KR20130119888A - Apparatus for processing video data having interdependencies - Google Patents

Abstract

An apparatus for processing video data having interdependencies is provided. The present invention generates an Media Processing Unit (MPU) by receiving an encapsulation of an Access Unit (AU), generating an MMT Asset based on the MPU, and generating an MMT based on the MMT asset. Generating a packet and transmitting the MMT packet over a network.

Description

A device for processing video data having a mutual dependency {APPARATUS FOR PROCESSING VIDEO DATA HAVING INTERDEPENDENCIES}

The present invention relates to a video data processing apparatus, and more particularly, to a video data processing apparatus including video data having mutual dependencies in different objects according to each dependency.

In the video standard, an access unit is one that can be decoded on its own.

For example, in the "Advanced Video Coding (AVC) and Scalable Video Codec (SVC) standard", an access unit is "a set of network abstraction layer (NAL) units including exactly one primary coded picture". It is defined as Here, the primary coded picture includes everything from the base layer of the SVC to a specific enhancement layer, and means whole data capable of decoding one picture.

As another example, the HEVC standard defines an access unit as "a set of NAL units capable of decoding one video in decoding order." This means that all data for constituting one image in the access unit must be included as a whole.

As another example, in the MPEG-2 System Standard for SVC (In MPEG2 System Standard for SVC), the access unit is referred to as the "dependency representation" of the data portion for each enhancement layer of the SVC. In order to configure the AU, it is specified that the dependency representation of the base layer to the dependency representation of the enhancement layer up to a specific layer is arranged in the order of the hierarchy relationship. This means that the access unit of the SVC should include all data from the base layer to the enhancement layer required.

That is, the definition of an access unit configured as a layer such as SVC video and including video data may decode one picture including all of the base layer and a specific enhancement layer. Yes ".

On the other hand, research is underway to reduce the overhead of the encapsulation layer (E-layer) that is responsible for packetization, fragmentation, synchronization and multiplexing of the media transmitted in the MMT system. With the recent demand for high quality and high speed media services, it is necessary for the current MMT system to encapsulate and send a large amount of timing information required for synchronization of media data such as pictures or slices to the receiver. It does not meet the situation.

The present invention proposes a header structure for indicating MPUs that depend on each other in order to reflect the hierarchical structure of the SVC video in an MPU structure that is a basic unit including one or more AUs.

The technical problem of the present invention is that when the video data having interdependencies such as Scalable Video Coding (SVC) or Multiview Video Coding (MVC) is stored in a file format, Branches provide for the operation of including individual data into different entities.

According to an aspect of the present invention, an apparatus for processing video data having a mutual dependency includes an encapsulation unit configured to receive an access unit (AU) and encapsulate it to generate a media processing unit (MPU). A packetizer which generates an MMT asset based on the MPU, generates an MMT packet based on the MMT asset, and a transmitter that transmits the MMT packet through a network, wherein the MPU has a dependency relationship with another MPU. And a dependency indicator that is exclusively allocated between the dependency indicator indicating the presence or absence of the dependency property and the MPU with the dependency.

According to the present invention, video data having interdependencies can be included in different entities.

1 is a block diagram schematically showing the configuration of an MMT packet transmission apparatus according to an embodiment of the present invention.
2 shows an example of an SVC-based layered video structure according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Also, in order to clearly illustrate the present invention in the drawings, portions not related to the present invention are omitted, and the same or similar reference numerals denote the same or similar components.

The objects and effects of the present invention can be understood or clarified naturally by the following description, and the purpose and effect of the present invention are not limited by the following description.

The objects, features and advantages of the present invention will become more apparent from the following detailed description. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the following, an MMT asset is a logical data entity composed of at least one MPU with the same MMT asset ID or a specific data chunk with a format defined in another standard. The MMT asset is the largest data unit to which the same composition information and transmission characteristics apply.

The MMT packet is a format of data generated or consumed by the MMT protocol.

The MMT payload format is a format for payload of an MMT package or MMT signaling message to be delivered by an MMT protocol or an internet application layer protocol (eg, RTP).

The MMT Processing Unit (MPU) is used in MPEG Media Transport (MMT) and is a unit of a new media bundle that bundles data of a basic unit processed by the system when transferring or archiving media. The MPU is a generic container independent of the media codec and can accommodate at least one AU and information related to additional transmission and consumption. For non-temporal data, the MPU may accept a portion of data that does not fall within the AU range. MPU is encoded media data that can be processed completely and independently. In this context, processing means encapsulation or packetization into an MMT package for transmission.

1 is a block diagram schematically showing the configuration of an MMT packet transmission apparatus according to an embodiment of the present invention. The MMT packet transmission apparatus may include an encapsulation unit 110, a packetization unit 120, and a transmission unit 130.

Referring to FIG. 1, the encapsulation unit 110 receives an i-th access unit (AU) as an input and encapsulates it to generate a media processing unit (MPU). The access unit may be replaced with a media fragment unit (MFU).

According to the present invention, the MPU may include information on dependency with other MPUs and may be indicated by using a dependency indicator or a dependency identifier.

Table 1 below shows an example of the MPU structure including the MPU interdependencies.

Syntax Number of bits Mnemonics mpu () { dependency_indicator 2 bslbf if (dependency_indicator == '10' || dependency_indicator == '11')
{
dependency_identifier
}


TBD

Here, the dependency indicator (dependency_indicator) is an indicator indicating whether or not the MPU has a dependency relationship with another MPU and the characteristics of the dependency relationship.

Table 2 below shows an example of the details of the dependency indicator when the dependency indicator is 2 bits.

Dependency indicator name The details 00 No dependency MPU can decode by itself, no other MPU is needed to decode the MPU 01 Not used N / A 10 Used by other MPUs The MPU has a dependency on another MPU, which is required for decoding the other MPU.
(I.e., an MPU can decode itself, but without it, another MPU may not be able to decode) 11 Requires other MPUs MPU has dependencies on other MPUs and needs another MPU to decode the MPU

Meanwhile, in Table 1, the dependency identifier (dependency_identifier) is an ID allocated exclusively among MPUs having dependencies therebetween. In this case, the MPUs that depend on each other may exist in a single asset or may exist across a plurality of assets.

The dependency information between each other (eg, which MPU depends on which MPU, the number of MPUs depending on the other), etc. may be provided through another method using the dependency identifier.

Here, the asset is a unit including one or two or more MPUs as a storage unit of the media data, as well as the MPU, and is a unit containing homogeneous media data.

The same media data may mean data composed of the same video codec or audio codec, data composed of the same file format, data composed of the same MPEG2-TS stream, or the like.

Meanwhile, each MPU may include at least one MFU header (MFUH), and the MFUH may include an indicator indicating the number information of the AU (eg, "number_of_au") and an indicator indicating the length of the AU (eg, "au_length") may be further included.

Here, "number_of_au" means the number of AUs that are configured as MFUs in the current MPU. If the corresponding MPU needs another MPU to form one complete AU (eg, if the dependency indicator is '11' in Table 1 above), then "number_of_au" is the portion of each AU that this MPU contains. It means the number of data.

"au_length" means the size of each AU included in the current MPU. If the corresponding MPU needs another MPU to constitute one complete AU (eg, when the dependency indicator is '11' in Table 1 above), "au_length" is partial data of each AU included in the MPU. Means the size.

Meanwhile, the packetizer 120 generates an MMT packet by performing packetization based on the MPU encapsulated by the encapsulation unit 110. The packetizer 120 may generate an MMT asset based on the MPU, and generate an MMT packet based on the MMT asset. The MMT packet may include additional information such as composition information (CI) and transport characteristics (TC).

The transmitter 130 transmits the packetized MMT packet through the packetizer 120 to the receiver through the network 140. The network 140 includes at least one of a broadcasting network and an IP network.

2 shows an example of an SVC-based layered video structure according to the present invention.

Referring to FIG. 2, "(a)" is a diagram listed in order of a base layer, a first enhancement layer, and a second enhancement layer, and "(b)" is listed as a serial in decoding order. It is also. "(a)" and "(b)" differ in the arrangement order of the structures of the same SVC-based layered video.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventive concept as defined by the appended claims. But is not limited thereto.

In the above-described exemplary system, the methods are described on the basis of a flowchart as a series of steps or blocks, but the present invention is not limited to the order of the steps, and some steps may occur in different orders or simultaneously . It will also be understood by those skilled in the art that the steps shown in the flowchart are not exclusive and that other steps may be included or that one or more steps in the flowchart may be deleted without affecting the scope of the invention.

Claims (1)

An apparatus for processing video data having a mutual dependency,
An encapsulation unit configured to receive an access unit (AU) and encapsulate the media to generate a media processing unit (MPU);
A packetizer configured to generate an MMT asset based on the MPU, and generate an MMT packet based on the MMT asset;
It includes a transmission unit for transmitting the MMT packet through a network,
And the MPU includes a dependency indicator exclusively allocated between a dependency indicator indicating a dependency of another MPU and a dependency indicator or an MPU having a dependency.

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