KR20180035194A - Method for generating and playing object-based audio contents and computer readable recordoing medium for recoding data having file format structure for object-based audio service - Google Patents

Abstract

Disclosed are a method for generating and playing object-based audio content and a computer-readable recording medium for recoding data with a file format structure for an object-based audio service. The method for generating object-based audio content includes the steps of: receiving a plurality of audio objects; generating at least one preset by using the plurality of audio objects which are inputted; and storing a preset parameter about an attribute of the at least one preset and the plurality of audio objects. The preset parameter is stored in a box form defined in a media file format with regard to the object-based audio contents. Accordingly, the present invention can efficiently store the preset for the plurality of audio objects.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for generating and reproducing object-based audio content, and a file format structure for object-based audio service. FORMAT STRUCTURE FOR OBJECT-BASED AUDIO SERVICE}

The present invention relates to an object-based audio content creation / playback method capable of efficiently storing preset information on object-based audio content, and a computer-readable recording medium storing data having a file format structure for object-based audio service.

The present invention is derived from research conducted as part of the development of IT source technology of the Ministry of Knowledge Economy and the Korea IT Industry Promotion Agency. [Project number: 2008-F-011-01, - Development of 3D broadcasting technology of Muan Xing Ding Doll (cont.)].

Conventional audio signals provided through broadcasting services such as TV broadcasting, radio broadcasting, and DMB (Digital Multimedia Broadcasting) are audio signals obtained from various sound sources are mixed and stored / transmitted as one audio signal.

In such an environment, it is possible for the viewer to adjust the intensity of the entire audio signal, but it is impossible to control the characteristics of the audio signal for each sound source such as adjusting the intensity of the audio signal for each sound source included in the audio signal.

However, when authoring audio contents, if audio signals of respective sound sources are independently synthesized without being synthesized, the contents reproducing terminal can watch the corresponding contents while controlling the intensity of audio signals for each sound source.

An audio service that allows a user to independently store / transmit a plurality of audio signals at a storage / transmission end and allow the user to listen to and control each audio signal in a receiver (content reproduction apparatus) is referred to as an object-based audio service .

In such an object-based audio service, a property such as a position, a sound intensity, and an acoustic characteristic according to the position of each object is defined and provided as a preset, thereby allowing the user to utilize them for reproduction of audio contents. That is, if a plurality of preset audio information is generated and included in a file, the object-based audio service can be reproduced more efficiently on the receiving side.

The existing ISO Base Media File Format (ISO-BMFF) defines a file structure that includes various types of media such as audio, video, and still images. The above file structure is flexible and expandable in the interchange, management, editing, and presentation of media.

Adding or storing audio track and preset information in these ISO-based media file formats will provide more efficient object-based audio services.

It is an object of the present invention to provide a method of generating object-based audio content capable of efficiently storing a preset for a plurality of audio objects.

A method of generating object-based audio content according to an exemplary embodiment of the present invention includes receiving a plurality of audio objects, generating at least one preset using the input plurality of audio objects, And storing a preset parameter for an attribute of the at least one preset, wherein the preset parameter is stored in the form of a box defined in a media file format for the object-based audio content.

In this case, the media file format may be an ISO base media file format.

The box also includes a moov box, the moov box includes a first box defined within the moov box, the first box includes a second box defined within the first box, Wherein the preset parameter includes a first preset parameter and a second preset parameter, wherein the first preset parameter includes at least one of the number of the at least one preset and at least one of preset IDs of any one of the at least one preset Wherein the first preset parameter is stored in the first box, and the second preset parameter is stored in the second box.

According to another aspect of the present invention, there is provided a method of reproducing object-based audio content, the method comprising: restoring a plurality of audio objects and at least one preset from object-based audio content; And reproducing the output audio signal, wherein each of the at least one preset includes a preset parameter, and the preset parameter includes a media file associated with the object-based audio content Based audio content in the form of a box defined in the format.

According to another aspect of the present invention, there is provided a computer-readable recording medium on which data having a file format structure for an object-based audio service is recorded. The computer-readable recording medium includes an ffp box for storing standard information of object- An mdat box for storing a plurality of audio objects constituting audio contents and a moov box for storing meta data for presenting the stored plurality of audio objects, Preset parameters for attributes of at least one preset created using a plurality of audio objects are stored in either the fift tip box or the move box.

According to the present invention, a preset for a plurality of audio objects can be efficiently stored.

1 is a diagram showing a basic form of a media file format structure for storing object-based audio contents according to an embodiment of the present invention.
2 is a diagram showing a relationship between a track and a channel according to an embodiment of the present invention.
3 is a flowchart illustrating a method of generating object-based audio content according to an exemplary embodiment of the present invention.
4 is a diagram illustrating a structure of 'moov' according to an embodiment of the present invention.
FIG. 5 is a flowchart illustrating a method of reproducing object-based audio content according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 6 is a flowchart illustrating a method of reproducing object-based audio content according to another embodiment of the present invention.
7 and 8 are diagrams showing a structure of a file format for storing object-based audio content including description information according to an embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

1 is a diagram showing a basic form of a media file format structure for storing object-based audio contents according to an embodiment of the present invention.

Referring to FIG. 1, a media file format structure for storing object-based audio content includes an ff tip box (hereinafter, referred to as 'ftyp') storing standard information of object-based audio content (Hereinafter referred to as " moov ") for storing metadata (for example, decoding time) for presentation of a plurality of audio object data constituting object-based audio contents, (Hereinafter referred to as " mdat ") in which a plurality of audio object data is stored.

'ftyp' and 'moov' are configured to include a meta box (hereinafter referred to as 'meta'). Generally, 'meta' includes descriptive metadata of a plurality of audio object data stored in 'mdat' .

Here, the media file format structure for storing object-based audio contents is preferably an ISO-based media file format (ISO-BMFF) structure.

Hereinafter, a method for generating object-based audio content by storing a preset associated with playback of object-based audio content along with an ISO-based media file format (ISO-BMFF) structure together with a plurality of audio objects will be described. However, as described above, the object-based audio content generation method described below is not limited to the object-based audio content having the ISO-based media file format (ISO-BMFF) structure, and may store multimedia data such as MP4 files The present invention is also applicable to multi-channel audio content having a media file format structure.

Before describing a method of generating object-based audio content according to an embodiment of the present invention, a preset parameter indicating a property of a preset stored in object-based audio content will be described first. The preset parameter may include at least one of the preset information listed below.

1. Preset name, preset ID

'Preset name' means a string corresponding to a preset, and 'Preset ID' means an integer corresponding to each preset corresponding to a preset.

2. Number of Presets, Default Preset ID (ID)

The 'number of presets' refers to the number of presets included in the object-based audio content.

The 'default preset ID' refers to a preset ID to be played first in an initial state in which there is no user interaction when object-based audio content is played back. The default preset ID may correspond to any one of the preset IDs included in the object-based audio content.

3. Whether or not preset information is displayed

Preset information display information includes preset information (for example, volume information for each input track or input channel, frequency gain information for each input track or input channel, which will be described below) To be displayed to the user.

4. Whether the preset can be edited

'Editable Preset' means information on whether a user can edit a preset when playing object-based audio content.

5. The number of input tracks, the ID of the input track, the number of input channels per input track

The number of input tracks means the number of input tracks stored in the object-based audio content. Here, the input track may correspond to a sound source. That is, when the object-based audio contents are composed of a vocal, a piano, and a drum, each of the vocal, piano, and drum may be composed of one track.

'ID of the input track' means an integer corresponding to each input track.

The 'number of input channels per input track' means the number of channels included in each input track.

Hereinafter, the relationship between tracks and channels will be described with reference to FIG.

2 is a diagram showing a relationship between a track and a channel according to an embodiment of the present invention.

In Fig. 2, the vocal track 210, the piano track 220, and the drum track 230 are shown.

When recording a sound source, when each sound source is recorded in two channels (i.e., a stereo channel), each track may include two channels. That is, when a vocal, a piano, and a drum are recorded in two channels, the vocal track 210 is composed of a first channel 211 and a second channel 212, and the piano track 220 includes a first channel 221 And a second channel 222. The drum track 230 may include a first channel 231 and a second channel 232. 2, all the tracks include the same channel, but the number of channels included in each track may be different from each other.

In this case, when the author of the object-based audio content sets a preset for each track, a plurality of audio objects may correspond to a track, and when a preset is set for each channel, a plurality of audio objects may correspond to a channel.

6. Type of output channel, number of output channels

The 'output channel type' means information on which channel the object-based audio contents are reproduced, and the 'number of output channels' means the number of output channels according to the output channel type.

7. The number of frequency bands for sound equalization, the center frequency of each frequency band, the bandwidth of each frequency band,

The number of frequency bands refers to the number of frequency bands to which sound equalization is to be applied to compensate for distortion of a signal occurring during signal amplification or transmission.

8. Volume information by input track or by input channel

The " volume information " means information about the volume of each of a plurality of audio objects. When the audio object corresponds to the input track, the 'volume information per input track' is stored in the object-based audio content. If the audio object corresponds to the input channel, 'volume information per input channel' is stored in the object- do.

9. Frequency gain information by input track or input channel

The 'frequency gain information' refers to information on the frequency gain when sound equalization is applied. When the audio object corresponds to the input track, 'frequency gain information per input track' is stored in the object-based audio content, and when the audio object corresponds to the input channel, 'frequency gain information per input channel' / RTI >

10. Preset global volume information

The 'preset global volume information' refers to information for adjusting the volume of a plurality of audio objects.

11. The size of the sound image and the angle of the sound image

The 'size of sound image' and the 'angle of sound image' mean the size value and the angle value of sound image formed by a plurality of channels stored in the object-based audio content.

The author of the object-based audio content may generate the object-based audio content by storing preset parameters including at least one of the listed information according to the ISO-based media file format structure through various methods.

3 is a flowchart illustrating a method of generating object-based audio content according to an exemplary embodiment of the present invention.

First, in step 310, a plurality of audio objects are input.

Next, in step 320, at least one preset is generated using the plurality of input audio objects.

Finally, in step 330, a plurality of audio objects and preset parameters for the attributes of the preset are stored. As mentioned above, the preset parameter may include at least one of the listed information.

In this case, the preset parameters are stored in the form of boxes defined in the media file format for object-based audio content.

Hereinafter, the process of storing the preset parameters in step 330 will be described in detail.

Storing the preset parameters in the meta '' present in the '' meta or 'moov present in the' ftyp '

According to one embodiment of the present invention, a preset parameter is defined as 'meta' (hereinafter referred to as 'first meta') existing in 'ftyp' or 'meta' ). ≪ / RTI >

That is, as described above, the first 'meta' or the second 'meta' may include description information (or description metadata) indicating general information on object-based audio contents such as a song title, an artist name, ) May be stored, and the preset parameter may be stored together with the description information.

Preset parameters are stored in ' meta ' where the description information is stored and in a separate ' meta '

According to an embodiment of the present invention, a preset parameter may be stored in a separate 'meta' that is different from 'meta' in which description information about object-based audio content is stored.

This is because the description information is related to the identification of the object-based audio content, and the preset parameter is related to the reproduction of the object-based audio content. Since the attributes of the information are different from each other, .

As an example, the description information may be stored in the first 'meta' and the preset parameters may be stored in the second 'meta'.

In ISO-based media file format, 'ftyp' and 'moov' each contain only one 'meta' at a lower level, since only one 'meta' can exist within one level. Therefore, in order for the description information and the preset parameter to be separately stored, the description information and the preset parameter must be stored in the 'meta' (i.e., the first 'meta' and the second 'meta') existing at different levels. In this case, since the preset parameter has the attribute of the metadata for the presentation, the description information can be stored in the first 'meta', and the preset parameter can be stored in the second 'meta'.

As another example, the description information is stored intactly in 'meta' (first meta 'and second meta'), and preset parameters are stored in a meco box existing in 'ftyp' or 'moov' quot; meco ").

'meco' is an additional metadata container box for storing additional metadata defined in the ISO-based media file format, and 'meco' stores separate metadata not defined in the ISO-based media file format. . Therefore, the preset parameter may be stored in either 'meco' existing in 'ftyp' or 'meco' existing in 'moov'.

' moov Preset parameters are stored in the newly defined box in '

According to one embodiment of the present invention, the preset parameter may be stored in a newly defined box in 'moov'.

As described above, since the preset parameter and the description information have different attributes, it is desirable that the preset parameter be handled separately from the description information. Also, since the preset parameters have attributes of metadata for presentation, they are preferably stored in 'moov'. Therefore, in order to efficiently manage the preset parameters, it is desirable to define a new box in 'moov' and to store the preset parameters in the newly defined box.

4 is a diagram illustrating a structure of 'moov' according to an embodiment of the present invention.

As shown in FIG. 4, two boxes may be defined in 'moov'.

The first box is a box defined in 'moov', and the first box stores a first preset parameter which is a preset parameter indicating the overall information of the preset. Hereinafter, the first box will be referred to as a preset contain box, that is, 'prco'.

For example, the first preset parameter may include at least one of the number of the above-mentioned preset and the default preset ID. The default preset ID means a preset ID to be played first in an initial state in which no user interaction occurs when object-based audio content is played back. The default preset ID may correspond to any one of the preset IDs included in the object-based audio content.

The second box is a box defined in 'prco', and the second box stores a second preset parameter which is a parameter for the attribute of the preset.

For example, the second preset parameter may include information other than the number of the preset and the default preset ID among the listed information. Hereinafter, the second box will be referred to as a preset box, that is, 'prst'.

Within 'prco' there is 'prst' as many as the number of presets contained in object-based audio content. If the preset is not stored in the object-based audio content, there is no 'prst' in 'prco'.

For example, 'prst' may store preset parameters including the number of presets and the preset information other than the default preset ID in the above-mentioned preset information.

According to an embodiment of the present invention, when 'moov' includes 'prco' and 'prst', the structure of the ISO based media file format may be as shown in Table 1.

ftyp file type and compatibility moov container for all the metadata mvhd movie header, overall declarations trak container for an individual track or stream tkhd track header, overall information about the track tref 트랙 참조 용기 edts edit list container elst an edit list mdia container for the media information in a track mdhd media header, overall information about the media HDLR handler, declares the media (handler) type minf media information container smhd sound media header, overall information (sound track only) hmhd hint media header, overall information (hint track only) nmhd Null media header, overall information (some tracks only) dinf data information box, container dref data reference box, declares source (s) of media data in track stbl sample table box, container for the time / space map stsd sample descriptions (codec types, initialization etc.) stts decoding time-to-sample stsc sample-to-chunk, partial data-offset information stsz sample sizes (framing) stz2 compact sample sizes (framing) stco chunk offset, partial data-offset information co64 64-bit chunk offset prco container for the presets prst preset box, container for the preset information mdat media data container free free space skip free space meta Metadata HDLR handler, declares the metadata (handler) type dinf data information box, container Dref data reference box, declares source (s) of metadata items iloc item location iinf item information xml XML container bxml binary XML container pitm primary item reference

Hereinafter, one embodiment of the syntax and semantics of 'prco' and 'prst' will be described in detail.

Table 2 shows one embodiment of the syntax of 'prco'.

Preset Container Box
Box type : 'prco'
Container: Movie Box ('moov')
Mandatory: Yes
Quantity: Exactly one

syntax

aligned (8) class PresetContainerBox extends Box ('prco') {
unsigned int (8) num_preset;
unsigned int (8) default_preset_ID;
}

The semantics according to the syntax of Table 2 are as follows.

'num_preset' means the number of presets in 'prco'.

'default_preset_ID' means the default preset ID. If the author does not set 'default_preset_ID', the preset ID of the preset with the smallest preset ID value may be set to 'default_preset_ID'.

If 'default_preset_ID' is set to '0', among the plurality of audio objects included in the object-based audio content, the bitstream of the audio objects encoded and stored by the multi-object audio coding (SAOC) The object-based audio contents can be reproduced in accordance with the preset stored in the memory. A detailed description thereof will be made with reference to FIG. 6.

Table 3 shows the general syntax of 'prst'.

Preset Box
Box type: ' prst '
Container: Preset Container Box ('prco')
Mandatory: No
Quantity: zero or more

syntax

aligned (8) class PresetBox extends FullBox ('prst', version = 0, flags) {
unsigned int (8) preset_ID;
unsigned int (8) num_preset_track;
unsigned int (8) preset_track_ID [num_preset_track];
unsigned int (8) preset_type;
unsigned int (8) preset_global_volume;

if (preset_type == 0) {}
if (preset_type == 1) {}
if (preset_type == 2) {}
if (preset_type == 3) {}
if (preset_type == 4) {}
if (preset_type == 5) {}
if (preset_type == 6) {}
if (preset_type == 7) {}
if (preset_type == 8) {}
if (preset_type == 9) {}
if (preset_type == 10) {}
if (preset_type == 11) {}
string preset_name;
}

The semantics according to the syntax of Table 3 are as follows.

'version' means the version of 'prst'.

'flags' denotes flag information about whether to display information stored in 'prst' to the user and whether to allow the user to edit information stored in 'prst', when reproducing object-based audio contents.

'flags' is flag information having a data type of 8-bit integer, and can have the same meaning as in Table 4.

Flags Display Edit 0x01 disable disable 0x02 enable disable 0x03 enable enable

That is, if 'flags' is 0x01, the preset related information stored in the 'prst' is not displayed to the user when reproducing the object based audio content, and the user can not edit the preset related information stored in the 'prst'.

If 'flags' is 0x02, the preset related information stored in 'prst' is displayed to the user when playing the object based audio content, but the user can not edit the information stored in 'prst'.

If 'flags' is 0x03, the information stored in 'prst' is displayed to the user when playing object-based audio content, and the user can edit the information stored in 'prst'.

'preset_ID' means a preset ID and can have a value of 1 or more.

'num_preset_track' means the number of input tracks associated with the preset.

'preset_track_ID [num_preset_track]' means an array that stores the ID of the input track.

'preset_name' means preset name.

'preset_global_volume' means preset global volume information.

Generally, to emphasize the rhythm of object-based audio content, the author creates a preset by increasing the volume of the percussion instrument sound, such as a drum, relative to the volume of other instrument sounds.

However, if the relative volume difference between the percussion sound and the other instrument sound is small, you will not feel a sufficient rhythm. Conversely, if the relative volume difference between percussive sounds and other instrument sounds is large, the overall volume becomes smaller. This is due to the fact that the percussion sound generally has the same properties as the effector, and the high frequency component of the percussion sound is larger than the sound of other instruments over the total playback period of the object-based audio contents.

For example, if the volume of a preset consisting of vocals, pianos, and drums is set to [250, 200, 400], the overall volume is adequate but the rhythm is not emphasized, The rhythm is emphasized but the overall volume is reduced.

This can be solved by further storing the preset global volume information in the object-based audio content. The preset global volume information is information for adjusting the overall volume of the audio object constituting the preset.

의 비율로 더 커지게 된다. That is, if the volume value of the entire input track is stored based on the basic global volume value set in the object-based audio content, and the preset global volume value is created to be larger than the existing global volume value, Relative volume difference during playback

. ≪ / RTI >

As an example, if the preset global volume value is set to 100 when the default global volume value is '50' and the volume value of the preset composed of [vocal, piano, drum] is [100, 150, 400] Will be doubled. As a result, the volume of the vocal and piano constituting the main melody becomes twice as large, so that the overall volume of the object-based audio contents becomes appropriate, and the volume of the drum also doubles, thereby emphasizing the rhythm.

When the volume is amplified using the preset global volume value as described above, sound quality deterioration such as clipping may occur. However, in general, when the percussion sound is increased to a certain level or more, Based on the experimental fact that it is difficult to recognize, the sound quality deterioration due to the use of the preset global volume information will not be a problem.

In addition, the preset global volume information can also be used to increase the overall volume size when the default global volume value is the maximum.

That is, in playback of general object-based audio content, it is impossible to adjust the volume of each audio object if the default global volume value is maximum. However, if the preset global volume information is stored in the object-based audio content, the object-based audio content can be reproduced with a volume larger than the maximum value of the basic global volume value.

'preset_type' means the preset type.

According to one embodiment of the present invention, the preset type can be determined based on the type of mixing information, the application object of the mixing information, and the change in the mixing information according to the reproduction time of the object-based audio content. Hereinafter, a method of determining a preset type will be described in detail.

First, the preset type can be determined based on the type of the mixing information.

As an example, the mixing information may include at least one of volume information and sound equalization information. Hereinafter, a preset created considering only volume information will be referred to as a volume preset, a preset created considering only equalization information will be referred to as an equalization preset, a preset created considering both volume information and equalization information, / Volume equalization preset.

Next, the preset type can be determined based on the application target of the mixing information.

That is, the preset type can be determined according to whether the input track is regarded as an audio object and the mixing information is applied, or whether the input channel is regarded as an audio object and the mixing information is applied. Hereinafter, a preset created by considering an input track as an audio object is referred to as a track preset, and a generated preset that regards an input channel as an audio object is referred to as a channel preset.

Finally, the preset type can be determined based on whether the mixing information changes according to the playback time of the object-based audio content.

That is, as the object-based audio content is reproduced, the preset type can be determined according to whether the mixing information has a constant value or whether the mixing information changes. Hereinafter, a preset in the case where the mixing information does not change is referred to as a static preset, and a preset in the case where the mixing information changes is referred to as a dynamic preset.

According to an embodiment of the present invention, when storing a dynamic preset in the object-based audio content, a 'prst' may include a table for mapping an input track ID and mixing information of the input track ID . In this case, the mixing information according to the sampling number of the input track can be derived based on the existing ISO-BMFF and the 'stts' (decoding time to sample box) and the mixing information stored in the table ('stts' The relationship between the decoding time and the sample number is stored). This allows random access to the playback of the object-based audio content, and the amount of mixing information stored in the object-based audio content can be reduced.

In the case of generating a preset using the above-mentioned information, the preset types can be classified as shown in Table 5. Although Table 5 shows that 12 presets may be present, this may be further extended according to the classification elements.

preset
_type static (S)
/ dynamic (D) track (T)
/ channel (C) volume
(Vol) equalization
( Eq ) meaning 0 S T Vol - static track volume preset One S T Vol Eq static track volume preset with equalization 2 S T - Eq static track equalization preset 3 D T Vol - dynamic track volume preset 4 D T Vol Eq dynamic track volume preset with equalization 5 D T - Eq dynamic track equalization preset 6 S C Vol - static object volume preset 7 S C Vol Eq static object volume preset with equalization 8 S C - Eq static object equalization preset 9 D C Vol - dynamic object volume preset 10 D C Vol Eq dynamic object volume preset with equalization 11 D C - Eq dynamic object equalization preset

Referring to Table 5, it can be seen that the mixing information includes volume information and equalization information, which are stored in 'prst' in a different form depending on the preset type. Here, the storage format of the mixing information can be largely classified according to whether the preset type is a static preset or a dynamic preset.

1. If the preset type is a static preset

If the preset type is a static preset, the mixing information in the plurality of frames constituting the object-based audio content is the same, and thus the same mixing information is stored for each audio object. Here, the storing form of the mixing information can be classified in detail according to whether the preset type is a track preset or a channel preset.

1.1. If the preset type is static / track preset ('preset_type' value is 0, 1 or 2)

When the mixing information is stored for each track, the output channel type may be determined according to an input trick having the largest number of channels among the input tracks. For example, when the first input track includes two channels and the second input track includes one channel, the number of channels included in the first input channel is larger, so that the output channel type is set to stereo Can be determined.

In this case, the syntax of the preset in 'prst' may be as shown in Tables 6 to 8.

if (preset_type == 0) {// static track volume preset
for (i = 0; i <num_preset_track; i ++) {
unsigned int (8) preset_volume;
}
}

if (preset_type == 1) {// static track volume preset with equalization
for (i = 0; i <num_preset_track; i ++) {
unsigned int (8) preset_volume;
unsigned int (8) num_freq_band;
for (j = 0; j <num_freq_band; j ++) {
unsigned int (16) center_freq;
unsigned int (16) bandwidth;
unsigned int (8) preset_freq_gain;
}
}
}

if (preset_type == 2) {// static track equalization preset
for (i = 0; i <num_preset_track; i ++) {
unsigned int (8) num_freq_band;
for (j = 0; j <num_freq_band; j ++) {
unsigned int (16) center_freq;
unsigned int (16) bandwidth;
nsigned int (8) preset_freq_gain;
}
}
}

The semantics according to the syntax of Tables 6 to 8 are as follows.

'preset_volume' means volume information.

The volume information may include a volume gain value between the input volume value of the input track and the output volume value of the output track. The volume gain value may be expressed as a percentage or in decibels (dB).

In addition, volume gain values expressed in percent or decibels may be quantized and stored. In this case, the quantized volume gain values can be expressed as shown in Tables 9 and 10.

index 0 One 2 3 149 200 value (ratio) 0 0.02 0.04 0.06 3.98 4.00

index 0 One 2 3 4 5 6 7 8 9 10 11 12 13 value (dB) -25 -21 -18 -15 -12 -8 -5 -3 -One 0 One 2 3 4

'num_freq_band' means the number of frequency bands to which sound equalization is applied, and has an integer value ranging from 0 to 32 inclusive.

'center_freq' means a center frequency in each frequency band, and has an integer value of 0 to 20,000 (unit: Hz).

'bandwidth' refers to the bandwidth of each frequency band, and has an integer value from 0 to 20,000 (unit: Hz).

'preset_freq_gain' means a frequency gain value in each frequency band.

Like the volume gain value, the frequency gain value can also be expressed as a percentage or decibel (dB), and the frequency gain value expressed as a percentage or decibel can also be quantized and stored. In this case, the quantized frequency gain values can be expressed as shown in Table 11.

index 0 One 2 3 149 200 gain 0 0.02 0.04 0.06 3.98 4.00

1.2. Preset type is static / channel preset ('preset_type' value is 7, 8, 9)

When the mixing information is stored for each channel, the mixing information can be stored in consideration of the number of input tracks, the number of channels per input track, and the output channel type. In this case, the syntax of the preset in 'prst' may be as shown in Tables 12 to 14.

if (preset_type == 6) {// static object volume preset
unsigned int (8) num_input_channel [num_preset_track];
unsigned int (8) output_channel_type;
for (i = 0; i <num_preset_track; i ++) {
(j = 0; j < num_input_channel [i]; j ++) {
for (k = 0; k <num_output_channel; k ++) {
unsigned int (8) preset_volume;
}
}
}
}

if (preset_type == 7) {// static object volume preset with equalization
for (i = 0; i <num_preset_track; i ++) {
(j = 0; j < num_input_channel [i]; j ++) {
for (k = 0; k <num_output_channel; k ++) {
unsigned int (8) preset_volume;
unsigned int (8) num_freq_band;
for (m = 0; m <num_freq_band; m ++) {
unsigned int (16) center_freq;
unsigned int (16) bandwidth;
unsigned int (8) preset_freq_gain;
}
}
}
}
}

if (preset_type == 8) {// static object equalization preset
for (i = 0; i <num_preset_track; i ++) {
(j = 0; j < num_input_channel [i]; j ++) {
for (k = 0; k <num_output_channel; k ++) {
unsigned int (8) num_freq_band;
for (m = 0; m <num_freq_band; m ++) {
unsigned int (16) center_freq;
unsigned int (16) bandwidth;
unsigned int (8) preset_freq_gain;
}
}
}
}
}

Semantics according to the syntax shown in Tables 12 to 14 are as follows.

'num_input_channel [num_preset_track]' means an array storing information on the number of channels per input track.

As an example, 'num_input_channel [num_preset_track]' may be configured using 'channel_count' information existing in 'moov' / 'track' / 'media' / 'minf' / 'stbl' / 'stsd' Num_input_channel [num_preset_track] 'is a value of' 1 'when the input track includes a mono channel,' 2 'is a value of' num_input_channel [num_preset_track] 'when the input track includes a stereo channel, When 5 channels are included, 'num_input_channel [num_preset_track]' may have a value of '5', respectively.

'output_channel_type' denotes an output channel type, and 'num_output_channel' denotes a number of output channels. As an example, 'output_channel_type' and 'num_output_channel' may have the relationship shown in Table 15.

output_channel_type Meaning num _output_channel 0 mono channel One One tere channel 2 2 5 channel 5

According to an embodiment of the present invention, when the preset type is static / object / volume preset and the number of output channels is 5, the mixing information stored in 'prst' can be expressed as shown in Table 16.

preset_track_ID = 1  reset_track_ID = 7 L R M 출력 채널 채널 L 50 0 50 R 0 80 50 C 50 80 0 Ls 0 0 30 Rs 0 0 30

In this case, each parameter stored in 'prst' has the following relationship.

* num_preset_track = 2

preset_track_ID [2] = [1,7]

num_input_channel [2] = [2, 1]

num_output_channel = 5

Preset_volume = [50, 0, 50, 0, 0, 0, 80, 80, 0, 0, 50, 50, 0, 30,

Here, if 'preset_volume' is examined, it can be seen that some mixing information is stored redundantly. In this case, since the amount of information to be stored is unnecessarily increased, a method for reducing the amount of information stored in 'prst' is required. A more detailed description will be given in the section of "2-, D, LA" below.

2. If the preset type is dynamic preset

When the preset type is a dynamic preset, since the mixing information changes in a plurality of frames constituting the object-based audio contents, different mixing information can be stored.

Accordingly, the mixing information may be represented by a matrix according to a frame number (or a sampling number), and the matrix may be expressed in the form of a table that maps a frame of the input track and corresponding mixing information .

Hereinafter, a method of storing the mixing information when the changing mixing information is displayed in the form of a mapping table as shown in Table 17 will be described in detail.

sampling number Input Track preset_track ID = 1 preset_track ID = 3 One 50 20 2 50 20 9 50 20 10 50 20 11 50 10 12 50 10 19 50 10 20 50 10 21 70 60 22 70 60 29 70 60 30 70 60

end. The mixing information value according to the frame number is stored as it is

I. The mixing information value according to the frame number is stored as the mixing information difference value with respect to the reference value and the reference value

The reference value means a reference mixing information value in the reference frame. Therefore, the reference mixing information value in the reference frame and the difference value between the mixing information in the frame other than the reference frame and the reference mixing information value can be stored in 'prst'.

If the reference value is 0, Table 17 can be simplified as shown in Table 18.

sampling count Input Track preset_track ID = 1 20 50 10 70 sampling count Input Track preset_track ID = 3 10 20 10 10 10 60

Accordingly, when the mixing information is stored in 'prst' in the form of a table as shown in Table 18, it is possible to reduce the amount of information to be stored.

All. The mixing information is stored using the flag information indicating the redundancy

The present invention stores flag information indicating that the mixing information value of the current frame is the same as the mixing information value of the previous frame without storing the mixing information value when the mixing information value of the previous frame is the same as the mixing information value of the current frame Thereby reducing the amount of information stored in 'prst'.

In this case, even if the value of the mixing information changes with time, it is not likely that the mixing information changes for each frame, so it is not efficient to give a flag value for each frame.

Therefore, according to the object-based audio content generation method according to the embodiment of the present invention, the mixing information value and the flag information can be stored based on the information about the frame interval in which the mixing information changes.

For example, when the mixing information changes as shown in Table 17, the mixing information (i.e., volume information) can be regarded as being changed in units of ten frames. Therefore, Table 17 can be expressed briefly as shown in Table 19.

preset_volume 50 50 70 20 10 60 volume_flag 0 One 0 0 0 0 modified preset_volume 50 _ 70 20 10 60

Therefore, each parameter stored in 'prst' has the following relationship.

dynamic_interval = 10

volume_flag = [0, 1, 0, 0, 0, 0]

preset_volume = [50, 70, 20, 10, 60]

Here, 'dynamic_interval' denotes a frame interval, and 'volume_flag' denotes volume flag information. If the mixing information of the previous frame and the mixing information of the current frame are the same, 'volume_flag' has a value of '1'. If the mixing information of the previous frame and the mixing information of the current frame are different, 'volume_flag' Lt; / RTI &gt;

Referring to this, it can be understood that a plurality of frames included in the object-based audio content are divided into frame groups according to specific frame intervals, and the mixing information is stored for each frame group.

That is, according to an embodiment of the present invention, when the first group mixing information for the first frame group and the second group mixing information for the second frame group are different, the preset parameter stored in 'prst' First flag information indicating that the first group mixing information and the second group mixing information are different from each other, and the number of frames included in each of the plurality of frame groups (i.e., the frame interval) .

In contrast, when the first group mixing information and the second group mixing information are the same, the preset parameters stored in 'prst' include first group mixing information and second group mixing information indicating that the first group mixing information and the second group mixing information are identical. Flag information, and the number of frames included in each of a plurality of frame groups included.

la. The number of times the mixing information changes, and the frame number of the frame in which the mixing information changes,

According to the present invention, the number of times the mixing information changes, the frame number of the frame in which the mixing information changes, and the mixing information corresponding thereto are stored. Therefore, this scheme is a more efficient method than the above-described method in terms of random access.

For example, when the mixing information changes as shown in Table 17, the number of changes of the mixing information stored in 'prst', the frame number at which the mixing information changes, and the mixing information (i.e., volume information) are as follows.

num_updates = 3

updated_sample_number = [1, 11, 21]

preset_volume = [50, 20, 50, 10, 70, 60]

Herein, 'num_updates' indicates the number of times the mixing information is changed (updated), and 'updated_sample_number' indicates the frame number at which the mixing information is changed (updated).

In the above, methods for efficiently storing the mixing parameter when the mixing information is changed according to the reproduction time have been described in detail. The above measures are also applicable when the preset type is a static preset and the stored mixing information is overlapped.

For example, in the case where the mixing information stored in 'prst' is displayed as shown in Table 16, and the mixing information is stored according to the above-mentioned 'scheme' using the flag information, It can be deformed.

preset_volume 50 0 50 0 0 0 80 80 0 0 50 50 0 30 30 volume_flag 0 0 0 0 One One 0 One 0 One 0 One 0 0 One modified preset_volume 50 0 50 0 _ _ 80 _ 0 _ 50 _ 0 30 _

Therefore, each parameter stored in 'prst' has the following relationship.

volume_flag = [0, 0, 0, 0,1,1,0,1,0,1,0,1,0,0,1]

preset_volume = [50, 0, 50, 0, 80, 0, 50, 0, 30]

In this case, the syntax of the preset in 'prst' shown in Table 12 can be modified as shown in Table 21. [

if (preset_type == 6) {// static object volume preset
unsigned int (8) num_input_channel [num_preset_track];
unsigned int (8) output_channel_type;
unsigned int (16) num_volume_flag;
for (i = 0; i <num_volume_flag; i ++) {
unsigned int (8) volume_flag;
if (volume_flag == 0) {
unsigned int (8) preset_volume;
}
}
}

The semantics according to the syntax of Table 21 are as follows.

'volume_flag' means volume flag information, and 'volume_flag' has a data type of 1 bit integer. 'volume_flag' has a value of '1' when the mixing information of the previous frame is the same as the mixing information of the current frame, 'volume_flag' is '1' when the mixing information of the previous frame is different from the mixing information of the current frame, 0 &quot;.

'num_volume_flag' means the array length of 'volume_flag'.

Hereinafter, an embodiment for storing mixing information of a dynamic preset in 'prst' will be described in detail based on the preset storing method described above.

2.1. If the preset type is dynamic / track preset ('preset_type' value is 3, 4 or 5)

As mentioned above, when the preset type is track preset, the type of the output channel may not be considered in storing the mixing information.

According to an embodiment of the present invention, the syntax of a preset in 'prst' may be as shown in Tables 22 to 24. The syntax shown in Tables 22 to 24 is a syntax related to a method for storing mixing information using the above-described scheme of "a ".

if (preset_type == 3)) {// dynamic track volume preset
unsigned int (16) num_updates;
for (i = 0; i <num_updates; i ++) {
unsigned int (16) updated_sample_number;
for (j = 0; j &lt;num_preset_track; j ++) {
unsigned int (8) preset_volume;
}
}
}

if (preset_type == 4) {// dynamic track volume preset with equalization
unsigned int (16) num_updates;
for (i = 0; i <num_updates; i ++) {
unsigned int (16) updated_sample_number;
for (j = 0; j &lt;num_preset_track; j ++) {
unsigned int (8) preset_volume;
unsigned int (16) num_freq_band;
for (k = 0; k <num_freq_band; k ++) {
unsigned int (16) center_freq;
unsigned int (16) bandwidth;
unsigned int (8) preset_freq_gain;
}
}
}
}

if (preset_type == 5) {// dynamic track equalization preset
unsigned int (16) num_updates;
for (i = 0; i <num_updates; i ++) {
unsigned int (16) updated_sample_number;
for (j = 0; j &lt;num_preset_track; j ++) {
unsigned int (16) num_freq_band;
for (k = 0; k <num_freq_band; k ++) {
unsigned int (16) center_freq;
unsigned int (16) bandwidth;
unsigned int (8) preset_freq_gain;
}
}
}
}

The semantics according to the syntax of Tables 22 to 24 are as follows.

'num_updates' means the number of times the mixing information changes (updates).

'updated_sample_number' means a frame number at which the mixing information is changed (updated).

Further, in the case of storing the mixing information according to the above-mentioned "D" scheme, the syntax of Table 22 can be modified as shown in Table 25. [

if (preset_type == 3)) {// dynamic track volume preset
unsigned int (8) dynamic_interval;
unsigned int (32) num_volume_flag;
for (i = 0; i <num_volume_flag; i ++) {
unsigned int (8) volume_flag;
if (volume_flag == 0) {
unsigned int (8) preset_volume;
}
}
}

The semantics according to the syntax of Table 25 are as follows.

'dynamic_interval' means the frame interval.

2.2. If the preset type is dynamic / channel preset ('preset_type' value is 9, 10, 11)

As described above, if the mixing information is stored for each channel, the mixing information can be stored in consideration of the number of input tracks, the number of channels per input track, and the type of output channel.

In this case, the syntax of the preset in 'prst' may be as shown in Tables 26 to 28. The syntax of Tables 26 to 27 is a syntax related to a method of storing mixing information using the above-described method of "a ".

if (preset_type == 9) {// dynamic object volume preset
unsigned int (16) num_updates;
for (i = 0; i <num_updates; i ++) {
unsigned int (16) updated_sample_number;
for (j = 0; j &lt;num_preset_track; j ++) {
for (k = 0; k <num_input_channel [j]; k ++) {
for (m = 0; m <num_output_channel; m ++) {
unsigned int (8) preset_volume;
}
}
}
}
}

if (preset_type == 10) {// dynamic object volume preset with equalization
unsigned int (16) num_updates;
for (i = 0; i <num_updates; i ++) {
for (j = 0; j &lt;num_preset_track; j ++) {
for (k = 0; k <num_input_channel [i]; k ++) {
for (m = 0; m <num_output_channel; m ++) {
unsigned int (8) preset_volume;
unsigned int (8) num_freq_band;
for (m = 0; m <num_freq_band; m ++) {
for (n = 0; n <num_freq_band; n ++) {
unsigned int (16) center_freq;
unsigned int (16) bandwidth;
unsigned int (8) preset_freq_gain;
}
}
}
}
}
}
}

if (preset_type == 11) {// dynamic object equalization preset
unsigned int (16) num_updates;
for (i = 0; i <num_updates; i ++) {
for (j = 0; j &lt;num_preset_track; j ++) {
for (k = 0; k <num_input_channel [i]; k ++) {
for (m = 0; m <num_output_channel; m ++) {
unsigned int (8) num_freq_band;
for (m = 0; m <num_freq_band; m ++) {
for (n = 0; n <num_freq_band; n ++) {
unsigned int (16) center_freq;
unsigned int (16) bandwidth;
unsigned int (8) preset_freq_gain;
}
}
}
}
}
}
}

In the above description, the mixing information includes only the volume information and the equalization information. However, according to an embodiment of the present invention, the mixing information includes a size value of a sound image formed by at least one input channel, And may further include an angle value. The magnitude value of the sound image and the angular value of the sound image are preset parameters that determine the virtual position of the sound image.

In this case, the angular value of the sound image can be quantized and stored. For example, the angle value of the sound image can be expressed in the form of a table as shown in Table 29.

index 0 One 2 3 4 5 6 value (°) 0 5 10 15 20 25 30 index 7 8 9 10 11 12 13 value (°) 40 50 60 70 80 90 100 index 14 15 16 17 18 19 20 value (°) 110 120 130 140 150 160 170 index 21 22 23 24 25 26 27 value (°) 180 190 200 210 220 230 240 index 28 29 30 31 32 33 34 value (°) 250 260 270 280 290 300 310 index 35 36 37 38 39 40 41 value (°) 320 330 335 340 345 350 355

According to an embodiment of the present invention, the object-based audio content may further include a mono / stereo audio signal which is a downmixed signal of an audio signal mixed based on any one of the at least one preset.

The mono / stereo audio signal is stored for compatibility with an audio playback device that is not capable of playing object-based audio content.

When an object-based audio content further includes a mono / stereo audio signal, in an audio device capable of reproducing object-based audio content, object-based audio content is played based on a plurality of audio objects and at least one preset, A mono / stereo audio signal is reproduced in an audio device in which reproduction of the contents is impossible. Accordingly, object-based audio content can be reproduced regardless of the type of the audio device.

As an example, a mono / stereo audio signal may be stored in 'mdat'. In this case, the semantics of flags in 'moov' / 'trak' / 'tkhd' can be modified as shown in Table 30. In Table 30, the underlined part is the semantics to be deleted, and the part indicated in bold is the added semantics.

flags - is a 24-bit integer with flags; the following values are defined:

- Track_enabled: Indicates that the track is enabled. Flag value is 0x000001. A disabled track (the low bit is zero) is treated as if it were not present.
- Track_in_movie: Indicates that the track is used in the presentation. Flag value is 0x000002.
- Track_in_interaction_movie: Indicates that the track is used in an interactive music player. Flag value is 0x000002.
- Track_in_non_interaction_movie: Indicates that the track is used in a non-interactive music player. Flag value is 0x000003.
- Track_in_preview: Indicates that the track is used when previewing the presentation. Flag value is 0x000004.

Preset parameters are stored in 'trak' existing in ' moov ' using MPEG-4 Binary format For Scene ( BIFS )

According to one embodiment of the present invention, a preset parameter may be stored in a track box (hereinafter referred to as 'trak') existing in 'moov' using MPEG-4 BIFS.

In this case, the first preset parameter (for example, the number of the preset, the default preset ID, etc.) indicating the overall information of the preset among the preset parameters may be stored in the above-described 'prco' .

When the first preset parameter is stored using the newly defined node in the BIFS, the node interface can be represented as shown in Table 31. In Table 31, 'PresetSound' means the newly defined node.

노드 인터페이스

PresetSound {
exposedField SFNode source NULL
exposedField SFInt32 numPresets 1
exposedField SFInt32 default_preset_ID 1
}

The semantics according to the node interface in Table 31 are as follows.

The 'source' field follows the semantics of subclause 7.2.2.116 of ISO / IEC 14496-11: 2005.

The 'numPreset' and 'default_preset_ID' fields follow the semantics of 'prco' described above.

Preset parameters indicating volume information among the preset parameters can be stored in an appropriate combination of AudioMix node and WideSound node.

Among the preset parameters, preset parameters indicating equalization information may be stored using PROTO audioEcho among existing AudioRXProto nodes, or may be stored using newly defined nodes in BIFS.

When storing the equalization information (more precisely, the frequency gain value) using the newly defined node in the BIFS, the node interface can be represented as shown in Table 32. In Table 32, 'PersetAudioEqualizer' means a newly defined node.

노드 인터페이스
PresetAudioEqualizer {
eventIn MFNode addChildren
eventIn MFNode removeChildren
exposedField MFNode children []
exposedField SFInt32 numInputs 1
exposedField MFFloat params []
}

The semantics according to the node interface in Table 32 are as follows.

The 'children' field is the output of nodes that can be mixed at the same time. An example of a 'child' field is AudioSource, AudioMix, and the like.

'addChildren' means the list of nodes added to the 'children' field.

'removeChildren' means the node list to be removed from the 'children' field.

The 'numInputs' field indicates the number of input tracks.

The 'params' field is a matrix of [numInputs x 3 .numFreqBands], where each row stores equalization parameters (equalization information) of frequency bands applied to each input track. This can be shown in Table 33.

Data Type Function Default value Range float numFreqBands 2 0,… , 32 float [] centerFreq [] 0,… , 20000 float [] bandwidth [] 0,… , 20000 float [] gain One 0.1, ... , 10

Here, 'numFreqBands' is the number of frequency bands, 'centerFreq' is the center frequency in each frequency band, 'bandwidth' is the bandwidth in each frequency band, and 'gain' is the gain value per frequency band.

That is, each line of the 'params' field is structured as follows.

numFreqBands = params [0]

centerFreq [0 ... numFreqBands-1] = params [1 ... numFreqBands]

bandwidth [0 ... numFreqBands-1] = params [numFreqBands + 1 ... 2 占 numFreqBands]

gain [0 ... numFreqBands-1] = params [2 .numFreqBands + 1 ... 3 .numFreqBands]

Preset parameters are stored in 'xml' in 'meta' using MPEG-4 Lightweight Application Scene Representation ( LASeR )

According to an embodiment of the present invention, a preset parameter may be stored in an XMl box (hereinafter referred to as 'xml') existing in 'meta' using MPEG-4 LASeR.

In this case, an element and an attribute as shown in Table 34 can be newly defined to store the preset parameter.

i. presetContainer element

semantics

The presetContainer element stores the same information as the above 'prco'.

attribute

'numPreset' means the number of presets.
'defaultPresetID' means the default preset ID.

ii. preset element

semantics

The preset element stores the same information as 'prst' described above. Preset elements also exist as children of the presetContainer element.

attribute
We use the syntax and semantics of 'prst' in ISO-BMFF described above as attributes.

Other

According to an embodiment of the present invention, when preset information is already described in a file including a plurality of audio objects, the preset information may be referred to in an object-based audio content format, or the preset information may be referred to as an object- To store preset parameters in the form of an object-based audio content format.

According to an embodiment of the present invention, when preset information is described in a file configured in a scene expression language format such as BIFS or LASeR, the preset information is referred to in an object-based audio content format, Based audio content format schema to store preset parameters in the form of object-based audio content formats.

Also, according to an embodiment of the present invention, when obtaining preset information from a file composed of only a preset, it may be referred to in an object-based audio content format. In addition, preset information stored in a file composed only of a preset can be stored as an object-based audio content format.

As described above, the description information (or description metadata) is additionally stored in the object-based audio content, and the stored description information can be utilized for searching and filtering the object-based audio content. Hereinafter, a method of storing description information will be described with reference to FIGS. 7 and 8. FIG.

7 and 8 are diagrams showing a structure of a file format for storing object-based audio content including description information according to an embodiment of the present invention.

In the ISO-based object-based audio content file format, the description information includes metadata for expressing an album (hereinafter referred to as' album level metadata '), metadata for expressing a song (hereinafter referred to as' song level metadata &quot;), and metadata for representing a track (hereinafter referred to as track level metadata). Here, each of the meta data can be summarized as shown in Table 35.

Description Level album song track title o o o singer o o - composer - o - lyricist - o - performing musician - - o genre o o - file date o o o CD track number of the song - o - production o o - publisher o o - copyright information o o - ISRC
(International Standard Recording Code) - o - imgae o o - URL
site address related to the music and the artist (eg album homepage, fan cafe, music video) o o -

The above metadata can be classified into two types: " metadata for expressing a song and a track "and" metadata for representing an album ". Here, the "metadata for representing an album" represents common information about songs stored in the same album among songs stored in the object-based audio content.

album level metadata can be stored in 'ftyp' / 'meta', song level metadata in 'moov' / 'meta', track level metadata in 'moov' / 'trak' / 'meta' respectively. Table 36 summarizes them.

Metadata Location  track level trak / meta box  song level  moov / meta box  album level  meta box of file

The form of the ISO-based object-based audio content file format structure in which the metadata is stored can be illustrated in FIGS. 7 and 8. FIG. The format structure shown in FIG. 7 is a single type file structure, and the format structure shown in FIG. 8 is a multiple type file structure.

Here, the metadata may be managed according to mp7t (mpeg-7 type).

More specifically, 'CreationInformation', 'MediaInformation', and 'Semantics DS' of MPEG-7 can be used for track level metadata and song level metadata. MPEG-7 'ContentCollection DS' and 'CreationInformation DS' can be used for album level metadata. This is because the album level metadata contains structure information for a plurality of songs included in one album.

These can be summarized as shown in Table 37 to Table 39.

Tag Name Semantics CreationInformation / Creation / Creator [@ type = "Instrument"] The title of the track - FamilyName, GivenName} (Arist name) - CreationInformation / Creation / Creator [Role / @ herf = "urn: mpeg: mpeg7: RoleCS: 2001: PERFORMER"] / Agent [@xsi:
- Name / (Group Name) - CreationInformation / Creation / Creator [Role / @ herf = "urn: mpeg: mpeg7: RoleCS: 2001: PERFORMER"] / Agent [@xsi: The name of a musician who is performing, such as vocal, guitar, keyboard and so on CreationInformation / CreationCoordinates / Date / TimePoint Time point of the recording

Tag Name Semantics CreationInformation / Creation / Title [@ type = "songTitle"] The title of the song - FamilyName, GivenName} (Arist name) - CreationInformation / Creation / Creator [Role / @ herf = "urn: mpeg: mpeg7: RoleCS: 2001: PERFORMER"] / Agent [@xsi:
- Name / (Group Name) - CreationInformation / Creation / Creator [Role / @ herf = "urn: mpeg: mpeg7: RoleCS: 2001: PERFORMER"] / Agent [@xsi: The name of a musician such as singer, composer and lyricist CreationInformation / Classification / Genre [@ herf = "urn: id3: v1: genreID"] Genre CreationInformation / CreationCoordinates / Date / TimePoint Time point when the song is released Semantics / SemanticBase [@xsi: type = "SemanticStateType"] / AttributeValuePair CD track number of the song CreationInformation / Creation / Abstract / FreeTextAnnotation Information on production, Publisher and site address related to the music and the artist
(eg album homepage, fan cafe and music video) CreationInformation / Creation / copyrightString Textual label indicating information that may be displayed or otherwise made known to the end user MediaInformation / MediaIdentification / EntityIdentifier ISRC CreationInformation / Creation / TitleMedia [@ type = "TitleImage"]

Tag Name Semantics ContentCollection / CreationInformation / Creation / Title [@ type = "albumTitle"] The title of the album - FamilyName, GivenName} (Arist) - ContentCollection / CreationInformation / Creation / Creator [Role / @ href = "urn: mpeg: mpeg7: RoleCS: 2001: PERFORMER"] / Agent [@xsi: name)
- Name / (Group Name) - CreationInformation / Creation / Creator [Role / @ herf = "urn: mpeg: mpeg7: RoleCS: 2001: PERFORMER"] / Agent [@xsi: The name of representative musician of the album ContentCollection / CreationInformation / Classification / Genre [@ href = "urn: id3: v1: genreID"] Genre ContentCollection / CreationInformation / CreationCoordinates / Date / Timepoint Time point when the album is related ContentCollection / CreationInformation / Creation / Abstract / FreeText Anotation Information on production, publisher and site address related to the music and the artist
(eg album homepage, fan cafe and music video) ContentCollection / CreationInformation / Creation / CopyrightString Textual label indicating information that may be displayed or otherwise made known to the end user ContentCollection / CreationInformation / Creation / TitleMedia [@type = "TitleImage"] The title of the multimedia content in image form

In addition, the object-based audio content may include audio content-related information such as lyrics of the song. If the audio content-related information is displayed on the audio content reproduction apparatus when the object-based audio content is reproduced, It is possible to provide an object-based audio service to the user. The audio content related information may be changed according to the playback time of the object-based audio content. Hereinafter, the audio content related information that changes according to the playback time will be referred to as 'Timed Text'.

The object-based audio content file format can provide Timed Text using Timed Text standards such as 3GPP TS 26.245 (hereinafter referred to as '3GPP Timed Text') and MPEG-4 Streaming Text Format.

As an example, when providing Timed Text using 3GPP Timed Text, 3GPP Timed Text may be configured to include a text sample and a sample description.

Here, the text sample may comprise a text string and a sample modifier, which contains information about how to render the text string.

Text samples are stored in ISO-BMFF as a single track (ie a text track) in 'mdat'. Stored text samples are synchronized with timed media such as audio tracks using information stored in 'stts', 'stsc', 'stco', etc. in 'moov' / 'trad' / 'mdia' / 'minf' / 'stbl' Is reproduced.

The sample description also includes information about how the text is rendered. For example, the sample description contains information about the location of the displayed text, the color of the text, the background color, and so on. The sample description, on the other hand, can be described in 'stsd' by extending 'SampleEntry' to 'TextSampleEntry'.

The method of generating object-based audio contents according to an embodiment of the present invention has been described above. Hereinafter, a method of reproducing object-based audio content generated according to the object-based audio content generation method will be described with reference to FIG.

FIG. 5 is a flowchart illustrating a method of reproducing object-based audio content according to an exemplary embodiment of the present invention. Referring to FIG.

First, in step 510, a plurality of audio objects and at least one preset are restored from the object-based audio content.

In this case, the object-based audio content is generated according to the object-based audio content generation method described with reference to FIG.

In step 520, a plurality of audio objects are mixed based on at least one preset to generate an output audio signal.

In step 530, the generated output audio signal is reproduced.

As described above, when the default preset ID value included in the preset parameter has a value of '0', the object is encoded according to the preset stored in the bitstream of the audio objects encoded and stored by the multi-object audio compression technique (SAOC) Based audio content can be reproduced. Hereinafter, referring to FIG. 6, a process of reproducing object-based audio content based on a preset stored in the bitstream of audio objects coded and stored by the multi-object audio compression technique (SAOC) I will explain.

FIG. 6 is a flowchart illustrating a method of reproducing object-based audio content according to another embodiment of the present invention.

First, in step 610, it is determined whether or not a preset exists in the object-based audio content.

If it is determined in step 610 that a preset exists (i.e., 'num_preset' has a value other than '0'), in step 620, it is determined whether a default preset ID exists in the object-based audio content.

If it is determined in step 620 that a default preset ID exists (i.e., 'default_preset_ID' is determined to have a value other than '0'), in step 630, a preset having the same preset ID as the default preset ID And mixes the plurality of audio objects on the basis of the audio signal to generate an output audio signal. In step 670, the output signal to be generated is reproduced.

If it is determined in step 610 that a preset does not exist (i.e., 'num_preset' has a value of '0'), or if it is determined in step 620 that a default preset ID does not exist default_preset_ID 'has a value of' 0 '), it is determined in step 640 whether an SAOC bitstream exists.

If it is determined in step 640 that a SAOC bitstream exists, it is determined in step 650 whether a preset exists in the SAOC bitstream.

If it is determined in step 650 that a preset is present in the SAOC bitstream, then in step 670, a plurality of audio objects are mixed based on the first preset contained in the SAOC bitstream to produce an output audio signal, ) Reproduces the output signal to be generated.

If it is determined in step 640 that the SAOC bitstream does not exist, or if it is determined in step 650 that there is no preset in the SAOC bitstream, it is determined that there is no preset in the object-based audio content, Do not play content.

In addition, embodiments of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Examples of program instructions, such as magneto-optical and ROM, RAM, flash memory and the like, can be executed by a computer using an interpreter or the like, as well as machine code, Includes a high-level language code. The hardware devices described above may be configured to operate as one or more software modules to perform operations of one embodiment of the present invention, and vice versa.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (12)

An object-based audio content generation apparatus comprising:
The object-based audio-content creating apparatus includes:
A processor for generating at least one preset associated with a plurality of audio objects and generating object-based audio content comprising the plurality of audio objects, the at least one preset,
Lt; / RTI &gt;
Wherein the preset includes information related to boxes and offsets associated with synchronization. The method according to claim 1,
Wherein the preset is editable by a user,
Wherein the object-based audio content is provided according to a media file format including track information. The method according to claim 1,
Wherein the object-
(ii) the number of output channels according to the type of the output channel, (iii) the gain information for the audio object, and ( iv) an object-based audio content generation device including a virtual position and an angle of the audio object. An object-based audio content reproducing apparatus comprising:
The object-based audio content reproducing apparatus includes:
A processor for extracting at least one preset and a plurality of audio objects associated with a plurality of audio objects from object-based audio content, and reproducing the object-based audio content using the preset and audio objects,
Wherein the preset includes information related to boxes and offsets associated with synchronization. 5. The method of claim 4,
Wherein the preset is editable by a user,
Wherein the object-based audio content is provided according to a media file format including track information. 5. The method of claim 4,
Wherein the object-
(ii) the number of output channels according to the type of the output channel, (iii) the gain information for the audio object, and ( iv) an object-based audio content reproduction device including a virtual position and an angle of the audio object. A method for generating an object-based audio content,
Creating at least one preset associated with a plurality of audio objects; And
Generating the object-based audio content including the plurality of audio objects, the at least one preset,
Lt; / RTI &gt;
Wherein the preset includes information related to boxes and offsets associated with synchronization. 8. The method of claim 7,
Wherein the preset is editable by a user,
Wherein the object-based audio content is provided according to a media file format including track information. 8. The method of claim 7,
Wherein the object-
(ii) the number of output channels according to the type of the output channel, (iii) the gain information for the audio object, and ( iv) an object-based audio content generation method including a virtual position and an angle of an audio object. An object-based audio content reproducing method,
Extracting at least one preset and a plurality of audio objects associated with a plurality of audio objects from object-based audio content; And
Playing the object-based audio content using the preset and audio objects
Lt; / RTI &gt;
Wherein the preset includes information related to boxes and offsets associated with synchronization. 11. The method of claim 10,
Wherein the preset is editable by a user,
Wherein the object-based audio content is provided according to a media file format including track information. 11. The method of claim 10,
Wherein the object-
(ii) the number of output channels according to the type of the output channel, (iii) the gain information for the audio object, and ( iv) an object-based audio content reproduction method including a virtual position and an angle of an audio object.

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