KR102149019B1 - 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

A computer-readable recording medium recording data having a file format structure for an object-based audio content generation/reproducing method and an object-based audio service is disclosed. The object-based audio content generation method includes receiving a plurality of audio objects, generating at least one preset using the input plurality of audio objects, and the plurality of audio objects and the at least one preset. Storing a preset parameter for an attribute, wherein the preset parameter is stored in the form of a box defined in a media file format for the object-based audio content.

Description

Computer-readable recording medium recording data with a file format structure for object-based audio content creation/playback and object-based audio service. FORMAT STRUCTURE FOR OBJECT-BASED AUDIO SERVICE}

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

The present invention is derived from research conducted as part of the IT source technology development of the Ministry of Knowledge Economy and Information and Communication Research Promotion Agency (Project Management Number: 2008-F-011-01, Project Name: Next Generation DTV Core Technology Development (Standardization Linkage) -Glasses-free personal 3D broadcasting technology development (continued)].

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

In such an environment, it is possible for the viewer to control 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 audio content is authored, if the audio signal for each sound source is not synthesized and stored independently, the content playback terminal can view the corresponding content while controlling the intensity of the audio signal for each sound source.

In this way, an audio service that independently stores/transmits several audio signals at the storage/transmission stage and enables users to listen while appropriately controlling each audio signal at a receiver (content playback device) is called an object-based audio service. .

In this object-based audio service, properties such as the location of each object, sound intensity, and acoustic characteristics according to the location of the objects are defined and provided as presets, so that the user can utilize them for playing audio content. That is, if a plurality of preset audio information is generated and provided in a file, the object-based audio service can be played more efficiently at the receiving side.

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

If audio tracks and preset information are added to the ISO-based media file format and stored or transmitted, object-based audio services can be more efficiently provided.

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

The object-based audio content generation method according to an 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 the plurality of audio objects , And storing a preset parameter for the 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.

In addition, the box includes a move box, the move box includes a first box defined in the move box, and the first box includes a second box defined in the first box, The preset parameter includes a first preset parameter and a second preset parameter, and the first preset parameter is at least among the number of the at least one preset and a preset ID (ID) of any one preset among the at least one preset. One may be included, and the first preset parameter may be stored in the first box, and the second preset parameter may be stored in the second box.

In addition, a method for reproducing object-based audio content according to an embodiment of the present invention includes the steps of restoring a plurality of audio objects and at least one preset from object-based audio content, and the plurality of audio objects based on the at least one preset. Mixing to generate an output audio signal, and playing the output audio signal, wherein each of the at least one preset includes a preset parameter, and the preset parameter is a media file related to the object-based audio content It may be stored in the object-based audio content in the form of a box defined in the format.

In addition, a computer-readable recording medium recording data having a file format structure for an object-based audio service according to an embodiment of the present invention includes a ftyp box for storing standard information of object-based audio content, and the object-based audio content. Including an mdat box for storing a plurality of audio objects constituting audio content, and a move box for storing metadata for presenting the stored plurality of audio objects, the A preset parameter for the attribute of at least one preset generated using a plurality of audio objects is stored in any one of the ftip box and the move box.

According to the present invention, it is possible to efficiently store presets for a plurality of audio objects.

1 is a diagram showing a basic form of a media file format structure for storing object-based audio content according to an embodiment of the present invention.
2 is a diagram illustrating 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 embodiment of the present invention.
4 is a diagram showing the structure of a'moov' according to an embodiment of the present invention.
5 is a flowchart illustrating a method of reproducing object-based audio content according to an embodiment of the present invention.
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 illustrating 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 of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments of the present invention exemplified below may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those of ordinary skill in the art.

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

Referring to FIG. 1, a media file format structure for storing object-based audio content is largely, a ftip box (hereinafter referred to as'ftyp) in which standard information of object-based audio content (ie, type information of object-based audio content file) is stored. '), a move box (hereinafter referred to as'moov') in which metadata (e.g., decoding time) for presentation of a plurality of audio object data constituting object-based audio content is stored. '), and an mdot box (hereinafter referred to as'mdat') in which a plurality of audio object data is stored.

'ftyp' and'moov' include a meta box (hereinafter referred to as'meta'), and in general,'meta' contains description metadata for a plurality of audio object data stored in'mdat'. Is saved.

Here, it is preferable that the media file format structure for storing object-based audio content is an ISO-based media file format (ISO-BMFF) structure.

Hereinafter, a method of generating object-based audio content by storing presets related to reproduction of object-based audio content together with a plurality of audio objects according to an ISO-based media file format (ISO-BMFF) structure will be described. However, as mentioned above, the object-based audio content generation method described below is not limited to object-based audio content having an ISO-based media file format (ISO-BMFF) structure, and stores multimedia data such as MP4 files. It is also possible to expand multi-channel audio contents having a media file format structure for this purpose.

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

1. Preset name, preset ID

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

2. Number of presets, default preset ID (ID)

The'preset number' means 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 without user interaction when object-based audio content is played. The default preset ID may correspond to any one preset ID from among preset IDs included in the object-based audio content.

3. Whether to display preset information

'Preset information display' refers to preset information when playing object-based audio content (for example, volume information for each input track or for each input channel or frequency gain information for each input track or for each input channel described below) Means information on whether to display to the user.

4. Whether the preset can be edited

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

5. Number of input tracks, ID of input tracks, 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 content is composed of vocals, pianos, and drums, each of the vocals, pianos, and drums may be composed of one track.

The “input track ID” 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, a relationship between a track and a channel will be described with reference to FIG. 2.

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

In FIG. 2, a vocal track 210, a piano track 220, and a drum track 230 are shown.

When recording a sound source, when recording each sound source in two channels (ie, a stereo channel), each track may include two channels. That is, when vocals, pianos, and drums 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 is a first channel 221 ) And a second channel 222, and the drum track 230 may be composed of a first channel 231 and a second channel 232. 2 shows that all tracks include the same channel, the number of channels included in each track may be different.

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 for each channel is set, the plurality of audio objects may correspond to a channel.

6. Type of output channel, number of output channels

The'type of output channel' means information on whether the object-based audio content is played through which channel, 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, and the bandwidth of each frequency band.

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

8. Volume information per input track or per input channel

'Volume information' means information on the volume of each of a plurality of audio objects. When an audio object corresponds to an input track,'volume information per input track' is stored in object-based audio content, and when an audio object corresponds to an input channel,'volume information per input channel' is stored in object-based audio content do.

9. Frequency gain information for each input track or for each input channel

'Frequency gain information' refers to information about frequency gain when sound equalization is applied. When an audio object corresponds to an input track,'frequency gain information for each input track' is stored in object-based audio content, and when an audio object corresponds to an input channel,'frequency gain information for each input channel' is object-based audio content. Is stored in.

10. Preset global volume information

'Preset global volume information' means information for adjusting the volume of all of the plurality of audio objects.

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

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

The author of the object-based audio content may generate object-based audio content by storing a preset parameter 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 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 a plurality of input audio objects.

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

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

Hereinafter, a process of storing the preset parameter 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 an embodiment of the present invention, the preset parameter is'meta' existing in'ftyp' (hereinafter referred to as a first'meta'), or'meta' existing in'moov' (hereinafter referred to as a second'meta'). Can be stored in).

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

Save the preset parameters and 'meta' description that the information is stored in another separate 'meta'

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

This is the point that description information is information related to the identification of object-based audio content, and the preset parameter is information related to reproduction of object-based audio content, and since the properties of both pieces of information are different, it is desirable to be separated from each other and managed. It is due to.

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

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

As another example, description information is stored in'meta' (the first'meta' and the second'meta') as it is, and the preset parameter is a meco box (hereinafter, referred to as'ftyp' or'moov'). It can be stored in'meco').

'meco' is a box for storing additional metadata specified in the ISO-based media file format (Additional Metadata Contain Box).'meco' stores separate metadata not specified in the ISO-based media file format. Can be. Accordingly, the preset parameter may be stored in either'meco' existing in'ftyp' or'meco' existing in'moov'.

' moov Save preset parameters in a newly defined box in '

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

As mentioned above, since the properties of the preset parameter and the description information are different from each other, the preset parameter is preferably managed separately from the description information. Also, since the preset parameter has the property of metadata for presentation, it is preferable to be stored in'moov'. Therefore, in order to efficiently manage the preset parameters, it is desirable to define a new box in'moov' and store the preset parameters in the newly defined box.

4 is a diagram showing the structure of a'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'. In the first box, a first preset parameter, which is a preset parameter indicating overall information of the preset, is stored. 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 presets and a default preset ID mentioned above. The default preset ID refers to a preset ID to be played first in an initial state without user interaction when object-based audio content is played. The default preset ID may correspond to any one preset ID from among preset IDs included in the object-based audio content.

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

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

In'prco', there are as many'prst' as the number of presets included in the object-based audio content. If the preset is not stored in the object-based audio content,'prst' does not exist in'prco'.

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

According to an embodiment of the present invention, when'moov' includes'prco' and'prst', the structure of an ISO-based media file format may be represented 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 track reference container 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, examples of the syntax and semantics of'prco' and'prst' will be described in detail.

Table 2 shows an example 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;
}

Semantics according to the syntax in Table 2 are as follows.

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

'default_preset_ID' means each default preset ID. When the author does not set the'default_preset_ID', the preset ID of the preset having the smallest preset ID value may be set as'default_preset_ID'.

If'default_preset_ID' is set to '0', the bitstream of audio objects encoded and stored with multi-object audio compression technology (SAOC: MPEG-D Spatial audio object coding) among a plurality of audio objects included in object-based audio content Object-based audio content may be played according to the preset stored in the. For a more detailed description of this, reference will be made to the description of 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;
}

Semantics according to the syntax in Table 3 are as follows.

'version' means the version of'prst'.

'flags' means flag information on whether to display information stored in'prst' to a user and whether to allow the user's editing of information stored in'prst' when playing object-based audio content.

'flags' is flag information having a data type of an 8-bit integer, and may 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, preset related information stored in'prst' is not displayed to the user when playing object-based audio content, and the user cannot edit preset related information stored in'prst'.

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

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

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

'num_preset_track' means the number of input tracks related to a preset.

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

'preset_name' means the preset name.

'preset_global_volume' means preset global volume information.

In general, in order to emphasize the rhythmic feeling of object-based audio contents, the author creates a preset by making the volume of a percussion instrument such as a drum relatively larger than that of other instrument sounds.

However, if the relative volume difference between the sound of percussion and other musical instruments is small, a sufficient sense of rhythm cannot be felt. Conversely, if the relative volume difference between the percussion sound and the sound of other musical instruments is large, the overall volume of the sound is reduced. This is due to the fact that, in general, the sound of percussion instruments has the same property as an effector, and thus the high frequency component of the percussion sound occupies a greater proportion than other instrument sounds over the entire reproduction period of the object-based audio content.

For example, if the volume value of the preset consisting of [Vocal, Piano, Drum] is [250, 200, 400], the overall volume is adequate, but the rhythmic feel is not emphasized, and the preset volume value is [100, 150, 400]. In this case, the sense of rhythm is emphasized, but the overall volume is reduced.

This can be solved by further storing preset global volume information in the object-based audio content. The preset global volume information is information for adjusting the overall volume of an audio object constituting a 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 greater than the existing global volume value, the object-based audio content The relative volume difference during playback

It becomes larger at the rate of.

As an example, if the default global volume value is '50' and the volume value of the preset consisting of [Vocal, Piano, Drum] is [100, 150, 400], if the preset global volume value is set to 100, each instrument Will double the volume. Accordingly, the volume of vocals and pianos constituting the main melody becomes about twice as large, so that the overall volume of the object-based audio content becomes an appropriate level, and the volume of the drum is also doubled, thereby emphasizing the sense of rhythm.

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

In addition, the preset global volume information may be used for increasing the overall volume size when the basic global volume value is the maximum.

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

'preset_type' means the type of preset.

According to an embodiment of the present invention, the preset type may be determined based on a type of mixing information, a target to which the mixing information is applied, and whether mixing information changes according to a reproduction time of object-based audio content. Hereinafter, a method of determining the preset type will be described in detail.

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

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

Next, the preset type may be determined based on a target to which the mixing information is applied.

That is, the preset type may be determined according to whether to apply mixing information by considering the input track as an audio object or applying mixing information by considering the input channel as an audio object. Hereinafter, a preset generated by considering an input track as an audio object is referred to as a track preset, and a generated preset in which an input channel is regarded as an audio object is referred to as a channel preset.

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

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

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

When a preset is generated using the above-mentioned information, the preset type can be classified as shown in Table 5. In Table 5, it is indicated that there may be 12 presets, but this may be further expanded according to classification factors.

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 according to 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. When the preset type is static preset

When the preset type is a static preset, since mixing information in a plurality of frames constituting object-based audio content is the same, the same mixing information is stored for each audio object. Here, the storage format of the mixing information may be classified in detail according to whether the preset type is a track preset or a channel preset.

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

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

In this case, the syntax of the preset in'prst' may be the same as 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;
}
}
}

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 an input volume value of an input track and an output volume value of an output track. The volume gain value can be expressed as a percentage or decibel (dB).

In addition, a volume gain value expressed as a percentage or decibel may be quantized and stored. In this case, the quantized volume gain value can be expressed as 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' refers to the number of frequency bands to which sound equalization is applied, and has an integer value of 0 or more and 32 or less.

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

'bandwidth' refers to the bandwidth of each frequency band, and has an integer value of 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 may also be expressed as a percentage or decibel (dB), and the frequency gain value expressed as a percentage or decibel may be quantized and stored. In this case, the quantized frequency gain value 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. When the preset type is static/channel preset (when the'preset_type' value is 7, 8, 9)

When the mixing information is stored for each channel, the mixing information may be stored in consideration of the number of input tracks, the number of channels per input track, and an output channel type. In this case, the syntax of the preset in'prst' may be the same as 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++){
for (j=0; j<num_input_channel[i]; j++){
for (k=0; k<num_output_channel; k++){
unsigened int(8) preset_volume;
}
}
}
}

if(preset_type == 7){ // static object volume preset with equalization
for (i=0; i<num_preset_track; i++){
for (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++){
for (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 of Tables 12 to 14 are as follows.

'num_input_channel[num_preset_track]' denotes an array that stores 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'. When the input track includes a mono channel,'num_input_channel[num_preset_track]' is a value of '1', when the input track includes a stereo channel,'num_input_channel[num_preset_track]' is a value of '2', and the input track is When 5 channels are included,'num_input_channel[num_preset_track]' may each have a value of '5'.

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

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

In addition, 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, mixing information stored in'prst' may be expressed as shown in Table 16.

preset_track_ID = 1 reset_track_ID = 7 L R M output channel volume 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, 30]

Here, looking at'preset_volume', it can be seen that some mixing information is redundantly stored. In this case, since the amount of information stored is unnecessarily increased, a method for reducing the amount of information stored in'prst' is required. For a more detailed description of this, refer to "2-B, C, D" below.

2. When the preset type is dynamic preset

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

Accordingly, the mixing information may be expressed as a matrix according to a frame number (or a sample number), and the matrix may be expressed in the form of a table for mapping a frame of an input track and mixing information corresponding thereto. .

Hereinafter, when the changing mixing information is displayed in the form of a mapping table as shown in Table 17, a method of storing the mixing information 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. Save mixing information value according to frame number as it is

I. Saving the mixing information value according to the frame number as a reference value and the difference value of mixing information about the reference value

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

If the reference value is 0, Table 17 can be briefly expressed as 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

Therefore, when 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 stored information.

All. Saving mixing information using flag information indicating overlapping

In this scheme, when the mixing information value of the previous frame and the mixing information value of the current frame are the same, the mixing information value is not stored, and flag information indicating that the mixing information value of the current frame and the mixing information value of the previous frame are the same. By doing so, it is a way to reduce the amount of information stored in'prst'.

In this case, even if the value of the mixing information changes over time, the possibility that the mixing information changes for each frame is not high, so it is not efficient to assign a flag value for each frame.

Accordingly, according to the method for generating object-based audio content according to an embodiment of the present invention, the mixing information value and flag information may be stored based on information on a frame interval in which the mixing information changes.

For example, when the mixing information changes as shown in Table 17, the mixing information (ie, volume information) may be regarded as changing in units of 10 frames. Therefore, Table 17 can be briefly expressed as 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' means a frame interval, and'volume_flag' means volume flag information. When 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', and when the mixing information of the previous frame and the mixing information of the current frame are different,'volume_flag' is of '0'. It has a value.

Referring to this, it may be understood that a plurality of frames included in the object-based audio content are divided into frame groups according to a specific frame interval, and 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' is the first group mixing information. Information, second group mixing information, first flag information indicating that the first group mixing information and the second group mixing information are different, and the number of frames (ie, frame intervals) included in each of the plurality of frame groups Include.

Conversely, when the first group mixing information and the second group mixing information are the same, the preset parameter stored in'prst' is a second group indicating that the first group mixing information and the first group mixing information and the second group mixing information are the same. It includes flag information, and the number of frames included in each of the included plurality of frame groups.

la. The mixing information is stored using 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 scheme, the number of times the mixing information is changed, the frame number of the frame in which the mixing information is changed, and the mixing information accordingly are stored. Therefore, this scheme can be said to be a more efficient method than the above-described'C' method in terms of random access.

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

num_updates = 3

updated_sample_number = [1, 11, 21]

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

Here,'num_updates' denotes a number of changes (updates) of the mixing information, and'updated_sample_number' denotes a frame number at which the mixing information is changed (updated).

In the above, when the mixing information changes according to the playback time, methods for efficiently storing the mixing parameter have been described in detail. The above schemes are also applicable when the preset type is a static preset, and thus stored mixing information is duplicated.

For example, when mixing information stored in'prst' is displayed as shown in Table 16, when mixing information is stored according to the above-described “C” scheme using flag information, Table 16 is as shown in Table 20. It can be transformed.

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 may 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;
}
}
}

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 a 1-bit integer. 'volume_flag' When the mixing information of the previous frame and the mixing information of the current frame are the same, the'volume_flag' has a value of '1', and when the mixing information of the previous frame and the mixing information of the current frame are different,'volume_flag' is' It has a value of 0'.

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

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

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

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

According to an embodiment of the present invention, the syntax of the preset in'prst' may be the same as Tables 22 to 24. The syntaxes shown in Tables 22 to 24 are syntaxes related to a method of storing mixing information using the method of “D” described above.

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<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<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<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;
}
}
}
}

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

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

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

In addition, when mixing information is stored according to the method of “C”, the syntax of Table 22 may 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;
}
}
}

Semantics according to the syntax of Table 25 are as follows.

'dynamic_interval' means frame interval.

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

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

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

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<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<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<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, it has been described that the mixing information includes only volume information and equalization information, but 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 the sound image. It may further include an angle value. The size value of the sound image and the angle value of the sound image are preset parameters that determine the virtual position of the sound image.

In this case, the angle value of the sound image may be quantized and stored. For example, the angle value of the sound image may 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

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

The mono/stereo audio signal is stored for compatibility with an audio reproducing device that cannot reproduce object-based audio content.

When the object-based audio content further includes a mono/stereo audio signal, an audio device capable of playing the object-based audio content reproduces the object-based audio content based on a plurality of audio objects and at least one preset, and In an audio device incapable of reproducing content, a mono/stereo audio signal is reproduced. Accordingly, object-based audio content can be reproduced regardless of the type of 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 the presentation by an interactive music player. Flag value is 0x000002.
-Track_in_non_interaction_movie: Indicates that the track is used in the presentation by 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.

Save preset parameters in'trak ' existing in'moov ' using MPEG-4 BIFS (Binary format For Scene)

According to an embodiment of the present invention, preset parameters 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 presets, default preset ID, etc.) representing the overall information of the preset among the preset parameters may be stored in'prco' described above, or a newly defined node in BIFS is used. Can also be saved.

When storing the first preset parameter by using a newly defined node in the BIFS, a node interface may be represented as shown in Table 31. In Table 31,'PresetSound' means a newly defined node.

node interface

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

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' field and the'default_preset_ID' field follow the semantics of'prco' described above.

In addition, among the preset parameters, a preset parameter indicating volume information may be stored by appropriately combining an AudioMix node and a WideSound node.

In addition, among the preset parameters, a preset parameter indicating equalization information may be stored using PROTO audioEcho among existing AudioRXProto nodes, or may be stored using a newly defined node in BIFS.

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

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

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

The'children' field means outputs of nodes that can be mixed at the same time. Examples of the'child' field include AudioSource and AudioMix.

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

'removeChildren' means a list of nodes to be deleted from the'children' field.

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

The'params' field is a matrix of [numInputs × 3·numFreqBands], and each row stores equalization parameters (equalization information) of a frequency band 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' denotes the number of frequency bands,'centerFreq' denotes a center frequency in each frequency band,'bandwidth' denotes a bandwidth in each frequency band, and'gain' denotes a gain value for each frequency band.

That is, each row of the'params' field is composed as follows.

numFreqBands = params [0]

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

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

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

Save preset parameters in xml in'meta' using MPEG-4 LASeR (Lightweight Application Scene Representation)

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

In this case, a preset parameter may be stored by newly defining an element and an attribute as shown in Table 34.

i. presetContainer element

semantics

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

attribute

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

ii. preset element

semantics

The same information as the'prst' described above is stored in the preset element. Also, the preset element exists as children of the presetContainer element.

attribute
The syntax and semantics of'prst' of ISO-BMFF described above are used as attributes.

Etc

According to an embodiment of the present invention, when preset information is already described in a file comprising a plurality of audio objects, the object-based audio content format is referred to, or the preset information is used in an object-based audio content format. Preset parameters can be saved in an object-based audio content format by transforming them to fit.

In addition, according to an embodiment of the present invention, when preset information is described in a file configured in the form of a scene expression language such as BIFS or LASeR, it is referred to in an object-based audio content format, or the preset information is referred to as an object. Preset parameters can be stored in the form of an object-based audio content format by modifying to fit the underlying audio content format schema.

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

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

7 and 8 are diagrams illustrating 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, description information is metadata for expressing an album (hereinafter referred to as'album level metadata'), and metadata for expressing a song (hereinafter, ' song level metadata'), and metadata for expressing a track (hereinafter, referred to as'track level metadata') may be included. Here, if each metadata is summarized, it can be expressed as 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 metadata can be classified into two types: "metadata for expressing songs and tracks" and "metadata for expressing albums". Here, "metadata for expressing an album" represents common information about songs stored in the same album among songs stored in object-based audio content.

Album level metadata may be stored in'ftyp'/'meta', song level metadata may be stored in'moov'/'meta', and track level metadata may be stored in'moov'/'trak'/'meta', respectively. In summary, it can be expressed as Table 36.

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

The format of the ISO-based object-based audio content file format structure in which the metadata is stored may be represented as shown in FIGS. 7 and 8. 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).

In more detail,'CreationInformation','MediaInformation', and'Semantics DS' of MPEG-7 may be used for track level metadata and song level metadata. For album level metadata,'ContentCollection DS' and'CreationInformation DS' of MPEG-7 can be used. This is because album level metadata contains structure information on a plurality of songs included in one album.

In summary, it can be expressed as Tables 37 to 39.

Tag Name Semantics CreationInformation/Creation/Creator[@type="Instrument"] The title of the track -CreationInformation/Creation/Creator[Role/@herf="urn:mpeg:mpeg7: RoleCS:2001:PERFORMER"]/Agent[@xsi: type = "PersonType"] / Name /{FamilyName, GivenName}(Arist name)
-CreationInformation/Creation/Creator[Role/@herf= "urn:mpeg: mpeg7: RoleCS:2001:PERFORMER"]/Agent[@xsi: type = "PersonGroupType"] /Name/(Group Name) The name of a musician who is performing instruments, 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 -CreationInformation/Creation/Creator[Role/@herf="urn: mpeg: mpeg7: RoleCS:2001:PERFORMER"]/Agent[@xsi: type = "PersonType"] / Name /{FamilyName, GivenName}(Arist name)
-CreationInformation/Creation/Creator[Role/@herf= "urn: mpeg: mpeg7: RoleCS:2001:PERFORMER"]/Agent[@xsi: type = "PersonGroupType"] /Name/(Group Name) 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 -ContentCollection/CreationInformation/Creation/Creator[Role/@href="urn: mpeg:mpeg7:RoleCS:2001:PERFORMER"]/Agent[@xsi:type = "PersonType"]/ Name /{FamilyName, GivenName}(Arist name)
-CreationInformation/Creation/Creator[Role/@herf= "urn:mpeg: mpeg7: RoleCS:2001:PERFORMER"]/Agent[@xsi: type = "PersonGroupType"] /Name/(Group Name) 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 a song. When the object-based audio content is played back, if the audio content-related information is displayed on the audio content playback device, it is more efficient. Object-based audio services can be provided to users. Audio content related information may be changed according to the playback time of the object-based audio content. Hereinafter, information related to audio content that changes according to the playback time will be referred to as'Timed Text'.

In the object-based audio content file format, Timed Text can be provided by 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, in the case of providing Timed Text using 3GPP Timed Text, the 3GPP Timed Text may be configured to include a text sample and a sample description.

Here, the text sample may include a text string and a sample modifier, and the sample modifier contains information on how to render the text string.

The text sample is stored as one track (ie, text track) in'mdat' in ISO-BMFF. Saved text samples are synchronized with timed media such as audio tracks using information stored in'stts','stsc', and'stco' in'moov'/'trad'/'mdia'/'minf'/'stbl'. Is reproduced.

In addition, the sample description includes information on how the text is rendered. For example, the sample description includes information on the position of the displayed text, the color of the text, and the background color. On the other hand, the sample description may be described in'stsd' by extending'SampleEntry' to'TextSampleEntry'.

In the above, a method of generating object-based audio content according to an embodiment of the present invention has been described. 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. 5.

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

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

In this case, the object-based audio content is generated according to the method of generating the object-based audio content described in FIG. 3.

In step 520, an output audio signal is generated by mixing a plurality of audio objects based on at least one preset.

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

As mentioned above, when the default preset ID value included in the preset parameter has a value of '0', the object according to the preset stored in the bitstream of the audio objects encoded and stored using multi-object audio compression technology (SAOC) The base audio content can be played. Hereinafter, the process of playing the object-based audio content based on the preset stored in the bitstream of the audio objects encoded and stored with multi-object audio compression technology (SAOC) will be described in detail with reference to FIG. I will explain.

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 a preset exists in the object-based audio content.

When it is determined that the preset exists in step 610 (that is, it is determined that'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 that the default preset ID exists in step 620 (that is, it is determined that'default_preset_ID' has a value other than '0'), in step 630, a preset having the same preset ID as the default preset ID is Based on the mixing of a plurality of audio objects to generate an output audio signal, step 670 reproduces the output signal to be generated.

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

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

When it is determined in step 650 that a preset exists in the SAOC bitstream, in step 670, an output audio signal is generated by mixing a plurality of audio objects based on the first preset included in the SAOC bitstream, and step 670 ) Plays the output signal to be generated.

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

Further, the embodiments of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in 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 specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Examples of program instructions such as magneto-optical, ROM, RAM, flash memory, etc., can be executed by a computer using an interpreter as well as machine code such as that made by a compiler. Contains high-level language code. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the embodiments of the present invention, and vice versa.

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but this is provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , If a person of ordinary skill in the field to which the present invention belongs, various modifications and variations are possible from these descriptions. Therefore, the spirit of the present invention is limited to the described embodiments and should not be defined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later fall within the scope of the spirit of the present invention. .

Claims (9)

delete In the object-based audio content generation device,
The object-based audio content generation device,
A processor that generates at least one preset related to a plurality of audio objects, and generates object-based audio content including the plurality of audio objects and the at least one preset,
Including,
The object-based audio content,
(i) The type of output channel, which is information on which channel the object-based audio content is played through, (ii) the number of input channels, (iii) the number of output channels according to the type of output channel, (iv) input Object-based audio content generation device including a volume gain between a channel and an output channel. The method of claim 2,
The preset is editable by the user,
The object-based audio content generation apparatus is provided according to a media file format including track information. In the object-based audio content reproducing apparatus,
The object-based audio content reproducing apparatus,
A processor for extracting at least one preset and a plurality of audio objects related to a plurality of audio objects from object-based audio content, and reproducing the object-based audio content using the preset and audio objects,
The object-based audio content,
(i) The type of output channel, which is information on which channel the object-based audio content is played through, (ii) the number of input channels, (iii) the number of output channels according to the type of output channel, (iv) input Object-based audio content reproduction apparatus including a volume gain between a channel and an output channel. The method of claim 4,
The preset is editable by the user,
The object-based audio content reproducing apparatus is provided according to a media file format including track information. In the object-based audio content generation method,
Generating at least one preset associated with a plurality of audio objects; And
Generating object-based audio content including the plurality of audio objects and the at least one preset
Including,
The object-based audio content,
(i) The type of output channel, which is information on which channel the object-based audio content is played through, (ii) the number of input channels, (iii) the number of output channels according to the type of output channel, (iv) input Object-based audio content generation method including a volume gain between a channel and an output channel. The method of claim 6,
The preset is editable by the user,
The object-based audio content is provided according to a media file format including track information. In the object-based audio content playback method,
Extracting at least one preset and a plurality of audio objects related to the plurality of audio objects from the object-based audio content; And
Reproducing the object-based audio content using the preset and audio objects
Including,
The object-based audio content,
(i) The type of output channel, which is information on which channel the object-based audio content is played through, (ii) the number of input channels, (iii) the number of output channels according to the type of output channel, (iv) input Object-based audio content reproduction method including a volume gain between a channel and an output channel. The method of claim 8,
The preset is editable by the user,
The object-based audio content is provided according to a media file format including track information.

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