoder 73Oe via a buffer Bl.

In accordance with an embodiment of the present invention,

the secondary audio may be audio to be reproduced

synchronously with the secondary video. The secondary audio

is defined by the secondary video/secondary audio combination

information. The secondary audio may be multiplexed with the

secondary video, and may be provided to the AV decoder 17b as

a main stream, or as a sub stream. The secondary audio

transport stream (TS) is separated from the main stream or

sub stream by the PID filter-1 720a or PID filter-2 720b,

respectively, and is then provided to the secondary audio

decoder 73Of via a buffer B2. As will be discussed in detail

below, the primary audio and secondary audio output by the

primary audio decoder 73Oe and the secondary audio decoder

73Of, respectively, are mixed by the primary audio mixer Ml

750a.

The interactive audio may be a linear-pulse-code-modulated

(LPCM) audio which is activated in accordance with an

associated application. The interactive audio may be

provided to the secondary audio mixer 750b, to be mixed with

the mixed output from the primary audio mixer 750a. The

interactive audio stream may be present in the storage 15 or

recording medium 30. Generally, the interactive audio stream

is used to provide dynamic sound associated with an

interactive application, for example, button sound.

The above-described audio mixing model operates on the basis

of a linear pulse code modulation (LPCM) mixing. That is,

audio data is mixed after being decoded in accordance with an

LPCM scheme. The primary audio decoder 73Oe decodes a

primary audio stream in accordance with the LPCM scheme. The

primary audio decoder 73Oe may be configured to decode or

down-mix all channels included in a primary audio sound track.

The secondary audio decoder 73Of decodes a secondary audio

stream in accordance with the LPCM scheme. The secondary

audio decoder 73Of extracts mixing data included in the

secondary audio stream, converts the extracted data to a mix

matrix format, and sends the resultant mix matrix to the

primary audio mixer (Ml) 750a. This metadata may be used to

control the mixing process. The secondary audio decoder 73Of

may be configured to decode or down-mix all channels included

in a secondary audio sound track. Each decoded channel

output from the secondary audio decoder 73Of may be mixed

with at least one channel output from the primary audio

decoder 73Oe.

The mix matrix is made in accordance with mixing parameters

provided from content providers. The mix matrix includes

coefficients to be applied to each channel of audio in order

to control mixing levels of the audios before summing.

The mixing parameters may include a parameter Pl used for

panning of the secondary audio stream, a parameter P2 used

for controlling the mixing levels of the primary and

secondary audio streams, a parameter P3 used for panning of

the interactive audio stream, and a parameter P4 used for

controlling the mixing level of the interactive audio stream.

The parameters are not limited to the names thereof. It will

be appreciated that there may be an additional parameters

produced by combining the above-described parameters or by

separating one or more parameters from the above-described

parameters in terms of function.

In accordance with the present invention, a command set may

be used as a source of the mixing parameters. That is, the

optical recording/reproducing apparatus 10 of the present

invention may control mixing of the primary audio with the

secondary audio to be reproduced along with the secondary

video, using the command set. A "command set," for example,

may be a program bundle for using functions of application

programs executed in the optical recording/reproducing

apparatus. The functions of the application programs are

interfaced with the functions of the optical

recording/reproducing apparatus by the command set. Thus, it

is possible to use various functions of the optical

recording/reproducing apparatus in accordance with the

command set. The command set may be stored in the recording

medium, to be provided to the optical recording/reproducing

apparatus. Of course, the command set may be equipped in the

optical recording/reproducing apparatus in the manufacturing

stage of the optical recording/reproducing apparatus. A

representative example of a command set is an application

programming interface (API). Mixing metadata may be used as

a source of the mixing parameters. The mixing metadata is

provided to the secondary audio decoder 730b in the secondary

audio. The following description will be given in

conjunction with the case in which an API is used as the command set.

In accordance with an embodiment of the present invention,

the secondary audio is panned using a command set such as an

API. Also, the mixing level of the primary audio or

secondary audio is controlled using the command set. The

system software of the optical recording/reproducing

apparatus 10 translates the command set to an Xl mix matrix,

and sends the Xl mix matrix to the primary audio mixer 750a.

For example, the parameters Pl and P2 are stored by the

controller 12 of FIG. 9 such as in the storage 15, and

converted by the controller 12 according to the player model

17a into the mix matrix Xl for use by the mixer Ml in the

playback system 17. The mixed output from the primary audio

mixer 750a may be mixed with an interactive audio in the

secondary audio mixer 750b. The mixing process carried out

in the secondary audio mixer 750b can be controlled by the

command set as well. In this case, the command set is

converted to an X2 mix matrix, and sends the X2 mix matrix to

the secondary audio mixer 750b. For example, the parameters

P3 and P4 are stored by the controller 12 of FIG. 9 such as

in the storage 15, and converted by the controller 12

according to the player model 17a into the mix matrix X2 for

use by the mixer M2 in the playback system 17.

The Xl mix matrix is controlled by both the mixing parameters

Pl and P2. That is, the parameters Pl and P2 simultaneously

send commands to the Xl mix matrix. Accordingly, the primary

audio mixer Ml is controlled by the Xl mix matrix. The

mixing parameter Pl is provided from the API or secondary

video decoder. On the other hand, the mixing parameter P2 is

provided from the API.

In the audio mixing model according to an embodiment of the

present invention, it is possible to turn on and off the

processing of the audio mixing metadata from a secondary

audio stream, using a metadata ON/OFF API. When the mixing

metadata is ON, the mixing parameter Pl comes from the

secondary audio decoder 73Of. When the mixing metadata is

OFF, the mixing parameter Pl comes from the API. Meanwhile,

in this embodiment, the audio mixing level control provided

through the mixing parameter P2 is applied to the mix matrix

formed using the mixing parameter Pl. Accordingly, when the

metadata control is ON, both the mixing metadata and command

set control the audio mixing process.

Meanwhile, 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.

In accordance with the present invention, the AV encoder 18 encodes the secondary audio associated with the secondary

video in the same stream as the secondary video. The

secondary video may be encoded in the same stream as the

primary video, or may be encoded in a stream different from

that of the primary video.

FIGs. 1OA and 1OB illustrates embodiments of a data encoding

method according to the present invention. FIG. 1OA

illustrates the case in which the secondary video and

secondary audio are encoded in the same stream as the primary

video. The case in which data is encoded in the same stream

as the primary video, namely, a main stream, is referred to

as an ^λ in-mux' type. In the embodiment of FIG. 1OA, 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 a video/audio

additional to the main video/audio. Playitems ^λ PlayItem-l'

and ^λ PlayItem-2' configuring the main path refer to

associated clips to be reproduced, and playing intervals of

the clips, respectively. In the STN table of each playitem,

elementary streams are defined which are selectable by the

optical recording/reproducing apparatus of the present

invention during the reproduction of the playitem. The

playitems ^λ PlayItem-l' and ^λ PlayItem-2' refer to a clip

^λ Clip-0' . Accordingly, the clip ^λ Clip-0' is included for the

playing intervals of the playitems ^λ PlayItem-l' and ^λ PlayItem-2' . Since the clip ^λ Clip-0' is reproduced through

the main path, the clip ^λ Clip-0' is provided to the AV

decoder 17b as a main stream.

Each of the sub paths ^λ SubPath-l' , ^λ SubPath-2' , and 'SubPath-

3' associated with the main path is configured by a

respective subplayitem. The subplayitem of each sub path

refers to a clip to be reproduced. In the illustrated case,

the sub path ^λ SubPath-l' refers to the clip ^λ Clip-0' , the sub

path ^λ SubPath-2' refers to a clip ^λ Clip-l' , and the sub path

^λ SubPath-3' refers to a clip ^λ Clip-2' . That is, the sub path

^λ SubPath-l' uses secondary video and audio streams included

in the clip ^λ Clip-0' . On the other hand, each of the sub

paths ^λ SubPath-2' and ^λ SubPath-3' uses audio, PG, and IG

streams included in the clip referred to by the associated

subplayitem.

In the embodiment of FIG. 1OA, the secondary video and

secondary audio are encoded in the clip ^λ Clip-0' to be

reproduced through the main path. Accordingly, the secondary

video and secondary audio are provided to the AV decoder 17b,

along with the primary video, as a main stream, as shown in

FIG. 8. In the AV decoder 17b, the secondary video and

secondary audio are provided to the secondary video decoder

730b and secondary audio decoder 73Of via the PID filter-1

720a, respectively, and are then decoded by the secondary

video decoder 730b and secondary audio decoder 73Of,

respectively. In addition, the primary video of the clip

^λ Clip-0' is decoded in the primary video decoder 730a, and

the primary audio is decoded in the primary audio decoder

73Oe. Also, the PG, IG, and secondary audio are decoded in

the PG decoder 730c, IG decoder 73Od, and secondary audio

decoder 73Of, respectively. When the decoded primary audio

is defined in the STN table as being allowed to be mixed with

the secondary audio, the decoded primary audio is provided to

the primary audio mixer 750a, to be mixed with the secondary

audio. As described above, the mixing process in the primary

audio mixer can be controlled by the command set.

FIG. 1OB illustrates the case in which the secondary video

and secondary audio are encoded in a stream different from

that of the primary video. The case in which data is encoded

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

a sub stream, is referred to as an ^λ out-of-mux' type. In the

embodiment of FIG. 1OB, the playlist includes one main path

and two sub paths ^λ SubPath-l' and ^λ SubPath-2' . Playitems

^λ PlayItem-l' and ^λ PlayItem-2' are used to reproduce elementary streams included in a clip ^λ Clip-0' . Each of the

sub paths ^λ SubPath-l' and ^λ SubPath-2' is configured by a

respective subplayitem. The subplayitems of the sub paths

^λ SubPath-l' and ^λ SubPath-2' refer to clips ^λ Clip-l' and

^λ Clip-2' , respectively. When the sub path ^λ SubPath-l' is

used along with the main path, for reproduction of streams,

the secondary video referred to by the sub path ^λ SubPath-l'

is reproduced along with the video (primary video) referred

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

^λ SubPath-2' is used along with the main path, for

reproduction of streams, the secondary video referred to by

the sub path ^λ SubPath-2' is reproduced along with the primary

video referred to by the main path.

In the embodiment of FIG. 1OB, the secondary video is

included in a stream other than the stream which is

reproduced through the main path. Accordingly, streams of

the encoded secondary video, namely, the clips ^λ Clip-l' and

^λ Clip-2' , are provided to the AV decoder 17b as sub streams,

as shown in FIG. 8. In the AV decoder 17b, each sub stream

is depacketized by the source depacketizer 710b. Data

included in the depacketized AV stream is provided to an

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

separated from the depacketized AV stream in the PID filter-2

720b in accordance with the kind of the data packet. For

example, when ^λ SubPath-l' is presented with the main path,

for reproduction of streams, the secondary video included in

the clip ^λ Clip-l' is provided 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 provided 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.

FIG. 11 is a schematic diagram explaining the playback system

according to an embodiment of the present invention.

"Playback system" means a collective of reproduction

processing means which are 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 10, but also can

reproduce and manage data stored in the storage 15 in

association with the recording medium (for example, after

being downloaded from the outside of the recording medium) .

In particular, the playback system 17 includes 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 included 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 information 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. 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 Ilia, 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 processes of the primary video, secondary video,

presentation graphics (PG) , interactive graphics (IG) , and

text sub titles. In accordance with the present invention, a

secondary video plane 740b is arranged in front of a primary

video plane 740a. Accordingly, the secondary video output

after being decoded is displayed on the secondary video plane

740b. Graphic data decoded by the presentation graphic

decoder (PG decoder) 730c and/or text decoder 73Og is output

from a presentation graphic plane 740c. Graphic data decoded

by the interactive graphic decoder 73Od is output from an

interactive graphic plane 74Od.

FIG. 12 illustrates an exemplary embodiment of the status

memory units equipped in the optical recording/reproducing

apparatus according to the present invention.

The player registers 17βb included in the optical

recording/reproducing apparatus 10 function as memory units

in which information as to the recording/playback status and

recording/playback environment of the player are stored. The

player registers 176b may be classified into general purpose

registers (GPRs) and player status registers (PSRs) . Each

PSR stores a playback status parameter (for example, an 'interactive graphics stream number' or a 'primary audio

stream number' ) , or a configuration parameter of the optical

recording/reproducing apparatus (for example, a ^λ player

capability for video' ) . Since a secondary video is

reproduced, in addition to a primary video, PSRs for the

reproduction status of the secondary video are provided. Also,

PSRs for the reproduction status of the secondary audio

associated with the secondary video are provided.

The stream number of the secondary video may be stored in one

of the PSRs (for example, a PSR14 120) . In the same PSR

(namely, PSR14), the stream number of a secondary audio

associated with the secondary video may also be stored. The

'secondary video stream number' stored in the PSR14 120 is

used to specify which secondary video stream should be

presented from secondary video stream entries in the STN

table of the current playitem. Similarly, the 'secondary

audio stream number' stored in the PSR14 120 is used to

specify which secondary audio stream should be presented from

secondary audio stream entries in the STN table of the

current playitem. The secondary audio is defined by the

secondary video/secondary audio combination information of

the secondary video.

As shown in FIG. 12, the PSR14 120 may store a flag

^λ disp_a_flag' . The flag Misp_a_flag' indicates whether

output of the secondary audio is enabled or disabled. For

example, when the flag ^λ disp_a_flag' is set to a value

corresponding to an enabled state, the secondary audio is

decoded, and presented to the user after being subjected to a

mixing process in the associated audio mixer such that the

decoded secondary audio is mixed with the primary audio

and/or interactive audio. On the other hand, if the flag ^λ disp_a_flag' is set to a value corresponding to a disabled

state, the secondary audio is not output even when the

secondary audio is decoded by the associated decoder. The

flag ^λ disp_a_flag' may be varied by the user operation (UO) ,

user command, or application programming interface (API) .

The stream number of the primary audio may also be stored in

one of the PSRs (for example, a PSRl 110) . The 'primary

audio stream number' stored in the PSRl 110 is used to

specify which primary audio stream should be presented from

primary audio stream entries in the STN table of the current

playitem. When the value stored in the PSRl 110 is varied,

the primary audio stream number is immediately changed to a

value identical to the value stored in the PSRl 110.

The PSRl 110 may store a flag ^λ disp_a_flag' . The flag

^λ disp_a_flag' indicates whether output of the primary audio

is enabled or disabled. For example, when the flag

^λ disp_a_flag ^/ is set to a value corresponding to an enabled

state, the primary audio is decoded, and presented to the

user after being subjected to a mixing process in the

associated audio mixer such that the decoded primary audio is

mixed with the secondary audio and/or interactive audio. On

the other hand, if the flag ^λ disp_a_flag' is set to a value

corresponding to a disabled state, the primary audio is not

output even when the primary audio is decoded by the

associated decoder. The flag ^λ disp_a_flag' may be changed by

user operation (UO), user command, or API.

FIGs. 13A to 13C illustrate sub path types according to the

present invention.

As described above with reference to FIGs. 1OA and 1OB, in

accordance with the present invention, the sub path used to

reproduce the secondary video and secondary audio is varied

depending on the method for encoding the secondary video and

secondary audio. Accordingly, the sub path types according

to the present invention may be mainly classified into three

types in accordance with whether or not the sub path is

synchronous with the main path. Hereinafter, the sub path

types according to the present invention will be described

with reference to FIGs. 13A to 13C.

FIG. 13A illustrates the case in which the encoding type of

data is the ^λ out-of-mux' type, and the sub path is

synchronous with the main path.

Referring to FIG. 13A, the playlist for managing the primary

and secondary videos, and the primary and secondary audios

includes one main path and one sub path. The main path is

configured by four playitems ( ^λ PlayItem_id' = 0, 1, 2, 3),

whereas the sub path is configured by a plurality of

subplayitems . The secondary video and secondary audio, which

are reproduced through the sub paths, are synchronous with

the main path. In detail, the sub path is synchronized with

the main path, using information ^λ sync-Playltem_id' , which

identifies a playitem associated with each subplayitem, and

presentation time stamp information ^λ sync_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 set time during the reproduction 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

provided to the AV decoder 17b as a main stream, whereas the

clip referred to by the subplayitem is provided to the AV

decoder 17b as a sub stream. The primary video and primary

audio included in the main stream are decoded by the primary

video decoder 730a and primary audio decoder 73Oe,

respectively, after passing through the depacketizer 710a and

PID filter-1 720a. On the other hand, the secondary video

and secondary audio included in the sub stream are decoded by

the secondary video decoder 730b and secondary audio decoder

73Of, respectively, after passing through the depacketizer

710b and PID filter-2 720b.

FIG. 13B illustrates the case in which the encoding type of

data is the ^λ out-of-mux' type, and the sub path is

asynchronous with the main path. Similar to the sub path

type of FIG. 13A, in the sub path type of FIG. 13A, secondary

video streams and/or secondary audio streams, which will be

reproduced through sub paths, are multiplexed in a state of

being separated from a clip to be reproduced based on the

associated playitem. However, the sub path type of FIG. 13B

is different from the sub path type of FIG. 13A in that the

presentation of the sub path can be begun at any time on the

timeline of the main path.

Referring to FIG. 13B, the playlist for managing the primary

and secondary videos and the primary and secondary audios

includes one main path and one sub path. The main path is

configured by three playitems ( ^x PlayItem_id' = 0, 1, 2),

whereas the sub path is configured by one subplayitem. The

secondary video and secondary audio, which are reproduced

through the sub path, are 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, this information is

not valid in the sub path type of FIG. 13B. Accordingly, the

user can view the secondary video at any time during the

presentation of the main path.

In this case, since the encoding type of the secondary video

is the ^λ out-of-mux' type, the primary video and primary audio

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

secondary video and secondary audio are provided to the AV

decoder 17b as a sub stream, as described above with

reference to FIG. 13A.

FIG. 13C illustrates the case in which the encoding type of

data is the ^λ in-mux' type, and the sub path is synchronous

with the main path. The sub path type of FIG. 13C is

different from those of FIGs. 13A and 13B in that the

secondary video and secondary audio are multiplexed in the

same AV stream as the primary video.

Referring to FIG. 13C, the playlist for managing the primary

and secondary videos and the primary and secondary audios

includes one main path and one sub path. The main path is

configured by four playitems ( ^λ PlayItem_id' = 0, 1, 2, 3) ,

whereas the sub path is configured by a plurality of

subplayitems. Each of the subplayitems constituting 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.

13A, each subplayitem is synchronized with the associated

playitem, using the above-described information. Thus, the

sub path is synchronized with the main path.

In the sub path type of FIG. 13C, each of the playitems constituting the main path and an associated one or ones of

the subplayitems constituting 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 provided to the AV decoder 17b as a main stream. The main stream, which is

packetized data including primary and secondary videos and

primary and secondary audios, is sent to the depacketizer

710a which, in turn, depacketizes the packetized data. The

depacketized primary and secondary videos and depacketized

primary and secondary audios are provided to the primary and

secondary video decoders 730a and 730b and primary and

secondary audio decoders 73Oe and 73Of in accordance with

associated packet identifying information, and are then

decoded by the primary and secondary video decoders 730a and

730b and the primary and secondary audio decoders 73Oe and

73Of, respectively.

The main stream and sub stream may be provided 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 provided 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 enable the

primary and secondary videos to be simultaneously reproduced.

In case that both the primary and secondary videos are stored

in the same clip, they are provided 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.

FIG. 14 is a flow chart illustrating a method for reproducing

data in accordance with the present invention.

When reproduction of data is begun, the controller 12 reads

out data from the recording medium 30 or storage 15 (S1410) .

The data not only includes primary video, primary audio,

secondary video, and secondary audio data, but also includes

management data for managing the reproduction of the data.

The management data may include a playlist, playitems, STN

tables, clip information, etc.

In accordance with the present invention, the controller 12

checks a secondary audio allowed to be reproduced along with

the secondary video, from the management data (S1420) . The

controller 12 also identifies a primary audio allowed to be

mixed with the secondary audio, from the management data

(S1420) . Referring to FIG. 5, information

^λ comb_info_Secondary_video_Secondary_audio' 520 defining

secondary audio allowed to be reproduced along with the

secondary video, the stream entries of which are stored in

the associated STN table, may be stored in the STN table.

Also, information ^λ comb_info_Secondary_audio_Primary_audio' ^r

510 defining primary audio allowed to be mixed with the

secondary audio may be stored in the STN table. One of the

secondary audio streams defined by the information

^λ comb_info_Secondary_video_Secondary_audio' 520 is decoded in

the secondary audio decoder 74Of (S1430), and is then

provided to the primary audio mixer 750a.

The stream number of the decoded secondary audio is stored in

the PSR14 120. In accordance with an embodiment of the

present invention, the PSR14 120 may store a flag

Misp_a_flag' . Under the condition in which the flag

^λ disp_a_flag' has been set to a value corresponding to a

disabled state, the secondary audio is prevented from being

output (OFF) . As described above with reference to FIG. 12,

the flag ^λ disp_a_flag' is variable by the user operation (UO) ,

user command, or API. That is, the output of the secondary

audio can be turned ON and OFF by the user operation (UO) ,

user command, or API.

The secondary audio decoded in the secondary audio decoder

73Of is mixed with the primary audio defined by the

information ^λ comb_info_Secondary_audio_Primary_audio' 510 in

the primary audio mixer 750a (S1440). The primary audio to

be mixed is provided to the primary audio mixer 750a after

being decoded in the primary audio decoder 73Oe.

The stream number of the decoded primary audio is stored in

the PSRl 110. In accordance with an embodiment of the

present invention, the PSRl 110 may store a flag

^λ disp_a_flag' . Under the condition in which the flag

^λ disp_a_flag' has been set to a value corresponding to a

disabled state, the primary audio is prevented from being

output (OFF) . As described above with reference to FIG. 12,

the flag ^λ disp_a_flag' is changeable by the user operation

(UO), user command, or API. That is, the output of the

primary audio can be turned ON and OFF by the user operation

(UO), user command, or API.

In accordance with the present invention, it is possible to

reproduce the secondary video along with the secondary audio.

Also, the content provider can control mixing of audios, or

can control output of an audio between ON and OFF statuses,

using a command set.

As apparent from the above description, in accordance with

the data reproducing method and apparatus, recording medium,

and data recording method and apparatus of the present

invention, it is possible to simultaneously reproduce primary

and secondary videos. In addition, the user or content

provider can control mixing of audios, or can control output

of an audio. Accordingly, there are advantages in that the

content provider can compose more diverse contents, to enable

the user to experience more diverse contents. Also, there is

an advantage in that the content provider can control audios

to be provided to the user.

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.