WO2022131754A1 - 샘플 단위의 랜덤 액세스를 지원하는 미디어 파일 생성/수신 방법, 장치 및 미디어 파일 전송 방법 - Google Patents
샘플 단위의 랜덤 액세스를 지원하는 미디어 파일 생성/수신 방법, 장치 및 미디어 파일 전송 방법 Download PDFInfo
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Definitions
- the present disclosure relates to a method and apparatus for generating/receiving a media file, and more particularly, to a method and apparatus for generating/receiving a media file supporting random access in units of samples, and media generated by the method/device for generating a media file of the present disclosure How to transfer files.
- an object of the present disclosure is to provide a method and apparatus for generating/receiving a media file supporting random access in units of samples.
- Another object of the present disclosure is to provide a method and apparatus for generating/receiving a media file that restricts a current sample to include an IRAP subpicture when random access occurs.
- Another object of the present disclosure is to provide a method and apparatus for generating/receiving a media file that limits the TemporalId value of a current sample to 0 when random access occurs.
- Another object of the present disclosure is to provide a method for generating a media file or a method for transmitting a media file generated by an apparatus according to the present disclosure.
- Another object of the present disclosure is to provide a recording medium storing a media file generated by the method or apparatus for generating a media file according to the present disclosure.
- Another object of the present disclosure is to provide a recording medium in which a media file received by a media file receiving apparatus according to the present disclosure and used for image restoration is stored.
- a method for receiving a media file includes: obtaining one or more tracks and a sample group from a media file; and recovering video data in the media file by restoring a sample included in the track based on the sample group. processing, based on which samples mapped to a stream access point sample group or random access recovery point sample group of a given type exist in the track, a current one of the mapped samples is selected from at least one IRAP ( Intra random access point) subpicture, based on the fact that the current sample includes a non-IRAP subpicture, belongs to the same coded layer video sequence (CLVS) as the current sample and the current sample in decoding order Samples following . may be limited to include at least one IRAP subpicture having the same subpicture index value as the non-IRAP subpicture.
- IRAP Intra random access point
- An apparatus for receiving a media file includes a memory and at least one processor, wherein the at least one processor obtains one or more tracks and a sample group from a media file, and based on the sample group, the Process the video data in the media file by recovering samples included in the track, wherein samples mapped to a stream access point sample group or random access recovery point sample group of a certain type are present in the track, the mapped Among the samples, a current sample is limited to include at least one intra random access point (IRAP) subpicture, and based on the current sample including a non-IRAP subpicture, the same coded layer video (CLVS) as the current sample. sequence) and following the current sample in decoding order may be limited to include at least one IRAP subpicture having the same subpicture index value as the non-IRAP subpicture.
- IRAP intra random access point
- CLVS coded layer video
- a method of generating a media file includes encoding video data, generating one or more tracks and sample groups for the encoded video data, and based on the generated tracks and sample groups, generating a media file, wherein based on the presence in the track of samples mapped to a stream access point sample group or random access recovery point sample group of a given type, a current sample of the mapped samples is at least one is restricted to include an intra random access point (IRAP) subpicture of A sample following the current sample may be limited to include at least one IRAP subpicture having the same subpicture index value as the non-IRAP subpicture.
- IRAP intra random access point
- An apparatus for generating a media file includes a memory and at least one processor, wherein the at least one processor encodes video data, and one or more tracks and sample groups for the encoded video data generate a media file based on the generated track and sample group, wherein samples mapped to a stream access point sample group or a random access recovery point sample group of a predetermined type exist in the track;
- a current sample is limited to include at least one intra random access point (IRAP) subpicture, and based on the fact that the current sample includes a non-IRAP subpicture, the same coded (CLVS) as the current sample layer video sequence) and following the current sample in decoding order may be limited to include at least one IRAP subpicture having the same subpicture index value as the non-IRAP subpicture.
- IRAP intra random access point
- a media file transmission method may transmit a media file generated by the media file generating method or apparatus of the present disclosure.
- a computer-readable recording medium may store a media file generated by the method or apparatus for generating a media file of the present disclosure.
- a method and apparatus for generating/receiving a media file supporting random access in units of samples may be provided.
- a method and apparatus for generating/receiving a media file that restricts a current sample to include an IRAP subpicture when random access occurs may be provided.
- a method and apparatus for generating/receiving a media file for limiting the TemporalId value of the current sample to 0 when random access occurs may be provided.
- a method for generating a media file or a method for transmitting a media file generated by an apparatus according to the present disclosure may be provided.
- a recording medium storing a media file generated by the method or apparatus for generating a media file according to the present disclosure may be provided.
- a recording medium in which a media file received by the media file receiving apparatus according to the present disclosure and used to restore an image is stored.
- FIG. 1 is a diagram schematically illustrating a media file transmission/reception system according to an embodiment of the present disclosure.
- FIG. 2 is a flowchart illustrating a method of transmitting a media file.
- FIG. 3 is a flowchart illustrating a method of receiving a media file.
- FIG. 4 is a diagram schematically illustrating an image encoding apparatus according to an embodiment of the present disclosure.
- FIG. 5 is a diagram schematically illustrating an image decoding apparatus according to an embodiment of the present disclosure.
- FIG. 6 is a diagram illustrating an example of a hierarchical structure for a coded image/video.
- FIG. 7 is a diagram illustrating an example of a media file structure.
- FIG. 8 is a view showing an example of the structure of the trak box of FIG.
- FIG. 9 is a diagram illustrating an example of an image signal structure.
- FIG. 10 is a diagram illustrating an example of subpictures having intra-sample hybrid NAL units according to the existing VVC file format.
- FIG. 11 is a diagram illustrating an example of subpictures having intra-sample hybrid NAL units according to an embodiment of the present disclosure.
- FIG. 12 is a flowchart illustrating a method for determining a sample attribute according to an embodiment of the present disclosure.
- FIG. 13 is a flowchart illustrating a method of generating a media file according to an embodiment of the present disclosure.
- FIG. 14 is a flowchart illustrating a method for receiving a media file according to an embodiment of the present disclosure.
- 15 is a diagram illustrating a content streaming system to which an embodiment of the present disclosure can be applied.
- a component when a component is “connected”, “coupled” or “connected” to another component, it is not only a direct connection relationship, but also an indirect connection relationship in which another component exists in the middle. may also include.
- a component when a component is said to "include” or “have” another component, it means that another component may be further included without excluding other components unless otherwise stated. .
- first, second, etc. are used only for the purpose of distinguishing one component from other components, and unless otherwise specified, the order or importance between the components is not limited. Accordingly, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment is referred to as a first component in another embodiment. can also be called
- the components that are distinguished from each other are for clearly explaining each characteristic, and the components do not necessarily mean that the components are separated. That is, a plurality of components may be integrated to form one hardware or software unit, or one component may be distributed to form a plurality of hardware or software units. Accordingly, even if not specifically mentioned, such integrated or dispersed embodiments are also included in the scope of the present disclosure.
- components described in various embodiments do not necessarily mean essential components, and some may be optional components. Accordingly, an embodiment composed of a subset of components described in one embodiment is also included in the scope of the present disclosure. In addition, embodiments including other components in addition to components described in various embodiments are also included in the scope of the present disclosure.
- the present disclosure relates to encoding and decoding of an image, and terms used in the present disclosure may have conventional meanings commonly used in the technical field to which the present disclosure belongs unless they are newly defined in the present disclosure.
- a “picture” generally means a unit representing one image in a specific time period
- a slice/tile is a coding unit constituting a part of a picture
- one picture is one It may be composed of more than one slice/tile.
- a slice/tile may include one or more coding tree units (CTUs).
- pixel or “pel” may mean a minimum unit constituting one picture (or image).
- sample may be used as a term corresponding to a pixel.
- a sample may generally represent a pixel or a value of a pixel, may represent only a pixel/pixel value of a luma component, or may represent only a pixel/pixel value of a chroma component.
- a “unit” may indicate a basic unit of image processing.
- the unit may include at least one of a specific region of a picture and information related to the region.
- a unit may be used interchangeably with terms such as “sample array”, “block” or “area” in some cases.
- an MxN block may include samples (or sample arrays) or a set (or arrays) of transform coefficients including M columns and N rows.
- current block may mean one of “current coding block”, “current coding unit”, “coding object block”, “decoding object block”, or “processing object block”.
- current block may mean “current prediction block” or “prediction target block”.
- transform inverse transform
- quantization inverse quantization
- current block may mean “current transform block” or “transform target block”.
- filtering the “current block” may mean a “filtering target block”.
- a “current block” may mean a block including both a luma component block and a chroma component block or “a luma block of the current block” unless explicitly stated as a chroma block.
- the luma component block of the current block may be explicitly expressed by including an explicit description of the luma component block, such as “luma block” or “current luma block”.
- the chroma component block of the current block may be explicitly expressed by including an explicit description of the chroma component block, such as "chroma block” or "current chroma block”.
- “/” and “,” may be interpreted as “and/or”.
- “A/B” and “A, B” may be interpreted as “A and/or B”.
- “A/B/C” and “A, B, C” may mean “at least one of A, B and/or C”.
- “or” may be construed as “and/or”.
- a or B can mean 1) “A” only, 2) “B” only, or 3) “A and B”.
- “or” may mean “additionally or alternatively”.
- FIG. 1 is a diagram schematically illustrating a media file transmission/reception system according to an embodiment of the present disclosure.
- a media file transmission/reception system 1 may include a transmission device A and a reception device B.
- the media file transmission/reception system 1 may support seamless media content reproduction by supporting MPEG-DASH (Dynamic Adaptive Streaming over HTTP)-based adaptive streaming.
- MPEG-DASH Dynamic Adaptive Streaming over HTTP
- the transmission apparatus A may include a video source 10 , an encoder 20 , an encapsulation unit 30 , a transmission processing unit 40 , and a transmission unit 45 .
- the video source 10 may generate or obtain media data such as video or images.
- the video source 10 may include a video/image capture device and/or a video/image generating device, or may be connected to an external device to receive media data.
- the encoder 20 may encode media data input from the video source 10 .
- the encoder 20 may perform a series of procedures such as prediction, transformation, and quantization according to a video codec standard, for example, a versatile video coding (VVC) standard, for compression and encoding efficiency.
- VVC versatile video coding
- the encoder 20 may output the encoded media data in the form of a bitstream.
- the encapsulation unit 30 may encapsulate the encoded media data and/or media data related metadata.
- the encapsulation unit 30 may encapsulate the data in a file format such as ISO BMFF (ISO Base Media File Format) or CMAF (Common Media Application Format), or process the data in the form of segments. have.
- Media data encapsulated in the form of a file (hereinafter, referred to as a 'media file') may be stored in a storage unit (not shown) according to an embodiment.
- the media file stored in the storage unit may be read by the transmission processing unit 40 and transmitted to the reception device B according to an on demand, non-real time (NRT) or broadband method.
- NRT non-real time
- the transmission processing unit 40 may generate an image signal by processing the media file according to an arbitrary transmission method.
- the media file transmission method may include a broadcast method and a broadband method.
- the media file may be transmitted using an MPEG Media Transport (MMT) protocol or a Real time Object delivery over Unidirectional Transport (ROUTE) protocol.
- MMT MPEG Media Transport
- ROUTE Real time Object delivery over Unidirectional Transport
- the MMT protocol may be a transport protocol supporting media streaming regardless of a file format or codec in an IP-based network environment.
- the media file may be processed in units of Media Processing Units (MPUs) based on MMT and then transmitted according to the MMT protocol.
- MPUs Media Processing Units
- the ROUTE protocol is an extension of File Delivery over Unidirectional Transport (FLUTE), and may be a transport protocol supporting real-time transmission of media files.
- FLUTE File Delivery over Unidirectional Transport
- the media file may be processed into one or more segments based on MPEG-DASH and then transmitted according to the ROUTE protocol.
- the media file may be transmitted over a network using HTTP (HyperText Transfer Protocol).
- Information transmitted through HTTP may include signaling metadata, segment information, and/or non-real time (NRT) service information.
- the transmission processing unit 40 may include an MPD generating unit 41 and a segment generating unit 42 in order to support adaptive media streaming.
- the MPD generator 41 may generate a Media Presentation Description (MPD) based on the media file.
- MPD is a file including detailed information on media presentation, and may be expressed in XML format.
- the MPD may provide signaling metadata, such as an identifier for each segment.
- the receiving device B may dynamically acquire segments based on the MPD.
- the segment generator 42 may generate one or more segments based on the media file.
- the segment may include actual media data and may have a file format such as ISO BMFF.
- the segment may be included in the representation of the video signal, and as described above, may be identified based on the MPD.
- the transmission processing unit 40 may generate an image signal according to the MPEG-DASH standard based on the generated MPD and segment.
- the transmitter 45 may transmit the generated image signal to the receiver B.
- the transmitter 45 may transmit an image signal to the receiver B through an IP network according to the MMT standard or the MPEG-DASH standard.
- the image signal transmitted to the receiving device B may include a PI document (Presentation Information document) including media data reproduction information.
- the video signal transmitted to the receiving device B may include the aforementioned MPD as reproduction information of media data.
- the MPD and the segment may be individually transmitted to the receiving device B.
- the first video signal including the MPD may be generated by the transmitting device A or an external server and transmitted to the receiving device B
- the second video signal including the segment may be generated by the transmitting device A may be generated and transmitted to the receiving device (B).
- the transmission processing unit 40 and the transmission unit 45 are illustrated as separate elements in FIG. 1 , they may be integrally implemented as a single element according to an embodiment.
- the transmission processing unit 40 may be implemented as an external device (e.g., DASH server) separate from the transmission device A.
- the transmitting device A may operate as a source device that generates a media file by encoding the media data
- the external device operates as a server device that generates an image signal by processing the media data according to an arbitrary transmission protocol. can do.
- the reception device B may include a reception unit 55 , a reception processing unit 60 , a decapsulation unit 70 , a decoding unit 80 , and a rendering unit 90 .
- the receiving device B may be an MPEG-DASH-based client.
- the receiver 55 may receive an image signal from the transmitter A.
- a video signal according to the MMT standard may include a PI document and a media file.
- the video signal according to the MPEG-DASH standard may include MPD and segments. According to an embodiment, the MPD and the segment may be separately transmitted through different image signals.
- the reception processing unit 60 may extract/parse the media file by processing the received image signal according to a transmission protocol.
- the reception processing unit 60 may include an MPD parsing unit 61 and a segment parsing unit 62 in order to support adaptive media streaming.
- the MPD parsing unit 61 may obtain an MPD from the received image signal, parse the obtained MPD, and generate a command required for segment acquisition. Also, the MPD parsing unit 61 may acquire media data reproduction information, eg, color conversion information, based on the parsed MPD.
- the segment parsing unit 62 may obtain a segment based on the parsed MPD and extract the media file by parsing the obtained segment.
- the media file may have a file format such as ISO BMFF or CMAF.
- the decapsulation unit 70 may decapsulate the extracted media file to obtain media data and related metadata.
- the obtained metadata may have the form of a box or track in a file format.
- the decapsulation unit 70 may receive metadata required for decapsulation from the MPD parsing unit 61 .
- the decoder 80 may decode the obtained media data according to a video codec standard, for example, a VVC standard. To this end, the decoder 80 may perform a series of procedures such as inverse quantization, inverse transformation, and prediction corresponding to the operation of the encoder 20 .
- the rendering unit 90 may render a decoded image or media data such as an image.
- the rendered media data may be reproduced through a display unit (not shown).
- FIG. 2 is a flowchart illustrating a method of transmitting a media file.
- each step of FIG. 2 may be performed by the transmitting apparatus A of FIG. 1 .
- step S210 may be performed by the encoder 20 of FIG. 1 .
- steps S220 and S230 may be performed by the transmission processing unit 40 .
- step S240 may be performed by the transmitter 45 .
- the transmitting apparatus may encode media data such as a video or an image ( S210 ).
- the media data may be captured/generated by the transmitting device or obtained from an external device (e.g., camera, video archive, etc.).
- Media data may be encoded in the form of a bitstream according to a video codec standard, for example, a VVC standard.
- the transmitting device may generate an MPD and one or more segments based on the encoded media data (S220).
- the MPD may include detailed information about the media presentation.
- a segment may contain actual media data.
- the media data may be encapsulated in a file format such as ISO BMFF or CMAF and included in a segment.
- the transmitting apparatus may generate an image signal including the generated MPD and segment ( S230 ).
- the image signal may be individually generated for each MPD and segment.
- the transmitting apparatus may generate a first image signal including the MPD and generate a second image signal including a segment.
- the transmitting device may transmit the generated image signal to the receiving device (S240).
- the transmitting apparatus may transmit an image signal in a broadcast manner.
- the MMT protocol or the ROUTE protocol may be used.
- the transmitting apparatus may transmit the image signal in a broadband method.
- the MPD and the video signal including the MPD are generated and transmitted by the transmitting device (steps S220 to S240). It may be generated and transmitted by an external server other than the
- FIG. 3 is a flowchart illustrating a method of receiving a media file.
- each step of FIG. 3 may be performed by the receiving device B of FIG. 1 .
- step S310 may be performed by the receiver 55 .
- step S320 may be performed by the reception processing unit 60 .
- step S330 may be performed by the decoder 80 .
- the receiving device may receive an image signal from the transmitting device ( S310 ).
- a video signal according to the MPEG-DASH standard may include an MPD and a segment.
- the MPD and the segment may be individually received through different image signals.
- the first image signal including the MPD may be received from the transmitting apparatus of FIG. 1 or an external server
- the second image signal including the segment may be received from the transmitting apparatus of FIG. 1 .
- the receiving device may extract the MPD and the segment from the received video signal and parse the extracted MPD and the segment ( S320 ). Specifically, the receiving device may parse the MPD to generate a command required for segment acquisition. In addition, the receiving device may obtain a segment based on the parsed MPD, and may obtain media data by parsing the obtained segment. According to an embodiment, in order to obtain the media data from the segment, the receiving device may perform decapsulation on the media data in the form of a file.
- the receiving device may decode media data such as an acquired video or image (S330).
- media data such as an acquired video or image (S330).
- the receiving device may perform a series of procedures such as inverse quantization, inverse transformation, and prediction. Then, the reception device may render the decoded media data and reproduce the media data through a display.
- FIG. 4 is a diagram schematically illustrating an image encoding apparatus according to an embodiment of the present disclosure.
- the image encoding apparatus 400 of FIG. 4 may correspond to the encoding unit 20 of the transmitting apparatus A described above with reference to FIG. 1 .
- the image encoding apparatus 400 includes an image dividing unit 410 , a subtracting unit 415 , a transforming unit 420 , a quantizing unit 430 , an inverse quantizing unit 440 , and an inverse transforming unit 450 . , an adder 455 , a filtering unit 460 , a memory 470 , an inter prediction unit 480 , an intra prediction unit 485 , and an entropy encoding unit 490 .
- the inter prediction unit 480 and the intra prediction unit 485 may be collectively referred to as a “prediction unit”.
- the transform unit 420 , the quantization unit 430 , the inverse quantization unit 440 , and the inverse transform unit 450 may be included in a residual processing unit.
- the residual processing unit may further include a subtraction unit 415 .
- All or at least some of the plurality of components constituting the image encoding apparatus 400 may be implemented as one hardware component (eg, an encoder or a processor) according to an embodiment.
- the memory 470 may include a decoded picture buffer (DPB), and may be implemented by a digital storage medium.
- DPB decoded picture buffer
- the image dividing unit 410 may divide an input image (or a picture, a frame) input to the image encoding apparatus 400 into one or more processing units.
- the processing unit may be referred to as a coding unit (CU).
- Coding unit is a coding tree unit (coding tree unit, CTU) or largest coding unit (LCU) according to the QT / BT / TT (Quad-tree / binary-tree / ternary-tree) structure recursively ( It can be obtained by dividing recursively.
- one coding unit may be divided into a plurality of coding units having a lower depth based on a quad tree structure, a binary tree structure, and/or a ternary tree structure.
- a quad tree structure may be applied first and a binary tree structure and/or a ternary tree structure may be applied later.
- a coding procedure according to the present disclosure may be performed based on the final coding unit that is no longer divided.
- the largest coding unit may be directly used as the final coding unit, and a coding unit of a lower depth obtained by dividing the largest coding unit may be used as the final cornet unit.
- the coding procedure may include procedures such as prediction, transformation, and/or restoration, which will be described later.
- the processing unit of the coding procedure may be a prediction unit (PU) or a transform unit (TU).
- the prediction unit and the transform unit may be divided or partitioned from the final coding unit, respectively.
- the prediction unit may be a unit of sample prediction
- the transform unit may be a unit deriving a transform coefficient and/or a unit deriving a residual signal from the transform coefficient.
- the prediction unit (the inter prediction unit 480 or the intra prediction unit 485) performs prediction on a processing target block (current block), and generates a predicted block including prediction samples for the current block.
- the prediction unit may determine whether intra prediction or inter prediction is applied to the current block or CU unit.
- the prediction unit may generate various information regarding prediction of the current block and transmit it to the entropy encoding unit 490 .
- the prediction information may be encoded by the entropy encoding unit 490 and output in the form of a bitstream.
- the intra prediction unit 485 may predict the current block by referring to samples in the current picture.
- the referenced samples may be located in the vicinity of the current block according to an intra prediction mode and/or an intra prediction technique, or may be located apart from each other.
- the intra prediction modes may include a plurality of non-directional modes and a plurality of directional modes.
- the non-directional mode may include, for example, a DC mode and a planar mode (Planar mode).
- the directional mode may include, for example, 33 directional prediction modes or 65 directional prediction modes according to the granularity of the prediction direction. However, this is an example, and a higher or lower number of directional prediction modes may be used according to a setting.
- the intra prediction unit 485 may determine the prediction mode applied to the current block by using the prediction mode applied to the neighboring block.
- the inter prediction unit 480 may derive the predicted block for the current block based on the reference block (reference sample array) specified by the motion vector on the reference picture.
- the motion information may be predicted as a block, sub-block, or sample unit based on the correlation between the motion information between the neighboring block and the current block.
- the motion information may include a motion vector and a reference picture index.
- the motion information may further include inter prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.) information.
- the neighboring blocks may include spatial neighboring blocks existing in the current picture and temporal neighboring blocks present in the reference picture.
- the reference picture including the reference block and the reference picture including the temporal neighboring block may be the same or different.
- the temporal neighboring block may be called a collocated reference block, a collocated CU (colCU), or the like.
- the reference picture including the temporal neighboring block may be referred to as a collocated picture (colPic).
- the inter prediction unit 480 constructs a motion information candidate list based on neighboring blocks, and provides information indicating which candidate is used to derive a motion vector and/or a reference picture index of the current block. can create Inter prediction may be performed based on various prediction modes. For example, in the skip mode and merge mode, the inter prediction unit 480 may use motion information of a neighboring block as motion information of the current block.
- a residual signal may not be transmitted.
- MVP motion vector prediction
- a motion vector of a neighboring block is used as a motion vector predictor, and a motion vector difference and an indicator for the motion vector predictor ( indicator) to signal the motion vector of the current block.
- the motion vector difference may mean a difference between the motion vector of the current block and the motion vector predictor.
- the prediction unit may generate a prediction signal based on various prediction methods and/or prediction techniques to be described later. For example, the prediction unit may apply intra prediction or inter prediction for prediction of the current block, and may simultaneously apply intra prediction and inter prediction. A prediction method that simultaneously applies intra prediction and inter prediction for prediction of the current block may be referred to as combined inter and intra prediction (CIIP). Also, the prediction unit may perform intra block copy (IBC) for prediction of the current block. The intra block copy may be used for video/video coding of content such as games, for example, screen content coding (SCC). IBC is a method of predicting a current block using a reconstructed reference block in a current picture located a predetermined distance away from the current block.
- CIIP combined inter and intra prediction
- IBC intra block copy
- the intra block copy may be used for video/video coding of content such as games, for example, screen content coding (SCC).
- IBC is a method of predicting a current block using a reconstructed reference block in a current picture located
- the position of the reference block in the current picture may be encoded as a vector (block vector) corresponding to the predetermined distance.
- IBC basically performs prediction within the current picture, but may be performed similarly to inter prediction in that a reference block is derived within the current picture. That is, IBC may use at least one of the inter prediction techniques described in this disclosure.
- the prediction signal generated by the prediction unit may be used to generate a reconstructed signal or may be used to generate a residual signal.
- the subtraction unit 415 subtracts the prediction signal (predicted block, prediction sample array) output from the prediction unit from the input image signal (original block, original sample array) to obtain a residual signal (residual signal, residual block, and residual sample array). ) can be created.
- the generated residual signal may be transmitted to the converter 420 .
- the transform unit 420 may generate transform coefficients by applying a transform technique to the residual signal.
- the transformation method may include at least one of Discrete Cosine Transform (DCT), Discrete Sine Transform (DST), Karhunen-Loeve Transform (KLT), Graph-Based Transform (GBT), or Conditionally Non-linear Transform (CNT).
- DCT Discrete Cosine Transform
- DST Discrete Sine Transform
- KLT Karhunen-Loeve Transform
- GBT Graph-Based Transform
- CNT Conditionally Non-linear Transform
- GBT means a transformation obtained from this graph when expressing relationship information between pixels in a graph.
- CNT refers to a transformation obtained by generating a prediction signal using all previously reconstructed pixels and based thereon.
- the transformation process may be applied to a block of pixels having the same size as a square, or may be applied to a block of variable size that is not a square.
- the quantization unit 430 may quantize the transform coefficients and transmit them to the entropy encoding unit 490 .
- the entropy encoding unit 490 may encode a quantized signal (information about quantized transform coefficients) and output it as a bitstream. Information about the quantized transform coefficients may be referred to as residual information.
- the quantization unit 430 may rearrange the block-type quantized transform coefficients into a one-dimensional vector form based on a coefficient scan order, and based on the quantized transform coefficients of the one-dimensional vector form, the quantized Information about the transform coefficients may be generated.
- the entropy encoding unit 490 may perform various encoding methods such as, for example, exponential Golomb, context-adaptive variable length coding (CAVLC), and context-adaptive binary arithmetic coding (CABAC).
- the entropy encoding unit 190 may encode information necessary for video/image reconstruction (eg, values of syntax elements, etc.) other than the quantized transform coefficients together or separately.
- Encoded information e.g., encoded video/image information
- NAL network abstraction layer
- the video/image information may further include information about various parameter sets, such as an adaptation parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS).
- the video/image information may further include general constraint information.
- the signaling information, transmitted information, and/or syntax elements mentioned in the present disclosure may be encoded through the above-described encoding procedure and included in the bitstream.
- the bitstream may be transmitted over a network or may be stored in a digital storage medium.
- the network may include a broadcasting network and/or a communication network
- the digital storage medium may include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, and SSD.
- a transmission unit (not shown) for transmitting the signal output from the entropy encoding unit 190 and/or a storage unit (not shown) for storing the signal may be provided as internal/external elements of the image encoding apparatus 100 , or transmission The unit may be provided as a component of the entropy encoding unit 490 .
- the quantized transform coefficients output from the quantization unit 430 may be used to generate a residual signal.
- a residual signal residual block or residual samples
- a residual signal residual block or residual samples
- the adder 455 adds a reconstructed signal (reconstructed picture, reconstructed block, reconstructed sample array) by adding the reconstructed residual signal to the prediction signal output from the inter prediction unit 480 or the intra prediction unit 485. can create When there is no residual for the block to be processed, such as when the skip mode is applied, the predicted block may be used as a reconstructed block.
- the addition unit 455 may be called a restoration unit or a restoration block generator.
- the generated reconstructed signal may be used for intra prediction of the next processing object block in the current picture, or may be used for inter prediction of the next picture after filtering as described below.
- LMCS luma mapping with chroma scaling
- the filtering unit 460 may improve subjective/objective image quality by applying filtering to the reconstructed signal. For example, the filtering unit 460 may generate a modified reconstructed picture by applying various filtering methods to the reconstructed picture, and store the modified reconstructed picture in the memory 470 , specifically, the DPB of the memory 470 . can be stored in The various filtering methods may include, for example, deblocking filtering, a sample adaptive offset, an adaptive loop filter, a bilateral filter, and the like. The filtering unit 460 may generate various types of filtering-related information and transmit it to the entropy encoding unit 490 as will be described later in the description of each filtering method. The filtering-related information may be encoded by the entropy encoding unit 490 and output in the form of a bitstream.
- the modified reconstructed picture transmitted to the memory 470 may be used as a reference picture in the inter prediction unit 480 .
- the image encoding apparatus 400 can avoid a prediction mismatch between the image encoding apparatus 400 and the image decoding apparatus, and can also improve encoding efficiency.
- the DPB in the memory 470 may store a reconstructed picture corrected for use as a reference picture in the inter prediction unit 480 .
- the memory 470 may store motion information of a block in which motion information in the current picture is derived (or encoded) and/or motion information of blocks in an already reconstructed picture.
- the stored motion information may be transmitted to the inter prediction unit 480 to be used as motion information of a spatial neighboring block or motion information of a temporal neighboring block.
- the memory 470 may store reconstructed samples of blocks reconstructed in the current picture, and may transmit the reconstructed samples to the intra prediction unit 485 .
- FIG. 5 is a diagram schematically illustrating an image decoding apparatus according to an embodiment of the present disclosure.
- the image decoding apparatus 500 of FIG. 5 may correspond to the decoding unit 80 of the receiving apparatus A described above with reference to FIG. 1 .
- the image decoding apparatus 500 includes an entropy decoding unit 510 , an inverse quantization unit 520 , an inverse transform unit 530 , an adder 535 , a filtering unit 540 , a memory 550 , It may be configured to include an inter prediction unit 560 and an intra prediction unit 565 .
- the inter prediction unit 560 and the intra prediction unit 565 may be collectively referred to as a “prediction unit”.
- the inverse quantization unit 520 and the inverse transform unit 530 may be included in the residual processing unit.
- All or at least some of the plurality of components constituting the image decoding apparatus 500 may be implemented as one hardware component (eg, a decoder or a processor) according to an embodiment.
- the memory 550 may include a DPB, and may be implemented by a digital storage medium.
- the image decoding apparatus 500 receiving the bitstream including the video/image information may reconstruct the image by performing a process corresponding to the process performed by the image encoding apparatus 400 of FIG. 4 .
- the image decoding apparatus 500 may perform decoding using a processing unit applied in the image encoding apparatus.
- the processing unit of decoding may be, for example, a coding unit.
- a coding unit may be a coding tree unit or may be obtained by dividing the largest coding unit.
- the reconstructed image signal decoded and output through the image decoding apparatus 500 may be reproduced through a reproducing apparatus (not shown).
- the image decoding apparatus 500 may receive the signal generated by the image encoding apparatus of FIG. 4 in the form of a bitstream.
- the received signal may be decoded through the entropy decoding unit 510 .
- the entropy decoding unit 510 may parse the bitstream to derive information (eg, video/image information) required for image restoration (or picture restoration).
- the video/image information may further include information about various parameter sets, such as an adaptation parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS).
- the video/image information may further include general constraint information.
- the image decoding apparatus may additionally use the information about the parameter set and/or the general restriction information to decode the image.
- the signaling information, received information and/or syntax elements mentioned in this disclosure may be obtained from the bitstream by being decoded through the decoding procedure.
- the entropy decoding unit 510 decodes information in a bitstream based on a coding method such as exponential Golomb encoding, CAVLC, or CABAC, and quantizes a value of a syntax element necessary for image reconstruction and a transform coefficient related to a residual values can be printed.
- the CABAC entropy decoding method receives a bin corresponding to each syntax element in a bitstream, and receives syntax element information to be decoded, and decoding information of neighboring blocks and to-be-decoded blocks, or information of symbols/bins decoded in the previous step.
- the CABAC entropy decoding method may update the context model by using the decoded symbol/bin information for the context model of the next symbol/bin after determining the context model.
- Prediction-related information among the information decoded by the entropy decoding unit 510 is provided to the prediction unit (the inter prediction unit 560 and the intra prediction unit 565), and the entropy decoding unit 510 performs entropy decoding. Dual values, ie, quantized transform coefficients and related parameter information, may be input to the inverse quantization unit 520 .
- information about filtering among the information decoded by the entropy decoding unit 510 may be provided to the filtering unit 540 .
- a receiving unit for receiving a signal output from the image encoding apparatus may be additionally provided as an internal/external element of the image decoding apparatus 500 , or the receiving unit is provided as a component of the entropy decoding unit 510 . it might be
- the image decoding apparatus may include an information decoder (video/image/picture information decoder) and/or a sample decoder (video/image/picture sample decoder).
- the information decoder may include an entropy decoding unit 510, and the sample decoder includes an inverse quantization unit 520, an inverse transform unit 530, an adder 535, a filtering unit 540, a memory 550, At least one of an inter prediction unit 560 and an intra prediction unit 565 may be included.
- the inverse quantizer 520 may inverse quantize the quantized transform coefficients to output the transform coefficients.
- the inverse quantizer 520 may rearrange the quantized transform coefficients in a two-dimensional block form. In this case, the rearrangement may be performed based on the coefficient scan order performed by the image encoding apparatus.
- the inverse quantizer 520 may perform inverse quantization on the quantized transform coefficients using a quantization parameter (eg, quantization step size information) and obtain transform coefficients.
- a quantization parameter eg, quantization step size information
- the inverse transform unit 530 may obtain a residual signal (residual block, residual sample array) by inversely transforming the transform coefficients.
- the prediction unit may perform prediction on the current block and generate a predicted block including prediction samples for the current block.
- the prediction unit may determine whether intra prediction or inter prediction is applied to the current block based on the prediction information output from the entropy decoding unit 510, and determine a specific intra/inter prediction mode (prediction technique).
- the prediction unit can generate a prediction signal based on various prediction methods (techniques) to be described later is the same as described in the description of the prediction unit of the image encoding apparatus 400 .
- the intra prediction unit 565 may predict the current block with reference to samples in the current picture.
- the description of the intra prediction unit 485 may be equally applied to the intra prediction unit 565 .
- the inter prediction unit 560 may derive the predicted block for the current block based on the reference block (reference sample array) specified by the motion vector on the reference picture.
- the motion information may be predicted as a block, sub-block, or sample unit based on the correlation between the motion information between the neighboring block and the current block.
- the motion information may include a motion vector and a reference picture index.
- the motion information may further include inter prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.) information.
- the neighboring blocks may include spatial neighboring blocks existing in the current picture and temporal neighboring blocks present in the reference picture.
- the inter prediction unit 560 may construct a motion information candidate list based on neighboring blocks, and may derive a motion vector and/or a reference picture index of the current block based on the received candidate selection information.
- Inter prediction may be performed based on various prediction modes (techniques), and the prediction information may include information indicating a mode (technique) of inter prediction for the current block.
- the adding unit 535 restores the obtained residual signal by adding it to the prediction signal (predicted block, prediction sample array) output from the prediction unit (including the inter prediction unit 560 and/or the intra prediction unit 565).
- a signal (reconstructed picture, reconstructed block, reconstructed sample array) may be generated.
- the predicted block may be used as a reconstructed block.
- the description of the adder 555 may be equally applied to the adder 535 .
- the addition unit 535 may be called a restoration unit or a restoration block generation unit.
- the generated reconstructed signal may be used for intra prediction of the next processing object block in the current picture, or may be used for inter prediction of the next picture after filtering as described below.
- LMCS luma mapping with chroma scaling
- the filtering unit 540 may improve subjective/objective image quality by applying filtering to the reconstructed signal.
- the filtering unit 540 may generate a modified reconstructed picture by applying various filtering methods to the reconstructed picture, and store the modified reconstructed picture in the memory 550 , specifically the memory 550 . It can be stored in DPB.
- the various filtering methods may include, for example, deblocking filtering, a sample adaptive offset, an adaptive loop filter, a bilateral filter, and the like.
- the (modified) reconstructed picture stored in the DPB of the memory 550 may be used as a reference picture in the inter prediction unit 560 .
- the memory 550 may store motion information of a block from which motion information in the current picture is derived (or decoded) and/or motion information of blocks in an already reconstructed picture.
- the stored motion information may be transmitted to the inter prediction unit 260 to be used as motion information of a spatial neighboring block or motion information of a temporal neighboring block.
- the memory 550 may store reconstructed samples of blocks reconstructed in the current picture, and may transmit the reconstructed samples to the intra prediction unit 565 .
- the embodiments described in the filtering unit 460, the inter prediction unit 480, and the intra prediction unit 485 of the image encoding apparatus 400 include the filtering unit 540 of the image decoding apparatus 500, The same or corresponding application may be applied to the inter prediction unit 560 and the intra prediction unit 565 .
- the quantization unit of the encoding apparatus may apply quantization to the transform coefficients to derive quantized transform coefficients, and the inverse quantization unit of the encoding apparatus or the inverse quantization unit of the decoding apparatus applies inverse quantization to the quantized transform coefficients to generate transform coefficients.
- a quantization rate may be changed, and a compression rate may be adjusted using the changed quantization rate.
- a quantization parameter QP
- QP quantization parameter
- quantization parameters of integer values from 0 to 63 may be used, and each quantization parameter value may correspond to an actual quantization rate.
- the quantization parameter QP Y for the luma component (luma sample) and the quantization parameter QP C for the chroma component (chroma sample) may be set differently.
- a transform coefficient C is taken as an input and divided by a quantization rate Q step , and a quantized transform coefficient C ⁇ can be derived based on this.
- a quantization rate is multiplied by a scale to form an integer, and a shift operation may be performed by a value corresponding to the scale value.
- a quantization scale may be derived based on the product of the quantization rate and the scale value. That is, the quantization scale may be derived according to the QP.
- a quantized transform coefficient C ⁇ may be derived based thereon.
- the inverse quantization process is an inverse process of the quantization process, and a quantized transform coefficient (C') is multiplied by a quantization rate (Q step ), and a restored transform coefficient (C') can be derived based on this.
- a level scale may be derived according to the quantization parameter, and the level scale is applied to the quantized transform coefficient C ⁇ , and a reconstructed transform coefficient C ⁇ is derived based on this.
- the reconstructed transform coefficient C ⁇ may be slightly different from the original transform coefficient C due to loss in the transform and/or quantization process. Accordingly, in the encoding apparatus, inverse quantization may be performed in the same manner as in the decoding apparatus.
- an adaptive frequency weighting quantization technique that adjusts quantization intensity according to frequency may be applied.
- the adaptive frequency-by-frequency weighted quantization technique may correspond to a method of applying different quantization strengths for each frequency.
- the weighted quantization for each adaptive frequency may be applied with a different quantization intensity for each frequency using a predefined quantization scaling matrix. That is, the above-described quantization/inverse quantization process may be performed further based on the quantization scaling matrix.
- a different quantization scaling matrix may be used according to the size of the current block and/or whether a prediction mode applied to the current block is inter prediction or intra prediction to generate a residual signal of the current block.
- the quantization scaling matrix may be referred to as a quantization matrix or a scaling matrix.
- the quantization scaling matrix may be predefined.
- quantization scale information for each frequency with respect to the quantization scaling matrix may be configured/encoded in the encoding apparatus and signaled to the decoding apparatus.
- the quantization scale information for each frequency may be referred to as quantization scaling information.
- the quantization scale information for each frequency may include scaling list data (scaling_list_data).
- the quantization scaling matrix may be derived based on the scaling list data.
- the quantization scale information for each frequency may include present flag information indicating whether the scaling list data exists.
- the scaling list data is signaled at a higher level (e.g., SPS)
- information indicating whether the scaling list data is modified at a lower level e.g., PPS, APS or slice header etc. is further included.
- FIG. 6 is a diagram illustrating an example of a hierarchical structure for a coded image/video.
- the coded video/video is a video coding layer (VCL) that handles video/video decoding processing and itself, a subsystem that transmits and stores encoded information, and exists between the VCL and the subsystem and is responsible for network adaptation. It may be classified as a network abstraction layer (NAL).
- VCL video coding layer
- NAL network abstraction layer
- VCL data including compressed video data is generated, or a picture parameter set (PPS), a sequence parameter set (SPS), a video parameter set (Video Parameter Set, A supplemental enhancement information (SEI) message additionally necessary for a parameter set including information such as VPS) or an image decoding process may be generated.
- PPS picture parameter set
- SPS sequence parameter set
- SEI Supplemental Enhancement Information
- a NAL unit may be generated by adding header information (NAL unit header) to a raw byte sequence payload (RBSP) generated in the VCL.
- RBSP refers to slice data, parameter set, SEI message, etc. generated in the VCL.
- the NAL unit header may include NAL unit type information specified according to RBSP data included in the corresponding NAL unit.
- the NAL unit may be divided into a VCL NAL unit and a non-VCL NAL unit according to the type of RBSP generated in the VCL.
- a VCL NAL unit may mean a NAL unit including image information (slice data)
- a non-VCL NAL unit may mean a NAL unit including information (parameter set or SEI message) required to decode an image. have.
- VCL NAL unit and non-VCL NAL unit may be transmitted through a network by attaching header information according to a data standard of a subsystem.
- the NAL unit may be transformed into a data form of a predetermined standard such as H.266/VVC file format, Real-time Transport Protocol (RTP), or Transport Stream (TS) and transmitted through various networks.
- RTP Real-time Transport Protocol
- TS Transport Stream
- the NAL unit type may be specified according to the RBSP data structure included in the corresponding NAL unit, and information on this NAL unit type may be stored in the NAL unit header and signaled.
- the NAL unit may be largely divided into a VCL NAL unit type and a non-VCL NAL unit type according to whether image information (slice data) is included.
- the VCL NAL unit type may be subdivided according to the property/type of a picture included in the VCL NAL unit
- the non-VCL NAL unit type may be subdivided according to the type of parameter set included in the non-VCL NAL unit.
- VCL NAL unit types according to a picture type is as follows.
- IDR_W_RADL Instantaneous Decoding Refresh
- IDR_N_LP VCL NAL unit type for an Instantaneous Decoding Refresh (IDR) picture, which is a type of Intra Random Access Point (IRAP) picture;
- IDR Instantaneous Decoding Refresh
- IRAP Intra Random Access Point
- the IDR picture may be the first picture in decoding order in the bitstream, or may be the first and subsequent pictures.
- a picture having a NAL unit type such as “IDR_W_RADL” may have one or more Random Access Decodable Leading (RADL) pictures associated with the picture.
- a picture having a NAL unit type such as “IDR_N_LP” does not have any leading picture associated with the picture.
- CRA_NUT VCL NAL unit type for a Clean Random Access (CRA) picture, which is a kind of IRAP picture;
- the CRA picture may be the first picture in decoding order in the bitstream, or may be the first and subsequent pictures.
- a CRA picture may be associated with a RADL or RASL (Random Access Skipped Leading) picture.
- GDR_NUT VCL NAL unit type for randomly accessible Gradual Decoding Refresh (GDR) pictures;
- STSA_NUT VCL NAL unit type for randomly accessible Step-wise Temporal Sublayer Access (STSA) pictures;
- RASL_NUT VCL NAL unit type for a RASL picture that is a leading picture
- a trailing picture is a non-IRAP picture, and may follow the IRAP picture or GDR picture associated with the trailing picture in output order, and may follow the IRAP picture associated with the trailing picture in decoding order.
- DCI_NUT non-VCL NAL unit type including DCI (Decoding capability information)
- VPS Video Parameter Set
- SPS_NUT non-VCL NAL unit type including SPS (Sequence Parameter Set)
- PPS_NUT non-VCL NAL unit type including PPS (Picture Parameter Set)
- Picture Header non-VCL NAL unit type including a picture header (Picture Header)
- NAL unit types may be identified by predetermined syntax information (e.g., nal_unit_type) included in the NAL unit header.
- the image / video information encoded in the form of a bitstream in the present disclosure not only includes picture partitioning information, intra / inter prediction information, residual information and / or in-loop filtering information, etc., It may include slice header information, picture header information, APS information, PPS information, SPS information, VPS information, and/or DCI.
- the encoded image/video information may further include general constraint information (GCI) and/or NAL unit header information.
- the encoded image/video information may be encapsulated into a media file of a predetermined format (e.g., ISO BMFF) and transmitted to a receiving device.
- a predetermined format e.g., ISO BMFF
- the encoded image information may be configured (or formatted) based on a predetermined media file format to generate a media file.
- the encoded image information may form a media file (segment) based on one or more NAL units/sample entries for the encoded image information.
- a media file may contain sample entry(s) and track(s) (Track(s)).
- the media file may include various records, and each record may include information related to a media file format or information related to an image.
- one or more NAL units may be stored in a configuration record (or decoder configuration record) field in the media file.
- the media file may contain an operating point record and/or an operating point group box.
- a decoder setting record supporting Versatile Video Coding (VVC) may be referred to as a VVC decoder setting record.
- an operating point recording that supports VVC may be referred to as a VVC operating point recording.
- sample used in the media file format may mean all data associated with a single time or single element of any one of three sample arrays (Y, Cb, Cr) representing a picture.
- sample may refer to all data associated with a single time of the track.
- the time may correspond to a decoding time or a composition time.
- sample may refer to a single element of any one of three sample arrays representing the picture.
- FIG. 7 is a diagram illustrating an example of a media file structure.
- the media file may have a file format according to ISO base media file format (ISO BMFF).
- ISO BMFF ISO base media file format
- a media file may contain one or more boxes.
- the box may be a data block or object including media data or metadata related to the media data. Boxes within a media file can be hierarchical. Accordingly, the media file may have a form suitable for storage and/or transmission of large-capacity media data. Also, the media file may have a structure that facilitates access to specific media data.
- the media file 700 may include an ftyp box 710 , a moov box 720 , a moof box 730 , and an mdat box 740 .
- the ftyp box 710 may include information related to a file type, a file version, and/or compatibility of the media file 700 . According to an embodiment, the ftyp box 710 may be located at the beginning of the media file 700 .
- the moov box 720 may contain metadata describing the media data in the media file 700 . According to an embodiment, the moov box 720 may exist in the uppermost layer among metadata-related boxes. Also, the moov box 720 may include header information of the media file 700 . For example, the moov box 720 may include a decoder configuration record as decoder configuration information.
- the moov box 720 is a sub box, and may include an mvhd box 721 , a trak box 722 , and an mvex 723 box.
- the mvhd box 721 may include presentation-related information (e.g., media creation time, change time, period, etc.) of media data in the media file 700 .
- presentation-related information e.g., media creation time, change time, period, etc.
- the trak box 722 may include metadata about a track of media data.
- the trak box 722 may contain stream-related information, presentation-related information, and/or access-related information for an audio track or a video track.
- a plurality of trak boxes 722 may exist according to the number of tracks present in the media file 700 . An example of the structure of the trak box 722 will be described later with reference to FIG. 8 .
- the mvex box 723 may include information on whether one or more movie fragments exist in the media file 700 .
- the movie fragment may be a part of media data obtained by dividing media data in the media file 700 .
- a movie fragment may include one or more coded pictures.
- a movie fragment may include one or more picture groups (GOPs), and each picture group may include a plurality of coded frames or pictures.
- the movie fragment may be stored in each of the mdat boxes 740 - 1 to 740 -N (where N is an integer greater than or equal to 1).
- the moof boxes 730-1 to 730-N may include movie fragments, that is, metadata for the mdat boxes 740-1 to 740-N. According to an embodiment, the moof boxes 730 - 1 to 730 -N may exist in an uppermost layer among metadata-related boxes of a movie fragment.
- the mdat boxes 740 - 1 to 740 -N may include actual media data.
- a plurality of mdat boxes 740 - 1 to 740 -N may exist according to the number of movie fragments present in the media file 700 .
- Each mdat box 740 - 1 through 740 -N may include one or more audio samples or video samples.
- a sample may mean an access unit (AU).
- the decoder setting record may include a parameter set as well as a size of a length field for indicating the length of a Network Abstraction Layer (NAL) unit to which each sample belongs.
- NAL Network Abstraction Layer
- the media file 700 may be processed and stored and/or transmitted in units of segments.
- the segment may include an initialization segment (I_seg) and a media segment (M_seg).
- the initialization segment I_seg may be an object type data unit including initialization information for accessing a representation.
- the initialization segment I_seg may include the aforementioned ftyp box 710 and/or moov box 720 .
- the media segment M_seg may be a data unit in the form of an object including temporally divided media data for a streaming service.
- the media segment M_seg may include the aforementioned moof boxes 730 - 1 to 230 -N and mdat boxes 740 - 1 to 740 -N.
- the media segment M_seg may further include a styp box including segment type related information and a sidx box including identification information of subsegments included in the media file 700 (however, optional).
- FIG. 8 is a view showing an example of the structure of the trak box of FIG.
- the trak box 800 may include a tkhd box 810 , a tref box 820 , and an mdia box 830 .
- the tkhd box 810 is a track header box, and includes header information of a track (hereinafter, referred to as 'corresponding track') indicated by the trak box 800, for example, creation/modification time of the corresponding track, track identifier, etc. can do.
- the tref box 820 is a track reference box and may include reference information of a corresponding track, for example, a track identifier of another track referenced by the corresponding track.
- the mdia box 830 may include information and objects describing media data in a corresponding track.
- the mdia box 830 may include a minf box 840 that provides information about the media data.
- the minf box 840 may include an stbl box 850 including metadata for samples including the media data.
- the stbl box 850 is a sample table box, and may include location information and time information of samples in a track. Based on the information provided by the stbl box 850, a reader may determine the sample type, sample size and offset within the container, and place the samples in the correct time order.
- the stbl box 850 may include one or more sample entry boxes 851 , 852 .
- Sample entry boxes 851 and 852 may provide various parameters for a particular sample.
- a sample entry box for a video sample may include the width, height, resolution and/or frame count of the video sample.
- a sample entry box for an audio sample may include a channel count, a channel layout and/or a sampling rate of the audio sample.
- the sample entry boxes 851 and 852 may be included in a sample description box (not shown) in the stbl box 850 .
- the sample description box may provide detailed information on a coding type applied to a sample and any initialization information required for the coding type.
- the stbl box 850 may include one or more sample to group boxes 853 , 854 and one or more sample group description boxes 855 , 856 .
- the sample to group boxes 853 and 854 may indicate a sample group to which a sample belongs.
- the sample-to-group boxes 853 and 854 may include a grouping type syntax element (e.g., grouping_type) indicating the type of the sample group.
- sample to group boxes 853 and 854 may contain one or more sample group entries.
- the sample group entry may include a sample count syntax element (e.g., sample_count) and a group description index syntax element (e.g., group_description_index).
- the sample count syntax element may indicate the number of consecutive samples to which the corresponding group description index is applied.
- the sample group may include a stream access point (SAP) sample group, a random access recovery point sample group, and the like, and details thereof will be described later.
- SAP stream access point
- the sample group description boxes 855 and 856 may provide a description of the sample group.
- the sample group description boxes 855 and 856 may include a grouping type syntax element (e.g., grouping_type).
- the sample group description boxes 855 and 856 may correspond to the sample to group boxes 853 and 854 having the same grouping type syntax element value.
- the sample group description boxes 855 and 856 may include one or more sample group description entries.
- the sample group description entries may include a 'spor' sample group description entry, a 'minp' sample group description entry, a 'roll' sample group description entry, and the like.
- media data may be encapsulated into a media file according to a file format such as ISO BMFF.
- the media file may be transmitted to the receiving device through an image signal according to the MMT standard or the MPEG-DASH standard.
- FIG. 9 is a diagram illustrating an example of an image signal structure.
- an image signal conforms to the MPEG-DASH standard and may include an MPD 910 and a plurality of representations 920 - 1 to 920 -N.
- the MPD 910 is a file including detailed information on media presentation, and may be expressed in XML format.
- MPD 910 includes information about a plurality of representations 920-1 to 920-N (e.g., bit rate of streaming content, image resolution, frame rate, etc.) and HTTP resources (e.g., initialization segment and media) Segments) of URLs.
- representations 920-1 to 920-N e.g., bit rate of streaming content, image resolution, frame rate, etc.
- HTTP resources e.g., initialization segment and media
- Each representation 920-1 to 920-N may be divided into a plurality of segments S-1 to S-K (where K is an integer greater than 1). have.
- the plurality of segments S-1 to S-K may correspond to the initialization segment and media segments described above with reference to FIG. 7 .
- the K-th segment S-K may represent the last movie fragment in each of the representations 920 - 1 to 920 -N.
- the number (ie, the value of K) of the segments S-1 to S-K included in each of the representations 920 - 1 to 920 -N may be different from each other.
- Each segment S-1 to S-K may contain actual media data, such as one or more video or image samples.
- the characteristics of the video or image samples contained within each segment S-1 to S-K may be described by the MPD 910 .
- each segment S-1 to S-K has a unique Uniform Resource Locator (URL), it can be accessed and restored independently.
- URL Uniform Resource Locator
- a video elementary stream that does not include any parameter sets may be defined. In this case, all parameter sets may be stored in one sample entry or a plurality of sample entries.
- a video and parameter set elementary stream that may include parameter sets and may have parameter sets stored in one sample entry or a plurality of sample entries may be defined.
- a non-VCL elementary stream including non-VCL NAL units synchronized with an elementary stream carried in a video track may be defined. In this case, the non-VCL track may not include a parameter set in the sample entries.
- the VVC file format defines various types of tracks as follows.
- a VVC track contains samples and NAL units in sample entries, possibly by referencing VVC tracks containing other sublayers of the VVC bitstream, and possibly VVC subpicture tracks. By referring to it, the VVC bitstream may be indicated.
- VVC track refers to VVC subpicture tracks
- the VVC track may be referred to as a VVC base track.
- VVC non-VCL track Adaptive Loop Filter (ALF), Luma Mapping with Chroma Scaling (LMCS) or Adaptive Parameter Sets (APSs) carrying scaling list parameters and other non-VCL NAL units, including VCL NAL units It can be stored in a track distinct from the track and transmitted over the track.
- the VVC non-VCL track may refer to the above track.
- a VVC subpicture track may contain a sequence of one or more VVC subpictures or a sequence of one or more complete slices forming a rectangular region.
- a sample of a VVC subpicture track may include one or more complete subpictures that are contiguous in decoding order or one or more complete slices that are continuous in decoding order and form a rectangular region.
- VVC subpictures or slices included in each sample of a VVC subpicture track may be consecutive in decoding order.
- VVC non-VCL tracks and VVC subpicture tracks may enable optimal delivery of VVC video in streaming applications.
- Each of the tracks may be carried within its own DASH representations.
- a DASH representation including a subset of VVC subpicture tracks and a DASH representation including non-VCL tracks may be requested by the client for each segment. can In this way, it is possible to avoid redundant transmission of APS and other non-VCL NAL units.
- a sample of a VVC track may be resolved into a picture unit (PU) including the following NAL units.
- PU picture unit
- An Access Unit Delimiter (AUD) NAL unit may be the first NAL unit in a sample.
- the sample is the first sample of the sequence of samples associated with the same sample entry, the parameter set and SEI NAL units contained in said sample entry.
- NAL unit having a nal_unit_type such as EOS_NUT, EOB_NUT, SUFFIX_APS_NUT, SUFFIX_SEI_NUT, RSV_NVCL_27, UNSPEC_30 or UNSPEC_31 in the sample (the NAL unit with this NAL unit type precedes the first VCL NAL unit in the PU) NAL units except for the first NAL unit among such NAL units in the sample; Otherwise all NAL units in the sample.
- the VVC subpicture track is in the order of the VVC subpicture track referenced in the 'subp' track reference (if num_subpic_ref_idx is 0 in the same group entry as the 'spor' sample group entry mapped to the sample), or mapped to the sample Order specified in the 'spor' sample group description entry (if num_subpic_ref_idx is greater than 0 in the same group entry as the 'spor' sample group entry mapped to the sample); All DCI, OPI, VPS, SPS, PPS, AUD, PH, EOS, EOB and AU (access unit)-level or picture-level non-VCL NAL units are excluded;
- the track reference can be decomposed as described below.
- the decomposed samples of the VVC subpicture track are non-VCL NAL unit(s) of time-aligned samples in the VVC non-VCL track may include
- NAL units in the sample with nal_unit_type such as EOS_NUT, EOB_NUT, SUFFIX_APS_NUT, SUFFIX_SEI_NUT, FD_NUT, RSV_NVCL_27, UNSPEC_30, or UNSPEC_31.
- each track reference in the 'subp' box may be decomposed as follows.
- each instance of the track reference subp_track_ref_idx in the 'spor' sample group description entry mapped to the sample may be decomposed as follows.
- Each sample of the VVC base track resolved from the 'subp' track references has no holes (i.e., the rectangular area is completely covered by the samples) and without overlaps (i.e. rectangular). In the region, the samples do not overlap and cover different regions), forming a rectangular region.
- the track reference may be decomposed into the VVC subpicture track.
- the track reference can be resolved to any one of the tracks in the 'alte' track group, and the specific track reference index value is within the previous sample. Once decomposed into a particular track, it may be forced to decompose into any of the following within the current sample.
- VVC subpicture tracks within the same 'alte' track group need to be independent of other VVC subpicture tracks referenced by the same VVC base track to avoid decoding mismatches, so that the following restrictions apply can be applied.
- VVC subpicture tracks contain VVC subpictures.
- VVC subpicture tracks that are initial selection or contain VVC subpictures with a different set of subpicture ID values than the previous selection
- the following steps may be performed.
- start code emulation prevention is re-done.
- the reader uses the bit position and subpicture ID length information in the 'spor' sample group entry to determine which bits to overwrite to update the subpicture IDs with the selected item.
- the reader needs to rewrite the PPS or SPS respectively with the selected subpicture ID values in the restored access unit (AU).
- the reader needs to include a copy of the previous PPS and SPS (when each of the PPS or SPS having the same PPS or SPS ID value does not exist in the access unit (AU)); Also, rewrite each of the PPS or SPS with the updated subpicture ID values in the reconstructed access unit (AU).
- the reader needs to include a copy of the PPS with the updated pps_mixed_nalu_types_in_pic_flag value in the reconstructed picture unit (PU).
- the reader can use the bit position in the 'minp' sample group entry to determine which bits to overwrite to update the pps_mixed_nalu_types_in_pic_flag.
- a stream access point (SAP) sample group may be used to provide information about all SAPs.
- the stream access point sample group will be abbreviated as a 'sap' sample group.
- the 'sap' sample group may be defined in, for example, a standard document such as ISO/IEC 14496-12.
- a specific example of the syntax grouping_type_parameter indicating the grouping type of the 'sap' sample group is shown in Table 1 below.
- grouping_type_parameter The syntax of grouping_type_parameter is specified as follows. ⁇ unsigned int(28) target_layers; unsigned int(4) layer_id_method_idc; ⁇
- syntax grouping_type_parameter may include syntax elements target_layers and layer_id_method_idc.
- the syntax element target_layers may indicate target layers for certain SAPs. Semantics of target_layers may be determined based on a value of the syntax element layer_id_method_idc. For example, when layer_id_method_idc is 0, target_layers may be reserved.
- layer_id_method_idc may indicate semantics of target_layers.
- layer_id_method_idc equal to 0 may indicate that target layers are composed of all layers represented by the track.
- the semantics of non-zero layer_id_method_idc may be specified by derived media file specifications.
- SAP may be interpreted as follows.
- SAP may indicate access to all sublayers present in the track.
- SAP may indicate access to all layers present within the track.
- the STSA picture with the lowest TemporalId present in the track can function as SAP. have.
- layer_id_method_idc 1 may be defined, for example, in a standard document such as ISO/IEC 14496-15.
- a gradual decoding refresh (GDR) picture in a VVC bitstream may generally be indicated as SAP type 4 within a 'sap' sample group.
- the VVC standard may support subpictures having different VCL NAL unit types within the same coded picture. GDR may be obtained by updating the subpictures of each subpicture index within the picture range to the IRAP subpicture.
- the VVC standard does not specify a decoding process starting from a picture having mixed VCL NAL unit types.
- the sample attribute in the media file may be defined as follows.
- a sample in a VVC track refers to a picture parameter set (PPS) with pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- PPS picture parameter set
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- sample attributes may be applied to the sample.
- the sample may be indicated as a type 4 SAP sample;
- the type 4 SAP sample may include GDR picture(s) with ph_recovery_poc_cnt greater than 0.
- Sample attribute 2 The sample is a 'roll' sample group description with a correct roll_distance value for a decoding process that omits decoding of subpictures having a specific subpicture index before the IRAP subpicture exists. ) can be mapped to an entry.
- the 'sap' sample groups are forced to be used in all tracks carrying the same VVC bitstream.
- a random access recovery point sample group may be used to provide information on recovery points for progressive decoding refresh (GDR).
- GDR progressive decoding refresh
- the random access recovery point sample group will be abbreviated as a 'roll' sample group.
- grouping_type_parameter When the 'roll' sample group is used together with VVC tracks, the syntax and semantics of grouping_type_parameter may be defined in, for example, a standard document such as ISO/IEC 14496-12. A specific example thereof is as described above with reference to Table 1.
- layer_id_method_idc equal to 0 or 1 may be used when pictures of target layers of a sample mapped to the 'roll' sample group are GDR pictures.
- layer_id_method_idc When layer_id_method_idc is 0, the 'roll' sample group may indicate behavior for all layers existing in the track. Meanwhile, the semantics of layer_id_method_idc equal to 1 may be defined in, for example, standard documents such as ISO/IEC 14496-15. For example, when layer_id_method_idc is 1, each bit in the target_layers field may indicate a layer carried in the track. Since the length of the field is only 28 bits, the indication of SAPs in the track may be constrained to a maximum of 28 layers. Each bit of the field starting from the least significant bit (LSB) may be forced to be mapped in ascending order of layer_id values with respect to the list of layer_ids associated with the corresponding sample.
- LSB least significant bit
- layer_id_method_idc equal to 2 or 3 may be used when all pictures included in target layers of a sample mapped to the 'roll' sample group are not GDR pictures. In this case, the following picture properties may be applied to pictures other than the GDR picture in the target layers.
- the referenced PPS has pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- At least one IRAP subpicture having the same subpicture index i exists in the current sample or a subsequent sample of the current sample within the same coded layer video sequence (CLVS).
- layer_id_method_idc When layer_id_method_idc is 2, the 'roll' sample group may indicate behavior for all layers existing in the track. Meanwhile, the semantics of layer_id_method_idc such as 3 may be specified in, for example, standard documents such as ISO/IEC 14496-15.
- SPS sequence parameter set
- PH picture header
- ph_gdr_pic_flag 1 (that is, the current picture is a GDR picture)
- ph_recovery_poc_cnt of a value corresponding to roll_distance of the 'roll' sample group description entry to which the sample is mapped have.
- ph_recovery_poc_cnt represents a recovery point in an output order of decoded pictures.
- a bitstream starting with a sample marked as belonging to a sample group having a layer_id_method_idc equal to 2 or 3 may satisfy bitstream conformance.
- the sample group may indicate characteristics applied when all reference layers of the dependent layer are available and decoded. .
- the sample group may be used to start decoding of a predicted layer.
- VVC file format allows a sample containing a picture with hybrid NAL units to be mapped to a 'roll' sample group. Its specific content is as defined below.
- a sample in a VVC track refers to a PPS with pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- At least one IRAP subpicture with the same subpicture index i exists in the current sample or a subsequent sample of the current sample within the same CLVS.
- sample attributes may be applied to the sample.
- Sample attribute 1 The sample may be indicated as a type 4 SAP (stream access point) sample.
- sample is a 'roll' sample group description ( description) entry.
- layer_id_method_idc such as 2 or 3 may be used when all pictures included in target layers of a sample mapped to the 'roll' sample group are not GDR pictures.
- the following picture properties may be applied to pictures other than the GDR picture in the target layers.
- the referenced PPS has pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- FIG. 10 A specific example of subpictures based on the picture properties is shown in FIG. 10 .
- FIG. 10 is a diagram illustrating an example of subpictures having intra-sample hybrid NAL units according to the existing VVC file format.
- the mdat box 1000 may include first to fourth samples Sample_0-Sample_3 .
- the first to fourth samples Sample_0-Sample3 may be included in two or more mdat boxes as shown in FIG. 10 .
- the first to fourth samples Sample_0-Sample3 may constitute one coded layer video sequence (CLVS).
- each of the first to fourth samples Sample_0-Sample3 may represent an access unit (AU).
- the first to fourth samples (Sample_0-Sample_3) are mapped to the 'roll' sample group, and the layer_id_method_idc for the first to fourth samples (Sample_0-Sample_3) is 2 or 3 (ie, the first It is assumed that all pictures included in target layers of the to fourth samples (Sample_0-Sample_3) are not GDR pictures).
- the first to fourth samples Sample_0-Sample_3 may include first to fourth subpictures Subpic_0-Subpic_3, respectively. According to the above-mentioned assumption, since each picture including the first to fourth subpictures Subpic_0-Subpic_3 is not a GDR picture, the picture attribute 2 described above may be applied to each picture.
- each of the first to fourth subpictures Subpic_0-Subpic_3 in each picture may be treated as one picture.
- At least one subpicture may be an IRAP subpicture.
- at least one of the first subpictures Subpic_0, at least one of the second subpictures Subpic_1, and the third subpictures included in the first to fourth samples Sample_0-Sample_3 At least one of Subpic_2) and at least one of the fourth subpictures Subpic_3 may be an IRAP subpicture. Accordingly, as shown in FIG. 10 , a case may occur where only the fourth sample Sample_3 includes IRAP subpictures. In this case, since the first to third samples Sample_0-Sample_3 include only non-IRAP subpictures, random access to the first to third samples Sample_0-Sample_3 cannot be performed correctly.
- a picture having a hybrid NAL unit type may be mapped to the 'roll' sample group regardless of the type of NAL units in the picture.
- a sample in which NAL unit types of RASL_NUT and RADL_NUT are mixed ie, including only non-IRAP subpictures
- the file format design should only allow pictures with hybrid NAL unit types, at least one of which is an IRAP type mapped to a 'roll' sample group, such as CRA_NUT, IDR_W_RADL or It should be IDR_N_LP.
- the current sample may include at least one IRAP subpicture or may have a TemporalId equal to 0.
- Embodiments of the present disclosure may include at least one of the following configurations. Depending on the embodiment, the above components may be implemented individually, or may be implemented in a combination of two or more.
- a picture other than a sample / GDR picture mapped to the 'roll' sample group may be forced to have at least one NAL unit of IRAP type.
- the IRAP type may include CRA_NUT, IDR_W_RADL, and IDR_N_LP.
- a picture other than a sample / GDR picture mapped to the 'roll' sample group may be forced to satisfy at least all of the following conditions.
- the referenced PPS has pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- Embodiment 1 of the present disclosure may be provided based on configuration 1 and configuration 2 described above.
- a sample mapped to a stream access point ('sap') sample group or a random access point ('roll') sample group may have a predetermined sample attribute.
- the specific details are as follows.
- a stream access point ('sap') sample group according to embodiment 1 may be used to provide information about all SAPs.
- the basic contents of the 'sap' sample group are as described above, and differences from the existing VVC file format will be mainly described below.
- the sample attribute in the media file may be defined as follows.
- a sample in a VVC track refers to a picture parameter set (PPS) with pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- PPS picture parameter set
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- subpicture index i of each of subpictures that are not IRAP subpictures in the current sample at least one IRAP subpicture in the sample belonging to the same CLVS as the current sample and following the current sample in decoding order exists.
- sample attributes may be applied to the sample.
- the sample may be indicated as a type 4 SAP sample;
- the type 4 SAP sample may include GDR picture(s) with ph_recovery_poc_cnt greater than 0.
- sample is a 'roll' sample group description ( description) entry.
- sample properties can be applied to the sample may mean that the sample can be mapped to a 'sap' sample group.
- sample properties can be applied to the sample may mean that all of the conditions can be applied as picture properties to the sample mapped to the 'sap' sample group according to an embodiment.
- the current sample may include at least one IRAP subpicture.
- a sample following the current sample in decoding order within the same CLVS may include an IRAP subpicture having the same subpicture index as the non-IRAP subpicture.
- only a sample having an IRAP type hybrid NAL unit type may be mapped to the type 4 'sap' sample group.
- a random access recovery point ('roll') sample group according to Embodiment 1 may be used to provide information about recovery points for GDR.
- the basic contents of the 'roll' sample group are as described above, and differences from the existing VVC file format will be mainly described below.
- a layer_id_method_idc equal to 2 or 3 may be used when all pictures included in target layers of a sample mapped to the 'roll' sample group are not GDR pictures. In this case, for pictures other than the GDR picture in the target layers, the following picture properties may be applied according to the first embodiment.
- the referenced PPS has pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- the picture properties may refer to conditions for mapping a specific sample (e.g., a sample that does not include a GDR picture in a target layer) to the 'roll' sample group according to an embodiment. For example, when each picture in the specific sample satisfies all of the picture properties, the specific sample may be mapped to a 'roll' sample group. On the other hand, if each picture in the specific sample does not satisfy at least one of the picture properties, the specific sample cannot be mapped to the 'roll' sample group.
- a specific sample e.g., a sample that does not include a GDR picture in a target layer
- FIG. 11 A specific example of subpictures based on the picture properties is shown in FIG. 11 .
- FIG. 11 is a diagram illustrating an example of subpictures having intra-sample hybrid NAL units according to an embodiment of the present disclosure.
- the mdat box 1000 may include first to fourth samples Sample_0-Sample_3 .
- the first to fourth samples (Sample_0-Sample_3) are mapped to the 'roll' sample group, and the layer_id_method_idc for the first to fourth samples (Sample_0-Sample_3) is 2 or 3 (ie, the first It is assumed that all pictures included in target layers of the to fourth samples (Sample_0-Sample_3) are not GDR pictures).
- the first to fourth samples Sample_0-Sample_3 may include first to fourth subpictures Subpic_0-Subpic_3, respectively. According to the above-mentioned assumption, since each picture including the first to fourth subpictures Subpic_0-Subpic_3 is not a GDR picture, the picture attribute 2 described above may be applied to each picture.
- each of the first to fourth subpictures Subpic_0-Subpic_3 in each picture may be treated as one picture.
- the first subpicture (Subpic_0) in the first sample (Sample_0) that is the current sample may be an IRAP subpicture.
- the second to fourth subpictures (Subpic_1-Subpic_3) in the first sample (Sample_0) are non-IRAP subpictures, respectively, picture attribute 2 described above for the second to fourth samples (Sample_1-Sample_3) -3 may be applied.
- the second subpicture Subpic_1 in the second sample Sample_1 may be an IRAP subpicture.
- the third subpicture Subpic_2 in the third sample Sample_2 may be an IRAP subpicture.
- the fourth subpicture Subpic_3 in the fourth sample Sample_3 may be an IRAP subpicture.
- each of the first to fourth samples Sample_0-Sample_3 may include one IRAP subpicture as shown in FIG. 11 . Accordingly, unlike the case of FIG. 10 , random access to a random sample (Sample_0-Sample_3) can be performed correctly.
- the current sample may include at least one IRAP subpicture.
- a sample following the current sample in decoding order within the same CLVS may include an IRAP subpicture having the same subpicture index as the non-IRAP subpicture.
- FIG. 12 A method of determining whether to apply the 'sap' / 'roll' sample attribute according to Example 1 is illustrated in FIG. 12 .
- FIG. 12 is a flowchart illustrating a method for determining a sample attribute according to an embodiment of the present disclosure.
- Each step of FIG. 12 may be performed by a media file generating device and/or a media file receiving device.
- each step of FIG. 12 will be described with reference to the media file receiving apparatus.
- the apparatus for receiving media files may determine whether a picture in a target sample has a hybrid NAL unit type ( S1210 ). In an example, the determination may be performed based on a predetermined flag (e.g., pps_mixed_nalu_types_in_pic_flag) in the PPS referenced by the picture. For example, when pps_mixed_nalu_types_in_pic_flag is 1, the media file receiving apparatus may determine that the picture has a mixed NAL unit type. Alternatively, when pps_mixed_nalu_types_in_pic_flag is 0, the apparatus for receiving media files may determine that the picture does not have a mixed NAL unit type. Meanwhile, the above-described step S1210 may correspond to condition 1 or picture attribute 1 regarding the sample attribute.
- a predetermined flag e.g., pps_mixed_nalu_types_in_pic_flag
- the media file receiving apparatus may not apply the 'sap' / 'roll' sample attribute to the target sample (S1260).
- the media file receiving apparatus may determine whether each subpicture included in the picture is treated as one picture (S1220). ). In an example, the determination may be performed based on a predetermined flag (e.g., sps_subpic_treated_as_pic_flag) in the SPS referenced by the picture. For example, when sps_subpic_treated_as_pic_flag is 1, the apparatus for receiving the media file may determine that each subpicture is treated as one picture. On the other hand, when sps_subpic_treated_as_pic_flag is 0, the media file receiving apparatus may determine that each of the subpictures is not treated as one picture.
- a predetermined flag e.g., sps_subpic_treated_as_pic_flag
- the media file receiving apparatus may not apply the above-described 'sap' / 'roll' sample attribute to the target sample ( S1260).
- the media file receiving apparatus may determine whether the current sample includes at least one IRAP subpicture (S1230). .
- the media file receiving device may not apply the aforementioned 'sap' / 'roll' sample attribute to the target sample. (S1260).
- the media file receiving apparatus performs the same CLVS with respect to the subpicture index i of the non-IRAP subpicture existing in the current sample. It may be determined whether an IRAP subpicture having the subpicture index i is present in the target sample that follows the current sample in decoding order within (S1240).
- the media file receiving apparatus may apply the above-described 'sap' / 'roll' sample attribute to the target sample (S1250).
- the target sample may be mapped to a 'sap' / 'roll' sample group.
- the media file receiving apparatus may not apply the 'sap' / 'roll' sample attribute to the target sample (S1260). .
- step S1220 to S1240 may correspond to condition 2 or picture attribute 2 regarding the above-described sample attribute.
- step S1220 may correspond to condition 2-1 or picture attribute 2-1.
- step S1230 may correspond to condition 2-2 or picture attribute 2-2.
- step S1240 may correspond to condition 2-3 or picture attribute 2-3.
- Embodiment 1 of the present disclosure only a sample having an IRAP-type hybrid NAL unit type may be mapped to a 'sap' or a 'roll' sample group. Accordingly, random access in units of samples may be correctly performed.
- Embodiment 2 of the present disclosure may be provided based on configuration 3 described above.
- a sample mapped to a stream access point sample ('sap') group or a random access point ('roll') sample group may have a predetermined sample attribute.
- a stream access point sample ('sap') group according to embodiment 2 may be used to provide information about all SAPs.
- the basic contents of the 'sap' sample group are as described above, and differences from the existing VVC file format will be mainly described below.
- the sample attribute in the media file may be defined as follows.
- a sample in a VVC track refers to a PPS with pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- At least one IRAP subpicture with the same subpicture index i exists in the current sample or a sample belonging to the same CLVS as the current sample and following the current sample (i.e., in samples belonging to the same CLVS, At least one IRAP subpicture exists for each subpicture index i).
- TemporalID may mean a temporal identifier for the NAL unit in the current sample;
- the current sample may include an IRAP type, for example, a NAL unit such as CRA_NUT, IDR_W_RADL, or IDR_N_LP.
- sample attributes may be applied to the sample.
- the sample may be indicated as a type 4 SAP sample;
- the type 4 SAP sample may include GDR picture(s) with ph_recovery_poc_cnt greater than 0.
- sample is a 'roll' sample group description ( description) entry.
- sample properties can be applied to the sample may mean that the sample can be mapped to a 'sap' sample group.
- sample properties can be applied to the sample may mean that all of the conditions can be applied as picture properties to the sample mapped to the 'sap' sample group according to an embodiment.
- the TemporalID value of the current sample may be 0.
- the current sample since the current sample includes an IRAP-type NAL unit, it may include at least one IRAP subpicture.
- a sample following the current sample in decoding order within the same CLVS may include an IRAP subpicture having the same subpicture index as the non-IRAP subpicture. . Accordingly, unlike the existing VVC file format, only a sample having an IRAP type hybrid NAL unit type may be mapped to the type 4 'sap' sample group. Accordingly, random access in units of samples may be correctly performed.
- a random access recovery point ('roll') sample group according to Embodiment 2 may be used to provide information about recovery points for GDR.
- the basic contents of the 'roll' sample group are as described above, and differences from the existing VVC file format will be mainly described below.
- a layer_id_method_idc equal to 2 or 3 may be used when all pictures included in target layers of a sample mapped to the 'roll' sample group are not GDR pictures. In this case, the following picture properties may be applied to pictures other than GDR pictures in the target layers.
- the referenced PPS has pps_mixed_nalu_types_in_pic_flag equal to 1 (ie, each picture referring to the PPS has a mixed NAL unit type).
- sps_subpic_treated_as_pic_flag[ i ] is 1 (ie, the i-th subpicture is treated as one picture).
- At least one IRAP subpicture with the same subpicture index i exists in the current sample or a sample belonging to the same CLVS as the current sample and following the current sample (i.e., in samples belonging to the same CLVS, At least one IRAP subpicture exists for each subpicture index i).
- TemporalID value of current sample is 0;
- TemporalID may mean a temporal identifier for the NAL unit in the current sample;
- the current sample may include an IRAP type, for example, a NAL unit such as CRA_NUT, IDR_W_RADL, or IDR_N_LP.
- the picture properties may refer to conditions for mapping a specific sample (e.g., a sample that does not include a GDR picture in a target layer) to the 'roll' sample group according to an embodiment. For example, when each picture in the specific sample satisfies all of the picture properties, the specific sample may be mapped to a 'roll' sample group. On the other hand, if each picture in the specific sample does not satisfy at least one of the picture properties, the specific sample cannot be mapped to the 'roll' sample group.
- a specific sample e.g., a sample that does not include a GDR picture in a target layer
- the TemporalID value of the current sample may be 0. Accordingly, the current sample may include at least one IRAP subpicture.
- a sample following the current sample in decoding order within the same CLVS may include an IRAP subpicture having the same subpicture index as the non-IRAP subpicture. . Accordingly, unlike the existing VVC file format, only samples having an IRAP-type hybrid NAL unit type may be mapped to the 'roll' sample group. Accordingly, random access in units of samples may be correctly performed.
- FIG. 13 is a flowchart illustrating a method for receiving a media file according to an embodiment of the present disclosure. Each step of FIG. 13 may be performed by the media file receiving apparatus.
- the media file receiving device may correspond to the receiving device B of FIG. 1 .
- the media file receiving device may acquire one or more tracks and sample groups from the media file received from the media file generating/transmitting device ( S1310 ).
- the media file may have a file format such as ISO Base Media File Format (ISO BMFF), Common Media Application Format (CMAF), or the like.
- the media file receiving apparatus may process the video data in the media file by restoring a sample included in the track based on the sample group (S1320).
- the video data processing includes a process of decapsulating a media file, a process of acquiring video data from the decapsulated media file, and a process of decoding the acquired video data according to a video codec standard, for example, the VVC standard.
- a video codec standard for example, the VVC standard.
- a current sample among the mapped samples may be limited to include at least one intra random access point (IRAP) subpicture.
- IRAP intra random access point
- samples mapped to a stream access point ('sap') sample group or a random access recovery point ('roll') sample group of a given type are based on the presence in the track
- a sample belonging to the same coded layer video sequence (CLVS) as the current sample and following the current sample in decoding order is the non-IRAP subpicture and It may be restricted to include at least one IRAP subpicture having the same subpicture index value.
- each picture included in the mapped samples may be limited to having a hybrid NAL unit type.
- each subpicture included in the mapped samples may be limited to being treated as one picture.
- the mapped samples may have only a hybrid NAL unit type of IRAP type.
- GDR gradual decoding refresh
- the TemporalID value of the current sample may be limited to 0.
- FIG. 14 is a flowchart illustrating a method of generating a media file according to an embodiment of the present disclosure. Each step of FIG. 14 may be performed by the media file generating apparatus.
- the apparatus for generating a media file may correspond to the transmission apparatus A of FIG. 1 .
- the apparatus for generating a media file may encode video data ( S1410 ).
- video data may be encoded through a prediction, transformation, and quantization process according to a video codec standard, for example, a VVC standard.
- the media file generating apparatus may generate one or more tracks and sample groups for the encoded video data (S1420).
- the apparatus for generating a media file may generate a media file based on the generated track and sample group (S1430).
- the media file may have a file format such as ISO Base Media File Format (ISO BMFF), Common Media Application Format (CMAF), or the like.
- a current sample among the mapped samples may be limited to include at least one intra random access point (IRAP) subpicture.
- IRAP intra random access point
- samples mapped to a stream access point ('sap') sample group or a random access recovery point ('roll') sample group of a given type are based on the presence in the track
- a sample belonging to the same coded layer video sequence (CLVS) as the current sample and following the current sample in decoding order is the non-IRAP subpicture and It may be restricted to include at least one IRAP subpicture having the same subpicture index value.
- each picture included in the mapped samples may be limited to having a hybrid NAL unit type.
- each subpicture included in the mapped samples may be limited to being treated as one picture.
- the mapped samples may have only a hybrid NAL unit type of IRAP type.
- GDR gradual decoding refresh
- the TemporalID value of the current sample may be limited to 0.
- the generated media file may be transmitted to a media file receiving apparatus through a recording medium or a network.
- a sample having an IRAP-type hybrid NAL unit type may be mapped to a 'sap' or a 'roll' sample group. Accordingly, random access in units of samples may be correctly performed.
- 15 is a diagram illustrating a content streaming system to which an embodiment of the present disclosure can be applied.
- the content streaming system to which the embodiment of the present disclosure is applied may largely include an encoding server, a streaming server, a web server, a media storage, a user device, and a multimedia input device.
- the encoding server generates a bitstream by compressing content input from multimedia input devices such as a smart phone, a camera, a camcorder, etc. into digital data, and transmits it to the streaming server.
- multimedia input devices such as a smartphone, a camera, a camcorder, etc. directly generate a bitstream
- the encoding server may be omitted.
- the bitstream may be generated by an image encoding method and/or an image encoding apparatus to which an embodiment of the present disclosure is applied, and the streaming server may temporarily store the bitstream in a process of transmitting or receiving the bitstream.
- the streaming server transmits multimedia data to the user device based on a user request through the web server, and the web server may serve as a mediator informing the user of any service.
- the web server transmits it to a streaming server, and the streaming server may transmit multimedia data to the user.
- the content streaming system may include a separate control server.
- the control server may serve to control commands/responses between devices in the content streaming system.
- the streaming server may receive content from a media repository and/or an encoding server. For example, when receiving content from the encoding server, the content may be received in real time. In this case, in order to provide a smooth streaming service, the streaming server may store the bitstream for a predetermined time.
- Examples of the user device include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate PC, Tablet PC (tablet PC), ultrabook (ultrabook), wearable device (e.g., watch-type terminal (smartwatch), glass-type terminal (smart glass), HMD (head mounted display)), digital TV, desktop There may be a computer, digital signage, and the like.
- PDA personal digital assistant
- PMP portable multimedia player
- PDA portable multimedia player
- slate PC slate PC
- Tablet PC Tablet PC
- ultrabook ultrabook
- wearable device e.g., watch-type terminal (smartwatch), glass-type terminal (smart glass), HMD (head mounted display)
- digital TV desktop
- desktop There may be a computer, digital signage, and the like.
- Each server in the content streaming system may be operated as a distributed server, and in this case, data received from each server may be distributed and processed.
- the scope of the present disclosure includes software or machine-executable instructions (eg, operating system, application, firmware, program, etc.) that cause operation according to the method of various embodiments to be executed on a device or computer, and such software or and non-transitory computer-readable media in which instructions and the like are stored and executable on a device or computer.
- software or machine-executable instructions eg, operating system, application, firmware, program, etc.
- Embodiments according to the present disclosure may be used to create and transmit/receive media files.
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Abstract
Description
The syntax of grouping_type_parameter is specified as follows. { unsigned int(28) target_layers; unsigned int(4) layer_id_method_idc; } |
Claims (15)
- 비디오 데이터를 포함하는 소정 포맷의 미디어 파일을 수신하는 미디어 파일 수신 장치에 의해 수행되는 미디어 파일 수신 방법으로서,미디어 파일로부터 하나 이상의 트랙 및 샘플 그룹을 획득하는 단계; 및상기 샘플 그룹에 기반하여 상기 트랙에 포함된 샘플을 복원함으로써, 상기 미디어 파일 내의 비디오 데이터를 처리하는 단계를 포함하고,소정 타입의 스트림 액세스 포인트 샘플 그룹 또는 랜덤 액세스 리커버리 포인트 샘플 그룹에 매핑된 샘플들이 상기 트랙 내에 존재하는 것에 기반하여,상기 매핑된 샘플들 중 현재 샘플은 적어도 하나의 IRAP(intra random access point) 서브픽처를 포함하도록 제한되고,상기 현재 샘플이 non-IRAP 서브픽처를 포함하는 것에 기반하여, 상기 현재 샘플과 동일한 CLVS(coded layer video sequence) 내에 속하고 디코딩 순서상 상기 현재 샘플에 후행하는 샘플은, 상기 non-IRAP 서브픽처와 동일한 서브픽처 인덱스 값을 갖는 적어도 하나의 IRAP 서브픽처를 포함하도록 제한되는미디어 파일 수신 방법.
- 제1항에 있어서,상기 매핑된 샘플들에 포함된 각각의 픽처는 혼성 NAL 유닛 타입을 갖는 것으로 제한되는미디어 파일 수신 방법.
- 제1항에 있어서,상기 매핑된 샘플들에 포함된 각각의 서브픽처는 하나의 픽처로 취급되는 것으로 제한되는미디어 파일 수신 방법.
- 제1항에 있어서,상기 랜덤 액세스 리커버리 포인트 샘플 그룹에 매핑된 샘플의 타겟 레이어 내에 포함되는 모든 픽처들은 GDR(gradual decoding refresh) 픽처가 아닌미디어 파일 수신 방법.
- 제1항에 있어서,상기 매핑된 샘플들은 IRAP 타입의 혼성 NAL 유닛 타입만을 갖는미디어 파일 수신 방법.
- 제1항에 있어서,상기 현재 샘플의 TemporalID 값은 0으로 제한되는미디어 파일 수신 방법.
- 메모리 및 적어도 하나의 프로세서를 포함하는 미디어 파일 수신 장치로서,상기 적어도 하나의 프로세서는,미디어 파일로부터 하나 이상의 트랙 및 샘플 그룹을 획득하고,상기 샘플 그룹에 기반하여 상기 트랙에 포함된 샘플을 복원함으로써, 상기 미디어 파일 내의 비디오 데이터를 처리하되,소정 타입의 스트림 액세스 포인트 샘플 그룹 또는 랜덤 액세스 리커버리 포인트 샘플 그룹에 매핑된 샘플들이 상기 트랙 내에 존재하는 것에 기반하여,상기 매핑된 샘플들 중 현재 샘플은 적어도 하나의 IRAP(intra random access point) 서브픽처를 포함하도록 제한되고,상기 현재 샘플이 non-IRAP 서브픽처를 포함하는 것에 기반하여, 상기 현재 샘플과 동일한 CLVS(coded layer video sequence) 내에 속하고 디코딩 순서상 상기 현재 샘플에 후행하는 샘플은, 상기 non-IRAP 서브픽처와 동일한 서브픽처 인덱스 값을 갖는 적어도 하나의 IRAP 서브픽처를 포함하도록 제한되는미디어 파일 수신 장치.
- 비디오 데이터를 포함하는 소정 포맷의 미디어 파일을 생성하는 미디어 파일 생성 장치에 의해 수행되는 미디어 파일 생성 방법으로서,비디오 데이터를 부호화하는 단계;상기 부호화된 비디오 데이터에 대한 하나 이상의 트랙 및 샘플 그룹을 생성하는 단계; 및상기 생성된 트랙 및 샘플 그룹에 기반하여, 미디어 파일을 생성하는 단계를 포함하고,소정 타입의 스트림 액세스 포인트 샘플 그룹 또는 랜덤 액세스 리커버리 포인트 샘플 그룹에 매핑된 샘플들이 상기 트랙 내에 존재하는 것에 기반하여,상기 매핑된 샘플들 중 현재 샘플은 적어도 하나의 IRAP(intra random access point) 서브픽처를 포함하도록 제한되고,상기 현재 샘플이 non-IRAP 서브픽처를 포함하는 것에 기반하여, 상기 현재 샘플과 동일한 CLVS(coded layer video sequence) 내에 속하고 디코딩 순서상 상기 현재 샘플에 후행하는 샘플은, 상기 non-IRAP 서브픽처와 동일한 서브픽처 인덱스 값을 갖는 적어도 하나의 IRAP 서브픽처를 포함하도록 제한되는미디어 파일 생성 방법.
- 제8항에 있어서,상기 매핑된 샘플들에 포함된 각각의 픽처는 혼성 NAL 유닛 타입을 갖는 것으로 제한되는미디어 파일 생성 방법.
- 제8항에 있어서,상기 매핑된 샘플들에 포함된 각각의 서브픽처는 하나의 픽처로 취급되는 것으로 제한되는미디어 파일 생성 방법.
- 제8항에 있어서,상기 랜덤 액세스 리커버리 포인트 샘플 그룹에 매핑된 샘플의 타겟 레이어 내에 포함되는 모든 픽처들은 GDR(gradual decoding refresh) 픽처가 아닌미디어 파일 수신 방법.
- 제8항에 있어서,상기 매핑된 샘플들은 IRAP 타입의 혼성 NAL 유닛 타입만을 갖는미디어 파일 수신 방법.
- 제8항에 있어서,상기 현재 샘플의 TemporalID 값은 0으로 제한되는미디어 파일 수신 방법.
- 제8항의 미디어 파일 생성 방법에 의해 생성된 미디어 파일을 전송하는 방법.
- 메모리 및 적어도 하나의 프로세서를 포함하는 미디어 파일 생성 장치로서,상기 적어도 하나의 프로세서는,비디오 데이터를 부호화하고,상기 부호화된 비디오 데이터에 대한 하나 이상의 트랙 및 샘플 그룹을 생성하며,상기 생성된 트랙 및 샘플 그룹에 기반하여, 미디어 파일을 생성하되,소정 타입의 스트림 액세스 포인트 샘플 그룹 또는 랜덤 액세스 리커버리 포인트 샘플 그룹에 매핑된 샘플들이 상기 트랙 내에 존재하는 것에 기반하여,상기 매핑된 샘플들 중 현재 샘플은 적어도 하나의 IRAP(intra random access point) 서브픽처를 포함하도록 제한되고,상기 현재 샘플이 non-IRAP 서브픽처를 포함하는 것에 기반하여, 상기 현재 샘플과 동일한 CLVS(coded layer video sequence) 내에 속하고 디코딩 순서상 상기 현재 샘플에 후행하는 샘플은, 상기 non-IRAP 서브픽처와 동일한 서브픽처 인덱스 값을 갖는 적어도 하나의 IRAP 서브픽처를 포함하도록 제한되는미디어 파일 생성 장치.
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Publication number | Priority date | Publication date | Assignee | Title |
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KR20160075553A (ko) * | 2013-10-23 | 2016-06-29 | 퀄컴 인코포레이티드 | 멀티-레이어 비디오 파일 포맷 설계들 |
KR20170043068A (ko) * | 2015-10-12 | 2017-04-20 | 삼성전자주식회사 | 미디어 전송 시스템에서 빠른 임의 접근 및 재생을 가능하게 하는 기법 |
KR20190131077A (ko) * | 2017-03-23 | 2019-11-25 | 퀄컴 인코포레이티드 | 비디오 코딩을 위한 서브-픽처 비트스트림들을 포함한 비디오 컨텐츠의 시그널링 |
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Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20160075553A (ko) * | 2013-10-23 | 2016-06-29 | 퀄컴 인코포레이티드 | 멀티-레이어 비디오 파일 포맷 설계들 |
KR20170043068A (ko) * | 2015-10-12 | 2017-04-20 | 삼성전자주식회사 | 미디어 전송 시스템에서 빠른 임의 접근 및 재생을 가능하게 하는 기법 |
KR20190131077A (ko) * | 2017-03-23 | 2019-11-25 | 퀄컴 인코포레이티드 | 비디오 코딩을 위한 서브-픽처 비트스트림들을 포함한 비디오 컨텐츠의 시그널링 |
Non-Patent Citations (2)
Title |
---|
"Versatile video coding; H.266 (08/20)", ITU-T STANDARD H.266, INTERNATIONAL TELECOMMUNICATION UNION, GENEVA ; CH, 29 August 2020 (2020-08-29), Geneva ; CH , pages 1 - 516, XP044301067 * |
ANONYMOUS: "Information technology — Coding of audiovisual objects — Part 12: ISO base media file format ", ISO/IEC 14496-12, 15 December 2015 (2015-12-15), pages 1 - 248, XP055942214 * |
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