JP2003066994A - Apparatus and method for decoding data, program and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a decoding process for multi-object data including audio data in response to the processing capability of a decoding apparatus. SOLUTION: When a load factor of a CPU by the decoding process increases, an object determining part 6 checks whether there are three or more multi-object data (the data under the decoding process). If three or more, two of the multi- object data are arbitrarily selected. After two of the multi-object data are selected, the object determining part 6 refers to criteria and priority and controls the decoding (reproducing) process of the multi-object data with the lowest priority for decoding. The criteria indicate which item has the highest priority among a scalability function, data contents, data size and volume. The priority indicates which item is prioritized and controlled to be decoded among human voice and music.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data decoding device, a data decoding method, a program, and a storage medium for decoding multi-object data including one or more object data.

[0002]

2. Description of the Related Art Information handled by multimedia is enormous and diverse, and it is necessary to process such information at high speed in order to put multimedia into practical use. In order to process information at high speed, data compression / decompression technology is essential. As such a data compression / decompression technology, there is an “MPEG” method. Above all MPEG
-4 is a more general-purpose encoding method that achieves low bit rate and multiple functions. MPEG-4 is mainly composed of three parts. Part 1 of "MPEG-4 System" (ISO /
IEC 14496 Part1) specifies the multiplexing structure and synchronization method for video and audio data. In Part 2, "MPEG-4 Visual" (ISO / IEC 14496 Part2),
A high-efficiency coding method of video data and a format of video data are specified. Part 3 “MPEG-4 Aud
"io" (ISO / IEC 14496 Part3) specifies a high-efficiency encoding method for audio data and an audio data format.

As described above, in the case of handling multi-object data (moving image data, music data, voice data, etc.) in MPEG-4, there are many situations in which various kinds of encoded data are processed at the same time, and the CPU load factor is high. Needless to say, has a great influence.

For example, since the composite image is composed of a plurality of images, the load of decoding processing is larger than that of a single image. In the software decoding process using a general-purpose CPU, the size and number of images that can be decoded within a predetermined time are limited by the processing capacity of the CPU. In addition, decoding of a moving image requires decoding within a predetermined time, but if decoding cannot be performed within the time, problems such as display delay and input buffer overflow occur.

From the above, in decoding a composite image, it is important to control the decoding process according to the processing capability of the decoding device. As a method for solving such a problem, the invention disclosed in JP-A-10-234014,
By setting a priority for a multiplexed signal such as a composite image (for example, the size of a target image) and performing a decoding process from a coded signal with a higher priority, the capability of the decoding means is multiplexed. This is a method in which the decoding process can be adaptively controlled so that the influence on the image is minimized even when it is not sufficient to decode all the encoded signals that have been processed.

[0006]

However, in the technique described in the above publication, the image data such as the composite image is taken into consideration, but the priority order regarding the audio data is not set. For example, while decoding (playing) music encoded data A as BGM,
In the situation where the audio coded data is decoded (reproduced), the priority order for the object is not set, so that it is not a general purpose in controlling the decoding process according to the processing capability of the decoding device. Absent.

The present invention has been made in view of the above problems, and an object of the present invention is to enable multi-object data including audio data to be decoded according to the processing capability of a decoding device. To do.

[0008]

In order to achieve the object of the present invention, for example, a data decoding device of the present invention has the following configuration.

That is, in a data decoding apparatus for decoding multi-object data including one or more object data, a priority item among the items relating to the object data and a decoding judgment of the object data corresponding to the item are set. A data decoding device comprising: setting means; and decoding control means for controlling the decoding means for decoding the object data according to the decoding judgment set by the setting means.

In order to achieve the object of the present invention, for example, the data decoding device of the present invention has the following configuration.

That is, a data decoding apparatus for decoding multi-object data including one or more object data, the detecting means detecting the load of the decoding processing, the decoding means for decoding the object data, and the detecting means. When the load of the decoding process detected by the means is large, the data decoding device is provided with a decoding control means for controlling the decoding means so as to finish the decoding of the object data having the largest load.

In order to achieve the object of the present invention, for example, the data decoding device of the present invention has the following configuration.

That is, a data decoding apparatus for decoding multi-object data including an audio bit stream, wherein a priority item among audio-related items and setting means for setting a decoding determination of the audio bit stream corresponding to the item. And a decoding control unit that controls the decoding unit that decodes the audio bitstream according to the decoding determination set by the setting unit.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, referring to the attached drawings, a data decoding device of the present invention will be described in detail according to a preferred embodiment applied to a decoding device for decoding encoded multimedia data.

[First Embodiment] FIG. 1 is a block diagram showing the basic arrangement of a data decoding apparatus according to this embodiment. In the figure, reference numeral 1 is an input device to which multi-object data such as an MPEG-4 video bit stream and an audio bit stream is input. 2 to 4 are
An audio decoding buffer that stores an audio bit stream input from the input device 1. The number of buffers is three in the figure, but is limited because it depends on the processing capability of a CPU (not shown). is not. The same applies to the video decoding buffer 5 that stores the video bitstream input from the input device 1.

Further, the data decoding apparatus according to the present embodiment acquires the attributes (file format, file size, etc.) of the object (audio bitstream, video bitstream) from the audio bitstream or video bitstream, and the CPU An object determination unit 6 that sets the decoding priority order of objects according to the load status, and a selector 7 that selects a decrypted object from the data set by the object determination unit 6 are provided. Also, a decoder 8 for decoding the object selected by the selector 7, an audio decoder 10 and a moving image decoder 11 provided inside the decoder 8 are provided.
And a CPU load information detection unit 11 for detecting the load condition (load factor) of the CPU 15 due to the decoding process of the object from the decoder 8, and output devices 12, 13 for outputting the decoded object.

Here, the audio bit stream is
AAC (Advanced Audio Coing) and TwinVQ (Tranform), which are encoding methods for music adopted in MPEG-4 audio
domain Weighted INterleave Vector Quantization),
CELP (Code Ex), which is an encoding method for speech (for voice)
cited Linear Prediction) and HVXC (Harmonic Vector eXc)
It is the data that has been encoded by itation coding, etc.

The number of audio decoders 9 provided inside the decoder 8 is not limited as long as it is a decoder conforming to MPEG-4 audio.

The multi-object data input to the input device 1 may be not only an audio bit stream and a video bit stream alone, but also a multiplexed stream including both audio and video. The basic configuration of the data decoding device in that case is shown in FIG. 2 as a block diagram. The same parts as those in FIG. 1 are designated by the same numbers.

The input multiplexed stream is the MP of FIG.
It is transmitted to the EG-4 system decoder a, and the time axis of each data (audio, video) is synchronized with the time axis inside the system decoder to synthesize a scene,
It is output (reproduced) from the output device b. Also, M
When separating the multiplexed audio data and video data, the PEG-4 system decoder a transmits object information (contents of multiplexed and separated audio data) to the object determination unit 6. Also, MP
EG-4 System Decoder a is ISO / IEC 14496 part 1 (M
The one specified by PEG-4 Systems) is used.

Next, referring to FIG.
Will be described in detail. FIG. 4 shows the object determination unit 6
3 is a block diagram showing the internal configuration of FIG. User setting section 6
At 0, the decryption priority contents input by the user are
It is saved in a table format as shown in FIG. Decoding priority contents input by the user are: -Scalability function presence / absence-Data contents (human voice or music?)-Data size (size of code amount) -Which item of volume volume has priority? It includes information indicating whether or not (setting of judgment criteria). Further, for example, when the highest priority item of the determination standard is “data content”, the data content also includes decoding determination information which occupies whether voice is prioritized or music is prioritized (priority setting). In the figure, as the decoding determination information, ◯ indicates that decoding is performed, and × indicates that decoding is not performed.

Further, these setting processes are performed by the judgment standard setting unit 62 and the priority order setting unit 61, and a memory (not shown) provided in each device (the judgment standard setting unit 62 and the priority order setting unit 61). Stored in. Further, in the judgment criterion setting unit 62, the audio decoding buffer 2 of FIG.
3,4, the data transmitted from the video decoding buffer 5 is acquired, and the multi-object data (copied by the decoding buffers 2, 3, 4, 5 is copied according to the contents of the table of FIG. 3 set by the user input. The original data (multi-object data input via the input device 1) is transmitted to the decoder 8 via the selector 7 and is subjected to normal decoding processing. However, regarding the video bit stream, the decoding priority is determined only by the scalability function and the data size.

First, when the scalability function is set to the highest priority item of the determination standard by the user setting, the multi-object data (audio bit stream, video bit stream, or both) is sent from the determination standard setting unit 62 by the header. Reading unit 63
Transmitted to. As for the audio bitstream, the header reading unit 63 reads the header stream of the audio bitstream (the header stream of the video bitstream is not read). From the read header stream (acquiring the audio codec type), the scalability detection unit 64 detects the presence or absence of the scalability function. Also, the priority setting unit 61 transmits the decoding determination content (see FIG. 3) corresponding to the presence or absence of the scalability function to the scalability detection unit 64. The decoding determination content of FIG. 3 defines that the decoding is performed when the scalability function is provided and the decoding is not performed when the scalability function is not provided. Then, each information is transmitted to the decoder operation unit 70 together with the presence or absence of the scalability function.

Next, when the data content is set to the highest priority item of the judgment standard by the user setting, the multi-object data is transmitted from the judgment standard setting unit 62 to the header reading unit 63 as in the case of the scalability function. To be done. As for the audio bitstream, the header reading unit 63 reads the header stream of the audio bitstream (the header stream of the video bitstream is not read). From the read header, the data content detection unit 65 detects the data content (human voice or music?) Of the audio bitstream (only the audio bitstream is the target). In addition, the priority setting unit 61 transmits the decoding determination content (see FIG. 3) corresponding to whether the data content is human voice or music to the data content detection unit 65. The decoding determination content of FIG. 3 defines that the decoding is performed in the case of human voice and the decoding is not performed in the case of music. And
Decoder operation unit 7 is provided with each information together with the data content.
0 is transmitted.

Next, when the data size is set to the highest priority item of the judgment standard by the user setting, the multi-object data is transmitted from the judgment standard setting unit 62 to the data size detection unit 66. Data size detector 6
In 6, the file size (code amount) of each of the video bit stream and the audio bit stream forming the multi-object data is detected. In addition, the priority setting unit 61 detects data size detection (see FIG. 3) corresponding to the size of the data size (determines the size of the data size based on whether the data size is larger or smaller than a predetermined threshold). It is transmitted to the unit 66. In the decoding determination content of FIG. 3, when the data size is large, the decoding is not performed,
It is defined that decoding is performed when the data size is small. Then, each information is transmitted to the decoder operation unit 70 together with the detected data size.

Next, when the sound volume is set as the highest priority item of the judgment standard by the user setting, the multi-object data is judged from the judgment standard setting unit 62 to the sound volume detection unit 67.
Be transmitted to. The volume detector 67 detects the volume of each object (only the audio bitstream is the target) from the decoded original data (determines whether the volume is larger or smaller than a predetermined threshold). It In addition, the priority level setting unit 61 transmits the decoding determination content (see FIG. 3) corresponding to the volume level to the volume level detection unit 67. The decoding determination content of FIG. 3 defines that the decoding is performed when the volume is high and the decoding is not performed when the volume is low. Then, each information is transmitted to the decoder operation unit 70 together with the volume.

However, in all the above cases, the multi-object data (operating object) is 3
When there are two or more, the criterion setting unit 62 selects and transmits appropriate two object data from three or more multi-object data, and the decoding priority order is determined for the two object data. It

Next, the decoder operation unit 70 will be described. First, when the scalability function is set as the highest priority item of the determination standard by the user setting, it is operating at the present time based on the two pieces of information (whether the scalability function is present or not and decoding determination) transmitted from the scalability detection unit 64. Information on the content for controlling the decoding process of the object data is transmitted to the selector 7 in FIG. For example, the content information is such that the processing content is switched so that the multi-object data (audio bit stream or video bit stream) having the scalability function is decoded in a lower layer.

Further, when the data content is set as the highest priority item of the determination standard by the user setting, two pieces of information (data content, data content,
From the decoding determination), the information of the content for controlling the decoding process of the multi-object data currently operating is transmitted to the selector 7 of FIG. For example, the content of the multi-object data (audio bitstream) is music data, but the decoding process is terminated.

When the data size is set as the highest priority item of the judgment standard by the user setting, the two information (data size, decoding judgment) transmitted from the data size detection unit 66 is used to operate at the present time. Information that controls the decoding process of multi-object data
It is transmitted to the selector 7 of FIG. For example, the data having the larger size of the multi-object data (audio bit stream or video bit stream) is information such that the decoding process is terminated.

When the volume is set as the highest priority item of the determination standard by the user setting, the volume detecting unit 67
From the two pieces of transmitted information (volume level, decoding determination), information about the content for controlling the decoding process of the multi-object data currently operating is transmitted to the selector 7 in FIG. For example, the data of the multi-object data (audio bit stream) with the lower volume is information having the content of ending the decoding process.

In addition, in the decoder operation unit 70, in parallel with the above-described processing operation, the determination standard setting unit 62 outputs information that two of three or more objects are selected from the determination standard setting unit 62. get. When the processing operation described above is completed, the decoder operation unit 70 refers to the CPU load information transmitted from the automatic setting unit 69, and sets the CP
When the U load factor still shows a high value (for example, when the CPU load factor exceeds a predetermined threshold value), the determination criterion setting unit 62 is instructed to repeat the above processing operation.

Next, the CPU load information acquisition unit 68 and the automatic setting unit 69 will be described. The CPU load ratio for each multi-object data detected by the CPU load information detection unit 11 of FIG. 1 is transmitted to the CPU load information acquisition unit 68 inside the object determination unit 6. The load factor acquired by the CPU load information acquisition unit 68 is transmitted to the automatic setting unit 69. This processing shall always be performed in real time.

The automatic setting unit 69 transmits to the decoder operation unit 70, as the decoding priority, for example, the information that the multi-object data having the scalability function is to be decoded with a lower layer. The decoder operation unit 70 transmits the information transmitted from the automatic setting unit 69 to the selector 7 of FIG. 1 and commands it to control the decoding process of the multi-object data currently operating. After controlling the decoding process of the multi-object data via the selector 7 and the decoder 8, when the CPU load factor still shows a high numerical value, the information is transmitted again to the automatic setting unit 69 inside the object determining unit 6. Then, the decoding process of the multi-object data is controlled with respect to the data size of the object having the second highest decoding priority after the scalability function, for example. Here, the decoding process of multi-object data having a large data size is ended. These processes control the decoding process of the multi-object data in the order of the data content of the object (human voice> music) and the volume of the object (high> low) in accordance with the decoding priority. When performing these processes, the user does not input the data of the contents indicating the decoding priority described above to the user setting unit 60, but needs to input the data of the contents of the above processing by the automatic setting unit 69. There is. In addition, the automatic setting unit 69 can simply end the decoding process of the multi-object data indicating the numerical value with the highest CPU load factor. When performing this processing operation, the user does not need to input anything to the user setting unit 60. The method for identifying the multi-object data indicating the highest CPU load factor is not particularly limited, but for example, referring to the file size of the multi-object data, the larger the size, the higher the CPU load factor. It may be estimated.

In the processing carried out by the object determining unit 6, when the target multi-object data includes a multiplexed stream, the decoding processing of the multiplexed stream is given the highest priority. However, in the case of “terminating the decoding process of the multi-object data indicating the highest CPU load factor” described above, either the audio bit stream or the video bit stream in the multiplexed stream is decoded. It is also conceivable to control the process. Further, the information regarding the multiplexed stream is sent by the MPEG-4 system decoder a to the criterion setting unit 62 of FIG.

Next, the header reading unit 63 will be described in detail. Here, ISO / IEC 14496 part 3 (MPEG-4
Audio) header stream (AudioSpecificC
Get the audio codec type from onfig ()). In the specification of ISO / IEC 14496 part 3 (MPEG-4 Audio), AudioSpecificConfig () is defined by the following syntax. Syntax AudioSpecificConfig () {AudioObjectType samplingFrequencyIndex if (samplingFrequencyIndex == 0xf) samplingFreqency channelConfiguration if (AudioObjectType == 1 || AudioObjectType == 2 || AudioObjectType == 3 || AudioObjectType == 4 || AudioObjectType == 6 || AudioObjectType = = 7) GASpecificConfig () if (AudioObjectType == 8) CelpSpecificConfig () if (AudioObjectType == 9) HvxcSpecificConfig () if (AudioObjectType == 12) TTSSpecificConfig () if (AudioObjectType == 13 || AudioObjectType == 14 || AudioObjectType == 15) StructuredAudioSpecificConfig ()} By reading the parameter of AudioObjectType of the above syntax, the type of audio codec specified by MPEG-4 can be acquired.

GASpecificConfig () represents AAC and TwinVQ encoding, and CelpSpecificConfig () represents CELP encoding and Hvxc.
SpecificConfig () is HVXC encoded, TTSSpecificConfig ()
Is TTS (Text To Speech) encoding, StructuredAudioSpecif
icConfig () represents Structured Audio encoding.
A description of each codec is omitted here.

In this way, the header reading unit 63 acquires the type of audio codec by reading the AudioOjectType parameter of the header stream, and the scalability detecting unit 64 and the data content detecting unit 6 are acquired.
5 transmits that information.

Next, the selector 7 and the decoder 8 will be described. Two processes are performed in the selector 7. First, as a first process, the multi-object data input to the input device 1 and accumulated in the audio buffers 2, 3, 4 and the moving image buffer 5 is stream-transmitted to the decoder 8 in real time. As the second processing, for the multi-object data transmitted from the audio buffers 2, 3, 4 and the moving image buffer 5, according to the information regarding the decoding priority order transmitted from the decoder operation unit 70 of the object determination unit 6, Control stream transmission.

The decoder 8 decodes the multi-object data transmitted from the selector 7 in real time and outputs (reproduces) it via the output devices 12 and 13.

Also, the MPEG having the structure shown in FIG.
In a data decoding device incorporating a -4 system decoder also, the multiplexed stream is decoded in real time and output (reproduced) via the output device b in FIG.

The CP in the CPU load information detector 8
As a U load factor detection technique, Japanese Patent Laid-Open No. 07-044423
The technique disclosed in Japanese Patent Publication is used.

FIG. 6 is a flow chart showing the outline of the operation from the increase of the CPU load factor (incapable of decoding within a predetermined time) to the decoding processing based on the decoding priority. First, when the CPU load information detection unit 11 detects that the CPU load factor due to the decoding process has increased (step S61), the information is sent to the object determination unit 6. When the object determination unit 6 receives this information,
Decoding priority (whether the user has made any settings in advance,
Whether or not) is referred to (step S62). Here in advance
If the decryption priority is set by the user or the automatic setting is performed (step S6)
3), multi-object data (data that is in the process of being decrypted) in the judgment criterion setting unit 62 of the object judgment unit 6
Is three or more, and if there are three or more, two of them are appropriately selected (step S64). In the two cases, the selection process is not performed.

If the user does not set the decoding priority or the automatic setting is not made (step S63), the decoding processing of the multi-object data having the highest CPU load factor is ended (step S70). . After selecting two pieces of multi-object data, refer to the determination criteria (which item of the scalability function, the data content, the data size, and the volume has the highest priority?) (Step S65) and the priority order (human voice, music Which is prioritized and which decoding process is controlled?) Is referred (step S66). After passing through these processes, the decoding (reproduction) process of the multi-object data with the lowest decoding priority is controlled (the decoding process is ended, the decoding is performed with a low layer, etc.) (step S6).
7). After the decoding process is controlled, the CPU load factor is referred to again (step S68), and when the CPU load factor indicates a high value (step S69),
The processing after step S64 is repeated.

The program according to the above flow chart is stored in a memory (not shown) in the data decoding apparatus according to the present embodiment, and is read and executed by a CPU (not shown). Each unit shown in FIG. 2 is controlled to perform the above-described processing.

[Second Embodiment] In the first embodiment,
The data decoding device that controls the decoding of the audio bitstream and the video bitstream has been described. In the present embodiment, the same decoding control as in the first embodiment can be performed by executing the decoding control program for the audio bit stream and the video bit stream (the program according to the flowchart shown in FIG. 6). Such computers will be described below.

FIG. 5 is a block diagram showing the basic configuration of a computer in this embodiment which functions as a data decoding device. 501 is a CPU, which is a RAM 502 or a ROM 50.
The program and data stored in 3 are read to control the entire computer, and the processing according to the flow chart shown in FIG. 6 is performed. In that case, the RAM 50
The program in accordance with the flowchart shown in FIG. 6 is loaded in No. 2.

A RAM 502 has an area for storing programs and data loaded from the external storage device 504 and the storage medium drive 509, and the CPU 501.
It also has a work area that is used when each process is performed.

A ROM 503 stores programs for controlling the entire computer, setting data, and the like. Fifty
An external storage device 4 such as a hard disk drive can store programs (for example, programs according to the flowchart shown in FIG. 6) installed from the storage medium drive 509 and data (for example, multi-object data). If the size of the work area used by the CPU 501 exceeds the size of the RAM 502, this work area can be provided as a file.

Reference numerals 505 and 506 denote a keyboard and a mouse, which are used as pointing devices, respectively, and can input the above-mentioned decoding priority order to the computer. Reference numerals 57 and 508 denote display devices and speakers used as output devices in FIGS. 1 and 2, and the display device 507 is composed of a CRT, a liquid crystal screen, or the like, and can display a decoded still image, moving image, or the like. The speaker 508 can output the decoded voice and music.

A storage medium drive 509 is a CD-RO.
A program, data, etc. are read from a storage medium such as M or DVD and output to the external storage device 504, RAM 502, or the like. A bus 510 connects the above-mentioned units.

A computer having the above configuration is shown in FIG.
Load the program according to the flowchart shown in
It is obvious that the multi-object data read from the external storage device 504 or the storage medium drive 509 is subjected to the decoding control to function as the data decoding device of the first embodiment.

[Other Embodiments] As described above, the object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the embodiment to a system or apparatus, and to provide a computer of the system or apparatus ( Needless to say, this is also achieved by the CPU or MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD
-ROM, CD-R, magnetic tape, non-volatile memory card, RO
M or the like can be used.

Further, by executing the program code read by the computer, not only the functions of the above-described embodiment are realized, but also the OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that this also includes the case where the above) performs a part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, based on the instruction of the program code, , The CPU provided in the function expansion board or function expansion unit performs some or all of the actual processing,
It goes without saying that the processing includes the case where the functions of the above-described embodiments are realized.

[0057]

As described above, according to the present invention,
It is possible to enable a decoding process according to the processing capability of the decoding device for multi-object data including audio data. In particular, by setting the decoding priority for the multi-object data including the audio data, it is possible to enable the decoding processing according to the processing capability of the decoding device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a data decoding device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a basic configuration of a data decoding device when multi-object data is a multiplexed bitstream.

FIG. 3 is a diagram showing a table of decoding priority contents.

FIG. 4 is a block diagram showing an internal configuration of an object determination unit 6.

FIG. 5 is a block diagram showing a basic configuration of a data decoding device that functions as a data decoding device according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing an outline of the operation from the increase of the CPU load factor to the execution of the decoding process based on the decoding priority order.

Claims (21)

[Claims] 1. A data decoding device for decoding multi-object data including one or more object data, wherein a priority item among items related to the object data and a decoding judgment of the object data corresponding to the item are set. A data decoding apparatus comprising: setting means; and decoding control means for controlling the decoding means for decoding object data in accordance with the decoding determination set by the setting means. 2. A data decoding apparatus for decoding multi-object data including one or more object data, wherein the detecting means detects a load of the decoding processing, the decoding means for decoding the object data, and the detecting means. When the load of the decoding process detected by the means is large, the data decoding device is provided with a decoding control means for controlling the decoding means so as to finish the decoding of the object data having the largest load. 3. A data decoding apparatus for decoding multi-object data including an audio bit stream, comprising a priority item among audio-related items, and setting means for setting decoding determination of the audio bit stream corresponding to the item. And a decoding control unit that controls the decoding unit that decodes the audio bitstream according to the decoding determination set by the setting unit. 4. A multiplexed stream decoding means for separating the multiplexed stream into a plurality of bit streams, decoding each of the separated bit streams, and synchronously outputting the decoded respective data, The data decoding device according to claim 3. 5. The multiplexed stream decoding means is MP
EG-4 system decoder, ISO / IEC 14496 pa
The data decoding apparatus according to claim 4, wherein the data decoding apparatus is defined by rt 1 (MPEG-4 Systems). 6. The decoding control means controls the decoding means so as to unconditionally decode the multiplexed stream, according to any one of claims 3 to 5. The described data decoding device. 7. The detection means for detecting the load of the decoding processing is further provided, and when the load of the decoding processing detected by the detection means is large, the decoding control means sets the setting means by the setting means. The data decoding device according to claim 3, wherein the decoding means is controlled based on a decoding determination corresponding to an item having a lower priority than the item. 8. The decoding means is a decoder compliant with MPEG-4 audio.
The data decoding device according to. 9. If, among the items related to the audio, the scalability function is given the highest priority by the setting means, the decoding control means refers to the header of the audio bitstream to check the scalability function of the audio bitstream. The data decoding apparatus according to claim 3, wherein the decoding unit is controlled by using information regarding presence / absence and a decoding determination corresponding to the highest priority item set by the setting unit. 10. The data decoding apparatus according to claim 9, wherein the decoding control unit controls the decoding unit to perform decoding processing on the audio bitstream in a lower layer. 11. Among the items related to the audio,
When the data content is set as the highest priority item by the setting unit, the decoding control unit refers to the header of the audio bitstream, and information regarding whether the data content of the audio bitstream is human voice or music, and the setting The data decoding apparatus according to claim 3, wherein the decoding means is controlled by using a decoding determination corresponding to the highest priority item set by the means. 12. Among the items relating to the audio,
When the data size is set as the highest priority item by the setting unit, the decoding control unit detects the file size of the audio bitstream and corresponds to the detected file size and the highest priority item set by the setting unit. The data decoding device according to claim 3, wherein the decoding means is controlled by using a decoding determination. 13. Among the items related to the audio,
When the volume is set as the highest priority item by the setting unit, the decoding control unit detects the volume from the audio bit stream decoded by the decoding unit, and the detected volume and the highest priority item set by the setting unit. The data decoding apparatus according to claim 3, wherein the decoding means is controlled by using a decoding determination corresponding to. 14. The audio bitstream comprises:
The data decoding device according to any one of claims 3 to 13, wherein the data decoding device is a bit stream encoded according to MPEG-4. 15. A data decoding method for decoding multi-object data including one or more object data, wherein a priority item among items related to the object data and a decoding determination of the object data corresponding to the item are set. A data decoding method, comprising: a setting step; and a decoding control step of controlling decoding of object data according to the decoding determination set in the setting step. 16. A data decoding method for decoding multi-object data including one or more object data, comprising a detecting step of detecting a load of the decoding processing, a decoding step of decoding object data, and the detecting step. And a decoding control step of controlling the decoding step so that the decoding of the object data having the largest load is ended when the decoding processing load detected in the step is large. 17. A data decoding method for decoding multi-object data including an audio bitstream, comprising a priority item among audio-related items and a setting step for setting a decoding determination of an audio bitstream corresponding to the item. And a decoding control step of controlling decoding of the audio bitstream in accordance with the decoding determination set in the setting step. 18. A multiplexed stream decoding step of separating a multiplexed stream into a plurality of bit streams, decoding each of the separated bit streams, and outputting each decoded data in synchronization with each other. The data decoding method according to claim 17. 19. A detection process for detecting the load of the decoding process, wherein when the load of the decoding process detected in the detection process is large, the decoding control process sets the decoding process in the setting process. 18. The data decoding method according to claim 17, wherein the decoding step is controlled on the basis of a decoding determination corresponding to an item having a lower priority than the item. 20. A program for executing the data decoding method according to any one of claims 15 to 19. 21. A computer-readable storage medium that stores the program according to claim 20.